Compendium Review: Unit 3 Chapters 11&12

Movement: Muscle and Bone Table of Contents: I. Introduction II. Muscle A. Overview of Muscular System B. Muscle cell structure 1. parts of muscle cells 2. calcium release in muscle C. Sliding Filament Model 1. whole muscle contraction 2. muscle contraction requires energy III. Bones A. Overview of skeletal system B. Structure of Bone 1. fetal bone formation 2. growth plate 3. medullary cavity C. Calcium Regulation and Bone D. Osteoporosis IV. Joints A. Movement Across Joints B. Technical Vocabulary 1. flexion and extension 2. adduction and abduction 3. rotation and circumduction C. Total Movement Picture V. Conclusion I am always in motion. Whatever it is that I’m doing, my body never seems to stop moving. And, there are times when I am not even conscious to particular movements that my body is creating. What causes the possibility for these bodily actions? Due to the structure of the human body, movement is caused by muscle, bone, and joints. And each part contains particular structures and processes that aid in the body’s motor output.

Movement occurs from the muscles in the body. And, “…all muscles, regardless of their particular type, can contract…and when muscles contract…the body…moves” (Mader 228). There are three types of muscle such as, smooth, cardiac, and skeletal, that has different structures, is located throughout different regions of the body, and has contrasting functions that are either involuntary or voluntary. Skeletal muscles, in particular, have several different functions such as, body support, and movement of bones, uphold body temperature, aid in the movement of cardiovascular veins and lymphatic vessels, and the protection of internal organs. The appearance of skeletal muscle has striated fibers that are attached to the body’s skeleton, allowing for voluntary movement. Skeletal muscles also operate in opposite pairs (bicep and tricep) to allow for the pulling of muscle contraction. The skeletal muscles, along with the other types of muscles, are made up of cells.
These cells are called muscle fibers that contain several components. And, “each muscle fiber…is innervated by a motor neuron that controls the contraction of the fiber” (entochem.tamu.edu/VertInvertContractswf/index.html). Each muscle cell has a plasma membrane called the sarcolemma. As in all cells throughout the body, the sarcolemma is a polarized membrane that allows for particles to pass in and out. The muscle cell also has cytoplasm called sacroplasm and an endoplasmic reticulum called the sacroplasmic reticulum. The sacroplasm contains all the organelles in the cell and the sacroplasmic reticulum is the, “…smooth ER of a muscle fiber that stores Ca2+” (Mader 232). But, the muscle fibers also have some special features. For example, the sarcolemma in the muscle fiber contains T-tubules that run the length of the cell and communicates
Figure 1: Structure of muscle cell
nerve impulses that create the release of calcium ions from the sacroplasmic reticulum. The release of calcium from the sacroplasmic reticulum occurs in several steps. First, motor neuron’s messages arrive at the ends of the neuron’s axon. Then, the process of the neuro-muscular junction synapse (small gap where the axon terminal is separated from the sarcolemma, causing the release of acetylcholine and the binding of this discharge with ACh receptors) precedes the motor neuron’s plan to the muscle fibers. Next, the process of action potential (the depolarization and repolarization of the sarcolemma by the opening and closing of sodium and potassium gates, causing voltage change) takes place in the sarcolemma. This voltage change from action potential causes the calcium ions to release from the sacroplasmic reticulum, which in turn causes the muscle to contract from the shortening of protein units. The shortening of the protein units, which are called actin and myosin units (or sacromeres) from the release of calcium can be applied to the sliding filament model.
The sliding filament model consists of the movement of the actin and myosin units. The actin units slide past the myosin units, creating an advance towards one another. This creates the shortening of the actin units by moving inward and the myosin units to almost fade away. This also occurs from the use of the energy, ATP, which is broken down by the myosin units in order for the myosin cross-bridges to connect to the actin units and pull them forward. Muscle filaments can also produce and use energy in other means. Figure 2: Sliding filament model where sarcomere shortens due to actin-myosin units pulling inward.
The use of energy can be produced and used by the CP pathway, which is anaerobic, fermentation, which is also anaerobic, and cellular respiration, which is aerobic. The CP pathway is, “the simplest and most rapid way for muscle to produce ATP…because it only consists of one reaction” (Mader 237). This reaction allows for creatine phosphate (ADP) to immediately change into creatine (ATP). This process is used when the muscles are used during short-term, intense exercise that lasts less than ten seconds. The process of fermentation, “…produces two ATP from the breakdown of glucose to lactate…” (Mader 237). This is also a rapid use of production of energy, but creates the buildup of lactate, which cannot be metabolized quick enough by the cells to maintain homeostasis. And, cellular respiration allows for the use of energy, but at a slower release, from stored energy in the muscles called glycogen. Along with movement occurring by the way of the muscles, it also happens with the aid of the bones.

The bones are a part of the body’s skeletal system. Bones have several functions that allow for survival. They help support the body such as, the legs and the pelvis, protect vital parts of the body such as, the brain, heart and lungs, and nerves in the spinal chord, produces blood cells, stores minerals such as, calcium and phosphate salts, and fat, and allows for flexible body movement. The bones within the body also have particular structures.
The structure of bones begins as early as fetal development and follows a process of fetal bone formation and remodeling that continues throughout a lifetime. And the process of bones growth can occur by several different cells such as, osteoblasts, osteocytes, and osteoclasts. It first begins with a bone model made of mostly cartilage. Then, bone-forming cells called osteoblasts, cover the main portion of the newly forming bone, which is called the diaphysis, with organic secretions and deposition of calcium. Next, blood vessels located within the bone, cause the osteoblasts to form spongy bone, which has thin plates that are separated by uneven spaces. After that occurs, the medullary cavity is formed, which is located in the diaphysis that will eventually composed of compact bone. Also, the second phase of ossification begins to appear on the epiphyses of the developing bone, which is the expanded area on the end of bones where red blood cells are created. Then, growth of the bones continues throughout adolescence, due to the cartilage within the medullary cavity. And lastly, the epiphysis growth plate, which is a grouping of cartilage below the epiphysis of the bones, allows for the body to keep increasing in length as long as the growth plates consist within the bones. But when the growth plates close off bone growth, the bone stops increasing length. Along with the growth of bones, the regulation of bone also occurs from calcium.
Inside bones, the mineral, calcium, is stored. The osteoclasts cells, which are, “…bone-absorbing cells…” (Mader 210) break down bone, which is then renewed by the osteoblasts. This process helps keeps bones at their strongest point and allows for the regulation of calcium into the bloodstream. It occurs with a negative feedback mechanism by keeping blood calcium levels at a constant state. But, there are results that can occur from the use of calcium that creates a contrary perspective of the role of bone.
The negative result of osteoporosis can occur. Osteoporosis is, “…a disease of bone in which the bone mineral density (BMD) is reduced, bone micro architecture is disrupted, and the amount and variety of non-collagenous proteins in bone is altered” (en.wikipedia.org/wiki/Osteoporosis). It occurs when calcium need within the body exceeds the role of bone support, causing bone resorption to take place more rapidly than calcium deposition from the
Figure 3: Osteoporosis in the bones.
osteoblasts and osteoclasts. Unfortunately, it can lead to many more incidences of bone fracture and effects more groups of elderly women. Osteoporosis can be prevented from healthy lifestyle choices such as, intake of calcium in diet and weight bearing activates. Along with the occurrence of movement from muscles and bones, joints also have a significant role.

Joints are the central area where bones are connected and muscles attach to or extend over. And there are specific kinds of joints. One type is called synovial joints. A synovial joint is, “…a joint having a cavity filled with synovial fluid, a lubricant for the joint” (Mader 222). This type of joint allows for a one way movement of the limbs, because they are structured like a pivot. As the body moves, the contraction of the muscles cause the bones to shift in relevance to another bone and is aided by the joints. There are also specifics that describe these movements permitted by synovial joints.
Figure 4: Structure of synovial joint.

The first is the action of flexion and extension. Flexion is the type of joint movement that decreases the angle of the joint and extension allows for the angle of the joint to increase. The second type of action is adduction and abduction. Adduction allows synovial joints to move body parts toward the center of the body and abduction allows the movement of body parts away from the center of the body. The third type is rotation and circumdution. Rotation is the synovial joint’s movement of it moving around its specific axis and circumfusion makes the bodily movement of a cone-shape. And lastly, the movement of inversion and eversion, allows for the foot to turn inward or outward. Overall, the process of the total movement picture possesses three major points.
The first point of the total movement picture is the process of neurons. Stimuli that are provided by the external or internal environments, triggers muscle to contract. Then, in order for muscles to contract, the actin and myosin units slide towards each other in the sliding filament model. And lastly, the muscles cause the drawing of bones that causes the movement across joints.

I am always in motion. And it is due to the structure of the human body of muscles, bones, and joints, that I am able to perform movement. Muscles consist of muscle fibers that allow for organelles to perform specific processes such as, calcium release, the sliding of actin-myosin units, and the use of energy. Bones help support the body, produce blood cells, store mineral salts, protect vital areas of the body, and allow for flexibility. And joints are the area where bones and muscles connect and are able to work together in unison by permitted movements. This provides total movement by response to stimuli by the nervous system.

Sources:
Works:
Human Biology 10e. Mader, Sylvia S.
en.wikipedia.org/wiki/Osteoporosis
entochem.tamu.edu/VertInvertContractswf/index.html
Pictures:

www.mhhe.com/.../s5/assets/images/anm5s5_1.jpg

www.ucl.ac.uk/news/ucl-views/images/osteo.jpg
trc.ucdavis.edu/.../week10/slidingfilament.gifwww.visit-islay.com/.../body_files/image002.gif

Lab Project #3: Build a Movable Limb

What causes a limb to move? The movement of bodily parts can be attributed to the bones, joints, muscles, and tendons. And, the occurrence of shifting limbs is also linked to the microscopic processes of neurons carrying action potential to muscle cells and the sliding filaments of actin and myosin units in muscle cells. But, looking at our body from an external perspective and trying to understand these actions can be a little hard to grasp. So, why not break it down into simplest terms with a three dimensional model made out of household materials.
Picture 1: All of the materials I used for this project.

This is a model of a movable limb using the materials: rigid wrap, sticks, Styrofoam ball, red pipe cleaners, and white clay. Starting with the exterior of the movable limb, I decided to work with the arm and I made a mold of my arm with the material, rigid wrap. Next, which is the joint and bones of the arm, I used a Styrofoam ball to represent the joint and sticks from my backyard to stand for the bones. The joint and bones of the arm are very vital to limb movement. Bones support and protect the body, allow
Picture 2: Materials rigid wrap, sticks, styrofoam ball, & red pipe cleaners used as arm form, bones, joint, and muscles.
for flexibility inside the body, store calcium, phosphate, and fat, and produce blood cells. They also perform several processes such as, bone growth and development, renewal of bone, and repair of a fracture. Then, bones are joined at joints, particularly in the arm, at a synovial joint. A synovial joint is filled with lubricant that provides free movement for the bone and muscles attached. As I continued building my model, I inserted the muscle and tendons into my mold. I used red pipe cleaners to represent the bicep and tricep muscle of the arm. And, I used white clay to stand for the tendons. The importance of muscle allows for the body to maintain posture, protect internal organs, and provide heat and
Picture 3: Materials white and yellow clay used for tendon and neuron.
movement. Inside the arm, there are two major muscles that are located within the upper region of it, which are the bicep and tricep. When the arm is straight, the bicep is relaxed and the tricep is contracted, which is displayed in the example of the model. And, when the arm is bent, the bicep is contracted and the tricep is relaxed, also displayed in model. The tendons aid in the attachment of muscle fibers to the skeleton. Along with the model that I created of the interior of the arm, there are also several smaller models that display the different microscopic processes
Picture 4: Model of arm mold, bones, and joint of the movable limb.
that happen inside the muscle cells.

Picture 5: Model of arm mold, bones, joint, muscle, and tendon. The arm is straight, meaning the bicep muscle is relaxed and the tricep muscle is contracted.

This is a model of a neuron using the materials: yellow clay, red and gold pipe cleaners, and blue tube beads. Starting with the neuron, I used yellow clay to represent the cell body and dendrites, which is the center of the neuron and the tiny branches that extend from the neuron. Then, I used gold pipe cleaners to represent the neuron’s axon and blue tube beads to stand for the Schwann cells that cover the axon. Neurons are cells that transmit nerve impulses to parts of the nervous system. And, the structure of the neuron consists of a cell body, which contains the nucleus,
Picture 6: Model of arm when it is bent, where the bicep muscle is contracted and the tricep muscle is relaxed.
dendrites, which receive signals from sensory receptors and other neurons, and an axon, which conducts the nerve impulse. The axon also has Schwann cells that wrap around it, which help protect the axon and carry out the process of action potential, which will be discussed later. In this particular model, there are three different neurons being shown that demonstrate the
Picture 7: Materials white, yellow, & green clay, gold pipecleaners, blue tube beads, and dowels used for potassium ions & gates, neuron & axon background, sodium ions & gates, axon, Schwann cells, and axon's direction of impulse.
direction of nerve conduction, beginning from the sensory receptors within the body’s senses, the sensory neuron (takes information to the nervous system), the interneron (receives information from sensory neuron), the motor neuron (takes information away from the nervous system), and ending with the
Picture 8: Model of neurons and how a nerve impulse is carried.
axon of a motor neuron. As the direction of impulse continues to the axon, this is where action potential occurs.

This is a model of action potential using the materials: yellow, green, and white clay, and a dowel. Starting with the axon of the neuron, I used a dowel to represent the direction of the impulse that was occurring. Then, I used yellow clay for the close-up of the
Picture 9 & 10: Model of action potential as the sodium gates open & close and the potassium gates open & close, changing voltage.
axon. Next, I used the green clay to represent the sodium ions and the sodium gates and white clay to represent the potassium ions and the potassium gates that are within the axonal membrane. Action
potential is the swift change in polarity of the membrane of an axon. The progression of action potential begins with the opening of the sodium gates, where sodium flows into the axon and depolarizes the membrane, creating a voltage change from -65 mV to +40 mV (these numbers signify the electrode inside the axon). Then, ending with the sodium gates closing and the potassium gates opening, allowing for potassium ions to flow out of the axon. This repolarizes the membrane of the axon by changing the voltage from +40 mV back to -65 mV. Action potential can also occur with the assistance of the Schwann cells.

Picture 11: Model of the propagation of action potential across the axon.

This is a model of the propagation of action potential using the materials: gold pipe cleaners and blue tube beads. Starting with the gold pipe cleaners, I used this to stand for the axon of a neuron. Then, I placed the blue tube beads onto the gold pipe cleaners to signify the location of the Schwann cells. In the action of propagation of action potential, the Schwann cells allow for action potential to jump across each one by the created gaps between them (saltatory conduction) in order to continue the process at a rapid pace. The process of action potential also occurs within muscle cells.


This is a model of a muscle cell using the materials: saran wrap, yellow clay, green and red pipe cleaners, and straws. Starting with the sarcolemma, I used saran wrap to represent the muscle cell membrane. Then, I used straws to represent the myofibril. And, I used the green pipe
Picture 12 & 13: Materials saran wrap, yellow & rust clay, green pipecleaners, & straws used for the sarcolemma, sacroplasmic reticulum, myosin unit, t-tubule membrane tubes, & bundle of muscle fibers.
cleaners to represent the t-tubule membrane tubes and yellow clay to represent the sacroplasmic reticulum. Lastly, I used red pipe cleaners to signify the muscle that the muscle cell was going in to. In a muscle cell, the sarcolemma is the plasma membrane of the muscle fiber, the myofibril is a bundle of small muscular filaments that aid in contraction of the
Picture 14: Model of muscle cell.
muscle, the t-tubule membrane is an extension of the plasma membrane that communicates nerve impulses to free calcium ions from the sacroplasmic reticulum, and the sacroplasmic reticulum stores calcium until action potential (conveyed by the t-tubules) causes the release. The muscle fiber goes into the muscle in order to carry action potential throughout the cells, which are stimulated by the axons of motor neurons.

Picture 15 & 16: Materials small red beads, large red beads, and blue pony beads used for actin filaments, actin unit, troponin, and calcium.
The release of calcium from the sacroplasmic reticulum can be displayed from this model using the materials: yellow clay, blue pony
Picture 17: Model of calcium release from the sacroplasmic reticulum.
beads, and a straw. Starting with the yellow clay, I used this to represent the sacroplasmic reticulum. Then, I used the blue pony beads to represent the calcium ions; and, I used the straw to represent the t-tubule. In the action of calcium release, the motor neuron nerve impulses travel to the axon and create a connection to the muscle cell (by way of synapse). The message that is communicated within the t-tubeles of the cell causes the calcium to release from the sacroplasmic reticulum. The calcium is then utilized in the actin-myosin units that cause them to shorten.


Picture 18: Model of single actin-myosin unit.
This is a model of a single actin-myosin unit using the materials: strands of red beads and rust clay. Starting with the red beads, I used this to represent the actin unit and I used the red clay to represent the myosin unit. Actin and myosin are the two major proteins that make up the filaments in myofibrils that make muscle. These units occur together to carry out several processes.

One process is the use of calcium (that is released by action potential in the sacroplasmic reticulum) as it binds to myosin. This is displayed in the following model using the materials: red beads,
Picture 18: Model of calcium binding to myosin.
green pipe cleaners, and different colored, blue pony beads. Starting with the red beads, I used this to represent the actin filament that also has black coloring that represents the myosin binding sites. Then, I used green pipe cleaners to represent the tropomyosin. And, I used the dark blue pony beads to represent the troponin and the light blue pony beads to represent the calcium. The actin protein unit also has sub-protein units called tropomyosin and troponin. The tropomyosin is threaded along the actin unit and the troponin is located amongst the threads at different sections. As calcium is released, it connects to the troponin, which causes the tropomyosin to move across the actin unit, exposing myosin-binding sites. Then, the process of muscle contraction can occur.

This is a model of myosin cross-bridges bringing actin filaments together using the materials:
Picture 19: Model of myosin cross-bridges bringing actin filaments together and shortening the muscle.
green pipe cleaners, small red beads, and rust clay. Starting with the green pipe cleaners, I used this to represent a section of the actin-myosin unit of one myofibril. Then, I used strung, small red beads to represent the actin units and rust clay to represent the myosin units. After the myosin binding sites are exposed on the actin units, the myosin units breakdown energy (ATP) to attach to the sites on the actin, forming cross-bridges. Then, energy is released from the myosin unit that allows for the cross-bridges to change their positions on the actin unit. This pulls the actin filaments to the center of the actin-myosin unit, causing the shortening of the muscle.

The movement of bodily parts can be attributed to the bones, joints, muscles, and tendons. And, the occurrence of shifting limbs is also linked to the microscopic processes of neurons carrying action potential to muscle cells and the sliding filaments of actin and myosin units in muscle cells. In order to understand the movement of the body, I made models of the arm and its basic internal parts, the neuron, the process of action potential, and the muscle cell, and the process of muscle contraction out of household materials. This project was very helpful for my learning style. It gave me a hands-on experience to understanding how the arm was structured and how movement occurred. I was able to finally grasp the processes of action potential and muscle contraction.

Ethical Issue Essay #3: Exercise...is the concept working?

The Less We Move, The Worse We Get

Looking back on my childhood, I always remember playing the hardest I could everyday. And, most of that time was spent outdoors, as I let my imagination lead the way. Lately, I have been noticing the childhood obesity epidemic within the city limits of Prescott, Arizona and I am shocked to see the large amounts of children who are overweight. When I was a child, I hardly ever remember the children around me being overweight, but today, it seems to be the norm. And, it is not just children who are being affected by the epidemic, but everyone is. What is happening to our lifestyles that are causing such a negative change in our bodies? Not only is the lack of proper diet a main culprit, but the importance of exercise has also taken a nosedive in our life choices. And, it is due to the lack of movement that the American population, amongst many others, has created such an issue of poor health. So, if we know that exercise is so vital, why isn’t the concept working? There are several viewpoints that provide the answers to such an uprising issue.

One viewpoint, given by James Hill, Holly Wyatt, and John Peters, provides an answer to the exercise issue by modifying the environment to reverse obesity. Due to the changes that the American population has made such as, the industrial revolution and the age of technology, our environment has been modified to the easiest extent. And, it has created the unintentional factors of weight gain. In the past, most eating behaviors and physical activity habits were performed from homegrown foods and physical labor. Today, our environment provides plentiful, inexpensive, high-energy food that is expended in sedentary pursuits. Not only has our poor lifestyle choices been provided by the booming industrial and technological movements, but also from the built, commercial, policy, and social/cultural environments. For example, our built environment is now filled with drive-thru windows that limit our physical activity levels. The commercial environment is now a big business of marketing foods, which are not recommended to be eaten frequently, and are especially aimed at young children by using cartoon and movie characters to advertise these foods. The policy environment has affected food intake by super sized, extra value meals that are loaded with sugar and fat. And the policies for physical activity are highly dependant on transportation, rather than using bikes or walking. And lastly, the social/cultural environment has provided deep-rooted belief that our society has to have a growing economy, by ways of buying many materials at the lowest prices and at this moment, not later. This belief makes it difficult for people to invest their future by making lifestyle changes in the present that will only provide results much later on. The plan to modify the environment to reverse obesity can occur by gradual changes in these environmental aspects. For example, our built environment should provide more sidewalks and bike paths than the typical urban sprawl. The commercial environment should provide more advertisement for nutrition and physical activity improvement by creative solutions like, cartoon and movie characters help promote healthy foods and automobile companies promote physical fitness by providing passes to state parks when a car is purchased. The policy environment should include physical activity at schools and in the workplace. And, the social/cultural environment should provide positive lifestyle choices like, healthy eating and physical fitness, by making them the norm so people will to conform to it and actually act upon it. There is also another viewpoint that provides answers to the issue of exercise.

A second stance, given by Georgia State University, provides answers to the exercise issue by physical activity. According to the viewpoint, more than 60% of United States adults do not participate in the recommended amount of activity. And, 25% of U.S. adults do not engage in any activity at all! In order to solve this dilemma, guidelines are given to help get into a groove of exercise that will not be strenuous and will be enjoyed. For example, they recommend incorporating physical activity through simple actions such as, walking stairs instead of taking the elevator, gardening, raking leaves, dancing, carrying a grocery basket rather than pushing a cart, playing with one’s kids, and parking in the farthest parking spot and walking to one’s destination. It also states that physical activity can also be achieved through a planned exercise routine or recreation with friends or family members. Furthermore, a physical activity pyramid has been created to help guide exercise into an individual’s life. All in all, physical activity should not be viewed as a chore, but as an adventure. Anyone who just decides to get up and start moving, no matter what is may entail, can improve overall health and have fun doing it. Although these two viewpoints both support the importance of exercise, there are some differences.

The first viewpoint provides a stance on improving all aspects of our environment to reverse the obesity epidemic. It uses hopeful techniques for the future by improving the built, commercial, policy, and social/cultural environments. It gives the entire population a chance to change for the better by stepping out of the developed negative paradigms of food and physical activity. Whereas, the second standpoint provides guidelines for incorporating physical activity into different lifestyles. It uses simplified tasks such as, walking stairs instead of using the elevator or gardening, as means to improve health. It gives individuals a chance to make better activity choices by easy to follow guidelines. While the first viewpoint provides countrywide solutions in reversing a particular epidemic, the second one gives individual solutions in well-being.

Looking back at my childhood, I was always active. And, I make sure that I am always participating in physical activity, because it feels good mentally, physically, and spiritually. Today, the childhood and adult obesity epidemic is becoming the norm, because of the lack of physical activity and poor food choices. But, everyone knows that exercise is so important to achieve optimal, lifelong health. Why is it not working? According to one perspective, the only way we can improve the obesity epidemic, is to improve all aspects of our environment such as, more sidewalks, healthy food and fitness advertisement, physical activity in schools and the workplace, and creating new norms of healthy lifestyles that people can easily conform to. Another viewpoint provides simple instructions to merely just get up and move such as, playing with one’s kids or carrying a grocery basket instead of pushing a cart while grocery shopping. And, it also supplies a physical activity pyramid for a daily guide. I love being active, but I do not look at exercise as another task I have to accomplish. Instead, I look at it as a benefit for my mental, physical, and spiritual state and that outlook gives exercise a source of entertainment for myself. In turn, I feel that individuals have to make the conscious choice to wanting to improve themselves through physical fitness that will push them to the edge, but will be fun as well. In the future, I believe that the issue of exercise will catch on in such a way that everyone will want to be a part of it. But, I think that can only happen if we are willing to let go of some of the luxuries to experience our “true” selves again.

Sources:
Pictures:
www.funmansion.com/images/exercise.png
www.speakwell.com/.../fitnessProgram.jpg

Movement Lab

Whether we are conscious of it or not, our muscles are always at work. And, it is due to our muscles within in our body that we are able to perform particular processes such as, walking, dancing, or simple movements such as, scratching an itch and clenching a fist. In the experiement of “How Do Your Muscles Work”, provided by Troy High Labs Online, can be used to determine how muscles react to particular situations. The first part of the lab offers an easy understaning of how muscles work from simple processes of muscle action. Then, the lab continues into the major part of the experiment, where the mucles are immersed in cold water and fatigued by repition. This lab is important, because it gives a hands-on learning experience to what actually happens to muscles in given circumstances. Also, provided below is the steps that were taken that were provided by the lab.

Troy High Labs Online: How Do Your Muscles Work?
INTRODUCTION:
Much of the work of the body depends on the contraction of skeletal
muscles. In this experiment you will first observe the characteristics of
muscle contraction and then will investigate the effects of two factors -
temperature and fatigue - on the action of your muscles.
MATERIALS:
dishpan of water
narrow strip of paper which will fit around upper arm
ice or snow
rubber ball or clothespin
timer (clock, watch, or stop watch)
PROCEDURE:
The following exercises will help you understand what happens to your
muscles when they contract.
Muscle Action
1. Place your fingers along the angle of your jaw just in front of your
ear. Grit your teeth and observe what happens to the hardness of the
muscles in your cheek.
2. With the thumb and little finger of one hand, span the opposite arm's
biceps (front muscle of the upper arm) from the elbow to as close to the
shoulder as possible. Bend the arm and observe the change in the length of
the muscle.
3. Wrap a strip of paper around your upper arm and mark the circumference
of your arm on the paper. Clench your fist tightly and mark the new
circumference on the paper. Observe what happens to the circumference of
the muscle.

Effect of Temperature on Muscle Action
1. Count the number of times you can make a fist in 20 seconds. Start with
your hand completely outstretched and make a tight fist each time. Do it
as rapidly as you can. Record the count in Figure 1.
2. Now submerge your hand in a dishpan of water to which has been added
snow or ice so that the temperature is near the freezing point. Leave your
hand in the water for one full minute.
3. Remove your hand and immediately count how

Picture: Clenching my fist before and after submerging hand in ice water.

many forceful fists you can
make in 20 seconds. Record in Figure 1.

Figure 1: Effect of Temperature on Muscle Action
Temperature Number of Fists

Normal 31
Ice Water 13

Effect of Fatigue on Muscle Action
1. Count how many times you can tightly squeeze a rubber ball in your hand
in 20 seconds. Record in Figure 2.
2. Repeat the squeezing nine more times and record results. Do not rest
between trials.
(An alternative procedure which works well is to open and close a
clothespin with the thumb and index finger while the other fingers are held
out straight.)

Picture: Squeezing a ball to find out what would happen after hand is fatigued.

Figure 2: Effect of Fatigue on muscle action
Trial # of Squeezes in 20 seconds
1 47
2 50
3 43
4 36
5 29
6 27
7 21
8 14
9 12
10 11

ANALYSIS OF DATA:
1. What are the three changes you observed in a muscle while it is working (contracted)?
The three changes I observed in muscle while it was working were the muscle became harder, larger, and became shorter and longer in length.
2. What effect did the cold temperature have on the action of your hand muscles? Explain.
The effect that the cold temperature had on the action of my hand muscles was that it slowed down the muscle’s contraction, the muscles became much more tense, and when I squeezed my hand, I had slight burning sensations in my lower palm. The reason why these reactions happened to my hand muscle, because as my hand was immersed in the ice cold water, my muscles were already contracting. They were already contracting to maintain homeostasis within the body, by speeding up the chemical processes in the cells from the reaction of the cold water. As I continued to clench my fist after I pulled my hand out of the water, the cells within the body had to work even harder to maintain equilibrium.
Attempts Number
3. What effect did fatigue have on the action of your hand muscles? Explain.
The effect that fatigue had on the action of my hand muscles was that it causes the muscles to expand and contract at a slower rate. And, as the squeezing of the ball continued, without rest, it became harder for my muscles to work at a constant rate. The reason why this occurred is due to cellular respiration. When oxygen is lacking in the cells, the normal process of cellular respiration leads to fermentation, where the cells work harder, but more quickly, to make energy. Then, the formation of lactate occurs, creating buildup, and fatigue of muscles.

Our muscles are always at work. And, it is due to our muscles within in our body that we are able to perform particular movements. In the experiement of “How Do Your Muscles Work”, provided by Troy High Labs Online, was used to determine how muscles react to particular situations. The first major part of the experiement displayed the reaction of the hand muscles when they are immersed in ice water, and then contracted for a short amount of time afterwards. The second major part of the lab displayed the reaction of the hand muscles when they are fatigued, by squeezing a ball continuously for an amount of time. The reasoning behind the particular reactions that occurred to the hand muscles in the two different experiments can be explained on a cellular level. During the clenching of the fist after being submerged

Picture: How muscle contraction occurs

in ice water, the muscles were much more tense and contraction slowed down. The cells within the body were reacting to the presence of cold by the sensory receptors in the peripheral nervous system. The central nervous system responded by creating more energy to be expended to contract the muscle, in order to maintain homeostasis in the body. While squeezing the ball continuously, the muscles contracted at a slower rate, due to fatigue. The cells within the body were lacking oxygen in order to fulfill the normal process of cellular respiration. This lead to fermentation, which created lactate buildup, and the end result of muscle exhaustion. Overall, this lab gives a hands-on understanding to what actually happens to muscles in given circumstances.

Sources:

Pictures: www.mmi.mcgill.ca/.../mandl-7no11firstframe.gif

Lab: www.troy.k12.us/thsbiology/labs_online/home_lab...

Compendium Review: Unit 3 Chapters 13&14

The Nervous System and Senses Table of Contents: I. Introduction II. The Nervous System A. General Functions B. Neurons 1. structure 2. types of neurons a. sensory b. motor 3. transmission of messages C. Myelin Sheath D. Nerve Impulse 1. resting potential a. sodium-potassium pump 2. action potential a. sodium gates open b. potassium gates open E. Synapse F. Spinal Chord Reflex 1. reflex arc III. Senses A. How Sensation Occurs B. Sensory Fields in Brain 1. cutaneous receptors 2. propioceptors C. Special Senses in Head 1. taste 2. smell 3. vision 4. hearing 5. equilibrium

Whenever I decide to cook a hearty meal, I tend to want to use the oven. But, I try to make sure that my thirteen-month-old daughter steers clear of the kitchen, because she is so curious of her surroundings and trouble seems to draw her in. When she is in the kitchen and starts barreling towards the stove, I stop her in her tracks by exclaiming, “That’s hot!” She usually looks at me with concern, then, repeats my warning, and trails off to find something else to get into. My daughter understands that when she touches something hot that it hurts. And, the reasons for that are due to the nervous system and the senses that human beings contain within their bodies. The nervous system is an extremely complex system that alerts humans of the internal and external environments through its specific functions and the five senses.

As stated earlier, the nervous system is a very multifaceted arrangement that alerts humans of the internal and external environments. It performs three basic functions that help the body maintain homeostasis. The first is sensory output. This is when the body gathers information about the conditions that arise within the inside or outside of the body. Next, the information that was gathered by sensory input is processed and analyzed by the spinal chord and brain. And the last function is motor output. After the brain processes the information provided, it initiates a response by causing the body muscles to move or glands to secrete. In order for these functions to occur, they need to be carried out by the cells of the nervous system.
The cells of the nervous system are called neurons. Neurons have three main parts. The first part of a neuron is the cell body. The cell body contains the nucleus, where it helps maintain function of the cell. The second part is the dendrites. Dendrites are the spider-like extensions from the nerve cell that, “…receive signals from sensory receptors or other neurons” (Mader 249). And, the last part, the axon, is the area of the cell where nerve impulses are transmitted. Although all the neuron cells in the body contain this type of structure, they can differ in outer appearance due to the different types of neurons.
Figure 1: The physical appearance of a neuron.
One type of neuron is called a sensory neuron. Sensory neurons “…send information from sensory receptors…toward the central nervous system” (faculty.washington.edu/chuder/cells.html). Therefore, they are located within the skin, eyes, nose, tongue, and ears. Another type of neuron is motor neurons. Motor neurons take information away from the central nervous system to muscle fiber or gland in the body. In order for each type of neuron to transmit information, they follow a particular process called action potential. Action potential, which will be discussed in more detail later, gives the ability of neurons to carry on ion diffusion through a rapid process of voltage change along the cell membrane. Along with the process of action potential, is the significance of the myelin sheath in neurons.
The myelin sheath is a protective barrier that covers the axon of a neuron. This sheath is formed by Schwann cells that contain the fatty substance of myelin in their plasma membranes. These cells wrap around the axon several times until the myelin sheath has formed, but does not cover the entire axon of a neuron. Instead, there are gaps that are created in between each sheath that is formed called nodes of Ranvier. The function of the myelin sheath aids the neuron in the process of action potential by allowing the action potential to jump to the nodes of Ranvier, which is called saltatory conduct. It also helps save the energy of the cell and speeds up the process of action potential. In accordance with the myelin sheath, the action of nerve impulse occurs.
The nerve impulse, “…convey(s) information within the nervous system” (Mader 250). And, it occurs throughout two different procedures. One of the procedures is called resting potential. During resting potential, the axon of the neuron is not administering an impulse. And, resting potential maintains its status for all neurons and muscle cells, so when they need to, they can send an impulse. This occurs from the application of the sodium-potassium pump. The sodium-potassium pump, “…actively transports
Na+ out of and K+ into the axon” (Mader 250). When a voltmeter is applied to a neuron that is at resting potential, it displays -70 mV, which is due to the unequal distribution of the sodium and potassium ions from the pump. Another procedure that conveys information within the nervous system is action potential. Action potential is a quick change of nerve impulses across the axon of a neuron. This occurs when the cell membrane is depolarized and then repolarized by the opening and closing of the sodium and potassium gates. As the voltage within the cell increases to -40 mV, “…sodium channels open and sodium ions flood inside” (web.lemoyne.edu). The flooding of the sodium ions causes a change in the mV inside the cell, making it go from a negative to a positive. This creates the depolarization of the cell. As the voltage of the cell increases to +50 mV, “…sodium channels close and potassium channels open so that potassium ions flood outside” (web.lemoyne.edu). The flooding of the potassium ions causes a decrease in the mV, returning the cell back to its negative charge, or resting potential. This creates the depolarization of the cell. As action potential nears the end of an axon, it it is accepted by a synapse.
A synapse is a nearby section of a neuron that can carry on the nerve impulse of action potential. In order for a neuron to receive a synapse, the arriving action potential from the axon releases calcium ions into the membrane of the cell to create attachment. Then, the receiving neuron secretes neurotransmitters and binds the two neurons together. Then, sodium ions diffuse into the neurotransmitters and the process of action potential maintains. As the information is transmitted throughout the neurons, the body responds with motor output.

The part of the body that proceeds with motor output is the spinal chord. And it is from the spinal chord that particular reflexes, such as the reflex arc, occur. The reflex arc is put into action from the information provided by the sensory and motor neurons. The sensory neurons provide information of sensory input to the spinal chord
Figure 2: The process of the reflex arc that occurs in the spinal chord.
through the process of action potential. And, motor neurons provide information of motor output away from the spinal chord, also through action potential. Then, the body either moves the muscle or secretion demanded. For example, if a person touches something that is hot, the sensory receptors in the skin send the message of the changes of the external environment. Then, the reaction, set forth by the motor neurons, occurs usually by the person wincing and expressing pain. In relation to the reflex arc, the activation of the different senses occurs.
The occurrence of sensation is provided by sensory receptors. These are specialized parts of the neurons that respond to external and internal stimuli and begin the process of action potential within the body. There are two types of sensory receptors. The first is proprioceptors. These sensory receptors are involved in information of sensing muscle tension and providing the muscles with position and posture. The second is cutaneous receptors. Cutaneous receptors are reflex actions by bringing information of pain, pressure, temperature, and touch. As these sensory receptors bring the information to the specialized neurons, and eventually to the brain, the brain organizes the information into different sensory fields in order to understand and respond to the messages received. The visual cortex of the brain forms visual information of the external stimuli. And the sensory cortex of the brain, detects the sensation of touch from the entire surface of the body. Along with the special sensory receptors, are specialized senses located in the head.

There are five senses that are located within the head that provide the understanding of the body’s outer surroundings. The first two senses are taste and smell. Both of these senses are called, “…chemical senses because their receptors are sensitive to molecules in the food we eat and the air we breathe” (Mader 278). Taste is achieved by the taste buds located on the tongue. They are separated into four major groups of salty, sweet, sour and bitter and are located in particular regions of the tongue. The brain receives the information of taste by nerve impulses within the pores of the taste buds. Then, they reach the taste cortex of the brain and are deciphered as the major groups of taste. Smell is achieved by the olfactory cells located within the uppermost area of the nose. The brain receives the information of smell by
Figure 3: The five senses: taste, smell, vision, hearing, and equilibrium.
nerve fibers in the olfactory cells. The smell of a scent is broken down into what type of molecule that is being provided, so the brain can understand what odor is being stimulated. Then, the neurons that were stimulated by the olfactory cells transmit the message to the olfactory areas of the cerebral cortex, and the information is analyzed. Lastly, the brain sends messages back to the nasal cavity to identify what has been smelled. The third sense is vision. The eye consists of three layers. The first is the sclera, which is the outer layer, which supports and protects the eye. Second, is the choroid, which is the middle layer, absorbs light rays that have strayed from its original formation. And, the third is the retina, which is the inner layer, which has the sensory receptors for color, dull, and bright light. The outside of the eye draws the light rays into the retina, where the sensory receptors create the visual information that is provided. Then, nerve impulses transmit the information to the occipital lobe of the brain, where it is interpreted and applied. And the last two senses are hearing and equilibrium. The three parts of the ear attain hearing. First, the outer ear leads the external noise into the middle ear. Then, the middle ear amplifies the noise provided. Last, the inner ear receives the noise through its sensory receptors. The sensory receptors, which are tiny hair cells, provide nerve impulses to the temporal lobe of the cerebral cortex for interpretation and application of the noise. The sense of equilibrium is also achieved from the sensory receptors in the inner ear. They detect rotational and gravitational equilibrium. As each type of equilibrium occurs, membranes within the inner ear are displaced. The sensory receptors pick up the changes and send impulses to the brain.

Whenever I use the oven for cooking, I warn my daughter that it is hot. She responds to my warning by retreating her curiosity, because her nervous system and senses have provided past information that touching something hot hurts. The nervous system is a very complex arrangement that contains basic functions. These basic functions are performed by different neurons that transmit messages by processes such as, resting and action potential, and synapse. Also, once the information has reached the spinal chord and brain, it can be deciphered and acted upon through the reflex arc. The senses also provide an understanding of the body’s external environment from particular sensory receptors like, cutaneous receptors and proprioceptors that are sent to different sensory fields in the brain. And, the head has five special senses: taste, smell, vision, hearing, and equilibrium, that allows for the body to respond to different stimuli. The nervous system and the senses are very vital to survival, because without them, living things would cease to exist.

Sources:
Pictures:
1. www.bcm.edu/cain_foundation/noframes/html/pag...
2. academic.kellogg.cc.mi.us/herbrandsonc/bio201...
3. imagecache2.allposters.com/images/pic/JAG/03-...

Works:
Human Biology, 10e. Mader, Sylvia s.
faculty.washington.edu/chudler/cells.html
web.lemoyne.edu/~hevern/psy340/lectures/psy340.02.2a.neur.impulse.html

Nervous Function Lab

QUESTIONS ABOUT LEECH NEUROPHYSIOLOGY LAB:
Figure 1: Picture of manipulator with the oscillope trace to find a cell in the dissected leech.
Figure 2: Picture of shape of sensory neuron found by the oscillope trace. The cell was dyed and viewed with an ulra-violet light.

1. What is the electrode measuring?

The electrode is measuring the activity of the neurons by establishing electrical contact with a non-metallic substance.

2. Why use leeches in neurophysiology experiments?

The reason why leaches are being used in this neurophysiology experiment and others is, they have a simple system. This simple system is easier to understand than the system of humans. And, the facts that are discovered within the simple system, like the leech, may be applied to understanding the human brain.

3. What is the difference between a sensory and a motor neuron?

The difference between a sensory neuron and a motor neuron is that a nerve cell that a sensory neuron conducts impulses from a sense organ to the central nervous system, whereas a motor neuron conveys impulses from the central nervous system to a muscle, gland, or other effector tissue.

4. Do you think a leech experiences pain? What is pain?

Yes, I think leeches experience pain, because they contain nerve cells that collect touch information from the skin and transmit to the brain for interpretation. But, in this experiment, the leech is placed into an anesthetic, so maybe it did not feel the pain in the experiment. Pain is a distressing sensation in a particular part of the body that is felt by nerve fibers that send the message of distress up the spinal chord and into the brain for interpretation.

5. What were the two most interesting things about doing this lab?

The two most interesting things about doing this lab were the dissecting of the leech and the dyeing of the cell in order to see the neuron in the UV light.

6. Anything you found confusing or didn't like about the lab?

I did not find anything confusing or anything that I did not like about the lab. It was very simple and fun.

Source:

www.hhmi.org/biointeractive/vlabs/neurophysiology/index.html

Lab Project #2: Exercise Physiology

The circulatory system is a vast environment containing several components. It contains arteries, capillaries, and veins, which all assist in the process of transporting blood to and from the heart and lungs. But, the capillaries is the main site where red blood cells exchange oxygen-rich blood with the oxygen-poor blood from the cells. This process is vey vital to the survival of every cell within the body, because the use of oxygen is needed in the processes of cell metabolism and cellular respiration. Cell metabolism occurs within the mitochondria of the cell, where nutrients that are digested from the body are used to make quick energy, glucose, for the cells. This is also a part of cellular respiration. Cellular respiration consists of the cycles of glycolysis, citric acid cycle, and the electron transport chain. It is within each of these cycles that oxygen is used to breakdown glucose and convert it into ATP. In accordance with the complexity and processes of the circulatory system and the cells, this lab project, called Exercise Physiology, was performed by myself in order to measure different body metabolic factors such as pulse, respiration rate, and blood pressure.

In the lab, Exercise Physiology, I measured the metabolic rates of pulse, respiration rate, and systolic and diastolic blood pressure four different ways. First, I measured a baseline reading for each metabolic rate by staying at rest for ten minutes. I was able to use this baseline as a comparison of my normal blood pressure to that of the three activities I performed. Then, I performed my first activity of Tae Bo for five minutes and measured each metabolic rate after that performance. Third, I executed the activity of twenty push-ups, then measuring the different rates for that action. Lastly, I performed the activity of jogging in place for two minutes and calculated the rates for that occurrence.

Before I performed this lab, I decided upon a hypothesis. I hypothesized that after I performed each activity, the pulse, respiration rate, systolic, and diastolic blood pressure would all increase in comparison to my baseline rates.

The procedure I followed for the Exercise Physiology Lab is:

1. Sat and rested for ten minutes

2. Baseline blood pressure was measured by my husband with a bloodpressure cuff and stethiscope.

3. Then, measured my baseline pulse by placing my fingers on my cartoid artery and counting each beat for 30 seconds. I multiplied the number I recieved by two to find the result for one minute.

4. And, measured my baseline respiration rate by counting each breath for fifteen seconds and multiplying the result I received by four to equal one minute.

5. I repeated steps one through four, five other times.
6. Then, I performed my first activity of Tae Bo, which I did for five minutes.
7. My husband measured by blood pressure again.

8. Then, I measured my pulse rate and respiration rate.

9. I performed Tae Bo two other times and measured each rate afterwards.

10. Then, I performed my second activity, twenty pushups.

11. Measured my blood pressure, pulse rate, and respiration rate.

12. I peformed twenty pushups two other times and measured each rate afterwards.

13. Then, I performed my third activity of running in place for two minutes.

14. Measured my blood pressure, pulse rate, and respiration rate.

15. I performed running in place two other times and measured each afterwards.

16. Then, I found the average for my baseline rate, activity one, two, and three of each metabolic rate.

This is my metabolic data table where I recored my results for each metabolic rate and found the averages for each.

Figure 1: This is the activity of resting for ten minutes. I did this to find out what my baseline pulse rate, respiration rate, and systolic and diastolic blood pressure would be. This was performed four other times.


Figure 2: This is where my husband measured my systolic and diastolic blood pressure by using the blood pressure cuff and stethiscope. I had this done for baseline rate and activities one, two, and three.

Figure 3: This is the first activity of Tae Bo. I performed this for five minutes. Then, I continued with measuring my pulse rate, respiration rate, and systolic and diastolic blood pressure. I performed this activity two other times.

Figure 4: This is the second activity of twenty push-ups. Then, I continued with the measurements of each metabolic rate. I performed this activity two other times.

Figure 5: This is the third activity of running in place for two minutes. Then, I continued with the measurementsof each metabolic rate. I performed this activity two other times.

After I finished the main procedure of the Exercise Physiology Lab, I gathered my data and placed it into four bar graphs. I was able to compare the results I had received. The first graph consists of the comparison of my average baseline systolic rate with my average systolic rates for activities one, two, and three. I had originally hypothesized that my average systolic rate would increase in relation to my baseline systolic. As it turns out, all three activities did raise my average systolic rate, especially when I performed activity #2 of twenty push-ups. The second graph consists of the comparison of my average diastolic rate with my average diastolic rates for activities one, two, and three. I had hypothesized that my average diastolic rate would increase

in relevance to my baseline diastolic. As it turns out, it did increase when I performed activities two and three, but when I performed activity #1 of Tae Bo, it stayed the same. The third graph consists of the comparison of my average baseline pulse rate with my average pulse rate for activities one, two, and three. I hypothesized that my average pulse rate would increase in relation to my average baseline pulse rate. As it turns out, my average pulse rate did increase for activities two and three, but it decreased when I performed activity #1 of Tae Bo. The fourth graph consists of the comparison of my average baseline respiration rate with my average respiration rate for activities one, two, and Figure 6: Bar graph of average baseline systolic vs. average systolic from activities one, two, and three. three. I originally hypothesized that my average respiration rate would increase in relation to my average baseline respiration. As it turns out, my average respiration rate did increase, especially when I jogged in place for two minutes.

Figure 7: Bar graph of average baseline diastolic vs. average diastolic for activities one, two, and three.

Figure 8: Bar graph of average baseline pulse rate vs. average pulse rate for activities one, two, and three.

Figure 9: Bar graph of average baseline respiration rate vs. average respiration rate for activities one, two, and three.

After I compared the results of my Exercise Physiology Lab, I was concerned as to whether or not there were any problems with my techniques that I performed or if there were any other factors affecting the outcome of the reuslts.

Beginning with the comparison with my average baseline diastolic with my average diastolic after performing the activities. I was surprised to find how close the averages were to my baseline after performing such rigorous activities. But, maybe they would of been higher if I performed the activites for a longer amount of time. Next, I was really surprised to see that my average pulse rate for activity #1, Tae Bo, was lower than my average baseline pulse rate, considering that I was being much more active than resting. Overall, I felt like my experiment results were not that accurate, because my blood pressure seemed really low to what it normally is when it is measured by my primary care physcian. I think the blood pressure cuff that I had used need to be re-callibrated. Also, the times that I had performed each resting activity and exercise activity, I was really tired.

The circulatory system contains arteries, capillaries, and veins that assist in the transport of blood to and from the heart and lungs. The capillaries house most of the exchange of oxygen-rich and oxygen-poor blood with the cells, in order to carrry out cellular metabolism and respiration properly. The Exercise Physiology Lab that I performed by finding my average baseline pulse rate, respiration rate, systolic and diastolic blood pressure and comparing that to different metabolic rates results after performing activities like, Tae Bo, pushups, and jogging, provided some interesting results. Mostly all of the activities I performed had shown that my metabolic rates had increased compared to my average resting rates. But, there were some surprises, for example, my average pulse rate during Tae Bo had decreased and average diastolic rate during the same activity stayed the same. In general, most exercise activities will increase metabollic rates, which in turn will speed up the processes within the circulatory system.

Sources:

Pictures:

Graphs: nces.ed.gov/nceskids/createagraph/default.aspx