1. To present the doctor’s notes portion of the case with a description of the following terms or concepts: Diaphoresis- is the medical term for profuse sweating or perspiring. The skin’s sweat glands sweat to aid in fever management. When your body temp rises you autonomic nervous system causes you eccrine glands to secrete fluid onto the surface of the skin where it cools as it evaporates. Motor dysfunction_ All motor dysfunction means is abnormality in the use of the motor system, or where a muscle or nerve cannot control motion. Paresthesia_ this is know as the sensation of tickling, tingling, pricking, or burning of someone’s skin with no long term affect.
The most common sensation is known as “pins and needles”. Cyanotic- This means there is a bluish color to a persons skin because of lack of oxygen saturation. Hypoventilation- This is known as respiratory depression. This is when ventilation is inadequate and cannot perform the needed gas exchange. Gastric lavage- This means having to pump someone’s stomach or irrigate it. The doctor would put a flexible tube down the throat and would suck out the contents and rinse out the stomach with a saline solution. Oxygen saturation- this is the amount of oxygen in the hemoglobin in the body. Or the percentage of hemoglobin binding site in the bloodstream occupied by oxygen.
2. How many elements are contained in a molecule of Tetrodatoxin? What are the names of these elements? There are four different elements and they are 11 carbon, 17 hydrogen, 3 nitrogen and 8 oxygen.
3. What types of chemical bonds are found in this molecule? Describe the structure of those bonds. The chemical bonds found are covalent bonds, which are bonds that share electrons.
4. As mentioned in the case description, tetrodotoxin is a molecule that blocks voltage-gated sodium ion channels. Describe the structure of a sodium ion. A sodium ion is a sodium ion that has been oxidized, which means losing one electron and gaining a positive charge. The structure of a sodium ion is an atom with 11 protons in its nucleus and 10 electrons in its orbital’s.
5. What is a voltage- gated sodium ion channel? What is it made of? What is its function? A sodium channel is a place where the membrane on a nerve cell can open up and let sodium ion in. In a voltage gated sodium channel the sodium ions are let through by an opening that is voltage regulated. Voltage-gated sodium ion channels are responsible for action potential initiation and propagation in excitable cells.
6. Why do sodium ion need channels in order to move into and out of cells? Channels are needed in order to have an action potential and in order to repolarize the channels have to inactivated also known as sodium channel inactivation and it opens up a voltage gated potassium channel which shifts things back to resting potential.
7. Describe the process involved in the movement of ions through these channels. Sodium wants to move through the channel because of diffusion. There is a high concentration of them on the outside of the cell and inside the cell is negative. The sodium wants inside but we don’t let it that’s how we get the potential energy. Chemical forces drive the potassium out of the cell and that’s how we get depolarization.
8.When nerve cells are at rest, there is a equal amount of positive and negative charges on either side of a nerve cell membrane. This charge difference is called an electrical potential. Describe this potential when the neuron is at rest ( resting potential). During resting potential the potassium channels close, and both the sodium and potassium channels return to their normal states. A stimulus will have to initiate the action potential and be great enough o open the voltage gated sodium channels. The channels open at a Tran membrane potential or called the threshold.
9. What is happening to the electrical potential of a neuron when it generates an action potential? What is the function of the action potential in neurons? When the threshold is reached and an action potential is started the sodium channel activation gates open and sodium rushes into the cytoplasm, and rapid depolarization occurs. The Tran membrane potential changes from a -60 to a positive value.
10. Describe the role of sodium ions and sodium channels in the action potential. When the threshold is reached it opens the sodium channels and the sodium rushes into the cell and causes a depolarization, when the Tran membrane potential reaches +30 mV the voltage gated sodium channels close. This is known as sodium channel inactivation and then the voltage gated potassium channels open. The potassium moves out and the Tran membrane potential shifts back towards resting levels. The sodium channels remain closed until the membrane has repolarized to near threshold levels.
11. What would happen to a neuron if it were exposed to tetrodotoxin? Be specific regarding its effect on the ability of a neuron to communicate. When tetrodotoxin binds to the sodium ion channels it prevents sodium from entering the cell. This would stop it from depolarizing and would block the cell from starting an action potential. The neuron communicates by using action potential as a signal so it would be incapable of communicating.
12. Now that you have explained some of the basic biology of this case, explain why Dr. Westwood experienced numbness after eating his puffer fish meal. The tetrodotoxin inhibits the neurons that transmit sensory information to the brain. Because the neuron could not communicate, the area affected by the tetrodotoxin would be experienced as a numbness.
13. Paralysis is a term used to describe the loss of function of muscle. If tetrodotoxin’s effect is on neurons, why did Mr. Westwood experience paralysis? Tetrodotoxin binds to sodium ions and sodium ions contribute greatly to action potential in muscle cells also. So the tetrodotoxin could inhibit muscle activity too.
14. Explain how tetrodotoxin is involved in the development of hypotension and hypoventilation. The tetrodotoxin blocks the diffusion of sodium ion through sodium channels. This prevents action potentials in nerve cells. Our nerve cells are what causes the action potential involved with the contraction of our muscles to help us inhale. The nerves regulate the rate and strength of contraction in the heart so it would eventually cause hypoventilation.
15. Briefly describe there role of the autonomic nervous system in human physiology. What are the two divisions of this system? We have our parasympathetic nervous system and our sympathetic nervous system. The sympathetic is our fight or flight responses and the parasympathetic is our rest and recover. These two nervous systems are both involuntary. 16. Atropine was administered in the ED as part of Dr. Westwood’s case. What effect did it have on his vitals after it was administered? Atropine acts as an antagonist within the central nervous system which means it acts as a blocker of specific cellular functions. What part of the autonomic nervous system does atropine block to produce its effect on Dr. Westwood? Atropine is a Anti-cholinergic. It is an antagonist that binds to Muscarinic Receptor on postsynaptic neuron and reduces parasympathetic effect and lets sympathetic Dominate. So it blocks the effects of vagal nerve activity on the heart.