Nervous System

Question 1

Central Nervous System

Answer 1

brain and spinal cord.

Question 2

What is the CNS derived from?

Answer 2

neuroectoderm

Question 3

Peripheral Nervous System

Answer 3

nerves and ganglia

Question 4

What is the PNS derived from?

Answer 4

neural crest cells

Question 5

Nerves

Answer 5

carry signals from the CNS to the target tissues.

Question 6

Ganglia

Answer 6

collection of neurons that relay signals to target signals

Question 7

Parts of Neuron

Answer 7

cell body (soma), nucleus, dendrites, axon, axon terminals

Question 8

Dendrites

Answer 8

receive signals from other tissues or nerves and relay them to the nucleus for processing

Question 9

Axon

Answer 9

signals head away from the nucleus on their way to other nerves or effector tissues

Question 10

Axon Terminals

Answer 10

signal passed to another neuron at a synapse or transferred to effecter tissues at neuromuscular junctions

Question 11

Neuroglia

Answer 11

cells that support and surround neurons. Provide half the mass of the cells. Provide mechanical and metabolic support

Question 12

Gray Matter

Answer 12

parts of the brain with a high density of neuronal cell bodies. Unevenly sized neurons

Question 13

White Matter

Answer 13

where there are clusters of neurons’ axons

Question 14

Astrocytes

Answer 14

the most numerous neuroglial cells in the gray matter. Protect and nurture neurons, fill much of the space between neurons. Surround blood vessels to form blood-brain barrier

Question 15

Microglia

Answer 15

mesenchymal cells. Have immune function and are considered part of the macrophage-monocyte defense system

Question 16

Ependymal Cells

Answer 16

cuboidal cells that line the ventricles of the brain and spinal canal. May have cilia or micorvilli

Question 17

Oligodendrocytes

Answer 17

most numerous neuroglial cells in white matter. Surround axons and form the myelin.

Question 18

Schwann Cell

Answer 18

neuroglial cells in white matter of PNS

Question 19

Nodes of Ranvier

Answer 19

gaps between Schwann Cells

Question 20

Histologic appearance of myelin

Answer 20

myelin is fatty and lost in processing so all you see are clear spaces surrounded by the pink of the Schwann cytoplasm

Question 21

Cross Section

Answer 21

tiny pink circles = axons
Surrounded by clear space = myelin
Scattered nuclei

Question 22

Longitudinal Section

Answer 22

pink lines (axons) surrounded by bubbly clear spaces (myelin) and some pink stuff (Schwann cytoplasm). Scattered nuclei

Question 23

Choroid Plexus

Answer 23

makes the cerebrospinal fluid that bathes and nurtures CNS.

Question 24

What reabsorbs cerebrospinal fluid?

Answer 24

arachnoid villi

Question 25

Hydrocephalus

Answer 25

failure of cerebrospinal fluid to be reabsorbed; results in accumulation of fluid and dilation of the ventricles

Question 26

Meninges

Answer 26

connective tissue layers that surround the CNS. Provides support for the blood vessels that feed the brain and spinal cord Keep the cerebrospinal fluid close to the brain and spinal cord Tether the brain and spinal cord to the overlying bone

Question 27

Layers of Meninges

Answer 27

Pia Mater, Arachnoid Mater, Dura Mater

Question 28

Cerebrum

Answer 28

cranial 2/3 of brain. gray matter on outside and white matter inside. Neurons arranged in layers called laminar cortex.

Question 29

Cerebellum

Answer 29

caudal 1/3 of brain. Has Purkinje cell layer between gray and white matter

Question 30

Nuclei

Answer 30

collections of neurons in CNS

Question 31

Spinal Cord

Answer 31

white matter outside, gray matter inside. Central canal runs through the middle. Surrounded by meninges

Question 32

Ganglia

Answer 32

collections of neurons in the peripheral nervous system. located near the spinal cord and scattered throughout the body. Supportive neuroglial cells called satellite cells

Question 33

Nerves

Answer 33

collections of neurons in the PNS. carry signals from the CNS to target tissues. supportive neuroglial cells called Schwann cells

Question 34

What is a collection of axons in the CNS?

Answer 34

tract

Question 35

What is a collection of axons in the PNS?

Answer 35

nerve