Nervous System I

Question 1

Afferent neurons

Answer 1

Sensory neurons that receive stimuli from the environment and the body. Impulses travel to the CNS. Most are pseudounipolar.

Question 2

Efferent neurons

Answer 2

Motor neurons that control effector organs. Impulses travel away from the CNS.

Question 3

Somatic efferent neurons

Answer 3

Voluntary muscle

Question 4

Autonomic efferent neurons

Answer 4

Involuntary smooth muscle (sympathetic and parasympathetic systems)

Question 5

Interneurons

Answer 5

They form functional networks and circuits that coordinate all neural activity. Impulses travel within the CNS. Most are multipolar

Question 6

Central nervous system (CNS)

Answer 6

Cerebrum, cerebellum, and spinal cord

Question 7

Peripheral nervous system (PNS)

Answer 7

All nervous tissue outside of the CNS

Question 8

Functions of nerve cells

Answer 8

Irritability, conductivity, secretion

Question 9

Glial cells

Answer 9

Support and protect neurons

Question 10

Axon

Answer 10

long processes

Question 11

Dendrites

Answer 11

short processes

Question 12

3 types of neurons

Answer 12

bipolar, multipolar, and pseudounipolar

Question 13

Schwann cells

Answer 13

Cells that contain myelin and can form a covering around the axon. Located in the PNS

Question 14

Perikaryon

Answer 14

Cell body of a neuron

Question 15

Oligodendrocytes

Answer 15

Predominant glial cells in white matter that wrap around the axon of the CNS

Question 16

Nissl bodies

Answer 16

Regions of the RER in the cell body and dendrites where protein synthesis occurs

Question 17

Axoplasm

Answer 17

low content of protein that has many ions that contribute to the electric current

Question 18

Initial segment

Answer 18

Non-myelinated site where the stimulus is initiated/suppressed down the axon.

Question 19

Retrograde transport

Answer 19

From the axon terminal to the perikaryon, dynein

Question 20

Anterograde transport

Answer 20

From the perikaryon to the axon terminal, kinesin

Question 21

Chemical synapse

Answer 21

Nerve impulse is passed by diffusion of neurotransmitter vesicles into a space that are received by receptors

Question 22

Electrical synapses

Answer 22

Nerve impulse is passed by connexins that provide a tight junction in the synapse

Question 23

Na+/K+ pump

Answer 23

ATPase takes 3 Na+ ions out and 2 K+ into the cell

Question 24

Depolarization

Answer 24

Na+ enters the cell as the impulse travels down the axon

Question 25

Repolarization

Answer 25

K+ leaves the cells after the impulse has passed the axon. Voltage goes below the normal level

Question 26

Action potential

Answer 26

Highest potential an impulse can reach before repolarization.

Question 27

Hyperpolarization

Answer 27

Bringing the voltage back to resting potential

Question 28

Myelin sheath

Answer 28

Layers of membrane on an axon that insulates and prevents leakage of charge

Question 29

Saltatory conduction

Answer 29

Impulse travels quicker in a myelinated sheath

Question 30

Nodes of Ranvier

Answer 30

Spaces between cells that are left unmyelinated. Only place where depolarization occurs.

Question 31

Cholinergic junction

Answer 31

release acetylcholine (parasympathetic)

Question 32

Adrenergic junction

Answer 32

release norepinephrine (sympathetic)