Neuron structure

Athletes often drink energy drinks in order to keep healthy and in top condition.  When athletes sweat, they lose electrolytes. Electrolytes are ions with an electrical charge that control cell membrane stability and carry electrical charges for muscle contractions caused by nerve impulses. Without a proper electrolyte balance, muscle cells struggle to do their job. This can lead to muscle cramps. If electrolyte depletion is prolonged it can lead to muscle strains or pulls. Overall, your body needs ions for energy, and sports drinks replenish these ions, thus, giving you more energy.

Common sports drinks

Common sports drinks

The sciatic nerve is the longest neuron in the human body. It begins near the lumbar and sacral plexuses where the nerve roots exit the spinal cord, and continues through the buttocks, down the leg and into the feet. In its largest spot, it is about as big around as a man’s thumb.


Neurophysiology Virtual Lab

Humans and animals have very similar nervous systems. Even though humans have a much more complex system, the basic functions of our nervous system is quite similar to that of animals, even leeches. Within the nervous system there are neurons. Different neurons have different functions within the nervous system. Sensory neurons tell the brain about the internal and external environment. Motor neurons contract muscles and mediate behavior. Communication neurons transmit signals from one area of the brain to another. It is important for there to be different neurons because the brain must perform many different tasks. The lab showed how neurons respond to different stimuli. For example, you would not want all of your neurons to respond to the slightest touch, such as the feather. Nor would you want all of your neurons to be able to feel the harshest touch, like the probe. Many different types of specialized neurons are needed in order to be able to pick up specific stimuli. The lab showed that leeches, and humans, have neurons that can pick up all types of different stimuli.

On the left is a picture of a X cell, which responds to no stimuli. The right a picture of a P cell, which responds only to probe.  Sources:

Brilliant Brains

The brain is arguably the most interesting organ in the entire human body. When most people think of the brain, they think of a something that looks like a football shaped ball of double bubble chewing gum. But it’s so much MORE  than that!;_ylu=X3oDMTBxNG1oMmE2BHNlYwNmcC1hdHRyaWIEc2xrA3J1cmwEaXQD/RV=2/RE=1421670845/RO=11/

.Since the brain is responsible for performing so many different tasks, it needs to be separated into many different parts and sections. The outside layer of tissues is called the meninges. The Meniges is made up of several layers itself like the Dura Meter(outer layer), Arachnoid layer (middle), and the Pia Mater (inner layer). These serve to help protect the brain from injury and to help hold it in place.

Here is a look at the inside of the brain made out of play-doh.

Here is a look at the inside of the brain made out of play-doh.

Here is a look at the side view of a sample brain. (ironically it does look a little like gum).

Here is a look at the side view of a sample brain. (ironically it does look a little like gum).

Next comes the cerebral hemispheres. The surface of these hemispheres is what makes the brain have “ridges” and “grooves.” Luckily, these ridges and grooves (called gyri and sulci) are the reason that humans have higher order thinking. The cerebrium has 4 major lobes, the frontal, parietal, occipital, and temporal. The frontal lobes are responsible for problem solving, judgment, and motor function. The parietal love for managing sensation, handwriting and body position. The temporal is for memory and hearing, and the occipital lobe is the brains visual processing system. Some other specialized areas in the cerebrum are the somatic sensory area (receives impulses from the bodies sensory receptors), primary motor area (sends impulses to skeletal muscles) and broca’s area (involved in the ability to speak).  Inside the cerebral hemispheres lies the diencephalon. The Diencephalon is made up of the thalamus, hypothalamus, and the epithalamus. The epithalamus houses the endocrine gland and forms cerebrospinal fluid, a fluid vital in surrounding the brain and spinal cord. Next comes the hypothalamus, which performs several vital functions for the body, such as regulate body temperature, control water balance and regulate metabolism. On top of the hypothalamus is the Thalamus. The thalamus is the “relay” station for sensory impulses, and transfers these impulses to the correct part of the cortex for localization and interpretation.

Then, there is the brain stem. The brain stem attaches to the spinal cord, and is made up of the midbrain, pons, and the medulla oblongata. The midbrain is responsible for housing the reflex centers for vision and hearing. The pons is responsible for controlling ones breathing. Finally, the medulla oblongata contains control centers for heart rate, breathing, blood pressure, swallowing, and vomiting. Since the medulla oblongata merges with the spinal cord, it is an especially delicate and sensitive place on the body.

Finally, there is the Cerebellum. It provides involuntary coordination of body movements. Most importantly is provides the ability to “learn” body movements through comparator activities.

Sources: Gardner notes

See, way more than a pile of gum.

three questions 1/16/15

Wow, I feel like I haven’t done one of these since last year (that’s right I went there).

1. What tasks have you completed recently?

Recently, I have come back to school from winter break, which is a pretty big accomplishment in itself. Over the break I learned how to ice climb. Once back at school I finished a timed writing in AP Literature and finished a test in anatomy (thanks for that).

2. What have you learned recently?

I learned that timed writings do not become any more fun the second time around. I’ve also learned more about the executive branch in AP government.  I also have gotten a “peek behind the curtain” at how CRAZY the human brain is.

3. What are you planning on doing next?

Next I plan on reading Crime and Punishment and Wuthering Heights. I also will take another timed writing in English. In anatomy I plan on studying for my next test and taking the flipped notes on time (maybe).


Believe it or not, it takes a lot to allow even the simplest of muscle movements. In order to contract, many microscopic structures are uniquely suited to do a specific job. The epimysium is wrapped around the entire cell and is made of dense irregular tissue. Inside the epimysium is the perimysium, made of fibrous connective tissue. The perimysium wraps around fascicles- bundles of muscle fibers grouped together. Inside the muscle fibers is the sarcolemma, which serves as a sort of cell membrane. Directly inside the sarcolemma is the sarcoplasmic reticulum. The sarcoplasmic reticulum houses transverse tubules, or “T-tubules.” These allow chemical changes in polarity to quickly enter the cell. The sarcoplasmic reticulum also allows calcium to diffuse through it to the cytoplasm. The muscle fiber also contains mitochondria, which house ATP. ATP is vital for energy in the muscle. Also inside the sarcoplasm is glycosomes; granules of glycogen that provide glucose during muscular activity. It also has myoglobin, which stores red pigment which stores oxygen. Myosin is a rod like structure with a “head.” When actin bonds with this head, it creates a crossbridge.

The first step to creating a contraction is to go into labor. Haha just kidding, it’s  to generate an action potential. After this action potential, the electrochemical gradient is disrupted causing depolarization. This causes calcium to be released which then bonds to the troponin. The troponin then pulls the tropomyosin off of the actin sites. Once the actin sites are revealed, they bond to the myosin heads to create a crossbridge. Contraction then begins with repeated cycles of the crossbridge binding. You could think of contraction like shaking someone’s hand. The myosin and the actin are the two hands, and when they connect, one pulls the other (that’s the contraction). In order to shade hands both peoples fingers must be outstretched, not in a ball (just like the actin sites must be out, not covered by the tropomyosin). This is all powered by ATP (but so is everything else in our bodies.) After the contraction, the electrochemical gradient must be restored; repolarization. The sarcoplasmic reticulum now re-absorbs the calcium is released and the tropomyosin re-covers the actin sites. The body needs this time to recover so that it can collect enough ATP to keep contracting the muscle. You could think of this like shooting a gun. After each shot, you have to reload. Unless you are a semi-automatic machine gun. You ever seen one of those things shoot? They’re incredible. Alas, if humans were guns we would not be semi-automatic machine guns, we would be muskets. French Revolution muskets. Cause the French are classy. Overall, if muscles could not contract, then human’s would not be able to even perform simple movements. If someone is unable to move it is safe to say that homeostasis has been disrupted.

Visual image of the muscle contraction process

Three questions 11/21/14

1. What tasks have you completed recently?

I have taken an exam in math. I have also taken a vocab and Oedipus test in English. Finally, I have completed an exam in Anatomy.

2. What have you learned recently?

I have learned all about the skeletal system. I have also learned how messed up Oedipus’s life is. I also learned how a bill becomes a law.

3. What are you planning on doing next?

I plan on continuing to work hard for all my classes. I will keep reading the novel “Long days journey into night” in AP literature. I will also keep studying my muscular system notes.

Skin and Bones

Both the integumentary system and the skeletal system are essential for maintaining homeostasis, and for human survival. One of the main functions of both systems is protection. The integumentary system protects underlying tissues and organs from diseases and temperature change. Similarly, the skeletal system also protects the body. The rib cage and sternum helps protect the lungs and heart. The skull helps protect your brain. Thus, both systems work together in order to protect the body from harm and help to maintain homeostasis.

Both systems also work to help the body move. The skeletal system is composed of joints, cartilage, and ligaments that make it possible for bones to move. The connective tissue in the dermis layer of the integumentary system helps the skin stretch, to accompany the moving of the bones.

The integumentary system also absorbs and synthesizes Vitamin D. It then sends this vitamin D to its best friend, the skeletal system, to be stored. Vitamin D helps the bones absorb calcium and therefore become stronger. Without the integumentary system, the skeletal system would lack this important nutrient and become more susceptible to diseases such as osteomalacia and rickets.

Each of these systems relies on the other to operate properly and efficiently. They both work together to maintain homeostasis and keep us alive. Thanks bones and skin!

For more information about how each system interacts with one another, view this video!