L50 Hypothalamus + use L for labeled pics!

Question 1

define anhydrosis.

Answer 1

absence or deficiency of sweating

Question 2

what are the 5 basic processes that the hypothalamus controls?

Answer 2

1. blood pressure and electrolyte composition
2. temperature
3. energy metabolism
4. reproduction
5. emergency responses

Question 3

what are the 3 ways that the hypothalamus carries out its 5 control processes?

Answer 3

1. autonomic function
2. endocrine function
3. motivation and behavior

Question 4

give an example how BP modulation via the 3 pathways used by the hypothalamus.

Answer 4

• hypothalamus can influence ANS (SNS + PNS) to change BP via heart rate and contractility
• endocrine output of the hypothalamus can modulate ADH release from post. pituitary to hang BP via kidney reabsorption
• hypothalamus can influence motivational system to either sit and rest or engage in exercise

Question 5

the hypothalamus maintains _______ within a narrow physiological window via its regulatory mechanisms even though our external environments have a wide range of variability.

Answer 5

homeostasis

Question 6

describe the endocrine function/chemical signaling of pheromones.

Answer 6

released by a species and travel through air to reach their target cell on another individual of that species

Question 7

describe the endocrine function/chemical signaling of autocrine and paracrine.

Answer 7

provide feedback to the releasing cell itself

or provides feedback to its neighbors

Question 8

describe the endocrine function/chemical signaling of endocrine.

Answer 8

release hormone into the blood to reach their target

Question 9

describe the endocrine function/chemical signaling of neurons.

Answer 9

transmitter released onto target to elicit action

Question 10

describe the endocrine function/chemical signaling of neuroendocrine.

Answer 10

a hybrid which released their neurohormone into the blood and they travel through the blood to target cell

Question 11

where are neuroendocrine chemical signaling pathways found and what are they connected to?

Answer 11

found in the hypothalamus

connected from the hypothalamus to the ant/post pituitary

Question 12

what are the relevant structures of the hypothalamus?

Answer 12

periventricular zone
medial zone
lateral zone

Question 13

where is the periventricular zone?

Answer 13

adjacent to the 3rd ventricle

Question 14

what does the medial zone contain?

Answer 14

most of the distinct nuclei of the hypothalamus

Question 15

what does the lateral zone contain?

Answer 15

less defined nuclei but is rich in fiber tracts which connects the hypothalamus to other areas of the brain

Question 16

what are the boundaries of the hypothalamus?

Answer 16

• anterior commissure (next to inter ventricular foramen)
• lamina terminalis (closure of rostral neuropore)
• optic chiasm
• mamillary bodies
• hypothalamus sulcus (continuation of sulcus limitans)

Question 17

what are the nuclei of the anterior pituitary hypothalamo-adenohypophyseal pathway?

Answer 17

parvoventricular and arcuate nuclei

Question 18

what neurohormones does the anterior pituitary release?

Answer 18

TSH
ACTH
LH
FSH
GH 
prolactin
beta endorphin

mneumonic - FLAT PEG

Question 19

what happens with a release of CRH?

Answer 19

causes a release of ACTH which acts on the adrenal cortex to release cortisol into the blood which acts on various target cells

Question 20

what happens with a release of TRH?

Answer 20

causes a release of TSH which cause the thyroid gland to secrete T3 and T4

Question 21

what happens with a release of GnRH?

Answer 21

causes release of LH and FSH which causes gametogeneic and sex steriof proaction in gonads

Question 22

what happens with a release of GHRH and inhibiting somatostatin?

Answer 22

causes a release of GH and causes linear growth

Question 23

what happens with a release of prolactin inhibiting hormone (DA)?

Answer 23

causes a release of prolactin which stimulates lactogenesis

Question 24

what are the nuclei in the posterior pituitary / hypothalamo-neurohypophyseal pathway?

Answer 24

paraventricular and supraoptic nucleus

Question 25

what neurohormones are released from the posterior pituitary?

Answer 25

ADH (vasopressin) and oxytocin *note there are no regulatory hormones from the PP because it controlled under direct neuralgic connections

Question 26

what does release of ADH (vasopressin) cause?

Answer 26

vasoconstriction, water reabsorption in kidney

Question 27

what does release of oxytocin cause?

Answer 27

uterine contraction, milk ejection

Question 28

what does the ventromedial nucleus of the hypothalamus do to feeding?

Answer 28

decreases feeding behavior

Question 29

what does the lateral hypothalamus do to feeding?

Answer 29

increases feeding behavior mneumonic - "Late night Snack" lateral = snacking

Question 30

what is the short term feedback mechanism for feeding in the hypothalamus?

Answer 30

blood glucose levels

Question 31

what is the long term feedback mechanism for feeding in the hypothalamus?

Answer 31

leptin - released from adipose will reach arcuate n. which sends inhibitory interneurons to the lateral hypothalamus to suppress eating!

Question 32

what are the 2 ways information is received by the brain to regulate water balance?

Answer 32

angiotensin - passes the BBB of the subfornical organ | vagus n. - sends BP info via mechani-sensitive endings in the heart

Question 33

how does the hypothalamus influence water conservation?

Answer 33

elicits the posterior pituitary to release ADH as a neuroendocrine signal on the kidney it also send neuronal output to our motivation system controlling drinking behavior

Question 34

what does the anterior hypothalamus do in terms of regulating body temperature?

Answer 34

decreases body temperature *also has temp sensitive cells to detect body temp changes which is integrated with somatosensory temp information

Question 35

what does the posterior hypothalamus do in terms of regulating body temperature?

Answer 35

increases body temperature

Question 36

how are changes in body temperature modulated by the hypothalamus?

Answer 36

temperature changes are induced via ANS which constrict/dilate vessels also uses signals to motivational centers to seek warmer/cooler environments

Question 37

describe ventromedial hypothalamic syndrome (Frohlich syndrome).

Answer 37

disorder of caloric balance causing obesity attributed to damage of the ventromedial nucleus

Question 38

describe diabetes insipidus.

Answer 38

absence of ADH causes excessive thirst and urination | this may be due to a lesion of the supraoptic or paraventricular nuclei somewhere int he post. pituitary tract

Question 39

describe hypothermia.

Answer 39

due to lesions of the posterior hypothalamus leaving the anterior hypothalamus unopposed this causes a decrease in metabolic rate and vasodilation resulting in decreased body temp

Question 40

describe hyperthermia.

Answer 40

due to lesion of the anterior hypothalamus leaving the posterior hypothalamus unopposed this causes increase metabolic rate, shivering and vasoconstriction results in increase body temp