Neural Control Of Exercising Muscle 1

What are the major divisions of the nervous system?

Central Nervous System

Peripheral Nervous System

Divisions of PNS?

sensory: afferent: incoming
motor: efferent: outgoing

Divisions of motor neurons?

somatic: voluntary, to skeletal muscles
autonomic: involuntary, to viscera

Divisions of autonomic?

sympathetic: fight or flight
parasympathetic: rest and digest

What is a neuron?

the basic structural unit of the nervous system and has the same structure everywhere in the body

What are the three major regions of a neuron? What are their functions?

cell body (soma): interprets if the signal is strong enough to send on or stop
dendrites: receptive regions
axon: transmission wire

What supports and protects the nerve fiber? What are their function?

Schwann cells: allow for saltatory conduction to take place meaning that the Na+ jumps between the nodes of Ranvier to save time

What is the space between Schwann cells called?

Nodes of Ranvier

What is the term when Schwann cells come together at the axon?

myelin sheath

The nerve before the synaptic cleft, then the nerve after the synaptic cleft are called what?

presynaptic nerve
postsynaptic nerve

What is the space between the presynaptic and postsynaptic nerve called?

synaptic cleft

What creates electrical signal?

Na+ K+ Ca++

How is resting membrane potential defined?

the difference in electrical charges outside and inside of the cell

What are the types of gradients?

charge gradient
concentration gradient

Which charge is stronger?

charge is stronger than concentration

What type of transport is the Na+/K+ pump? Explain why.

active transport because it requires energy to go against the current

Define threshold.

the minimum potential reached before an action potential is generated

What is the process of depolarization?

when the inside of the cell becomes less negative, Na+ channels open and enter the cell

What is the process of hyperpolarization?

when the inside of the cell becomes more negative, K+ channels open and leave the cell

What is a graded potential? What is an action potential?

when a stimulant does not meet threshold; helps to decide whether to pass the signal to the axon and can excite or inhibit a neuron
when a stimulant meets threshold and the signal gets sent; passes the signal down the axon and can only be excitatory

Do all APs begin as GPs? How strong must a GP be to become an AP?

yes; must depolarize to threshold

What is the absolute refractory period?

the time during depolarization that the neuron is unable to respond to another stimulus because it is already responding to a different stimulus

What is the relative refractory period?

the time during repolarization when the neuron can only respond to very strong stimulus

What is multiple sclerosis?

the degeneration of myelin