Terms and Definitions

Question 1

Sarcomere

Answer 1

Repeating unit of a myofibril

Question 2

Neuron

Answer 2

The functional unit of the nervous system, a nerve cell

Question 3

Synapse

Answer 3

The interface between a neuron and another cell.

Question 4

Neurotransmitter

Answer 4

A chemical released by a neuron. The chemical travels across the synaptic cleft allowing the neuron to communicate with another cell.

Question 5

Motor unit

Answer 5

One motor neuron and all the fibers it innervates

Question 6

All or nothing law skeleton muscle contraction

Answer 6

An individual muscle fiber contracts with maximum force and response to an action potential.

Question 7

Subthreshold stimulus

Answer 7

A stimulus too small to create an action potential in a neuron

Question 8

Threshold stimulus

Answer 8

A stimulus strong enough to create one action potential in a neuron

Question 9

Sub maximal stimulus

Answer 9

Stimuli of increasing strength that create more action potentials in motor neurons

Question 10

Maximal stimulus

Answer 10

A stimulus that is strong enough to create action potential in all the motor neurons innervating a whole muscle

Question 11

Muscle tone

Answer 11

The state of parcel contraction in a muscle even when the muscle is not being used.