Lab Chapter 26: The Brain and Cranial Nerves

Question 1

Meninges

Answer 1

three layers of connective tissue membranes that surround the brain

Question 2

Dura mater

Answer 2

outermost, protective layer; helps partition the brain

Question 3

Arachnoid Mater

Answer 3

middle layer; seen as a fine sheet of tissue spanning grooves on brain surface

Question 4

Subarachnoid space

Answer 4

located directly beneath arachnoid mater; filled with cerebrospinal fluid; contains large blood vessels

Question 5

Pia Mater

Answer 5

delicate inner layer; follows ridges and grooves of brain; cannot really be peeled away

Question 6

Cerebrum

Answer 6

the largest portion of the brain; responsible for conscious control

Question 7

Gyri (Singular: gyrus)

Answer 7

ridges on the brain

Question 8

Sulci (Singular: sulcus)

Answer 8

grooves in the brain

Question 9

Flow of CS Fluid through the Ventricles

Answer 9

Start in the lateral vetricles which are connected to the third ventricle through an interventricular foramen. From there the cerebral aqueduct connects the third ventricle to the fourth ventricle then down the subarachnoid space and the central canal of the spinal cord

Question 10

longitudinal fissure

Answer 10

separates cerebral hemispheres

Question 11

olfactory bulb

Answer 11

project from anteroventral portion of the cerebrum; receives axons of olfactory nerves from a nasal cavity

Question 12

Olfactory tract

Answer 12

connects olfactory bulbs to olfaction centers of the brain

Question 13

cerebral cortex

Answer 13

outer layer of cerebrum; consists of gray matter

Question 14

Corpus callosum

Answer 14

transverse band of white fibers that connects the right and left cerebral hemispheres

Question 15

fornix

Answer 15

forms the floor of lateral ventricles

Question 16

lateral ventricle

Answer 16

paired chamber in cerebrum; contains choriod plexus (which produces cerebrospinal fluid); separated by septum pellucidum; continuous with third ventricle

Question 17

gray matter

Answer 17

located on periphery in brain; made up of neuron cell bodies

Question 18

white matter

Answer 18

located at core in brain; made up of axons and dendrites of neurons; myelin of axons gives it it’s white color

Question 19

diencephalon

Answer 19

connects cerebral hemispheres to brain stem; consists of epithalamus, thalamus, and hypothalamus

Question 20

epithalamus

Answer 20

roof of third ventricle; contains pineal gland

Question 21

pineal gland

Answer 21

located on posterior epithalamus; endocrine gland that secretes the hormone melatonin; involved with regulation of sleep-wake cycle & some aspects of mood; regulates estrus cycle in seasonal breeders such as sheep

Question 22

thalamus

Answer 22

major relay station of ascending sensory information (performs some initial processing of sensory information by filtering out some signals); contains many different nuclei

Question 23

third ventricle

Answer 23

chamber located in the diencephalon; contains choroid plexus

Question 24

hypothalamus

Answer 24

integrated neural and endocrine functions; crucial to homeostatic regulation of internal environment

Question 25

Optic chiasma

Answer 25

“X” located immediately anterior to infundibulum; location of partial decussation of optic nerves

Question 26

pituitary gland

Answer 26

important neuroendocrine “master” gland weged into sella turcica; not part of the hypothalamus, but connected to it

Question 27

Brain Stem

Answer 27

responsible for many of the lower involuntary functions of the brain; consists of midbrain, pons, and medulla oblongata

Question 28

Midbrain

Answer 28

consists of corpora quadrigemina and cerebral peduncles

Question 29

cerebral aqueduct

Answer 29

connects third and fourth ventricles; separates corpora quadregemina from cerebral peduncles

Question 30

cerebral peduncle

Answer 30

paired structure bulging from the ventral surface of the midbrain; contain corticospinal motor tracts descending toward spinal cord

Question 31

pons

Answer 31

contain nuclei involved in involuntary control of breathing

Question 32

medulla oblongata

Answer 32

physically connects spinal cord to brain; all ascending and descending pathways pass through; contains nuclei involved in regulation of vital body functions

Question 33

fourth ventricle

Answer 33

chamber located between medulla and cerebellum

Question 34

cerebellum

Answer 34

functions primarily in coordination of muscular contraction to allow smooth movements

Question 35

vermis

Answer 35

median section of the cerebellum

Question 36

Arbor vitae

Answer 36

white matter of cerebellum takes on the look of a tree; “tree of life”

Question 37

Olfactory

Answer 37

I, sensory; sense of smell

Question 38

Optic

Answer 38

II, sensory; sense of vision

Question 39

Oculomotor

Answer 39

III, motor; motor impulses to 4 of 6 extrinsic eye muscles

Question 40

Trochlear

Answer 40

IV, motor; motor impulses to superior oblique muscle of the eye

Question 41

Trigeminal

Answer 41

V, mixed; sensory information from head & face; motor signals to chewing muscles

Question 42

Abducens

Answer 42

VI, motor; motor impulses to lateral rectus muscle to abduct eye