Hypothalamus

Front 1

Baroreceptor Reflex

Back 1

hypothalamus: lateral paraventricular nucleus
afferent: barorecpetors in the aortic arch and carotid sinus
efferent: dorsal vagal nucleus of the medulla to regulate BP

Front 2

Temperature Regulation Reflex

Back 2

hypothalamus: pre-optic nucleus
affferent: thermosensitive neurons
efferent:
rostral hypothalamus: cutaneous vasodilation for heat dissipation
caudal hypothalamus: cutaneous vasoconstriction for heat conservation
reticulospinal pathways: shivering for heat production

Front 3

Water Balance Reflex

Back 3

anterior hypothalamus
afferent: osmolarity-sensitive neurons monitors blood
efferent: releases vassopressin to regulate resorption in kidney

Front 4

Hypothalamic Pituitary Adrenal Axis

Back 4

stress system response
hypothalamus release CRF
→adrenal pituitary releases ACTH
→adrenal gland releases cortisol
for a metabolic effect which stresses the brain and a negative feed back mechanism

immune system suppressed by CRF

Front 5

CRF
ACTH

Back 5

Corticotropin Releasing Factors
AdrenoCorticoTropic Hormoes

Front 6

Corticotropin Releasing Factors
(CRF)

Back 6

synthesized in the paraventricular nucleus of the hypothalamus
signaling hormone in stress response system
suppresses the immune system

Front 7

Hormones made by in the hypothalamus...

Back 7

CRF
oxytocin
vassopressin
GnRH

Front 8

GnRH

Back 8

regulates gonadotrophin release
embryologic origins: synthesized in olfactory epithelial cells (placodes)
fetal stage: migrates to hypothalamus

Front 9

Kallman's disease

Back 9

failure of GnRH synthesizing cells to migrate from olfactory epithelium to hypothalamus
→anosmia and abnormal gonad development

Front 10

Gonadotrophins

Back 10

anterior pituitary hormones
Folliculotrophin (FSH)
Luteotrophin (LH)

Front 11

Folliculotrophin
(FSH)

Back 11

anterior pituitary hormone
stimulates ovarian follicles to produce oestrogen

Front 12

Luteotrophin
(LH)

Back 12

anterior pituitary hormone
stimulates ovulation and corpus luteum to produce progesterone

Front 13

Somatotrophin
(STH)

Back 13

anterior pituitary growth hormone

Front 14

Thyrotrophin
(TSH)

Back 14

anterior pituitary hormone
stimulates thyroid gland to produce T3 and T4

Front 15

Corticotrophin
Adrenocroticotrophic hormone
(ACTH)

Back 15

anterior pituitary hormone
stimulates adrenal cortex to produce glucocorticoids

Front 16

Pleiotropic Obesity Syndromes

Back 16

mendelian disorders
clinical obesity
retardation
dysmorphic
organ abnormalities

Front 17

Suprachiasmatic nucleus

Back 17

bilaterally above optic chiasm medially

biological clock

Front 18

Interstitial nucleus

Back 18

bilaterally directly above the suprachiasmatic nuclei

dimorphic - can tell male from female

Front 19

Supraoptic nucleus

Back 19

bilaterally above optic chiasm laterally

can also synthesize vasopressin and oxytocin (mostly synthesized in PVN)

Front 20

Paraventricular Nucleus
(PVN)

Back 20

bilaterally directly above the suprachiasmatic nuclei at more rostral cross-section than the interstitial nuclei

produces vasopressin and oxytocin
houses most of the hormones

Front 21

Ventromedial Nucleus

Back 21

bilaterally directly below the supraoptic nuclei at a more rostral cross-section than the paraventricular nuclei

houses chemicals for energy balance

Front 22

Dorsomedial Nucleus

Back 22

bilaterally directly above the arcuate nuclei at a more rostral cross-section than the ventromedial nuclei

houses chemicals for energy balance

Front 23

Arcuate Nucleus

Back 23

bilaterally above the infundibulum

houses receptors for hormones synthesized outside the hypothalamus
ie. thermorecptors

critical for energy balance

Front 24

Prader-Willi Syndrome

Back 24

most common syndromal cause of obesity
AD
deletion of paternally imprinted gene on proximal long arm of chromosome 15

Front 25

Congential Leptin Deficiency

Back 25

monogenic human obesity syndrome
frameshift mutation of OB gene
no leptin produced
→hyperphagic - can't stop eating
Tx: Leptin injection

Front 26

Lateral Hypothalamus

Back 26

hunger center
stimulation = hunger

lesion → anorectic → lose weight

Front 27

Ventromedial Hypothalamus

Back 27

satiety center
stimulation = full

lesion → over eat → obesity

Front 28

Ob/Ob

Back 28

mutation in Ob gene
→ no leptin produced

Front 29

Db/Db

Back 29

have Ob gene to produce leptin
but have mutation for type 1 cytokine receptor that responds to leptin

clinically obese people who cannot lose weight

Front 30

Leptin

Back 30

appetite-suppressing hormone synthesized in brown adipose tissue that acts on type 1 cytokine receptors in the ventromedial hypothalamus (VMH)

regulates Ghrelin and PYY

Front 31

Leptin pathway

Back 31

Ob gene → leptin protein (fat cell) → blood stream → VMH (hypothalus) → satiety

Front 32

Melanocortin Receptors

Back 32

neurons in the arcuate nucleus in hypothalamus
critical to energy balance and obesity
stimulation reduces food intake

Front 33

Propiomelanocortin
(POMC)

Back 33

arcuate nucleus produces:
Adrenocorticotropic hormone (ACTH)
α,β,γ-Melanocyte stimulating hormones (MSH)
Endorphins

suppresses appetite

Front 34

Melanocortin Receptors

Back 34

5 G-protein coupled receptors that mediate teh actions of melanocortins (reduce food intake)
MC1R, MC2R, MC3R, MC4R, MC5R

Front 35

MC3R and MC4R

Back 35

Melanocortin recptors found in brain

Front 36

MC1R

Back 36

Melanocortin recptors found in melanocytes

Front 37

MC2R

Back 37

Melanocortin recptors found in the adrenal cortex responds to ACTH

Front 38

MC5R

Back 38

Melanocortin recptors found in sebaceous glands

Front 39

Agouti-related peptide
(AgRP)

Back 39

highly competitive anatonist of MC4R
leads to increased feeding by blocking MC4R stimulation

expressed in skin as freckles and as red hair

Front 40

MC4R mutation

Back 40

agouti will bind all the time: red hair, freckles, hyperphagia = obesity, accelerated growth and hyperinsulinemia

Front 41

Ghrelin

Back 41

synthesized in stomach and small intestine
appetite stimulating hormone regulated by Leptin
cycles throughout the day - high before meals

without it hypothalamus doesn't know when the body is hungry

Front 42

PYY

Back 42

synthesized in small intestines
appetite suppressing hormone regulated by Leptin

Front 43

Neuropeptide Y
(NPY)

Back 43

synthesized in arcuate nucleus
appetite stimulating hormone regulated by Leptin

Front 44

Cocaine and amphetamine regulated transcript
(CART)

Back 44

synthesized in arcuate nucleus
appetite suppressing hormone

Front 45

Arcuate nuclei produced hormones

Back 45

Adrenocorticotropic hormone (ACTH)
α,β,γ-Melanocyte stimulating hormones (MSH)
Endorphins
Cocaine and amphetamine regulated transcript (CART)

Front 46

Hunger hormones

Back 46

Ghrelin
Neuropeptide Y (NPY)
Agouti related peptide (AgRP

Front 47

Satiety hormones

Back 47

Leptin
α-Melanocyte stimulating hormones (α-MSH)
Cocaine and amphetamine regulated transcript (CART)
PYY