Sheep Brain

Question 1

Brainstem

Answer 1

Pons and medulla

Question 2

Pons

Answer 2

Axons of the middle cerebellar peduncle from the pontine nuclei forming a bulge on brainstem caudal to CN IV and those that cross midline form the pontine decussation

Question 3

Medulla

Answer 3

From pons to the C1 nerve
Trapezoid bodies and pyramids

Pyramids are the continuation of the crus cerebri of the mesencephalon as its axons travel caudally to influence cranial nerve motor nuclei in the brainstem and motor neurons in spinal cord

Question 4

Fourth ventricle

Answer 4

Dorsal surface of medulla and pons

Contains choroid plexus and CSF

Question 5

Cerebellar peduncles

Answer 5

Bundles of axons that relay info related to somatic sensation and movement into and out of the cerebellum

Question 6

Obex

Answer 6

Where fourth ventricle narrows to central canal of spinal cord

Gracile tubercle, cuneate and trigeminal tubercle

Beneath tubercles are tracts and nuclei containing nerves and axons which convey fine touch sensation for lower (gracile) and upper body (cuneate) and face

Question 7

Tegmentum

Answer 7

Middle portion of the midbrain between roof and floor

Question 8

Crus cerebri

Answer 8

Cerebral peduncle is the major highway of nerve fibers running throughout the brain in longitudinal direction

Continuation of white matter and turns into the pyramids caudally

Question 9

Choroid plexus

Answer 9

In ventricles CSF production

Question 10

Cerebral hemisphere

Answer 10

Hippocampus is medial and neocortex is expansive lateral wall

Accompanied by lateral ventricle

Question 11

Amygdala

Answer 11

Subcortical part of telencephalon and plays important role in emotion

Question 12

Optic tract

Answer 12

Terminates at lateral geniculate body

Processes visual info and communicates with the visual cortex in the occipital lobe

Question 13

Medial geniculate body

Answer 13

Smaller bump caudal to lateral geniculate which receives auditory input from caudal colliculus and communicates with auditory cortex in the temporal lobe

Question 14

Internal capsule

Answer 14

In rostral half, large fiber bundle that separates the caudate nucleus and putamen which are parts of the basal ganglia

Question 15

Globus pallidus

Answer 15

Small, basal ganglion, ventrally located

Question 16

Superhighway

Answer 16

Large number of axons traveling through the internal capsule, crus, cerebri and pyramids

Descending axons from cerebral cortex to the brain stem and spinal cord and ascending axons from the thalamus to cortex

Axons headed to brainstem innervate cranial nerve nuclei bilaterally and axons to spinal cord cross in pyramidial decussation at boundary between medulla and spinal cord

Question 17

White matter

Answer 17

Tracts that are analogous to large highways

Question 18

Gray matter

Answer 18

Tracts that are analogous to local neighborhoods