Lab 4 Review: Central Nervous System

Question 1

name the three layers of the meninges

Answer 1

dura mater: fibrous connective tissue
arachnoid mater: elastic and loose covering (like spiderwebs)
pia mater: delicate connective tissue (pia=tender)

Question 2

choroid plexus

Answer 2

a specialized network of epithelial cells lining the ventricles that produces cerebrospinal fluid

Question 3

what part takes up 80% of the mass of the brain?

Answer 3

the cerebrum

Question 4

Gray matter in the brain:

Answer 4

contains mostly cell bodies, dendrites and glial cells

Question 5

white matter in the brain:

Answer 5

contains mostly axons

Question 6

corpus collosum

Answer 6

tract of white matter that connects the two hemispheres in the brain: enables inter-cerebral communication

Question 7

function of the cerebrum:

Answer 7

conscious mind: Awareness, sensory perception, voluntary motor initiation, communication, memory
storage, understanding, etc.

Question 8

gyri

Answer 8

ridges

Question 9

sulci

Answer 9

shallow grooves

Question 10

fissures

Answer 10

deep grooves

Question 11

Diencephalon

Answer 11

*Forms the central core of the brain
surrounded by the cerebral hemispheres
*Consists of three paired structures:
I. Thalamus
II. Hypothalamus
III. Epithalamus

Question 12

thalamus

Answer 12

*Largest region of the diencephalon
*Gateway to the cerebral cortex
*Sorts, edits, and relays sensory information
*Relays impulses between the cerebral cortex and
cerebellum (Co-ordinates motor function)
*Mediates learning and memory

Question 13

hypothalamus

Answer 13

-Anterior aspect of the diencephalon
-Integration site for the autonomic nervous system: Blood pressure, heartbeat, digestive tract motility, etc.
*Center for emotional responses–Perception of pleasure, fear and rage
*Regulates food and water intake, body temperature and biological rhythms
*Serves an neuroendocrine function–Controls release of hormones by the anterior pituitary; Produces posterior pituitary hormones

Question 14

Epithalamus

Answer 14

*Most dorsal portion of the diencephalon
*contains pineal gland—pea-shaped endocrine organ that secretes melatonin
*Regulates sleep-wake cycles

Question 15

Brainstem

Answer 15

*Controls automatic behaviors necessary for survival
*Associated with cranial nerves: Innervation of head
*Consist of 3 regions
I. Midbrain
II. Pons
III. Medulla oblongata

Question 16

Midbrain

Answer 16

*Located between the diencephalon and pons
*Site of the cerebral aqueduct: Channel between third and fourth ventricles
*Contains domelike protrusions along the dorsal aspect
-Superior colliculi: Visual reflex centers
-Inferior colliculi: Auditory relay centers

Question 17

function of superior colliculi

Answer 17

visual reflex centers

Question 18

function of inferior colliculi

Answer 18

auditory relay centers

Question 19

Pons

Answer 19

*Forms part of the anterior wall of the 4th ventricle
*Relays impulses between the motor cortex and
cerebellum: Relay station
*Controls breathing

Question 20

Medulla Oblongata

Answer 20

*Joins inferiorly with the spinal cord
*Forms part of the ventral wall of the 4th ventricle
*Relays sensory information from muscles and joints to
cerebellum
*Participates in control of visceral functions: Heart rate, Blood Pressure, Digestion

Question 21

cerebellum

Answer 21

*Comprised of 2 hemispheres connected by vermis
*Arbor vitae—distinctive tree-like pattern of white matter
*Provides precise timing and appropriate patterns of
skeletal muscle contraction (smooth, coordinated body movement) (“cerabell-u-da-ball”)

Question 22

endoneurium

Answer 22

surrounds each axon (nerve fiber)

Question 23

perineurium

Answer 23

surrounds groups of nerve fibers into fascicles

Question 24

epineurium

Answer 24

tough fibrous sheath that surrounds groups of fascicles into a nerve

Question 25

Pathogenesis of alzheimer’s disease involves destruction of nerve cells by two distinct mechanisms:

Answer 25

-Beta-amyloid plaques
-Neurofibrillary tangles (tau protein)