Hypothalamus And Pituitary

Question 1

What hypothalamic nucleus release CRH

Answer 1

PVH

Question 2

What hypothalamic nuclei release GnRH

Answer 2

Scattered ones

Question 3

What hypothalamic nuclei release TRH

Answer 3

Periventricular zone

Question 4

What hypothalamic nuclei releases oxytocin and ADH

Answer 4

PVH

Question 5

What hormones are produced in the arcuate nucleus

Answer 5

PRH/PIH/Dopamine?GRH/GIH

Question 6

Neuroendocrine reproductive principles of hypothalamus

Answer 6

• GnRH (LHRH)
• released at median eminence to anterior pituitary
• drives pituitary release of LH and FSH
• GnRH neurons are also diffusely distributed beyond the pre optic area

Question 7

Reproductive behavior and puberty

Answer 7

• initiated when dormant GnRH neurons become active
• GnRH neurons receive excitator and inhibitory neural input
• timing of puberty can be delayed via inhibitory input
• non-neuroendocrine neurons involved in sexual drive, arousal
• descending projections to spinal cord regulate genital function

Question 8

The PVH which releases CRH receives ____________ input from many brain regions

Answer 8

Excitatory and inhibitory

Question 9

Physical stressors that can activate the HPA axis

Answer 9

• hypoglycemia, hypotension, hypovolemia, cold, exercise
• these stimuli activate brainstem system which project to PVH, especially norepi neurons in medulla, which directly project to PVH

Question 10

Physiological stressors and the HPA axis

Answer 10

• social stress, fear-inducing situations/environments.

- stimulate cortical and limbic regions which activate intermediary brain regions, which then project to the PVN

Question 11

What brain regions can act to inhibit the PVH

Answer 11

Hippocampus and prefrontal cortex (GABA)

Question 12

Glucocorticoid receptors in the brain

Answer 12

-widely expressed in the brain and glucocorticoids are known to influence cognitive and emotional function and behavioral regulation

Question 13

What does cortisol bind to inthe brain

Answer 13

Mineralocorticoid

Question 14

Pronglonged glucocorticoid receptor activation

Answer 14

Bad
-excessive changes in neuronal excitability, dendritic atrophy, increased vulnerability to hypoxia, stroke, traumatic injury, MDD

Question 15

Deficient glucocorticoid secretion

Answer 15

Risk factor for psychiatric disorders such as PTSD

Question 16

Hypothalamic tumor (hamartoma)

Answer 16

• grows into sella turcica and crutches pituitary
• if entire pituitary damaged=pan-hypopituitarism, loss of all hormones
• irritate optic nerves/chiasm/tracts
• abnormal neuronal activity in regions to project to hypothalamus

Question 17

Pan-hypopituitarism

Answer 17

• deficiency of multiple or all pituitary hormone release
• hamartoma
• pituitary adenoma, non-functioning type
• meningioma, craniopharyngioma
• trauma, infections, autoimmune, pituitary apoplexy

Question 18

How is pan-hypopituitarism treated

Answer 18

Hormone replacement

Question 19

Pituitary apoplexy

Answer 19

Hemorrhage of pituitary tumor leading to pan-hypopituitarism

Question 20

Signs of pituitary apoplexy

Answer 20

Meningeal irritation signs, bilateral cancerous sinus syndrome

Question 21

Pituitary adenoma-hyper-secretory type

Answer 21

• slow growing, originating from anterior pituitary
• and form from any cell type in ant pituitary
• secrete one or more hormones in excess
• hormone secretion by tumor not controlled by hypothalamus

Question 22

Pituitary adenoma, non functionin or silent adenoma

Answer 22

Do not secrete hormones, therefore can grow large before symptoms present

Question 23

Various potential neurological signs of pituitary tumor

Answer 23

• HA
• bitemporal hemianopia
• hydrocephalus
• herniation syndrome