hypothalamus + limbic system

Anterior pituitary (Adenohypophysis)

produces and secretes hormones related to growth, metabolism, reproduction

(TSH, prolactin, growth hormones, LH, ACTH)

posterior pituitary (neurohypophysis)

stores and releases (DOES NOT PRODUCE ANYTHING) hormones synthesized in the thalamus. Regulates water balance, uterine contractions, social bonding, and milk ejection

(vasopressin, ADH, oxytocin)

hypothalamus

-tuber cinerum (feelings and behaviors)

-mammillary bodies (memory processing and emotional response)

-infundibulum to pituitary stalk (facilitates hormone exchange between ant/post pituitary and helps control growth, metabolism, and reproduction)

Hypothalamus - thermoregulation

anterior: detects increased body temp & activates heat dissipation

Anterior lesion: hyperthermia

posterior: conserves heat

posterior lesion: poikilothermia (dysregulation of hot and cold)

Hypothalamus - weight control

lateral: appetite

lateral lesion: causes weight loss

medial: inhibiting appetite

medial lesion: Weight gain

hypothalamus - circadian rhythm regulator

anterior lesion - insomnia (too much histaminergic neurons)

posterior lesion - hypersomnia (not enough histaminergic and orexin neurons)

human growth hormone (HGH)

accelerates body growth, insulin antagonism

Produced in anterior pituitary

prolactin

stimulates secretion of milk and maternal behavior, inhibits ovulation

Produced in anterior pituitary

luteinizing hormone (LH)

stimulates ovulation in females and testosterone secretion in males

Produced in anterior pituitary

follicle stimulating hormone (FSH)

stimulates ovarian follicle growth in females, and spermatogenesis in males

Produced in anterior pituitary

Adrenocorticotropic hormone (ACTH)

stimulates adrenal cortex secretion and growth, steroid production

Produced in anterior pituitary

thyroid stimulating hormone (TSH)

stimulates thyroid secretion and growth

Produced in anterior pituitary

arginine vasopressin

promotes water retention and regulates plasma osmolarity

if its lacking patient has excessive thirst and urination

if excessive patient has swelling and excessive water retention

secreted from posterior pituitary

supraoptic nuceli

oxytocin

causes ejection of milk and uterine contraction

secreted from posterior pituitary

paraventricular nuclei

paraventricular and supraoptic nuclei

reduce water balance

produce ADH and oxytocin

destruction causes diabetes insipidus

anterior hypothalamic nucleus

thermal regulation (dissipation of heat)

stimulates parasympathetic NS

destruction results in hyperthermia (patient won't be able to sweat, regulate body temp)

preoptic area

contains sexually dimorphic nucleus

regulates release of gonadotropic hormones

suprachiasmatic nucleus

receives input from retina

controls circadian rhythms (sleep issues if lesioned)

dorsomedial nucleus

stimulation results in obesity and savage behavior

can be related to eating disorders

posterior nucleus

thermal regulation (conservation of heat)

destruction results in inability to thermoregulate

stimulates the sympathetic NS

Lateral nucleus

stimulation induces eating

destruction results in starvation

mammillary body

-receives input from hippocampal formation via fornix

-projects to anterior nucleus of the thalamus

-contains hemorrhagic lesion in wernicke's encephalopathy (stops it from worsening

ventromedial nucleus

satiety center

destruction results in obesity and savage behavior

arcuate nucleus

produces hypothalamic releasing factors

contains DOPA-ergic neurons that inhibit prolactin release

mammillothalamic tract function

origin: medial and lateral nuclei of mammillary bodies

targets: dorsal and ventral tegmental nuclei and anterior thalamic nuclei

function: supports spatial memory

ventral amygdalafugal tract

origin: basolateral nucleus and central nucleus (of amygdala

targets: medial dorsal nucleus of thalamus, hypothalamus, basal forebrain, brainstem, nucleus accumbens

function: associative learning

entorhinal cortex

involved in memory formation, navigation (spatial) and perception of time

subiculum

part of the hippocampal formation and receives info from hippocampus to relate it to cortex and subcortex areas

fornix

functions in memory consolidation with hippocampus, episodic memory, spatial memory, emotional regulation, reward processing and motivation

cingulate gyrus

functions in emotional regulation, sensory perception, limbic system integration, reward processing, social cognition, self awareness, sleep regulation

What does the amygdala do after and emotional stimulus?

regulates stress, sympathetic control and reflexes

HPA Axis

-hypothalamus releases CRH to the anterior pituitary

-anterior pituitary released ACTH to adrenal cortex

-adrenal cortex releases cortisol that provides negative feedback to the hypothalamus

hypothyroidism

-rarely caused by pituitary or hypothalamic insufficiency

-sx: weight gain, cold intolerance, smooth + dry skin, hair loss, depression, constipation, fatigue

hyperthyroidism

-TSH secreting adenoma

-graves disease, toxic goiter, thyroiditis produces hyperthyroidism

-sx: nervousness, tremor, excessive sweating, weight loss, heat sensitivity, increased sympathetic output, increased bowl movement

Cushing's syndrome

glucocorticoid excess

ACTH adenoma

sx: round face, truncal obesity, purplish skin marks, thin skin, easy bruising, poor wound healing, HTN, diabetes, osteoporosis , amenorrhea, myopathy, fatigue, mania and or depression