Exercise 17 Review Sheet - Gross Anatomy of the Brain & Cranial Nerves
A fiber tract that provides for communication between different parts of the same cerebral hemisphere is call a(n) *association* tract, whereas one that carries impulses from the cerebrum to lower CNS areas is called a(n) *projection* tract.
The caudate nucleus, putamen, and globus pallidus are collectively called the *basal nuclei*.
A(n) *gyrus* is an elevated ridge of cerebral tissue.
The convolutions seen in the cerebrum are important because they increase the *surface area*.
In your own words, describe the firmness and texture of the sheep brain tissue as observed when you cut into it.
Jell-O! Firm but squishy and delicate.
oculomotor (III) vagus X
raising the eyelids; pupillary constriction
optic (II)
reading the newspaper
hypothalamus
site of regulation of body temperature and water balance; most important autonomic center
optic chiasma
site where medial fibers of the option nerves cross
vagus (X)
slowing the heart; increasing motility of the digestive tract
forebrain
the diencephalon, including the thalamus, optic chiasma, and hypothalamus
hindbrain
the medulla oblongata, pons, and cerebellum
cerebral aqueduct
connects the third and fourth ventricle
medulla oblongata
contains autonomic centers regulating blood pressure, heart rate, and respiratory rhythm, as well as coughing, sneezing, and swallowing centers
What is the function of the basal nuclei?
control voluntary movement
thalamus
encloses the third ventricle
trigeminal (V)
feeling a toothache
fornix
fiber tract involved with olfaction
A brain hemorrhage within the region of the right internal capsule results in paralysis of the left side of the body. Explain why the left side (rather than the right side) is affected.
fibers cross to the opposite side of the body thru the medulla
pons/medulla relationship
human: inferior, straight up & down sheep: superior, longitudinal
interthalamic adhesion
human: large, against corpus callosum sheep: small space between
olfactory bulb
human: smaller sheep: larger
pineal gland
human: smaller sheep: larger
location of cranial nerve III
human: thinner and lower sheep: thicker and higher
thalamus
important synapse site for afferent fibers traveling to the sensory cortex
pia mater
innermost meninx covering the brain; delivate and highly vascular
primary visual cortex
occipital
tentorium cerebelli
a dural fold separating the cerebrum from the cerebellum
Identify the meningeal (or associated) structures described below. *MENINX*
*DESCRIPTION*
Provide the name and # of the cranial nerves involved in each of the following activities, sensations, or disorders. *NERVE*
*DESCRIPTION*
falx cerebri
a dural fold that attaches the cerebrum to the crista galli of the skull
What is the striatum, and how is it related to the fibers of the internal capsule?
fibers of internal capsule pass thru dien. and basal nuclei, giving them their stripes (and therefore, its name)
relative size of superior and inferior colliculi
human: larger sheep: smaller
facial (VII)
involved in Bell's palsy (facial paralysis)
corpus callosum
large commissure connecting the cerebral hemispheres
corpora quadrigemina
located in the midbrain; contains reflex centers for vision and audition
Patients in a vegetative state will often reflexively respond to visual and auditory stimuli. Where in the brain are the centers for these reflexes located?
midbrain
dura mater
outermost meninx covering the brain; composed of tough fibrous connective tissue
accessory (XI)
rotating the head
olfactory (I)
smelling a flower
arachnoid villi
structures instrumental in returning cerebrospinal fluid to the venous blood in the dural venous sinuses
olfactory cortex
temporal
In which of the cerebral lobes are the following functional areas found? *FUNCTIONAL AREA*
*LOBE*
Using the letters in front of terms from question 5, match the appropriate structures with the descriptions given below. *STRUCTURE*
*DESCRIPTION*
When comparing human and sheep brains, you observed some profound differences between them. Record your observations in the chart. *STRUCTURE*
*HUMAN vs SHEEP*
Explain why trauma to the brain stem is often much more dangerous than trauma to the frontal lobes.
base contains more centers vital to life (breathing, heart rate, etc.)
Explain how this phenomenon relates to the unaffected parts of their brain involved in sensory input.
brainstem controls autonomic functions
Which of the following structures are not part of the brain stem?
cerebral hemispheres, cerebellum, diencephalon
trigeminal (V)
chewing food
mammillary body
human: larger sheep: smaller
corpus callosum
human: thicker, straighter sheep: thinner, more slanted
vestibulocochlear (VIII)
listening to music; seasickness
arachnoid mater
middle meninx; like a cobweb in structure
choroid plexus
structure that produces the cerebrospinal fluid
forebrain
the cerebral hemispheres
Cerebral spinal fluid flows from the fourth ventricle into the *subarachnoid space* surround the brain and spinal cord.
From this space it drains through the *arachnoid villi* into the *dural sinuses*.
Gray matter is composed of *neuron cell bodies*.
White matter is composed of *axons*.
Broca's area
frontal
primary motor cortex
frontal
III, IV, VI
involved in "rolling" the eyes (three nerves - provide numbers only)
dura mater
its outer layer forms the periosteum of the skull
Given that formalin hardens all tissue, what conclusions might you draw about the firmness and texture of living brain tissue?
living brain is much softer
primary somatosensory cortex
parietal
I, II, VIII
purely or mostly sensory in function (three nerves - provide numbers only)
cerebellum
responsible for regulation of posture and coordination of complex muscular movements
facial (VII)
secretion of saliva; tasting well-seasoned food
primary auditory cortex
temporal
Explain how patients in a vegetative state can have no damage to their cerebral cortex and yet lack awareness of their environment.
veg. state occurs because function of brain stem & dien. returns after coma, but cortical function does not
