Semester Reflection

So this semester has been interesting.  I like memorizing things more than the other stuff.  The skeleton labeling project was super easy and I could still label my part of the skeleton if I had labels with me.  Memorizing what things are called and where things go has always been one of my strong points.  Probably because I've always loved doing it.  I like knowing what things are called.  It's a lot more fun than watching a red line go up and down as Seth eats stuff. Even during the homeostasis lab I didn't have as much fun as I did learning about the neuromuscular junction or the skeleton.  And I was dipping people's hands in ice!
I'm probably just not very good at teamwork.  I've always preferred working by myself so I can control everything without having to worry if I'm being too bossy with the other people.  THE CONTROL IS MINE!  Even during team projects like the neuromuscular poster I'd catch myself starting something alone without telling anyone what I was going to do.  I know what I'm doing, I know what I want, why do they need to know?  Because you're a team you crazy!!  I'm just going to trust that that will sink in some day.

Basically, I want to do everything myself. Everyone else can just follow along and try to keep up.

Only otaku will understand how fitting this is... (From gametrailers.com)

The Nueromuscular Junction Saga

Okay, maybe that's not exactly how it happens, but I like it!

What really goes down is this:

Action potential travels down to the presynaptic terminal.  This opens the calcium ion channel.  The calcium ions enter the presynaptic terminal and cause the acetylcholines to move out into the presynaptic cleft.  In the cleft the acetylcoline molecules attach themselves to either side of a sodium ion channel and let all the sodium ions into the postsynaptic muscle fiber.  This allows for movement.  After the sodium ions have left acetylcholinsterase splits the acetylcholine into choline and acetyc acid.  The choline molecule returns to the presynaptic terminal alone and bonds with another acetyc acid inside the terminal to start the process all over again.  Pretty cool, huh?

Now, to give credit where credit is due! I drew the little people and Megan Crawford drew all the bad guys.  Then, Jenna and Seth helped us color.  Yay the magic of teamwork!

EMG Lab

Logger pro is freeeeaaaky!  And I think it hates me because it won't let me do what I want.  And I can't take screenshots on the mac because it sucks too.  Unfortunately this blog shall not have the pictures of Seth's diagrams from eating food but I'll describe them!
In this lab we hooked Seth up to a computer, attaching electrodes to the top and bottom of his jaw muscle.  We did this so we could measure the activity of his muscle while he ate.  Different foods displayed more activity, narrower wavelengths and higher altitudes, than others.  Things like the marshmallow and poptart required more activity out of his jaw muscle than things like gatorade and bananas.   Every time Seth chewed on something it sent recordable impulses to the electrodes and we were able to see the measurements on our graph.  When the lines were higher and closer together it meant that Seth was taking more work to eat the item.  When he drank the gatorade the line was practically flat, just little bumps going along it.  I've been told that we'll learn more about what this means next semester.  I look forward to the enlightening!!

The Interminable Bone Chronicle

The skeletal system build the framework of the body, protects our internal organs, and helps us move around. Our skeleton is always regrowing and rebuilding itself. We have a new skeleton about every ten years. Osteoclasts are cells that break down the bone matrix crested by osteoids. Osteoblasts create ossification centers that create bone from other tissues.
Hormonal controls in the body decide when you start and stop growing.  When bones grow, they form cartilage on the ends of the bones that harden and become bone over time. If something is messed up in the hormone signal then you would grow forever or stop growing too soon.  Wolff's Law states that bones grow or remodel in response to forces or demands placed upon it.  For example, bones would grow differently in space than they do under the strain of Earth's gravity.  Bones will form to match the duties they perform, so if you are in space and unable to walk around you'll lose bone mass.
But what happens when bones break?  Bone fractures are classified by the completeness of the break, the position of the bone after the fracture, and the orientation of the bone to the long axis.  Cominuted breaks are fragmented breaks.  The break of the bone looks kind of frayed and splintered.  Compression breaks are usually found in the vertebra.  The bones are kind of smashed together looking, compressed on top of each other.  Spiral breaks happen when the bone has been twisted, this usually happens in contact sports.  epiphyseal breaks are breaks in the cartilage and take the longest time to heal.  A depressed break is a break that has been pressed inward.  Greenstick breaks don't go completely through the whole bone and are usually only seen in children.  When a bone breaks the torn blood vessels hemorage and blood clots around the break, causing the area to swell.  This is called hematoma formation.  The bone needs to be set when the fibrocarilaginous callus forms, osteoblasts and fibroblasts move to the area of the fracture and begin reconstructing the bone.  The bone must be set so that it can be properly reconstruted.  Capillaries grow into the tissue and start cleaning out any debris inside the break.  Finally, the callus begins to harden and creates a firm union between the two ends of the bone.  The whole process takes 2-3 months.
In class we had a wee contest for the skeletal structure.  We split into groups of five and began memorizing bones.  I took the thoracic and pelvic region of the skeleton.  In the race I correctly placed 55 labels on my area of the skeleton.  I didn't get to place two of my labels but that's only because 4 minutes isn't enough time to figure out how to place labels comfortable and securely on the rib cage of a plastic skeleton.  Altogether my team placed 181 labels, meaning we totally pwned the other groups.  The race was fun and we gained eternal glory!
And that concludes the skelly-ton!

The Integumentary Summary

From Ludwig's Integumentary notes.

Skin color comes from melanin, carotene, and hemoglobin.  Melanin is produced and gives the skin a darker more tan color.  Carotene is the yellow orange pigment of the skin and hemoglobin is the reddish pigment.  Different glands in the skin keep the skin from overheating or keep our skin soft.  Sweat glands in our bodies secrete cerumen and milk.  The sebaceous glands are found all over the body and soften skin when they're stimulated by hormones by secreting an oily substance called sebum.The skin has three awesome layers.  The epidermis is the outermost layer of the skin.  It's the stratified layer filled with keratinocytes, melanocytes, Merkel cells, and Langerhans cells.  Under that lies the dermis.  This layer is much thicker than the epidermis.  Most cells here are fibroblasts, macrophages, and white blood cells.  The dermis also has two layers in itself, the papillary and reticular layers.  The last layer of the skin is the hypodermis.  It's composed of adipose and areolar connective tissue.
The hair and nails are also part of the integumentary system.  Hair keeps the body warm.  It is made of dead keratinized cells and colored by melanocytes at the base of the hair.  Nails are simply a modification of the epidermis.

Now for the fun stuff.

Melanoma image from Skinipedia.

The major types of skin cancer are melanoma, squamous cell carcinoma, and basal cell carcinoma.
Melanoma is the most dangerous type of skin cancer.  It's very malignant and people often mistake it for a birthmark, or vice versa.
The way to tell if a spot is melanoma is to check it with the ABCD rule.  Assymetry, Border, Color, and Diameter.  A spot of melanoma will be asymmetrical.  The border will be jagged and uneven.  The color of melanoma is much darker than a normal birthmark and can sometimes be shades of red or blue.  And if the diameter is bigger than 6mm, which is about the size of a pencil eraser, then you should get the spot checked for melanoma.  Melanoma is usually treated by removing the spot, but if it's 4mm thick into the epidermis then chances of survival are very low.

Third degree burn from burn remedies.com.  Ouch...

Being on the outside of our bodies our skin is also susceptible to burns.  First degree burns are just a red mark that only damages the epidermis.  Second degree burns damage through the epidermis and into the upper regions of the dermis.  They look a lot like first degree burns but may also blister.  Third degree burns damage through the entire thickness of the skin.  They don't hurt very much because nerve endings have been damaged and they are generally bright red, black, or ashy white.  Doctors and nurses use the rule of nines to estimate the severity of burns.  Burns are severe if 25% of the body has second degree burns, 10% of the body has third degree burns, or if third degree burns are on the hands, face, or feet.  One of the major dangers of burns is dehydration.

The integumentary system is a massive and rather complicated thing.  There are a lot of dangers to the skin but somehow everything works out all right.  Usually.