Anatomy

Question 0

What is the function of the lateral area of the hypothalamus? What does destruction result in?

Answer 0

Hunger

Destruction leads to anorexia, failure to thrive in infants.

Question 1

What is the function of the suprachiasmatic nucleus?

Answer 1

Circadian rhythm

Question 2

What is the function of the ventromedial area of the hypothalamus? What does destruction result in?

Answer 2

Satiety

Destruction results in hyperphagia.

Question 3

What parts of the hypothalamus does leptin act on? What is the effect?

Answer 3

• INHIBITS the lateral area, which suppresses hunger

- STIMULATES the ventromedial area, which activates satiety

Question 4

What is the function of the anterior hypothalamus? Damage leads to?

Answer 4

Cooling, parasympathetic
damage leads to heat intolerance

(Anterior, parAsympathetic, A/C = anterior, cooling)

Question 5

What is the function of the posterior hypothalamus? Damage leads to?

Answer 5

Heating, sympathetic

damage leads to cold intolerance

Question 6

Loss of touch sensation affecting the entire right side (upper and lower extremities, face) represents a lesion where? No motor deficits.

Answer 6

lesion of left thalamus
Thalamic syndrome – total sensory loss on contralateral side of body

damage to thalamic VPL and VPM nuclei = complete contralateral sensory loss

Question 7

What mutation is associated with ALS? How can you differentiate between ALS and syringomyelia?

Answer 7

zinc-copper superoxide dismutase mutation (SOD1) – free radical injury in neurons
most cases are sporadic

Syringomyelia has sensory loss – loss of pain and temperature sensation.
NO SENSORY LOSS IN ALS.

Question 8

What sensory system uses the lateral geniculate nucleus as a relay nucleus? The medial geniculate nucleus?

Answer 8

LGN of the thalamus = visual information
sends visual info from the optic tracts to the visual cortex

MGN of the thalamus = auditory information
sends auditory info from the superior olive and inferior colliculus of the pons to the auditory cortex (temporal lobe)

Question 9

Nausea and vomiting after chemotherapy due to activation of what site in the brain?

Answer 9

chemoreceptor trigger zone (CTZ), dorsal surface of the medulla

located in the area postrema (no BBB, so samples chemicals circulating in blood)

Question 10

What lobe does Meyer’s loop run through from the lateral geniculate nucleus? What lobe do the dorsal optic radiations run through?

Answer 10

Meyer’s loop (lower retina, upper visual field) takes a circuitous route anteriorly through the TEMPORAL lobe

Dorsal optic radiations (upper retina, lower visual field) pass from the LGN through the PARIETAL lobe

Question 11

Which nerve damaged if loss of sensation in pinky? What deformity?

Answer 11

Ulnar nerve

“claw hand”

Question 12

Describe the path of the pupillary light reflex.

Answer 12

Optic nerve, chiasma, tract, LGN
to pretectal nucleus
to bilateral Edinger-Westphal nuclei
to ciliary ganglion (travels with CN III)
to the pupillary constrictor muscle

Question 13

Neurofibromas in neurofibromatosis I are derived from what cells?

Answer 13

neural crest cells

Question 14

Lesion which cranial nerve leads to hyperacusis (increased sensitivity to sound)?

Answer 14

Facial nerve

innervates the stapedius muscle, which stabilizes the stapes ossicle

Question 15

Which sense does not have a relay nucleus in the thalamus? What are the relay nuclei in the thalamus and what sensory pathways do they relay?

Answer 15

Olfactory

Ventral posterolateral (VPL) = ALS, dorsal columns
Ventral posteromedial (VPM) = trigeminal, gustatory/taste
Lateral geniculate (LGN) = vision
Medial geniculate (MGN) = auditory

Question 16

Injury of which nerve leads to “wrist drop”?

Answer 16

radial nerve injury

weakness of forearm and hand extensors

Question 17

Where do the three branches of CN V exit the skull?

Answer 17

Standing Room Only

V1: Superior orbital fissure
V2: foramen Rotundum
V3: foramen Ovale

Question 18

Injury to what nerve causes “foot drop”?

Answer 18

Common peroneal injury
cannot dorsiflex or evert foot
characteristic high-stepping gait seen

Question 19

Name the 3 important dopaminergic systems, their function, and associated disease.

Answer 19

Mesolimbic-mesocortical

• regulates behavior
• hyperactive in schizophrenia

Nigrostriatal

• coordination of voluntary movements
• decreased activity in Parkinson’s

Tuberinfundibular

• controls prolactin secretion via dopamine-dependent prolactin tonic inhibiton
• block of pathway results in hyperprolactinemia

Question 20

Where does the trigeminal nerve arise?

Answer 20

level of the middle cerebellar peduncle at lateral aspect of the mid-pons

Question 21

Afferent limb of gag reflex? Efferent?

Answer 21

Glossopharyngeal (CN IX) - afferent

Vagus (CN X) - efferent

Question 22

Palsy of which nerve is responsible for VERTICAL diplopia? Classic presenting symptom?

Answer 22

CN IV (trochlear nerve -- superior oblique)
injury to CN IV means eye is deviated upward

double vision when walking down stairs or reading newspaper
most noticeable when eye looking down toward nose

Question 23

What nerves in addition to CN VIII can be affected by an acoustic neuroma at the cerebellopontine angle?

Answer 23

CN V (trigeminal) and CN VII (facial)

Question 24

What connects the lateral ventricles to the 3rd? The 3rd to the 4th ventricle? The 4th to the subarachnoid space?

Answer 24

Lateral ventricles to 3rd: two foramina of Monro

3rd to 4th: cerebral aqueduct

4th to subarachnoid: two foramina of Luschka (lateral) and foramen of Magendie (medial)

Question 25

What provides general sensation to the anterior 2/3 of the tongue? Gustatory innervation?

Answer 25

general sensation: mandibular branch of trigeminal (V3)

gustatory innervation: chorda tympani branch of facial nerve (VII)

Question 26

What nerves mediate the ankle jerk reflex? The anocutaneous reflex?

Answer 26

Ankle jerk/Achilles reflex: S1-S2
tests the integrity of the sciatic nerve

Anocutaneous reflex: S2-S4
tests integrity of the pudendal nerve that innervates perineum
damage also causes saddle anesthesia