DSA Hypothalamus/Limbic

Question 1

What are the 3 parts of the hypothalamus and general location?

Answer 1

Mammilary bodies- posteriorly

• –thin swelling Tuber cinereum
• –Median eminence narrowing into the infundibulum–attaches to pituitary

Question 2

What would damage to the lateral hypothalamic zone cause?

Answer 2

a decrease in feeding behaviors (w/ weight loss)

-contains the median forebrain bundle

Question 3

What are the Hypothalamic nuclei in the Medial-Supraoptic zone?

Answer 3

Supraoptic/Paraventricular: oxytocin and ADH–>assoc with the posterior pituiatry
+damage can cause diabetes insipidus– increased h2o intake and urine output

Suprachiasmatic: involved in circadian rhythms (retinal input)

Anterior: temperature regulation and some visceral/somatic function

Question 4

What are the Hypothalamic nuclei in the Medial- Mammilary/Posterior zone?

Answer 4

MM nucleus:
Afferents–>hippocampus via fornix
Efferents–>to thalamus and brainstem

Damage: can’t process short term events into longterm memory

Question 5

What are the Hypothalamic nuclei in the Medial- Tuberal region?

Answer 5

Ventromedial: “satiety”
–damage: excessive eating and weight gain

Dorsomedial: adds to emotional behavior ++sham rage (biting, clawing, hissing, back arch)
–damage: decreased aggression and feeding

Question 6

What is the blood supply of the Hypothalamus?

Answer 6

Circle of Willis

Anteromedial group: Ant communicating +Ant cerebral

Posteromedial group: Post communicating +posterior cerebral

Question 7

What are the major Afferent and Efferent paths of the hypothalamus.

Answer 7

Afferent: Fornix; Medial Forebrain Bundle MFB; Amygdalohypothalamic fibers-stria terminalis and ventral amygdalofugal paths

Efferent: Mammillary fasciculus–splits into mammilothalamic and mammillotegmental tracts;
Hypothalamothalanic fibers

Question 8

What are the direct links from the hypothalamus to the ANS?

Answer 8

Hypothalamomedullary (medullary): solitary, dorsal vagal motor, ambiguus
Hypothalamospinal (spinal)

Horner’s syndrome can occur in outflow to face/head with lesions, as well as sympathetic issues in the body

Question 9

What are the indirect links to the ANS from the hypothalamus?

Answer 9

Posterior Longitudinal fasciculus and Memmillotegmental tract: target the PAG

Question 10

What do know about the Supraopticohypohysial tract?

Answer 10

axons of the neurons in SON and ParaVentricularN
-produces oxytocin and ADH in posterior pituitary

Stored: Herring bodies
Released: plexus of PP

Question 11

What to know about the Tuberoinfundibular tract?

Question 12

What receives input from the retina and helps to mediate circadian rhythms-opposing the drive for sleep?

Answer 12

Suprachiasmatic nucleus

-gene products control pineal grand secretion of melatonin

Question 13

What is the Papez circuit?

Answer 13

Part of limbic system- esp the Cingulate gyrus

• physio mechanism for emotion and memory
• modulates feelings

CG–Hippo(subiculum/entorhinal)–Fornix–M Mammilary nuc–Ant nuc–CG

Question 14

What is the path for Hippocampal learning/memory action?

Answer 14

Dentate gyrus–CA3–CA1–Subiculum—–Efferent–>fornix

Question 15

Where does the Amygdala send efferent fibers?

Answer 15

Stria terminalis to the hypo and basal gang (motor reponse)

Ventral amygdalofugal path to hypo/septal nuclei or brainstem/raphe nuc/dorsal motor vagus

Question 16

What might the Septal region of Limbic control?

Answer 16

Rage behavior

Question 17

What does the nucleus accumbens play a role in?

Answer 17

addiction and chronic pain from the amygdala and hippocampus

Question 18

Where is the VTA? and what does it contribute to?

Answer 18

Medial to Substantia nigra

-reward/motivation as well as addcition

Question 19

What would a bilateral lesion to the hippocami cause?

Answer 19

Amnesia- anterograde episodic memory (new material)

Question 20

What is presented with Korsakoff’s syndrome?

Answer 20

degeneration of mammillary bodies

• difficulty learning new tasks/forming long-term
• hard to understand written material/conduct meaningful convo
• confabulation of memory fragments

Thiamine def (alcoholism)

Question 21

Typical Olfaction disorders?

Answer 21

Anosmia (CN1)

Phantosmia (hallucination): distort smell or perception that there is smell (lesion of anterior/medial temporal lobe)

Question 22

What presents in Kluver-Bucy Syndrome?

Answer 22

Amygdaloid complex via temporal lobe lesion

• visual agnosia (can’t recognize sight)
• hyperorality
• hypermetamorphosis (overactive hipster)
• placidity (not showing fear/anger)
• hyperphagia (excessive eating)
• hypersexuality