Hypothalamus

Question 1

Borders

Answer 1

part of diencephalon

ant: optic chiasma, lamina terminalis
lat: optic tract, temporal lobe, internal capsule
post: mammillary body, cerebral peduncle
sup: hypothalamic sulcus

Question 2

Lateral zone

Answer 2

1. anterior: lateral nuclei, fiber bundle to forebrain/brainstem, parasympathetic activity
2. Middle: initiate eating + drinking

Question 3

Medial zone

Answer 3

1. anterior:
   - preoptic
   - anterior
   - suprachiasmatic
   - supraoptic
   - paraventricula
2. middle:
   - dorsomedial
   - ventromedial
   - arcuate
3. posterior:
   - posterior
   - mammillary

Question 4

Nuclei of pre optic and anterior hypothalamic area

Answer 4

connected to limbic system
efferent fibers to caudal hypothalamus and brain stem
neurons in preoptic- involved in onset of puberty and timing of ovulation, + sexually dimorphic area + blood pressure + body temp.

Question 5

Nuclei of supraoptic region

Answer 5

Suprachiasmatic nucleus: retinal efferents + collaterals. biological clock
Supraoptic and paraventricular nuclei: produce peptide hormones- oxytocin, ADH

Question 6

Nuclei of infundibular region

Answer 6

Anterior nucleus: regulate temperature
Dorsomedial and ventromedial nuclei: center of sated + GI tract
Infundibular nucelus: tuberoinfundibular neurons -neurosecretory cells

Question 7

Nuclei of posterior hypothalamus and mammillary region

Answer 7

Posterior nucleus: regulate temperature

Mammillary nuclei: relay site of Papez circuit, mammillothalamic tract + mammillotegmental tract, memory + sexual

Question 8

Hypothalamic pathways

Answer 8

Hypothalamospinal tract:
-ant. and medial -> trophotrop (parasymp.)
-post. and lat. -> ergothrop (symp.)
Dorsal longitudinal fasiculus:
-brain stem to hypothalamus
Medial forebrain bundle:
-olfactory - hypothalamus - brain stem
Mammillothalamic fasiculus:
-Paperz ring
Fornix:
- from hippocampus
Retina - optic nerve

Question 9

Function of hypothalamus

Answer 9

Feeding center
Control of drinking
Control of temperature
Control of cycle of sleeping and wakefulness
Memory and behavior
Control of autonomic system
Endocrine center

Question 10

Parvocellular nuclei

Answer 10

production of releasing- inhibiting hormones

control of adenohypophysis

Question 11

Releasing hormones

Answer 11

1. Thyreotropin-releasing: paraventricular, ventromedial, dorsal
2. Corticotropin releasing: medial paraventricular, arcuate, periventricular
3. Gonadotropin releasing: medial preoptic
4. Growth hormone releasing: arcuate
5. Prolactin releasing

Question 12

Inhibiting hormones

Answer 12

1. Somatostatin: periventricular
2. Dopamin: arcuate
3. Melanotropin-release-inhibiting

Question 13

Autonomic pathways from hypothalamus

Answer 13

Medial forebrain bundle: parasymp. from septal nucleus, Brocas diagonal band, nucleus accumbens, basal nucleus of Meynert
Dorsal longitudinal fasciculus: symp. from amygdala