Physiology

Question 1

Nervous System

Answer 1

Network of specialized cells that collect, process, and communicate information rapidly between different parts of the body. Complex process based on simple flows of ions across membranes.

Question 2

What is the funcitonal unit of the nervous system?

Answer 2

the Neuron or nerve cell

Question 3

Resting Potential

Answer 3

charge difference across the membrane of a neuron at rest.

Question 4

Action Potential

Answer 4

rapid change of charge distribution that travels down the neuron undiminished. Depolarization leads to repolarization within milliseconds, refractory period for things to get back in order.

Question 5

What creates the Resting Potential?

Answer 5

3 Na+ are pushed out of the matrix, and 2 K+ are pushed in one ATP. However, K+ leak back out in channels that are always open due to concentration gradient. A balance of forces creates the resting potential.

Question 6

First step in an action potential?

Answer 6

Sodium (Na+) channels open due to a voltage change. (voltage gated).

Question 7

What goes into the falling phase?

Answer 7

Membrane becomes more permeable to potassium (K+) when voltage gated K+ channels open at the peak of depolarization.

Question 8

Synapses

Answer 8

When an action potential gets to the axon terminal, Ca2+ channels open, vesicles respond by fusing with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft… these then go on to bind with stuff on the other side, and are eventually reabsorbed.

Question 9

Neurotransmitters

Answer 9

Endogenous chemicals that relay, amplify, and modulate signals between a neuron and another cell (probably a neuron, though it could also be a muscle or gland). They are formed in the cell body and transported to the axon terminals.

Question 10

Excitatory vs. Inhibitory Synapses

Answer 10

Excitatory: increase likelihood of an action potential by causing depolarization. Inhibitory: decrease likelihood, cause hyperpolarization.