UNIT 4: REPRODUCTION Compendium Review-1

TOPICS
1. Human Life Cycle: Mitosis and Meiosis

2. Male/Female Reproductive Systems

3. Fetal Development and Birth

4. HIV/AIDS

Let me begin by saying that reproduction is the process of a sperm and a fertilized egg joining together, and forming a miraculous new little individual. In this section I will be discussing the above topics in a more detailed fashion. To begin, I would like to discuss the 2 different cell divisions in the human cycle: Mitosis and Meiosis. Next I will review the Male and Female reproductive systems that aid in the development of a new organism which leads into the next topic: Fetal development and Birth. Lastly I will go over a few of the common STD's. The beginning life of a fetus is an absolute miracle, that I myself am blessed with right now.

HUMAN LIFE CYCLE: MITOSIS AND MEISOSIS. We learned in prior chapters of the 2 different phases associated with the human life cycle: Mitosis and Meiosis. Glance at a scanner and then at the finished picture, this "duplication division" is known as Mitosis (Mader 320). This process occurs throughout the cell development. Recall that this process goes through 4 different phases: Prophase, Anaphase, Metaphase, and Telephase. The second process is Meiosis: " A specialized process of cell division that produces gametes(eggs and sperms)" (ref article). It is also known for reducing its diploid cells to haploid cells. In number sense; a sperm and egg both carry 23 chromosomes, therefore when fertilized the new cell has 46 chromosomes. "The first cell of a new human being is called the zygote" (Mader 320). During this step, the offspring gets a copy of each parents chromosomes. And the sex of the baby and hair color is determined at this point. The picture to the right is the process of the haploid cells(egg and sperm) joining together to form the zygote. To lead into the next topic I would like to mention where the production of sperm takes place in the male and females. Most of us have studied this before, but in review the males produce in the testes and the females in the ovaries. Now that we have a general idea of the egg being fertilized, I would like to discuss the male and female reproductive systems.

MALE REPRODUCITVE SYSTEM: Testes, Epididymis, Vas deferens, seminal vesicles, Prostate gland, Urethra, Bulbourethral glands, and Penis. To begin this system, once the sperm has begun production in the testes, the epididymis is the actual site where it matures. The traveling sperm enters a long narrow tube, vas deferens, which is also a storage organ. This leads to the ejaculatory ducts, which enters into the urethra. The seminal vesicles "contribute nutrients and fluid" (Mader 321). The other glands that are helpful in providing fluid for the sperm are the prostate and bulbourethral glands. The testis have seminiferous tubules, which are packed with little cells going through spermatogenesis "the production of sperm" (Mader 323). Hormones play a big role in the sexual drive, gonoadotropin-releasing hormone(GnRH), release 2 well known hormones: follicle-stimulating hormone(FSH) and lutenizing hormone(LH). "FSH promotes the production of sperm, LH controls the production of testosterone" (Mader 324). This occurs in the males.

FEMALE REPRODUCTIVE SYSTEM: Ovaries, Oviducts, Uterus, Cervix, and Vagina. Again, the ovaries are the site of egg production. The 2 hormones in the female system are estrogen and progesterone. To start the cycle, the oviducts most commonly known as the fallopian tubes, is the spot of fertilization. During ovulation, the little egg is guided to the fallopian tubes from 2 different sweeping actions, fimbria and cilia. "A developing embryo normally arrives at the uterus after several days, and then implantation occurs" (Mader 324). The uterus is where the developing fetus lives. This organ is very muscular and durable, just think, the average 7 pound baby kicks around inside of this structure!!! The vagina has 2 different functions: penis enters during intercourse, and it is the pathway canal during delivery. The females also release the FSH and LH, as do males. These hormones are important during the ovarian cycle. Fertilization occurs when the sperm travels its course towards the fallopian tubes. This is the beginning stage of Pregnancy. The next topic will describe the fetal development process.

FETAL DEVELOPMENT: At this point, the developing baby is known as an embryo. The development is divided into 3 different stages: Pre-embyonic(which is mentioned above- takes place during fertilization), embyonic(week 2-2 months), and fetal development(3 months-9th month). There is so much information during each week of pregnancy, that it's hard to know where to start! During the embryonic development, the embryo implants itself to wall of the uterus, its home for 10 months! I remember looking at these pictures when I first found out I was pregnant thinking, WOW, these structures are forming into my little baby! The picture to the right shows the 1st week, not yet pregnant, but the conception stage. During the embryonic development, the hormone secreted is HCG, which helps distinguish pregnancy if a pregnancy test were taken. The book describes this tiny embryo as being the size of a"period at the end of this sentence" (Mader 357)!!!! Organ systems begin to develop later in this stage and by the 8th week the embryo looks more human-like. The picture to the right is an embryo at 8 weeks. As pregnancy progresses, the uterus grows as well. The fetal development is also an interesting part because the fetus's heartbeat can be heard with a doppler, starts its first awakening flutter sensation, the mothers belly is growing, and all of the systems are fully developed. As the months go on, the baby's body slowly forms into a proportional size. The picture below is a fetus at 23 weeks. There are obviously changes that occur in the mother during pregnancy. The book states the following changes: "Energy level fluctuates, uterus relaxes, and pulmonary valves increase" (Mader 368). Aside from those changes, the mother also experiences hormonal changes, body changes, and feelings of sickness. In the end these changes will be worth the miracle baby!

BIRTH. The first sign of labor, is the strength and timing of the contractions. "True labor is marked by uterine contractions that occur regularly every 15-20 minutes and last for 40 seconds or longer" (Mader 368). There are times that the mother may think she is having a contraction near the end of her pregnancy but is in fact known as, 'false labor.' The 3 stages of birth are: Stage 1 (dilation of cervix) Stage 2(child is born) and Stage 3(placenta expelled). There is much more emotional and physical details that could be added, but for this review I feel that the point is clear.

HIV/AIDS. "No war, natural disaster, or terrorist attack has ever killed more people than HIV/AIDS" (Mader 352)! That is absolutely sad, I wasn't aware of that fact. "World wide, an estimated 38.6 million people(36.3 million adults and 2.3 million children) are now living with HIV infection" (Mader 344). Scientists have been struggling to find a vaccine to prevent the spread of this horrific disease. There are many important factors that they need to study, such as: is the vaccine a short term protection and would it make the individual more vulnerable to the disease? HIV travels into the body and destroys the immune cells. Mainly the Helper T cells which are used to help destroy the body from infections. Many of the individuals living with this disease are those living in poor to low income countries. At the the top of the list is Africa and Asia, Latin America and Caribbean, North America, Europe and Central Asia, and final North Africa and the Middle East. As we are aware the transmission of HIV is through sexual contact, and sharing of needles with an infected person. There are drug therapies available, but it does not cure AIDS, it is used as treatment to help stop the spread into the cells of the body. Hopefully scientist will find a vaccine to help control this deadly disease. STDs caused by viruses are : HIV, genital warts, genital herpes, and Hepatitis. STDs caused by bacteria are: Chlamydia, Gonorrhea and Syphilis. Antibiotics are a way to cure the bacteria STDs. Again, hopefully the spread of these STDs will decrease as individuals avoid the chain of transmission.

In conclusion, I discussed the human cycle and how amazing it is to look at pictures of the process of the unborn baby. Meiosis is the process of game production, it reduces its diploid cells to haploid cells. Making a total of 46 chromosomes when the new cell is fertilized. I also reviewed both the male and female reproductive organs. Next I reviewed the process of fetal development, and how amazing each day the embryo/fetus grows! I actually go into more detail in the lab section, so I did not repeat myself in this review. Since I am pregnant, I feel its natural to be a little nervous that for some reason something may go wrong. Obviously there are babies born with certain deformities, and diseases, I just continue praying I will be blessed with a healthy baby. The last thing I discussed was STDs and HIV/AIDS. I will just repeat that hopefully individuals will think before the act, to help stop the spread of these horrific diseases!! I hope this review was worth while.

Works Cited:
Mader, Sylvia S. Human Biology. Boston:McGrawHill Companies, Inc. 2006.
quotes
http://www.americanpregnancy.org
first picture
http://www.med.upenn.edu/meded/public/berp/overview/BV-1.html
picture of embryo at 8 weeks
http://www.pregnancy-calendars.net
picture of fetus at 23 weeks
http://www.-ref.usc.edu
quote, picture of meiosis

UNIT 3: LAB PROJECT MOVABLE LIMB

MUSCLE CONTRACTION- LAB

As you are bending down to pick up a penny off of the ground, a process occurs in your limbs and tissues in order for this movement to take place. This lab project will hopefully give you a better understanding of how a muscle moves; my example is of a knee joint. Skeletal muscle is one the the 3 muscle tissues in the body, which are needed in order for a contraction to occur. "Skeletal muscle tissue moves the body by pulling on bones of the skeleton" (Martini 284). Within the skeletal muscle tissue is a single muscle fiber. My lab project shows in detail the start of a contraction, which occurs when an electric impulses travels down the length of a muscle fiber. Before it even gets to the muscle fiber, a motor neuron is the carrier of the information that brings the impulses away from the CNS to the muscle fiber. The axon is a snakelike figure that extends off of the motor neuron, responsible for conducting nerve impulses. I will also be describing the process of action potential, which is a nerve impulse traveling down the axon. At this point by reviewing the pictures will hopefully give a better understanding of how a muscle begins a contraction. There are 6 functions of a skeletal muscle: Movement, maintain body position and posture, support soft tissues, protect particles that enter and exit, maintain body temperature, and store nutrients. These functions are all necessary in order to provide a healthy movable muscle.

Above is a picture of a movable limb: a femur bone, tibia bone and between is the synovial joint. The middle picture is the same limb, but showing the Sartorium muscle, which helps with flexion of the knee and hip and also with rotation of the hip. There are several classifications of synovial joints, which basically allows for different types of range of motion. The knee joint can be described as a hinge joint, which allows motion similar to opening and closing of a door. The picture to the far right is a picture off of a website, but in more detail of the same limb I used.

Above is a picture of a motor neuron(green foam) the white strings off of the neuron are dendrites, the skinny white string is an axon, the pink beads represent the mylein sheath which is covered by Schwann cells, and the twizzler is a muscle fiber. As mentioned above the motor neuron carries nerve impulses away from the CNS to a muscle fiber. Messages are received from other neurons at the dendrites(strings off of the motor neuron). These messages are then passed onto the axon(skinny white string), in a form known as an action potential. At the end of each axon are synaptic terminals( a synapse is also a part), which is involved in the communication method to other cells. This picture basically shows how the neurons are moving towards a muscle cell, sending messages down the axon in form known as action potential getting ready to start a contraction.

This picture shows where the action potential occurs. It moves along the axon, stimulated from the electrical impulses. At first I used a white string for my axon, but for vision reasons I switched to a twizzler.

The next process is that of nerve impulses. Basically it is information that is moving along the axon, in the form of action potential, the electrical impulses are known as nerve impulses. There are 2 types of potentials: Resting(axon has no impulse movement, -65mV) and Action("rapid change in polarity across an axonal membrane as the nerve impulse occurs") (Mader 250). The pictures above are both Action potential. The first one is when the Sodium gates open(green balls are sodium) and Sodium enters the axon. The Potassium gate (blue structure) remains closed at this time. During this process, depolarization occurs, which is caused from the axon becoming more positive with the entrance of sodium. "The potential changes from -65mV to +40mv" (Mader 250). The next picture shows reporization: Potassium ions move out of the axon making the inside negative again. During this phase, Sodium gates are closed and Potassium gates swing open.

This picture is inside of the muscle fiber, showing the T tubule(black strings) and the sarcoplasmic reticulum (pink thread). The plasma membrane of a muscle fiber is known as the sarcolemma. T tubules are networks inside of the muscle fiber that carry electrical impulses to the cell. One of the important parts of the sarcoplasmic reticulum is that it is a storage unit for Calcium ions. The spider web structure formed from the T tubules and sarcoplasmic reticulum hold together hundreds of myofibrils. Inside the myofibril are many sacromeres. These structures are bundled with proteins: Thin (actin) and thick(myosin); these protein molecules are responsible for the muscle fiber to contract.

This picture shows the 2 different filaments I just mentioned. Note the little flaps on the Myosin structure(twizzler) these are called myosin heads, later I will show the interaction of the head connecting to the Actin, these are known as cross-bridges. The actin is intertwined with 2 strands: tropomyosin(pink string) and troponin(large green beads).

The start of the contraction begins when the neurotransmitter acetylcholine(ACh) is released and binds to a messenger in the sarcolemma(plasma membrane of the muscle fiber). This impulse travels down the network of T tubules and ends intertwining sarcoplasmic retiuclum. Calcium ions are released which leads to a sacromere contraction. The picture to the far right shows the release of calcium ions(yellow balls) which attach to actin filaments- on the troponin protein thread(large green beads).

Once the Calcium ions are attached to the Troponin, this causes the tropomyosin(pink string) to shift away, making room for mysoin to bind to actin. The picture above shows this process. The head of the mysoin attached to the actin filament. At this point ATP supplies the needed energy for a contraction to occur. The cross-bridges as mentioned above are a part of this process. Contraction beings when this cycle of cross-bridges binding, pivoting, and detachment occurs repeatedly. "The muscle fiber contracts as the sarcomeres, within the myofibrils, shorten" (Mader 232). Its difficult to show how sliding filaments work, but the actin filament slides toward the center of the sacromere when the head of the myosin pivots to the base of the actin filament. "When muscle cells contract, they create tension and pull on the attached tendons" (Martini 321).

In conclusion, our bodies are made of many cells, tissues, and muscles that help keep us functioning every second. This lab was definitely a piece of work, but it gave me a strong understanding of how a muscle contraction occurs. The skeletal muscle contains many muscle fibers packed with myofibrils. The myofibrils consist of sacromeres which are composed of thick(myosin) and thin(actin) filaments. When a sacromere shortens in length and actins slide past myosin, a muscle contraction occurs. The picture to the right is a quick outline of what I described throughout this lab. It's amazing how all of these processes I described occur in order for a muscle to move. Hopefully my write-up was helpful in showing how a neuron moves through the body just to allow you to bend a pick up the penny off of the ground.

Works cited:

http://hon.nucleusine.com/

picture of knee-muscles

Mader, Sylvia S. Human Biology. Boston: McGrawHill companies, Inc. 2008.

quotes

Martini, Fredric H. Fundamentals of Anatomy and Physiology. San Francisco: Pearson Education, Inc. 2006.

quotes

UNIT 3: Ethical Essay

ENDLESS POSSIBILITIES- Ethical Essay

As you are driving down the highway what billboard sign is most common? A picture promoting food such as a gigantic hamburger cooked to perfection; or a picture of an individual swimming in crystal blue water, promoting physical exercise. To me they both so pretty good, but in today's society our marketing focuses on the empty calorie foods most of us do not need. If there were more billboards promoting physical activity such as joggers, bikers, weight lifters, and walkers do you think individuals would be more motivated to exercise? It's a tough question to answer because many individuals in our society are accustom to feeding our bodies with the horrific amounts of sugars and fats, leaving physical activity as a last resort. The following is what I will base my essay off of, many individuals in our society are failing to keep a healthy/productive lifestyle. Unfortunately, obesity continues climbing as individuals dive into the marketing world. Doesn't it make sense to keep physically active to help prevent unnecessary weight gain? Is Marketing a growing problem at influencing many individuals into the good-tasting, high fat, and sugar products? Below is a brief opinionated view of the above questions.

Research has shown that "our environment promotes weight gain and increases obesity rates in the population"(enponline article). The same article explains how our communities play a big part in an individuals lack of exercise. What restaurant or Walgreen's doesn't have a drive through window? This little example shows how our communities are built around individuals who feel they don't need to walk a few extra steps. If drive throughs were taken away, do you really think that would decrease the obesity rate? I would say no because there would be other reasons why someone wouldn't want to walk the extra mile! The empty calorie foods many obese individuals consume are beyond plentiful. If the billboards of foods were taken down, do you think this would help lower obesity rates? Maybe for some individuals, but their habit of eating may be more than seeing a sign along side of the road. These obese individuals need to learn to commit themselves to a physical routine and eliminate the high empty calorie intake. I feel if a person enjoys eating, they most likely will not change their habits even though they know it is unhealthy. This health concern is just like smoking, drinking, and drugs. If the individual is not ready to stop their habit, it usually means they will not even try.

There are many benefits in staying physically active. Within the past few years, many communities have tried different routes at promoting exercise, some have been successful. An article talks about the 'Fun in Seven' which promotes people to stay active. The pyramid above is their goal, to try and do each activity every day. It also states, "Our bodies are made for action" (genesis article). The book also describes the importance of exercise, but all of us are aware of the benefits. Maybe by promoting fun activities our communities provide, rather than the restaurants, would increase individuals moods to be more active. As we are driving down highway 69 and see a billboard for ice skating at the events center, maybe more individuals would try this activity rather than sitting at a movie. How about a billboard near Granite Dells, promoting water activities or hiking? Even though we know these activities around, when we are trying to think of something to do for the evening, many of us think of sedentary activities. Even though we all know exercise promotes a healthier lifestyle, there are individuals that are not inspired by being physically active. How would our society help encourage them to stay active?

Beginning this essay I talked about the different billboard signs along the road side. Marketing tends to be an increasing reason why so many people give into the foods they advertise. The flashing signs grabs an individuals attention, especially if it is at a affordable price. "We are a consumer-driven society" (enponline article). In today's society, companies need to be competitive in order to stay in business. Therefore, many of them try and grab the customers attention by supporting the foods we do not need. Increase consumption of foods will always be a problem in our society because of technology and the options available are unlimited. While reading the first article I found it funny when it talked about finding ways to prevent obesity. One of the ideas was to have restaurants have information stating why a person should choose a healthy alternative. This type of information is too repetitive, I think most people know they should have fresh vegetables rather than french fries. I feel the main reason there are so many individuals ending up with obesity is due to the manufacturers producing the unlimited and endless possibilities of good tasting foods. If there were more healthy foods at a lower cost, maybe there would be less overweight individuals.

In conclusion there are many questions to be answered as to how to help prevent obesity. I personally feel eating is a habit just like smoking, drinking and drugs. In articles I've read, eating could be a pleasure seeking habit. Researchers are also well aware of the manufacturer's need of promoting their product; to grab the consumers attention in order to keep their business alive. The over consumption of high sugar and fat foods will be endless options since technology in today's world is amazing in itself. Finding ways to keep people physically active can be a challenge, especially if an individual has no desire to be active. Many communities are structured for these type. Hopefully obesity will decrease in the future and our society will focus on keeping active rather than the supply us with the endless food possibilities.

works cited:

http://genesis.bch.cuhk.edu.hk/fns/fun-in-seven/english/about_us.htmlwww.enponline.org/docs/2005/7812/7812.html

UNIT 3- MUSCLE LAB
The purpose of this lab was to observe the changes in muscle contractions under cold temperature and fatigue. Below I will explain the specific steps I took to observe these conditions, and the muscle's reaction. During contraction of a muscle, the control is made by the Central Nervous System: brain and spinal cord. While studying these chapters and researching, I have learned that during a muscle contraction, the length of the muscle changes, depending on the proteing sliding inside of the muscle fiber. Hopefully this lab will give you a better understanding of what is going on in the muscles while they are contracted, cooled, and fatigued.

The beginning of the procedure was to feel the muscle on your jaw, while clenching down. The brain sent signal for the action potential(communication method from neurons to tissues-muscles and glands) to stimulate the muscle fibers to act. This tightening, I believe is the work of the muscle fibers.

The next step was to measure my upper arm and mark the circumference, while relaxed. Next, I clenched my fist which raised my circumference to a minimal size.

The following steps: Making a tight fist with my hand outstretched 20 times. Result 39 times. Next I submerged my hand in near freezing water for one minute(which was 40 seconds, because it was too cold for me!) I quickly removed my frozen hand and repeated step one. Result 23 times. Therefore, when your extremity is cold it constricts the blood flow, causing my muscles to tense making it harder to clench my fist.

The next steps were to find the effect Fatigue has on muscles. During this exercise I squeezed a tennis ball in my hand 53 times in 20 seconds. I repeated this 9 more times and recorded my results (the graph to the right). Obviously during the repetitious fist clenching, squeezing a tennis ball became tiring and hard after several attempts. When a muscle becomes fatigued, the messages sent down the axon terminal become weak as our muscles tire.

1. What are the 3 changes you observed in a muscle while it is working? First the muscle acts in a strong/fast motion. As it works, the muscle slows down and becomes tired. The weak movements eventually occur when the muscle is worn to its limits.

2. What effect did cold temperature have on the action of your hand muscle? I briefly stated this while talking about the exercise. Submerging an extremity in cold water and then trying to move it, basically constricts the blood flow. This causes the muscle in the hand to tense and move slower than usual. Once the numbness wears off and the constant muscle movement continues; it helps dilate the cells and allow the extremity to move faster/easier.

In conclusion, this exercise shows that increase fatigue and cold wears a muscle down, lowering its ability to function to its fullest. In order for a muscle contraction to occur the 2 proteins, discussed in the review, actin and myosin are released and end up shortening the muscle fibers. The book talks about the release of Ca2+, which causes a contraction. This helps explain when the muscle is cold, contracted, and fatigued the muscle fibers are shorter than usual, taking longer for the energy molecule ATP to form. ATP helps keep the two proteins actin and myosin from binding to each other. At a cellular level, such as the contraction of the muscles, ATP is typically produced for muscle contraction. The amount of exercise or strength a muscle endures causes Ca 2+ to be released, actin and myosin slide around the muscle fiber, and the energy molecule ATP contracts the muscle. The numerous cells inside the muscles work hard during rest and during exercise. This lab proved that muscles become fatigued with lack of oxygen and energy it needs to release the necessary impulses to stay strong.

UNIT 3- Compendium: MOVEMENT

TABLE OF CONTENTS

1. Overview of Skeletal System

2. Bone Growth

3. Types of Muscles

This unit is composed of the skeletal and muscular systems. Above is my table of contents which I will provide in more detail below. The first review is the Skeletal System, which is made up of bones clicking and moving together to allow us to perform the activities we are doing. In my A & P class last semester, we looked at different organs on the Cadaver, which was my first experience. It is absolutely amazing to see the skeletal shape of the body with the organs in place. Inside each of us is a skeleton! Around the bones lie muscles that help with movement and protection against other organs. Muscles have a detailed job which I will do my best to explain, the picture I provide is helpful to follow along with. Both of these systems go hand-in-hand to provide our body with the proper movement, support, and functioning it needs to maintain homeostasis.

OVERVIEW OF SKELETAL SYSTEM: The book lists 5 functions of the skeleton: "supports the body, protects soft body parts, produces blood cells, stores minerals and fat, and permits flexible body movement" (Mader 208). These functions basically keep us alive and functioning. Each of our skeleton shapes began development while we were still an embryo, at about 6 weeks. "The bones that make up your skeleton are all very much alive, growing and changing all the time" (kids health article). Next I will discuss the different materials that make up the long bone, shown on the picture to the right. A long bone has an outer fibrous tissue known as the periosteum. The vessels on this tissue, break open the tissue and enter the bone. Next layer is the compact bone, if looking at a skeleton this is the note able tissue you see. Spongy bone is known for giving strength and the little spaces are composed of red bone marrow. One of the functions I mentioned was producing blood cells, this tissue does just that. Most babies bones are made up of a soft and flexible layer called cartilage, and as the baby grows the cartilage is replaced by bone. Athletes typically either pull/strain a ligament(bone to bone) or tendon(muscle to bone), made from the fibrous connective tissue. Fibrous joints connect without any movement. Another joint is Cartilaginous, which is attached by cartilage (spine or ribs). The last joint is Synovial, which helps protect the bones and allows it to move freely; since the synovial fluid acts as a barrier. The picture to the right shows a 'ball-and-socket' joint. I used to work on the Orthopedic/Med-Surg floor at Scottsdale Health care, and saw many fractured/broken hips. These individuals needed the physical therapy to learn the healing procedure and hip precautions, to prevent hip dislocation. the synovial joint movements discussed in this section are: Flexion-Extension, Adduction(moving arm/leg toward midline)-Abduction(moving arm/leg away from the mid line), Rotation-Circumduction, and Inversion(moving sole in)-Eversion(moving sole out). As discussed above, the skeletal system has many parts to hold up a strong framework.

BONE, GROWTH: The 3 different cell types of bones are: 1. Osteoblasts "bone-forming cells, promote the deposition of calcium salts into the matrix" 2. Osteocytes: "maintain the structure of bone" and 3. Osteoclasts: "break down the bone ad assist in depositing calcium and phosphate in the blood" (Mader 210). I stated earlier that during fetal development bones are begining to form, this formation is known as ossification. The book describes many different types of bones, but I will focus more on movement and structure. At this point in our lives we already know the importance of Calcium in our diets. To help keep our bones strong, and brittle-free. The book states the importance of Vitamin D, in that it helps absorb calcium. PTH keeps the bone recycling, rising the level of blood calcium. By the age of 25 an individuals bones have stopped growing. An average adults has "206" bones in their skeleton form (kids health article). Keeping our bones healthy and strong will hopefully lead to a less chance of developing bone diseases such as, Osteoporosis.

TYPES OF MUSCLES. "Humans have 3 types of muscle tissue: smooth, cardiac and skeletal" (Mader 228). The picture to the right shows what each muscle tissue looks like. Smooth muscle is known to be involuntary. Examples of where this type is found is the esophagus, stomach, bladder, intestines, and bronchi. Cardiac muscle is also involuntary and this is only find surrounding the heart. Lastly, the Skeletal muscle is voluntary, moves on our commands: arms, shoulder, knee. Its functions are support, movement, regulating temperature, and works to keep blood flowing. "Muscle is mainly composed of muscle cells" (wikipedia). These muscle cells are also known as muscle fibers. Inside each of these fibers are numerous little myofibrils, the "contractile portion of the muscle fibers" (Mader 232). The picture to the right is a muscle fiber(#3) and inside are the myofibrils(#4). If you were to pull out one of the myofibrils(long cylinder shape) and look at it under a microscope, you would find many sarcomeres. The membrane of a muscle fiber is known as a sarcolemma, the cytoplasm is sarcoplasm, and the ER is sarcoplasmic reticulum. By following along with the picture below will help explain the following structures. Within the sacromere are two protein filaments: myosin(thick- green structure) and actin(thin-orange coiled structure). Myosin is the big producer in the break down of ATP to occur. The two protein filaments go through a zig-zag sliding process in order for ATP to supply the necessary energy. In order for a muscle fiber to contract, the axons of motor neurons need to be in the nerves. The green flaps on the myosin filament is the axon terminal which are filled with synaptic vesicles containing acetylcholine-ACh(the axon terminal if flipped around resembles a shower head- the synaptic vesicles would be where the water squirts out). The gap from the axon terminal and the sarcolemma is known as the neuromuscular junction. When an impulse travels down the muscle fiber and reaches the axon terminal, it releases the ACh which binds to the sarcolemma. Calcium is also released from the sarcoplasmic reticulum, which aids in muscle contraction. The next two proteins to discuss are part of the actin filament(orange coiled structure): Tropomyosin(pink thread wrapped around the actin) and Troponin(blue clumps scattered across the actin). Once Calcium is released, myosin and actin are capable of binding.

Muscle Contraction: This is also known as a muscle twitch, it occurs when a muscle fibers lengthens or shortens. The book describes 3 different stages: latent, contraction, and relaxation periods. A motor unit is known as nerve and muscle fibers. I briefly described the process of the release of Calcium ions above and it relates again to the muscle contractions. When calcium exits the sarcoplasmic reticulum it contracts, and when calcium enters the fiber it relaxes. Interesting fact the book states is that a muscle has 4 energy sources: muscle triglycerides, plasma fatty acids, blood glucose, and muscle glycogen. "ATP is the immediate source of energy for muscle contractions" (wikipedia). The 3 ways the a muscle fiber collects the energy is through creatine phosphate, fermentation, and cellular respiration. To me these are a bit difficult to try and describe, so I will leave this information as mentioned above. We all get the annoying muscle spasms, for instance while swimming laps, cramps while jogging, the occasional eye twitching, or a sprained ankle. These are a few of the common muscle disorders we probably all experienced. Each movement between our muscles and bones is important for proper functioning as well as maintaining homeostasis.

In conclusion this review was a brief summary of the important structures of the skeletal system and the muscular system. Both systems work together to help our bodies move on command. The framework of a skeletal system has important functions for: support, protection, produce blood cells, store minerals and fats, and allow for movement. The 3 joints I discussed were fibrous, cartilaginous, and synovial. I also briefly touched on the importance of Calcium in our diet, to keep a strong and healthy bone structure. Muscle fibers work hard at making sure the body is able to perform muscle contractions by allowing the nerve impulses to travel its course. ATP is an important source of energy that is released, allowing the muscle to contract. I know I always say how amazing our body is, but I truly find it to be. Inside our body there is a strong skeletal structure with muscle surrounding to help with movement and protects all of our organs. Some movements are voluntary while others are not, regardless our strong body will fight to help maintain homeostasis.

WORKS CITED:

http://en.wikipedia.org/wiki/skeletal_system muscle and muscle fibers

picture of skeleton, muscle tissues, muscle fiber, and quotes

http://www.embl-heidelberg.de/cellBiophys/localprobes/motorproteins/myosin.html

picture of mysoin and actin

http://www.kidshealth.org/kid/body/bones_sw.html

quotes

http://www/shockfamily.net/skeleton/

picture of hip 'ball-and-socket

UNIT 3- LEECH LAB

Leech Neurophysiology Lab

This lab involved the dissection of a leech and then observing the nervous system under the microscope. It was interesting to start out with a leech on a tray, following the commands to dissect it, and then observing the cell under the microscope. I have had numerous encounters of these nasty, slimy worms stuck to me when I was little! Yuck! Below I will answer questions relating to the lab section. Hopefully by looking at the pictures you will have a general idea of the lab process it to look at the neurons of a leech under a microscope.





This picture shows the manipulator screen with the oscillope trace findings (purple boxes). It shows the chemical and physical parts of the neuron. Leeches consist of a brain, ganglia, and nerve cord. Looking at different cells by using the feather, probe and forceps to help move the tissue around to get a better view of the neuron cell and to check the response.








This picture shows using the dye injection and the ultra violet light to better visualize the neuron. Once the image was on the screen, it asked to identify the cell. To the right of the picture is a list of different cell types and the tools (feather, probe, forceps) used to get the image of the neuron. This particular cell is a dyed N cell used with forceps.


1. What is the electrode measuring? Electrodes record the activities that occur within the neuron. A good example of this is during defibulation. The electrodes placed on the individual sends an electrical shock to the heart, in hopes that it will beat again.

2. Why use leeches in neurophysiology experiments? Leeches have large neurons which makes it easier to experiment with. The background information in this lab also states that leeches have about 175 pairs of neurons.


3. What is the difference between sensory and motor neurons? Sensory neurons have nerve cells that relay external information to the CNS. This all depends on the organism. Motor Neuron are neurons found in the CNS with axons on the outside, giving control to muscles.

4. Do you think a leech experiences pain? What is pain? I would think leeches would feel pain. Everyone has a different pain tolerance and opinion of what pain is. To me pain is an injury that has an unbearable sensation(sharp, excruciating, throbbing).

5. What were the 2 most interesting things about doing this lab? Just being able to view a whole leech, using the tools to dissect, and observing the neuron under the microscope was quite interesting. It was also neat that it provided extra information and history on leeches as we clicked around trying to find a cell.

6. Anything you found confusing or didn't like about this lab? Trying to explain the pictures of what I did with the lab was hard. It's one of those things that you have to actually go through the process to know what it is I am talking about.


In conclusion this lab shows that inside of a slimy, disgusting leech are numerous neurons. Although it is hard to see the process of the lab, it mainly consisted of dissecting the leech, finding a cell, trying different tools to move back the tissue, using an ultra-violet light and a dye to get the finished product: a leech neuron. A leech consists of a brain, ganglia, and nerve cord which makes them an interesting lab animal to experiment on. Leeches are now being used for numerous medical reasons. A leech bite is used as an anticoagulant and vasodialtor, which comes from its saliva. This lab was able to show the amazing view of a neuron, found in a leech.

UNIT 3: Compendium Review: Nervous Function

TABLE OF CONTENTS

1. Overview of Nervous System: CNS and PNS

2. Action and Resting Potentials: passage of nerve impulses

3. Reflex Arch: Somatic and Autonomic System

4. Senses

Below I will discuss the importance of the Nervous system and how it ties in with our senses. Above I made a brief table of contents of what I will discuss. As we go about our daily lives, our bodies work hard to keep up with our actions. How exactly are we capable of doing what we do? The 2 parts of the Nervous System I am about to discuss will explain the messages our brains interpret and send to our systems. Each of our senses depend on the sensory receptors it contacts. Hopefully my explanation of the Nervous System and Senses will give you a better understanding of how nerve impulses are transmitted and interpreted.

Overview of Nervous System: CNS and PNS. This system is composed of two major systems: Central Nervous System (CNS) and Peripheral Nervous System(PNS). Giggling at a joke, whispering a secret, smelling the fresh rain, stubbing your toe, dipping into the swimming pool; are all actions occurring in our brain. The brain and spinal cord are part of the CNS; which functions as a control center for our body. While the nerves make up the PNS; which is like a mail carrier, in that they send messages from the brain to the body. "Neurons are the cells that transmit nerve impulses between parts of the nervous system" (Mader 248). The picture to the right is a neuron. Which is composed of 3 different parts. The finger like projections are dendrites(receive information from the environment), the center dot is the cell body(keeps the cell functioning), and the snakelike extension is the axon(takes information away from the cell). Together these structures work to carry nerve impulses either towards the cell body or away from the cell body. There are also 3 different types of neurons in the body: sensory(skin, eyes, nose), inter neurons, and motor(muscles and glands). Wrapped around most axons is a covering known as a mylein sheath. It serves as a protective wrap and as a "nerve regenerat[or] within the PNS" (Mader 249). Multiple Sclerosis (MS) is a disorder that occurs when the mylein sheath becomes injured, which interrupts the nerve impulse flow. I work with a few residents who have this disorder, so its interesting to get more familiar with it. The body is unable to repair any neurons or mylein. A few disabilities in the residents I work with are: loss of muscle strength and control in arms and legs, decrease sensation, and difficulties talking. The cause of this disease is unknown, but the book relates how the immune system may be a factor. "Neurons are the oldest and longest cells in the body" (Faculty article). The packed information of nerve impulses jump across the gap to pass on the information to yet another neuron.

RESTING AND ACTION POTENTIALS: The transportation of nerve impulses can be related to that of a communication network. Resting Potential refers to the axon resting and not sending an impulse. The voltmeter reading at rest is about "-65mV(milivolts), indicating that the inside of the neuron is more negative than the outside " (Mader 250). Note the picture to the right, which shows the molecule action during resting phase. Potassium, since it has a solid line, easily passes through the neuron membrane during resting potential. While the other molecules Chloride and Sodium, have more difficulties. Inside the neuron is like a matching game; for every 3 sodium molecules that exit, the neuron wants 2 potassium molecules to stay inside. Once the match is settled and the molecules are in place, the volts are measure: known as resting potential. Action Potential is known for its speedy impulse of sending information down an axon (as mentioned above, it moves away from the cell body). Since inside of the neuron is negative and the outside is more positive; during action potential the positive charged Sodium molecules are attracted to the inside neuron, which opens up the sodium channels. Once the neuron becomes more positively charged, depolarization occurs. But when the Potassium channels open (negative charged ion) and settle outside of the cell, repolarization occurs. Note the picture to the right, it shows that the sodium and potassium channels opening and closing as the molecules hustle to enter and exit the neuron. After the busy running around, the molecules settle back to where they started, resting.


Information from one neuron flows through to another neuron by crossing a synapse. This transportation is from the many molecules known as neurotransmitters, which make up a synapse. Neurostransmitters are, "stored in synaptic vesicles in the axon terminals" (Mader 252). The synpatic cleft "separates the sending neuron from the receiving neuron" (Mader 252). Neurotransmitters "diffuse across the synaptic cleft where they can bind with receptor sites [..] to influence an electrical response" (Washington article). Similar to a sticky spiders web, some bugs make a lot of movement once attached (start an action potential: sending the message) while some bugs are less active while stuck on the webb. In today's field of medicine, there are many drugs that can affect the release of the neurotransmitters. A few common molecules we are aware of are norepinephrine, dopamine, and serotonin. These neurotransmitters have different functions, such as, moods, temperature regulation, and emotions. The common anti depressant Prozac "blocks the removal of serotonin from a synapse" (Mader 253). Synapses send signals to relay a message throughout the body to cells, mostly to muscles and glands.


REFLEX ARCH: SOMATIC AND AUTONOMIC SYSTEM. To start this section, the purpose of describing the reflex arch first is because it is an automatic response to protect against danger. We have all experienced this reflex numerous times. When you grab the hot plate out of the microwave your first action is to quickly pull your hand away (hence dropping the plate). This quick action is actually going through many processes throughout your body. The first impulse is that of the sensory receptors which quickly sends nerve impulses to the "sensory fibers through the dorsal-root ganglia toward the spinal cord" (Mader 263). It then passes on to interneurons, which travel to a synapse connecting with a motor neuron found within the spinal cord. Once with the motor neuron, the impulse attaches to an effector, which causes your physical action. This whole processes is sent to the brain, which reads the information it receives and then sends an action. The Somatic System is part of the PNS, the voluntary body movement. These nerves consist of: skin, skeletal muscles, and tendons. Autonomic system is divided into the sympathetic and parasympathetic division. The ANS "controls homeostatic maintenance of the body's internal state" (Wikipedia). A few examples of these heart rate, breathing, blood pressure, and perspiration. Imagine being pinned under a car, the Sympathetic Nervous System, would quickly fall into this category. During this emergency your body would quickly speed up its control mechanisms. Your heart rate would increase, allows more oxygen flow, increases blood flow to skeletal muscles, and dilates pupils. Many people know this system as the "Fight or Flight" response. The Parasympathetic Nervous System is more of the relaxation phase. This phase includes: relaxed heart rate, constricts the bronchioles since the demand for oxygen is low, pupils constrict, and the digestive system is moving. The picture of the brain to the right just shows how amazing this structure is. All the information it collects and reads, is then interpreted and sent out binding to receptors and performing an action!

To begin, sensory receptors are: " dendrites specialized to detect certain types of stimuli" (Mader 274). The book describes two different types of sensory receptors: exteroreceptors (taste, smell, see, hear, and equilibrium) and interoceptors (blood pressure changes, water/salt balances, and blood pH). There are also 4 categories of sensory receptors: Chemoreceptors(taste and smell), Pain receptors (watch/notify us of danger), Photorecpetors(vision), Mechanoreceptors(hearing: yelling, music), and Thermoreceptors (temperature regulator). The process of sensation was described when I discussed the reflex arch. The sensory receptors related to the spinal cord impulses are: Proprioceptors (muscle tone), Cutaneous Receptors (skin sensitivity ), and Pain Receptors(damaged tissues).

Touch: The skin goes through the process of either a startle reflex with pain or a regular sensation. Below is a picture of the different layers of the skin.


Taste: The book states that humans have about "3,000 taste buds" (Mader 278). The tiny bumps on your tongue are surrounded by taste buds. There are 4 well known tastes we acquire: sweet, sour, salt, and bitter. I really do appreciate the fact that I can taste the difference between foods, because as you age, unfortunately, we loose our sense of taste.


Smell: Interestingly enough, "80-90% of what we perceive as taste actually is due to the sense of smell" (Mader 279). An article states because of this some argue that, "Taste and Smell should likewise be grouped together as one Sense" (wikipedia). The olfactory neurons in the nose provide us with odors. To the right is a picture of the nose, which shows the path of smell, and the top part shows the olfactory nerve.


Vision: The eyes have many different parts, as you can tell by the picture below. We see objects due to the light projecting on the retina. This could be a complex topic, but the main purpose is how we see and even before impulses reach the brain. This sense is anothermany of us take for granted. Not everyone has been blessed with the ability to see the world.

Hear: There are also many parts within the ear, as shown in the picture below. The pathway of hearing occurs when "sound waves enter the auditory canal" (Mader 287). Individuals hear different sounds at different pitches and tones. Some can't hear high squeaky voices, whiles others have difficulties with low tones.

While watching the 4th of July fireworks, I definitely experienced all the senses. Sitting on the grass, I touched the smooth grass blades between my fingers. Each Mike n Ike I plopped in my mouth was tasteful. Just enjoying the outside air was refreshing, as the evening cooled off. As the lights dimmed to God Bless America; the array of colors lite the evening sky and the bang of each firework sounded above.

In conclusion, the nervous system is composed of two main systems: Central Nervous System (brain and spinal cord) and Peripheral Nervous System(nerves). Neurons are packed with information, sending nerve impulses to different parts of the nervous system. The cell body, dendrites, and axons make up the parts of a neuron. Each part works together to interpret the nerve impulses: resting or action potential. I also discussed Somatic as being a voluntary body movement. We experience different reflexes, depending on the situation. Cutting your finger sends sensory receptors on a journey, which eventually reaches the brain. The end reaction is from the brains interpretation. The 5 senses were also briefly touched: touch, taste, smell, hear, and vision. Our world is full of senses that we tend to take for granted. The nervous system constantly sends nerve impulses throughout the system and relaying the messages to our brains to make an action possible.

Works Cited:

http://emc.maricopa.edu/faculty/farabee/BIOBK
picture of brain and neuron
http://en.wikipedia.org/wiki/somatic_nervous_system and sensesquotes
http://faculty.washington.edu/
picture of potentials and quote
http://freda.quyeung.net/5senses/
pictures of 5 senses
Mader, Sylvia S. Human Biology. Boston: McGrawHill Companies, Inc. 2008.