Unit 4 part 1 lab: fetal development

Event 1: Carnegie stage 10, which occurs after ovulation in the 21 to 23 day of a women’s cycle. This event is significant because the very beginning stages of development are starting for the eyes, ears and heart. It is a great example of how quickly that, what which was once an egg turns into a human.

Event 2: Carnegie stage 11 occurs 23-25 days after ovulation. It is the early development, which is most significant to me because it is when the building blocks for future development. Now the heart is beating, it is only the beginning; the heart is kind of practicing because the blood vessels have yet to develop. And we can now see the umbilical cord.



Event 3: Carnegie stage 16 occurs 37-42 days after ovulation. Now the brain has practically developed, specifically the part of the brain that controls the heart, breathing and muscles. The lower jaw is now visible, the hand starts to become it’s own part from the limb bud, and the thigh and foot can now be seen as a part of the leg bud.



Event 4: Carnegie stage occurs 42-44 days after ovulation. Now we’re cooking so much occurs in this stage. The heart is now separating into its four separate chambers and the diaphragm forms. The sense of smell develops in the brain, the ears are now visible and teeth begin to develop. Also the pituitary glad begins to form. It is about to decide which gender to be, and the trunk is becoming straighter preparing to become a spine.

Event 5: Carnegie stage 18 occurs 44-48 days post ovulation. The eyes develop color and the eyelid appears. Nipples are created on the chest and the kidneys start to produce urine. And the arms are ready to go.



Event 6: Carnegie stage 20 occurs 51-53 days after ovulation. Now the baby is starting to look like a human. It can now create voluntary movement, the nasal openings have formed, and the gender has been decided. The arms are full and bend at the elbow and the toes look like duck feet.

Event 7: Carnegie stage 23 occurs 56-60 days after ovulation the head is now standing up from the rest of the body. The ear is complete; the taste buds begin to form. Limbs are formed and the toes and fingers have separated. Now the tail has disappeared.



Event 8: Week 10 the baby can now be measured in inches and is about 1.25 to 1.68 inches long. The structure of the brain is complete and hair follicles start to form on the face. The baby can now make vocal sounds through the vocal cords, which have formed in the larynx. The gender organs are starting to show their gender. The nails begin to development and the skin becomes very sensitive.



Event 9: Week 12 the heart beat can now be detected. The spleen is ready to go. The gender organs are now visible and the gender of the baby can be identified. Sweet glands and hair start to grow.



Event 10: Week 16 figures prints are starting to develop. The ears are standing out from the head and are fully developed. The eyes are facing forward and the baby can now blink. I think this stage is most significant because the figure prints are developing, which are so significant in human life.



Note: I found so many stages to be significant that I did not span the whole pregnancy. I had no idea how much happened during development. I loved this assignment.

Unit 3 lab

I decided to do a model of the knee joint because I have recently started running so I have been extra interested in my knees lately. I did my best to show every part of the joint. I couldn’t figure out how to illustrate the movement.

I did the model of the knee joint including

Femur: represented my the top portion of a spoon

Patella: represented by the scoop part of the spoon

Quadriceps tendon: represented by blue rubber bands

Lateral Collateral ligament: represented by organ rubber band

Anterior cruciate ligament: yellow rubber band

Medical collateral ligament: tin foil

Meniscus: paper clip

Patella tendon: green rubber band

Tibia: Handle of the bottom spoon

Here’s the model of my knee






Here is a model of a neuron




Here is a model of a muscle cell






My main model represents the knee joint. I learned all about the different parts of the knee and what they do. How the muscles help to move my joint, and especially all the different parts.

I have to say that while I do end up learning a lot from the labs they are my least favorite activity in the course. It is not enjoyable and it is very hard to wrap my head around.

Unit 3 pt 2 lab

1. What are the three changes you observe in a muscle while it is working?

The muscle gets tighter to the tough, meaning that it is contracting. The muscle will also change length as in the experiment with the arm. And the circumference changes because when the muscle tightens it can also change shape somewhat.

2. What effect did the cold temperature have on the action of your hand muscle?

It significantly slowed down the rate at which I could contract. This happens because the cold slows down the metabolism inside the muscles cells, so the muscle has less energy to create movement with.

3. What effect did the fatigue have on the action on your hand muscles?

It made it harder to contract. It is because I am depleting the energy available to the muscle to contact, making it harder and harder.

Conclusion:

Cold slows down the metabolism inside the muscles cells, so the muscle has less energy to create movement with. Repetitive movement with one muscle or a set of muscles depletes the energy available to the muscle to contact, making it harder and harder.

Compendium Review Unit 3 pt 2

Table of Contents

1. Muscle cell structure
2. Calcium release in the muscle
3. Muscle contraction
4. Joints
5. Structure of a bone
6. Calcium regulation in the bones

1. Muscle cell structure

A single muscle cell has hundreds of myofibrils. Myofibrils are threads that run along the axis of the fibre. They all have actin acting and myosin. Actin facilitates cellular movement, it is also known as microfilaments or thin filaments. Myosin is a protein responsible for converting ATP energy to mechanically usable energy. The cells of muscles are also quite large and can be seen without a microscope.

a. Parts of a muscle cells

Muscle cells have a few main parts. Sarcolemma is the cell membrane that can create action potential to allow the muscle to do its job: move. Then there’s the sarcoplasmic reticulum and endoplasmic reticulum both regulate calcium ions. And finally the T-tubules get into the cell to contact the sacroplasmic reticulum.



2. Calcium release in the muscle

Calcium is a released in the muscle through a chain of actions. First the motor neuron sends a single to the axonal terminus, and then the synapse send the message to the muscle cell. The Sarcolemma or muscle cell membrane goes through action potential and on to the T-tubule system. There is a change in the voltage that creates the release of the calcium ions in the muscle cell. The presence of the calcium makes the cross-bridges go through a change in shape.

3. Muscle contraction

Muscle contraction requires ATP. There are three different ways to get the ATP. The first is Anaerobic in which phosphate is created and added to creatine to make ATP. The second is when glycogen and lactate are fermented to make ATP. And third Aerobic, glycogen or fatty acids are combined with water and oxygen to make the ATP. The energy is used to make the muscle cells move closer together to contract the muscle. Neurons are what tell the muscles to move based on stimulus from the outside world or through sensory input. Muscles contract when they slide filaments. The following website http://www.mpimf-heidelberg.mpg.de/~holmes/muscle/muscle1.html, has a really great explanation. “The contraction of voluntary muscles in all animals takes place by the mutual sliding of two sets of interdigitating filaments: thick (containing the protein myosin) and thin (containing the protein actin) organized in sarcomeres each a few microns long which give muscle its cross striated appearance in the microscope (Fig 1). The relative sliding of thick and thin filaments is brought about by ‘cross bridges’, parts of the myosin molecules which sticks out from the myosin filaments and interact cyclically with the thin filaments, transporting them by a kind of rowing action. During the process ATP (adenosine triphosphate) is hydrolyzed to ADP (adenosine diphosphate), the hydrolysis of ATP provides the energy.”

4. Joints

Joints connect different bones together; the synovial joints are what allow movement throughout the body because they are lubricated and can facilitate movement. The movement is created when muscles tug on the joint and we move.

5. Structure of a bone

Bones are actually living organisms in the body that have nerves blood supply and cells. There is connective tissue inside the bone that surrounds the blood vessels. Cells as they are in all parts of the body and the driving force of the bone creating bone tissue, breaking down old bone tissue.



a. Fetal bone formation

When bones form in the fetus they start with cartilage. Cartilage is thought of as a type of bone but is technically a type of very dense connective tissue. Once the cartilage has formed bony tissue fills around the blood vessels. The new bone tissue is formed inside of the cartilage at the growth plate that lies between the diaphylis and epiphysis and the two ends of the bone. Then the final bone starts to form, this happens in three stages.

b. Medullary cavity

The Medullary cavity is located in the diaphysis and is a hollow area shaped like a tube. This is where the bone marrow is and where the blood cells of the bone are created.



c. Bone tissue what's so special about bone tissue?

Bone tissue is what supports our body without it and our muscles we’d be a big lump on the floor. Bones also protect the organs from the outside world. And bones are kind enough to store most of our calcium and phosphate.

6. Calcium regulation in the bones

Bones store calcium and are essential to the health of the bone. Calcium is also needed for cell metabolism and muscle cells. When bone loses calcium they become weaker. It is the role of the thyroid and parathyroid to regulate calcium in the body. When bones don’t get enough calcium osteoporosis is manifested. Osteoporosis is a disease that effects more women than men and levels are high in the elderly. The weakness of the bones can lead to soreness and easy fractures and breaking.


Sources:
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cooper.section.1790, http://www.cytochemistry.net/Cell-biology/actin_filaments_intro.htm, http://www.mpimf-heidelberg.mpg.de/~holmes/muscle/muscle1.html, http://www.wisegeek.com/what-is-cartilage.htm, http://www.technion.ac.il/~mdcourse/274203/lect5.html, Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th

Compendium Review Unit 3 pt 1

Table of Contents

1. What does nervous system does
2. Diffusion and Action Potentials in Neurons
3. Myelin Sheath
4. Neurons
5. Synapse
6. Reflex arc (simple somatic function) and autonomic function
7. How Sensation happens
8. Sensory fields in the brain
9. Body Sensory
10. Special senses in the head


1. What does the nervous system does

The nervous system controls the intake of sensory information, processes the information and creates motor outputs, the response to the intake. All neurons in the nervous system send signals the same way. That is a very simple and basic explanation of the nervous system, it is way complicated.



2. Diffusion and Action Potential in Neurons

Diffusion is when move on transport proteins in the cell membrane. Action potential is the rapid transmission of messages that takes place in the body through the nervous system. This allows us to analyze the information of out environment quickly. It is done through diffusion in the cell membrane.



3. Myelin Sheath

The myelin sheath is one nerve that consists of hundreds or thousand of axons. It is a fat based nerve that helps to insolate neurons and to help with action potential. The myelin is located in the cells that surround the axon that are called Schwann cells, this allows action potential to go to nodes where the cell membrane is exposed. The saltatory or jumping of action potential, it saves energy and makes it more efficient.



4. Neurons

Neurons are the cells that transmit action potential and are the main cell in the nervous system. Neurons receive the information that they transmit from sensory cells or other neurons that already have the information. Neurons can be super long. The axon of the cell is what carries the message. One of the things I found most interesting about neurons is that they don’t procreate, go through mitosis or die. There are two main types of neurons; sensory neurons that give information to the organs and tissue, and motor neurons that send information to every muscle.





5. Synapse

Synapse occurs when the action potential has been carried out to the end. A Neurotransmitter is secreted to stimulate connecting neurons. According to http://www.biology-online.org/dictionary/Synapse there are 5 different kinds of synapse, they are as follows: “1. Chemical synapse: one in which an action potential causes the exocytosis of neurotransmitter from the presynaptic cell, which diffuses across the synaptic cleft and binds to ligand gated ion channels on the post synaptic cell. These ion channels then affect the resting potential of the post synaptic cell. 2. Electrical synapse: one in which electrical connection is made directly through the cytoplasm, via gap junctions. 3. Rectifying synapse: one in which action potentials can only pass across the synapse in one direction (all chemical and some electrical synapses). 4. Excitatory synapse: one in which the firing of the presynaptic cell increases the probability of firing of the postsynaptic cell. 5. Inhibitory synapse: one in which the firing of the presynaptic cell reduces the probability of firing of the postsynaptic cell.



6. Reflex arc (simple somatic function) and autonomic function

The Reflex arc is one of the coolest things I’ve learned about. The reflex arc is an arc of electrical current that jumps from one neuron to another to activate involuntary action. The axon forms a new synapse, which transmits the impulse to the motor neuron to send the single.



7. How Sensation happens

Sensations occur when our bodies sense something through conscious somatic sensory perception. There are special sensory receptors whose job it is to process the information that our senses are picking up. The receptor sells tell the sensory neurons what is going on through action potential. And finally the brain and the spinal cord figure out the details, of the what where and how much.

8. Sensory fields in the brain

This is done through large areas in the brain that organize information spatially. This is done for vision and touch through the skin.

9. Body Sensory

The body senses touch, pain, temperature and pressure through the skin. Our body knows the position it is in through proprioception. The body senses what is going on around it and information is sent through the neurons to the brain and spinal cord for interpretation.

10. Special senses in the head

Many of the senses that help us perceive the world and our place in it are located in the head. They are taste, smell, vision, hearing and equilibrium, which is a sense that is in the inner ear.


Works Cited:

http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0097305.html, http://www.merthyrlearns.com/mod/resource/view.php?id=5276, Sources: Sources: Frolich PowerPoint for cells and Human Biology 10th edition, Human Biology 10th

Unit 3 Ethical Issues essay

It was great to see this issue taken into account. I recently learned that the Prescott Unified School district only has Physical Education 2 to 3 days a week. I was outraged. So this was a particularly good time for me to this assignment.

It was interesting to see the first article, Essay on Obesity and the Environment Modifying the Environment to Reverse Obesity, actually take into account the fact that our daily lives don’t include physical activity like they used to. And because our lives are taken up with work that doesn’t include physical activity many have a hard time making time to get exercise. For me growing up, I never had a hard time getting exercise. But I was home schooled and lived in the forest, I was a total tomboy and spent my afternoons running around and climbing trees. And then I got into dance. I think that children and adults would benefit greatly from finding an activity that is fun for them. But then I quit dance and started college and it all went down hill from there. I stopped exercising. I lived a half hour drive out of town so there was no walking, and I just went home and watched TV with my parents. Getting rid of television when my boyfriend and I moved in was the best decision we have ever made. I feel that people shouldn’t have cable or satellite. I’m not saying that we shouldn’t have any TV. We could have it and some DVD’s for when we get sick and lie around, or for watching something educational but for the most part TV should be given up.

I love the ides in some of the other articles where they’ve made trails a very viable mode of transportation. I think that it would be hard to convince people to give up their comfy cars to walk on trails. But if the trails make it easier to get where you’re going then it might work. It’s all about giving people an incentive, they’re not going to do it just because they’ll get exercise or pollute less. Trails for walking and bicycles are something that should be much more encouraged in cities. But I will say that I don’t want roads to totally disappear. I did a lot of walking this summer, but now that it is cold I don’t want to walk. I would not trade a half hour walk to work at 5:30 in the morning for a 10-minute drive.

Then there’s the issue of how to get people to eat food that’s good for them. The psychology of eating has always fascinated me. I have always eaten healthy. I was raised that way and just never learned another way to exist. So I have a really hard time trying to understand why people don’t eat healthy food, so I am happy that this was brought up because I am nutrition major and I need to learn how to understand this. I agree with the first article that advertising is a huge part of promoting an unhealthy lifestyle. Children especially, being bombarded with these ads. My uncle, who’s a little radical, one time at a parade in town screamed at the Ronald McDonald going by on a float “You’re killing our children.” And that is true to some extent. I think for children this comes down partially to bad parenting. Parents give into their children too easily instead of saying “no” and sticking to it.

Eating well is a habit. I’m not sure what the best way to make the habit is, but I know that once you do it is hard to do anything else. If I eat out a couple times in a week I can feel it. It’s lower quality food that isn’t as healthy and my body let’s me know it.

I’m glad to see that there are so many people out their trying to fix the epidemic of obesity. I figure things can only get so bad, and once they do they’ll start to turn around.

Unit 3: Leech Lab

QUESTIONS ABOUT LEECH NEUROPHYSIOLOGY LAB:

1. What is the electrode measuring?

The electrode is measuring the difference of neuron membranes.

2. Why use leeches in neurophysiology experiments?

Because the neurons are easy to reach without having to disrupt the neuron.

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

A sensory neuron sends messages to the brain and spinal word, while the motor neuron sends messages to the muscles and organs.

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

Absolutely. I think that anything with nerves experiences pain.

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

Seeing the structure of a leach was interesting because we don’t have leeches her in the west. And getting to walk through doing the experiment virtually to see how it works without has to actually do it.

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

I did not like dissecting the leech. It was gross and sad, but at least it wasn’t real.