Peterson - Hypothalamus

Question 1

what does the hypothalamus connect with?

Answer 1

1. limbic system (emotions)
2. pituitary gland (endocrine)
3. visceral and somatic nuclei (motor and sensory)

Question 2

paraventricular zone

Answer 2

• suprachiasmatic nuclei –> circadian rhythm

- arcuate nuclei –> feeding behavior

Question 3

medial zone

Answer 3

• supraoptic nucleus –> secrete ADH
• medial preoptic nucleus –> sexual behavior, thermoregulation
• anterior nucleus –> cooling, parasympathetic
• periventricular nucleus –> secrete oxytocin
• dorsomedial nucleus
• ventromedial nucleus –> satiety
• posterior nuclei –> heating, sympathetic
• mammillary body

Question 4

lateral zone

Answer 4

• lateral nucleus
• lateral preoptic nucleus –> sleeping
• lateral tuberal nucleus –> feeding
• tuberomammillary nucleus –> sleep-wake cycle

Question 5

sensory neurons in the hypothalamus

Answer 5

detect

• temp of hypothalamus
• blood osmolality
• glucose concentration
• hormone concentration

Question 6

which efferent fibers are not seen in the afferent fibers?

Answer 6

• mammillothalamic and mammillotegmental tract

- pituitary gland

Question 7

role of arcuate nucleus

Answer 7

contain parvocellular neurons that trigger release of hormones in median eminence of hypothalamus
-travel down blood to release hormones from anterior pituitary

Question 8

hypothalamus - temp regulation

Answer 8

set point - 37C - detected by neurons in medial preoptic nucleus

• cold receptors –> constrict blood vessels 1st –> piloerection, shivering, increase BMR, voluntary 2nd
• heat receptors –> dilate blood vessels 1st –> sweating and voluntary 2nd

Question 9

hypothalamus - cardiovascular regulation

Answer 9

sense decrease in water loss –> decrease in BP and volume

• low blood volume/pressure –> baroreceptors –> CNX –> solitary tract nucleus
• increased osmolality –> osmoreceptors in vascular organ of lamina terminals detects osmolality
• decreased blood flow –> increase angII –> subfornical organ detects the decrease in blood flow

Question 10

where do inputs of hypothalamus go for cardiovascular regulation?

Answer 10

inputs –> medial preoptic nucleus –> ADH release from supraoptic nuclei

Question 11

hypothalamus - feeding regulation

Answer 11

1. ventromedial nucleus - rage and satiety; lesion –> obese (increased appetite)
2. lateral hypothalamic area - signals you to eat; lesion –> do not eat (decreased appetite)
3. arcuate nucleus - stomach distention, glucose levels, peptide hormones, receptors for ghrelin and leptin

Question 12

Prader willi syndrome

Answer 12

genetic - chromosome 15 deletion

• paternally expressed, maternally imprinted
• affected by defect in ventromedial nuclei