Hypothalamus

Question 1

hypothalamus regulates ____________

Answer 1

hypothalamus regulates WHOLE BODY HOMEOSTASIS

-ensures survival of individual and of species

Question 2

hypothalamus regulates whole body homeostasis via regulation of:

Answer 2

• ANS
• endocrine system
• somatic motor activity (drive-related behaviors)

Question 3

internal parameters that the hypothalamus maintains the set point for

Answer 3

• temperature
• pH
• water
• glucose concentration
• many others

Question 4

behaviors that the hypothalamus affects

Answer 4

• feeding
• drinking
• reproductive

SURVIVAL of individual and of species

Question 5

anterior border of the hypothalamus

Answer 5

lamina terminalis

Question 6

what separates the thalamus from the hypothalamus?

Answer 6

hypothalamic sulcus

Question 7

circumventricular organs

Answer 7

• no BBB
• –fenestrated capillaries instead of tight junctions)
• allow exchange of substances btwn blood and brain (imp bc hypothalamus responsible for whole body homeostasis)

w/ hypothalamus

• median eminence
• neurohypophysis
• organum vasculosum

Question 8

what causes hypothalamic disturbances

Answer 8

• inflammation
• tumors
• vascular disorders
• hydrocephalus

Question 9

clinical disorders associated with hypothalamic lesions

Answer 9

• hyper/hypothermia
• obesity/wasting
• diabetes insipidus
• disturbances of sleep
• emotional disorders
• hypogonadism and early puberty
• altered growth patterns

Question 10

sites associated with parasympathetic function tend to be located in _________ hypothalamus

Answer 10

sites associated with parasympathetic function tend to be located in ANTERIOR hypothalamus

preoptic area, anterior hypothalamus

Question 11

sites associated with sympathetic function tend to be located in _________ hypothalamus

Answer 11

sites associated with sympathetic function tend to be located in POSTERIOR hypothalamus

lateral and posterior hypothalamus

Question 12

______ and ______ systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary

Answer 12

MAGNOCELLULAR and PARVICELLULAR systems modulate hormone synthesis/release from posterior/anterior lobes of pituitary

Question 13

magnocellular system

Answer 13

• comprised of PVN (paraventricular) and SON (supraoptic) nuclei
• LARGE diameter neurons synthesize hormones (oxytocin, ADH)
• hormones transported to POSTERIOR pituitary for release into systemic circulation

Question 14

vasopressin

Answer 14

water reabsorption by kidney

• synthesized by magnocellular system
• released by posterior pituitary

Question 15

oxytocin

Answer 15

milk letdown, uterine contraction, pair bonding

• synthesized by magnocellular system
• released by posterior pituitary

Question 16

lactation reflex
afferent = _________
efferent = _________

Answer 16

lactation reflex
afferent = NEURAL
efferent = HORMONAL (oxytocin)

-neural stimulus from baby suckling –> dorsal column –> neurohypophusis –> oxytocin released –> milk letdown

Question 17

parvicellular system

Answer 17

• anterior lobe
• SMALL diameter hypothalamic neurons produce releasing and inhibiting factors that modulate synthesis and secretion of ANTERIOR pituitary hormones
• influences the pituitary via vasculature (hypophyseal portal vessels)

Question 18

hypophyseal portal system

Answer 18

-delivers hypothalamic releasing and inhibiting factors to the anterior pituitary

Question 19

hypothalmic substances that inhibit/stimulate release of pituitary hormones (and their pituitary correlate)

Answer 19

GnRH --> FSH, LH
GHRH --> GH
Somatostatin --> GH (inhibitory)
TRH --> TSH
Dopamine --> prolactin (inhibitory)
CRH --> ACTH

Question 20

CRH

Answer 20

• released by hypothalamus
• in response to stress
• causes ACTH release from pituitary
• ACTH: cortisol release from adrenal gland
• feedback signal = cortisol

Question 21

______ acts as a feedback signal for CRH release

Answer 21

CORTISOL acts as a feedback signal for CRH release

Question 22

T/F: hypothalamic nuclei stain differently and can be distinguished on a stained section

Answer 22

false. cannot distinguish them on a stained section

Question 23

medial preoptic area

Answer 23

• temperature regulation
• male sex behavior
• parental behavior
• sexually dimorphic nucleus

Question 24

anterior/supraoptic hypthalamic region contains which nuclei?

Answer 24

• superchiasmatic nucleus
• paraventricular/supraoptic nuclei
• anterior nucleus

Question 25

superchiasmatic nucleus

Answer 25

- master clock of brain - day/night rhythms - retinal input

Question 26

paraventricular and supraoptic nuclei

Answer 26

- synthesis of oxytocin and vasopressin - autonomic regulation - stress axis - metabolism

Question 27

anterior nucleus

Answer 27

- temperature regulation | - heat dissipation

Question 28

tuberal region of the hypothalamus contains which nuclei?

Answer 28

- VMN (ventromedial) - DMN (dorsomedial) - LH (lateral hypothalamic) - arcuate - periventricular

Question 29

arcuate nucleus

Answer 29

food intake and metabolism

Question 30

periventricular nucleus

Answer 30

reproductive cycles

Question 31

bilateral lateral hypothalamic (LH) lesion causes

Answer 31

-anorexia

Question 32

bilateral VMN lesion

Answer 32

- no satiety (voracious appetite) | - rage

Question 33

leptin

Answer 33

- hormone produced by fat tissue - acts in brain to modulate food intake - functions in feedback loops that regulate metabolism and body weight

Question 34

decreased leptin levels

Answer 34

- increased orexigenic peptides - stimulation of feeding behavior (LH) - decreased metabolism

Question 35

elevated leptin levels

Answer 35

- stimulation of anorexic peptides - inhibition of feeding behavior (LH) - increase in metabolism

Question 36

posterior region of hypothalamus contains which nuclei?

Answer 36

- mamillary bodies - posterior nucleus - subthalamic nucleus - lateral hypothalamic nucleus

Question 37

Korsakoff's Syndrome

Answer 37

- destruction of mamillary bodies (and DMN) - causes confabulatory amnesia) - associated with poor diet and alcoholism

Question 38

posterior nucleus

Answer 38

heat conservation

Question 39

heat dissipation vs heat conservation

Answer 39

Dissipation: - preoptic area (POA) - anterior hypothalamic area (AH) Conservation -posterior hypothalamus

Question 40

afferents to hypothalamus

Answer 40

- hippocampus - amygdala - septal nuclei - other limbic structures - retina - spinothalamic - visceral nuclei - physical stimuli

Question 41

which nuclei control endocrine system?

Answer 41

- supraoptic nucleus (SON) | - PVN (periventricular)

Question 42

which nuclei control ANS?

Answer 42

-PVN (periventricular) descending projections to craniosacral/thoracolumbar regions

Question 43

which nuclei control body temp?

Answer 43

- anterior (AH) | - POA (preoptic area)

Question 44

which nuclei control day night rhythms?

Answer 44

-SCN (superchiasmatic)

Question 45

which nuclei control food intake and metabolism?

Answer 45

- VMH - arcuate - DMH - PVN - LHA

Question 46

which nuclei control sleep wake cycles?

Answer 46

- AH (anterior) - POA (preoptic area) - posterior hypothalamus -melatonin

Question 47

median eminence

Answer 47

- swelling on base on hypothalamus on ventral surface - has rich plexus of capillaries - connects hypothalamus to pituitary - circumventricular organ (no BBB)

Question 48

tuberoinfundibular tract

Answer 48

-collection of axons carrying releasing/inhibiting factors to the median eminence

Question 49

VMN

Answer 49

satiety center

Question 50

lateral nucleus

Answer 50

feeding center

Question 51

leptin receptors are present on _________ nucleus

Answer 51

leptin receptors are present on ARCUATE nucleus