General Nervous System
What is another name for the cell body of a neuron?
Soma
How is the resting membrane potential maintained?
Sodium leaks into the cell via leaky sodium channels. Potassium leaks out of the cell via leaky potassium channels. The sodium potassium pump resets and pushes sodium out/potassium in
What is important about tendons?
Connect muscle to bone and are connected to successive layers of connective tissue throughout the muscle which is what allows contraction in myofibrils to transmit force to the whole muscle
What is the name of the site where the motor neuron connects to skeletal muscle?
The neuromuscular junction
What 2 characteristics of a neuron make them transmit neural impulses faster?
More myelin and a larger axon diameter
What is the portion of the neuron where action potentials begin?
The axon hillock
What is the resting membrane potential? What must happen to that potential to start an action potential?
-70mV in neuron and -90mV in tissue like muscle. A sufficient stimulus must bring the membrane potential to threshold
What is the t-tubule and what is the function?
Extension of the sarcolemma and it carries the AP deeper into the muscle
What is a motor unit?
One motor neuron and all the muscle fibers it connects to
Which side of the membrane has higher concentrations of sodium? What about potassium?
Sodium higher on the outside of the cell and potassium higher on the inside of the cell
What is the function of an oligodendrocyte? What about a Schwann cell?
Adds myelin to neurons in the CNS. One oligodendrocyte adds multiple sections of myelin.
Adds myelin to one section of neurons in the PNS.
Why does tetrodotoxin cause numbness specifically?
Tetrodotoxin stops the generation of action potentials by stopping voltage gated sodium channels from opening
The sliding filament theory states what?
During muscle contraction, actin slides past myosin as myosin pulls it. The sarcomere shortens but the filaments do not change length
What is the name of the neurotransmitter used for muscle contraction?
Acetycholine
What is the rate limiting enzyme in glycolysis?
PFK
What is the difference between the afferent branch of the nervous system and the efferent branch?
The afferent carries information to the CNS and the efferent carries information to our organs
What causes hyperpolarization at the end of an action potential?
The slow closure of K+ channels
How do troponin and tropomyosin work to regulate muscle contraction?
Calcium gets released from the SR and binds to troponin. This causes troponin to change shape and rotates tropomyosin exposing the myosin binding sites on actin.
Myosin is held in place by what? Actin is held in place by what? What is a sarcomere?
Myosin is held in place by the m-line. Actin is held in place by the z-disc (line) and a sarcomere is a portion of a myofibril from 1 z line to the next z line
It can rapidly phosphorylate ADP to replenish ATP
The site where two neurons come into contact is called what? How are neurotransmitters released one from neuron to another?
A synapse. The AP opens voltage gated calcium channels causing an influx of calcium into the neuron. This influx of calcium causes vesicles filled with NTs to move to the end of the axon terminal and get release into the synapse
WOO NICE PICK
Walk up to the board and write out the steps of an action potential
stimulus causes membrane potential to increase to threshold
sodium channels open and sodium rushes into the cell making it more positive
sodium channels close and potassium channels open causing an efflux of potassium from the cell making the cell more negative
potassium channels close slowly causing hyperpolarization. The sodium/potassium pump returns the charge to rest
BOARD QUESTION
write out the steps of the crossbridge cycle
on board not typing that essay
Board board board board
Walk through the steps of excitation contraction coupling and how muscle contraction ends
not typing that lol
What determines if a muscle is a fast twitch fiber or a slow twitch fiber?
The type of ATPase on the myosin