Gross/External Morphology of the Brain

Question 0

Tegmentum

Answer 0

Floor of the mesencephalon extending ventrally from the aqueduct to the SN

-Contains PAG, oculomotor nerve complex (at superior colliculus), trochlear nerve (at inferior colliculus), and red nucleus (eye reflexes)

Question 1

Tectum

Answer 1

Contains the superior and inferior colliculi; involved in visual and auditory reflexes respectively

Question 2

Cerebral peduncles

Answer 2

consist of the tegmentum and basal midbrain in the mesencephalon

Question 3

Substantia nigra

Answer 3

nucleus lying immediately dorsal to the crus cerebri; found in the basement midbrain

*Main nucleus which degenerates in Parkinson’s

Question 4

Crus Cerebri

Answer 4

Contains axons of the descending corticospinal tract that synapse onto anterior horn cells

Question 5

Vermis

Answer 5

midline of the cerebellum

Question 6

Sylvian Fissure

Answer 6

“Lateral Sulcus”

Medial border of the temporal lobe

Question 7

Primary Visual Cortex

Answer 7

Brodmann’s Area 17; also know as the calcarine cortex

• Greatest visual representation given to the fovea
• Small lesion can produce a scotoma or even a hemianopia

Question 8

Higher Order Visual Cortex

Answer 8

Brodmann’s Area 18, 19

-Lesions produce visual agnosias

Question 9

Primary Auditory Cortex

Answer 9

Area 41 (transverse temporal gyri of Heschl)

• Disproportionate representation given to human speech sounds
• lesions only produce dimunation of hearing, not deafness due to deep connections

Question 10

Higher Order Auditory Cortex

Answer 10

Contains Wernicke’s Area (22)

Necessary for the interpretation of spoken language

• Lesions in this area produce aphasia
• Patient’s speak language fluently but what they say is nonsense

Question 11

Primary Somatosensory Cortex

Answer 11

Areas 3, 1, 2

-Leg is represented medially; hand/face-laterally

• Lesions will produce deficits of fine appreciation of touch, vibration, and proprioception
• Non-specific pain can still be felt at level of thalamus

Question 12

Higher Order Somatosensory Cortex

Answer 12

Area 2, 5

Part of suprerior parietal lobule; lesions produce somatosensory agnosias

Question 13

Primary Motor Cortex

Answer 13

Area 4; “Precentral gyrus”

• Necessary for the initiation of voluntary motor movement; leg is represented medially/ hand & face, laterally
• Damage/loss of blood supply to this area will result in contralateral paralysis

Question 14

Lesion of Area 8

Answer 14

Found on the superior frontal gyrus; controls paired eye movements

-Causes both eyes to deviate to the side of the lesion

Question 15

Broca’s Area

Answer 15

Areas 44, 45; inferior frontal gyrus

Critically involved in the motor production of language

-Cortical damage results in understanding of language, but inability to speak it
in female children => strong recovery rate

Question 16

Prefrontal association cortex

Answer 16

Plays rolls in cognitive behavior and making executive decisions

Question 17

Limbic Association Cortex

Answer 17

Consists of the orbitofrontal cortex and part of the temporal lobe; involved in personality

-Lesions result in impaired personality, behavior, emotional lability

Question 18

Inferior Parietal lobule

Answer 18

Consists of Area 40(supramarginal) and 39 (angular gyri)

• Important for the perception and interpretation of written language
• Pts. show alexia and agraphia

Question 19

Pons divisions:

Answer 19

1 Dorsal tegmental zone- contains CN V-VII, ascending and descending fibers

2 Ventral/basal zone- Contains corticospinal tract fibers

Question 20

Cingulate Gyrus

Answer 20

Medially located cortical gyrus surrounding the corpus collosum; part of the limbic system

Question 21

First part of the brain to deteriorate in Alzheimer’s

Answer 21

Hippocampus

Question 22

Divides the diencepahlon into its two major areas

Answer 22

Hypothalamic sulcus

Question 23

Tumor of pineal gland

Answer 23

Blocks the aqueduct of Sylvius

=>non-communicating hydrocephalus

Question 24

Pars triangularis Pars opercularis

Answer 24

Located in the frontal lobe

Question 25

Folia

Answer 25

Folds of the cerebellar cortex