Chapter 7

Question 1

Association Neuron

Answer 1

A neuron within the CNS that conducts action potentials from one neuron to another within the CNS

Question 2

Ganglia

Answer 2

Collections of neuron cell bodies that are found outside of the CNS

Question 3

Nerves

Answer 3

Bundles of axons and their sheaths that extend out from the CNS

Question 4

Potential Difference

Answer 4

A measure of the charge difference across the cell membrane

Question 5

Excitability

Answer 5

The ability to undergo an action potential in response to a stimulus

Question 6

Sympathetic Division

Answer 6

Division of neurons of the ANS that prepare the body for increased energy expenditure

Question 7

Parasympathetic Division

Answer 7

Division of the neurons of the ANS that stimulate resting and nutrition related functions such as digestion, defecation, and urination

Question 8

Autonomic Nervous System

Answer 8

PNS neurons that transmit action potentials from the CNS to the smooth muscles, cardiac muscles, and glands

Question 9

Somatic Motor Nervous System

Answer 9

PNS neurons that transmit action potentials from the CNS to the skeletal muscles

Question 10

Spinal Nerves

Answer 10

Nerves of the PNS that originate from the spinal cord

Question 11

Cranial Nerves

Answer 11

Nerves from the PNS that originate from the brain

Question 12

Efferent Neurons

Answer 12

Neurons that transmit action potentials from the CNS to the effector organs

Question 13

Afferent Neurons

Answer 13

Neurons that transmit action potentials from sensory receptors to the CNS

Question 14

What is an Inhibitory Synapse?

Answer 14

Graded potentials that push the neuron further from threshold and make an action potential harder to achieve (hyperpolarization)

Question 15

What is an Excitatory Synapse?

Answer 15

It’s a graded potential that pushes the the neuron closer to the threshold and makes an action potential more likely (depolarization)

Question 16

What is depolarization?

Answer 16

The charge in the cell shifts from negative to positive-stimulates an action potential

Question 17

What is Repolarization?

Answer 17

Change in a membrane potential that returns it to a negative value just after the depolarization phase of an action potential has changed the membrane potential to a positive value

Question 18

What is Hyperpolarization?

Answer 18

A charge that takes a neuron farther away from producing an action potential

Question 19

What is an after-discharge response?

Answer 19

Persistence of response of muscle or neural elements after cessation of stimulation. Prolongs the effect of stimulus

Question 20

What is the sodium potassium exchange pump?

Answer 20

Sodium and Potassium ions are pumped in opposite directions across the membrane building up a chemical and electrical gradient for each. Functions to maintain electrical charge within the cell.

Question 21

What is a local potential?

Answer 21

A stimulus not strong enough to trigger an action potential-also known as a sub threshold stimulus

Question 22

What is temporal summation?

Answer 22

A single axon carries several action potentials within a small amount of time

Question 23

What is spatial summation?

Answer 23

Many axons all carry an action potential to the same neuron all at once. The sub threshold stimuli all come from different points in space.

Question 24

What is absolute refractory period?

Answer 24

The time during which another stimulus given to the neuron, no matter how strong, will not lead to a second action potential

Question 25

What is the difference between afferent and efferent Neurons?

Answer 25

Afferent-carries signals from the sensory receptors to the CNS

Efferent - carries signals from the CNS to effector organs, which are the muscles and glands

Question 26

What are the three kinds of circuits that can be formed by neurons?

Answer 26

Converging-many inputs are reduced to a limited output

Diverging-one input stimulates many outputs

Oscillating- prolongs the effect of a stimulus; it re stimulates itself