Forebrain Anatomy

Question 1

Which pathways relay in the thalamus?

Answer 1

large number: all sensory (except olfaction), limbic system, basal ganglia, cerebellum projections

Question 2

Where does ant subdivision of thalamic nuclei sit?

Answer 2

in a split in the internal medullary lamina

Question 3

Where is the reticular nucleus located?

Answer 3

along lateral aspect (collection of cell bodies)

Question 4

What functions is the hypothalamus critical in?

Answer 4

autonomic, endocrine, emotional and somatic functions

- maintains homeostasis

Question 5

How does the hypothalamus control the pituitary gland?

Answer 5

superior hypophyseal a.
- br internal carotid a.
- supply capillary bed in infundibulum -> drain into portal vessels in adenohypophysis
inferior hypophyseal a.
- br internal carotid
- supply neurohypophysis
- capillaries drain into cavernous sinus -> deliver ant and post pituitary hormones to systemic circulation

Question 6

Where does the second capillary bed of the pituitary gland lie?

Answer 6

around endocrine cells of adenohypophysis

Question 7

What are the two types of neuroendocrine cells?

Answer 7

parvocellular = end in median eminence (preoptic, VM, and arcuate nucleus)
magnocellular = end in post lobe (paraventricular and supraoptic nucleus)

Question 8

Where are the somas of neuroendocrine cells?

Answer 8

in hypophysiotrophic area

- cells located in lower half preoptic and tuberal regions

Question 9

What do parvocellular neurons give rise to?

Answer 9

tuberoinfundibulnar tract to infundibular capillary bed

Question 10

Where are the hormones of the posterior pituitary released?

Answer 10

neurons in paraventricular and supraoptic nuclei

Question 11

What hormones are related by posterior pituitary?

Answer 11

Antidiuretic hormone (vasopressin)
- increase water uptake by kidney, decrease urine output
oxytocin
- contraction of uterine and other smooth mm
- Breast feeding triggered by spinoreticular tract and spinohypothalamic tract

Question 12

What is lost in diabetes insidious?

Answer 12

ADH

Question 13

How does the hypothalamus control ADH release?

Answer 13

sense blood osmotic pressure and from input from subfornical circumventricular organ

Question 14

Which nuclei play role in hypothalamic regulation of feeding?

Answer 14

• interplay creates appestat that can be altered by serotonin
  lateral nucleus = stimulate feeding
  ventromedial = stimulate to recuse food (lesion it stimulates feeding)

Question 15

Which area is key to rage and fear?

Answer 15

ventromedial

Question 16

Male fight or flight response

Answer 16

• ACTH release from ant pituitary = increase cortisol

- show activation of lateral prefrontal cortex

Question 17

Female fight or flight reopen

Answer 17

tend and befriend - protect offspring; affiliate with social groups

• calming effects: oxytocin released in capillary bed of neurohypophysis and estrogen counteract sympathetic over activity due to stress
• show activation of cingulate gyrus (emotional control center)

Question 18

What does a lesion in post hypothalamus cause?

Answer 18

hyper somnolence (increased sleep) or coma

Question 19

Why is sexual arousal increased in men?

Answer 19

subset of neurons in medial aspect of preoptic nucleus (contains androgen receptors) is twice as large in males than females
- F estrogen rich receptors in VMN

Question 20

Memory control

Answer 20

mammillary bodies send info to ant nucleus (limbic relay nucleus); part of Papez circuit from hippocampus