Sheep eye dissection

1. Cornea- the transparent layer in front of the eye that protects it (was very hard and almost like a plastic during the dissection)
2. Sclera- the white outer layer of the eyeball and serves to protect the eye/contain its components (based off of observation) and connects the muscle
3. Optic nerve-  each pair of cranial nerves connect at the back of the eye; transmit signals to the brain from the retina at the back of the eye
4. Iris- a circular structure that controls the diameter of the pupil, thus the amount of light that enters the eye
5. Pupil- hole at the center or the iris that allows a certain amount of light into the eye
6. Ciliary body- controls the shape of the len, tissue that supplies eye with oxygen
7. Choroid- the pigmented vascular layer of the eyeball between the retina and the sclera;
8. Tapetum lucidum- lying right behind the retina, the tapetum lucidum is a refractory material that allows animals to see in the dark by reflecting the light (reason why animals eyes seem to flash back when photos are taken of them)
9. Retina- essentially the film in the camera; very thin and was VERY easy to peal back in the dissection
10. Lens- transparent, light bending structure, felt like a marble almost, like a marble split in half
11. Vitreous humor- clear gel that fills the space between the lens and the retina; is the ‘cushion’/filler/place holder for the lens  

Bird Brain

Bird Brains by Candace Savage

1. A thesis is established for the works could be that regardless of our relatively low expectations of birds, they are actually quite smart. The book supports this claim with relatively scientific evidence. It does this by proposing an idea and following it up with quotes from the conductor of the experiment. Usually the quotes are fairly specific, however I noticed that the quotes rarely explained the why to the results. This could be attributed to “anthropomorphism,” or,  “the too-easy ascription of human emotions and mental processes to nonhuman animals” (19). Although their results may have helped prove the thesis of the book, none of the information made connections to their ability of higher thinking, rather explained what the results meant. Personally I found that by doing this, the book almost took away the some credibility. Occasionally however, there were moments where the author did fill in some gaps as to why (I will cover this later). A theme of the book was this idea of learned versus innate characteristics. I found that the best example was in the story of Konrad Lorenz. Having a collection of tame Jackdaws, Lorenz decided to introduce a new fledgling. When he grasped the new bird, completely tamed members of the colony attacked him, pecking at Lorenz’s hand until the new jackdaw was released. However, he later learned that, “young jackdaws  had no inborn reaction to predators,” and instead, “had to learn from their parents’ example what to trust and what to fear… if the adults responded to someone or something with alarm, the young birds quickly developed an identical phobia” (26).  
1. Ultimately, to support the claim that birds are smarter than we perceive, Savage uses multiple subtopics; resource management, generic shape and pattern matching, and parental features. Although the birds’, “cerebral cortex (the organ of higher thought in humans and other mammals) looked distressingly small and poor developed,” they still “share the ‘cognitive capacities’ of many primates.” (26,18). So why do we seem regard primates more highly than birds. Interestingly enough, the birds, “brain to body ratio equals that of dolphins and nearly matches our own” (29)! I don’t know about you, but the insult, “bird brain,” just got a whole lot less offensive.
2. The book mentions several times about the plasticity of brains and how the bird is capable of learning new things/ modifying old. For example, a magpie was attempting to build a nest in a confined area. Instead of using the material that the male partner had brought, the female independently ventured out to gather softer materials such as newspaper and grass. Ultimately, instead of making the tough outer portion of the nest, the female magpie made only made the soft inner portion so that the nest could fit in the confined space. Another example of the plasticity of the brain is in the example of the blue jay. The blue jays have been known to build their nests lower to the ground, however, younger birds may try to build their nests higher up into the canopy to expose their nests to the sun. Although this may benefit them, it also puts them at a higher risk of predation. As a result, “the frequency of nesting in exposed locations dropped from eighty percent to fifty five percent after individuals suffered their third predatory experience when nesting in exposed locations” (47). Another way the reading connect to the class was through identification of the portions of the brain. As mentioned above, the cerebral cortex is the basis for all higher thinking and that is why the bird’s is relatively small. However, there was an adaptation that did allow for complex thinking. Not found in mammals, a miniature cerebral cortex can be found in birds.
3. If I could ask the author two questions they would probably be:
1. What can be said about the mating habits of the birds? Are they genetically imprinted in the bird’s mind or is it a learned characteristic? Can a bird be taught the ‘dance’ or ‘song’ of another bird species.
2. Can a bird species really learn and or make alternate neural pathways to adapt to its environment? Although the jay may move its nesting ground after the 3rd predatory encounter, is it really the cortex at work? Or is it still imprinted in the jays brain?
4. I really enjoyed this reading. Although I read it at 4:00 am, I had absorbed almost all of the information that I had read. Infact, I was probably more critical of the reading because it was so late at night. In my opinion, the reading was very realistic as it contained scientific evidence as well as facts about the information discussed (for example the cerebrum, how nests are built and so on). For starters, I will discuss the things that I liked. Specifically, I loved how the book incorporated images to accompany the subjects it discussed. It really helped visualize the material. Concepts that I enjoyed learning about were how the bird brain has a ‘mini cerebral cortex’ that is not found in mammals. I also enjoyed learning about how the certain birds adapted to their surrounding environment. Although it cannot be proven that the birds actually adapted to their environment, I found it to be an interesting hypothesis. I also liked how the book went into detail as to how birds identify their young. I had been interested as to how they recognized their own chicks among the rest of the newborns. What I did not like however, was how the book almost contradicted itself. One second it’s saying that birds are intelligent as they can recognize shapes, yet counters the point by mentioning anthropomorphism. The book then continues along the lines mentioning the interesting mental powers of certain birds. To me it just seemed counter intuitive.
5. The effects of this work are in the grey zone. Once again, there have been speculations of birds having a higher level of thinking, but the general opinion is that they do not. The book helps to explain and clear up these speculations and make some of the grey area black and white, narrowing bringing us closer to definite answer. The practical application of this book is that it allows an ordinary person to have an new appreciation for birds. Ultimately, I believe this book will be apart of the foundation for the research that eventually proves or disproves whether or not birds have a higher level of thinking.

Clay Brain

In this activity, we made a brain out of clay, who could have guessed with title. Essentially what we did to create the brains was look up the images of the brain along the left hemisphere along sagittal plane and the right cerebral hemisphere. We made sure to get the basic and most familiar lobes and other structures down on the cardboard first, then built our way to the more complex structures. Eventually we got to the point where we needed to label the structures, so me, being the lazy guy that I am, cut out the grading sheet and pasted it onto the cardboard. We then pulled pieces of the play-dough from each structure and placed it on the appropriate label. Although this was supposed to save us time, we still ended up finishing the project last. 

Hole in the Brain

So recently I read an article on a woman who was missing her cerebellum. Apparently she had the space that was originally taken up by the cerebellum was replaced with a fluid. I found this remarkable and so did the article as only 9 other people have survived such a condition into adulthood. Personally, I was curious as to what would happen if the fluid drained and if the fluid had made any other complications, or if it was actually beneficial in other ways (knowing the cleansing power of the fluid). Then I wondered what would happen if the pons part of the brain was missing.

Pons is located in the brain stem and is involved in sensory analysis. It is also involved in regulating levels of consciousness and sleep. Injury to pons is known to cause comas as well. Given all this information, I would assume that if the pons portion of the brain stem were to be missing, or removed, the patient would likely enter a coma, and likely lead to death. Unlike the cerebellum, the pons most likely could not be replaced due to its essential function.

Chicken Dissection Lab

Unfortunately I was absent for this assignment/dissection, however, I am still educated on the material. I asked class members who did do the lab, how it went and how the process of determining muscles went. They all, for the most part, referred to their in-class notes handouts of the human body. In general, the size of the muscles differed from chickens to humans, however the locations stayed the same. For example, the pectoralis major was far larger in the chicken than in the human. This difference is likely caused by the fact that to lift itself off the ground, the muscle would have to be larger. This causation ultimately results to form fits function. As the chicken needs to lift itself off the ground, the muscles need to be stronger, and therefore larger. In contrast, humans are far less reliant on the pectoralis major as we don't fly (if only). Some characteristic similarities are are in the trapezius and the deltoid. An important reminder is that muscles grow and atrophy depending on usage and resistance the muscle receives. This can help determine the physical activity and nature of the animal, for instance our largest muscle is the gluteus maximus which is due to our nature as a 2 legged animal.  

Not only are muscles used for movement, but so are bones and tendons. Muscles connect to the bone through tendons and help to show increase the range of motion and release tension. The bones allow for stability. As muscles contract, certain muscles contract as others relax. The muscle that contracts is called the agonist whereas the muscle that relaxes is the antagonist. For example in elbow extension, the triceps contracts, whereas the biceps relaxes. The lever system in this interaction allow the bicep to contract with less stress. These levers vary in class; each class identifies a different type of lever system.

Just as levers vary in class, so do tendons. There are two types, named, the origin, and the insertion. The origin is the end that does not move when the muscle moves while the insertion is the tendon that does move when the muscle contracts. The origin also tends to be more proximal while insertion tends to be more distal. The origin of a muscle attaches to a less movable bone whereas the insertion of a muscle attaches to a more moveable bone. The insertion also has less mass than the site of origin.

• The pectorals are predominantly used to control the movement of the arm, with the contractions of the pectoralis major pulling on the humerus to create lateral, vertical, or rotational motion
• large muscle in the upper chest, fanning across the chest from the shoulder to the breastbone

• thin, flat muscle found immediately underneath the pectoralis major

• The primary actions of this muscle include the stabilization, depression, abduction or protraction, upward tilt, and downward rotation of the scapula

1. The muscle also covers the lower tip of the scapula, or shoulder blade. When flexed, the muscle works at extending, adducting and rotating the arm.
2. One of the widest back muscles. Broad muscle bands cross the back, providing upright posture support. The trapezius muscle is a postural and active movement muscle, used to tilt and turn the head and neck, shrug, steady the shoulders, and twist the arms

• The deltoid muscle is responsible for the brunt of all arm rotation and allows a person to keep carried objects at a safer distance from the body.

2.  The triceps run along the humerus (the main bone of the upper arm) between the shoulder and the elbow. When the triceps are contracted, the forearm extends and the elbow straightens; if the triceps are relaxed and the biceps flexed, the forearm retracts and the elbow bends.

3.  The biceps brachii is a bi-articular muscle, which means that it helps control the motion of two different joints, the shoulder and the elbow. The function of the biceps at the elbow is essential to the function of the forearm in lifting.

1. Also called the brachialis anticus, its primary action is to flex the forearm muscles at the elbow
2. flexes the wrist and adducts it

1. Is a muscle located on the back portion of the lower leg, being one of the two major muscles that make up the calf. The flexing of this muscle during walking and bending of the knee creates traction on the femur, pulling it toward the tibia in the lower leg and causing the knee to bend.
2. It serves to steady the leg upon the foot.
3. the largest muscle located in the anterior compartment of the leg. Helps with dorsiflexion, which is the action of pulling the foot toward the shin.

- a group of muscles located in the front of the thigh

- The quadriceps assist in extending the knee

1. The muscle helps flex, adduct, and rotate the hip.
2. a tiny muscle, inferior to the iliotibial band.  It also provides lateral stability to the knee.

1. It is found on the back of the thigh and runs from the base of the pelvis to the back of the tibia, one of the bones that make up the lower leg. The muscle has several functions, including enabling the leg to flex and rotate, and serving as a thigh extensor
2. One of three hamstring muscles that are located at the back of the thigh. These three muscles work collectively to flex the knee and extend the hip.

1. The biceps femoris muscle is a double-headed muscle located on the back of thigh. It is important for knee flexion, internal and external rotation, and hip extension.
2. A large muscle group that includes the four prevailing muscles on the front of the thigh.They are crucial in walking, running, jumping and squatting. Because rectus femoris attaches to the ilium, it is also a flexor of the hip.

Unit 7 Reflection

In this unit we learned about the muscular system. We learned the physiological effects, as well as the anatomical features. We even learned about performance enhancing supplements affected the body.

So from an anatomical standpoint, we all know what muscles are and or do on a basic level. ‘They are the long stringy things that allow us to lift stuff? Right?’. Well yes, muscle fibers are essentially very long, thin, tubular cells, but they are not all just, “tubular’ dude” (smooth muscle). What is tubular however, are the components of the skeletal muscles. The skeletal muscles contain tubes, inside of tubes, inside of tubes. It’s tubeception! Anatomically speaking, the epimysium is the fascia that surrounds the entire muscles, the alpha tube if you will. Within the epimysium, muscle fibers are further contained in perimysium. The perimysium separates the bundles into 10- 100 muscles. Within the perimysium lies the endomysium, fascia that surround and capture individual muscle fibers. This structure allows the muscle's major  functions such as contractility and elasticity. Other characteristics of muscle include a pulley/lever system which reduces strain on muscles and allows for greater range of motion. A key example of such a system is shown in this gif, depicting the tensions of muscles required to move with and without the kneecap (the small rock represents the kneecap). A common theme that I’ve noticed is that where a limbs connect, there is usually such a system.

We also learned about how to properly name the muscles and such. Personally this subject was little bland and has little substance that can be commented on other than the fact that the muscles are named off of their form, function, and location. For example, the bicep has 2 origins, therefore, the bi- in bicep. We did a lab in which we explored the muscles and their joints and labeled them appropriately.

Then we learned how muscles move during stretches, notably the steps of contraction. One of the many steps include the chemical signals transferred through the neuron. This reminded me of the myelitis sheets and how these membranes allow the signal to be sent faster throughout the cell’s axon terminal. (check out our video here to see how contractions work)

After that we learned about the effects of muscle enhancements. This was probably my favorite section as we were able to talk about the pro’s and con’s of using such enhancements. A common theme I noticed was that the negative effects of the drugs will stay, while the positive effects will diminish with time. To enforce this idea, I made an advertisement.

In regards to my twenty time progress, you can click on the hyperlink to follow my progress. Other than missing a week of school, I really don’t have any questions as the unit answered most of them.