The Pituitary Gland

Question 1

what are the “master controllers” of the endocrine system?

Answer 1

The hypothalamus and pituitary

Question 2

what connects the hypothalamus to the pituitary?

Answer 2

stalk called the infundibulum.

Question 3

how big is the pituatary gland?

Answer 3

14 mm diamete

Question 4

what are the two types of tisue in the pituitary gland?

Answer 4

anterior and posterior pituitary

Question 5

what are the functions of hypothalamus?

Answer 5

cold
stress
metabolic demand
hydration status
exercise
day/night
menstrual cycle
sleep
breastfeeding
pregnancy
puberty

Question 6

what do hypothalamus and anterior pituitary release?

Answer 6

tropic and non-tropic hormones (tropic hormones govern the release of another hormone)

Question 7

what are all the hormones released by the hypothalamus?

Answer 7

neurohormones

Question 8

what are all the hormones released by the posterior pituitary?

Answer 8

neurohormones

Question 9

what are all the hormones released by the anterior pituitary?

Answer 9

classic endocrine hormones

Question 10

what are the 2 forms of hypothalmic neurohormones?

Answer 10

tropic and non-tropic

Question 11

what are tropic neurohormones?

Answer 11

neurohormones secreted into capillaries travelling to anterior pituitary. Govern release of anterior pituitary hormones

Question 12

what are non-tropic neurohormones?

Answer 12

neurohormones produced in the hypothalamus and travel to posterior pituitary (via axons of hypothalamic neurons) where they are released into blood

Question 13

where do all hypothalamic tropic hormones bind to?

Answer 13

receptors on anterior pituitary and stimulate/inhibit release of AP hormones

Question 14

what are the 5 trophic hypothalmic releasing hormones?

Answer 14

Thyrotropin Releasing Hormone (TRH)
Corticotropin Releasing Hormone (CRH)
Growth Hormone Releasing Hormone (GHRH)
Gonadotropin Releasing Hormone (GnRH)
Prolactin Releasing Hormone (PRH)

Question 15

what are the 2 trophic hypothalmic inhibiting hormones?

Answer 15

Growth Hormone Inhibiting Hormone (GHIH) aka somatostatin

Dopamine aka Prolactin Inhibiting Hormone (PIH)

Question 16

what are the 2 hypothalmic inhibiting hormones?

Answer 16

Growth Hormone Inhibiting Hormone (GHIH) aka somatostatin

Dopamine aka Prolactin Inhibiting Hormone (PIH)

Question 17

are all of these hypothalmic hormones peptides?

Answer 17

yes except dopamine

Question 18

what is the hypothalamo-hypophyseal portal system?

Answer 18

Network of tiny vessels which transfer trophic hormones from hypothalamus to anterior pituitary

Question 19

what type of tissue is the anterior pituitary?

Answer 19

true endocrine tissue

epithelial origin

Question 20

how is the anterior pituitary connected to the hypothalmus?

Answer 20

via capillary portal system

Question 21

what is the anterior pituitary also called?

Answer 21

adenohypophysis

Question 22

which part of the pituitary gland makes up 2/3rds of the gland?

Answer 22

anterior

Question 23

what type of tissue is the posterior pituitary gland?

Answer 23

neuroendocrine tissue

Question 24

what is the tissue origin of the posterior pituitary gland?

Answer 24

neural

Question 25

what is the connection betwen posterior pituitary and hypothalamus?

Answer 25

neural connection

Question 26

what is the posterior pituitary gland also called?

Answer 26

neurohypophysis

Question 27

what is the production of the anterior pituitary hormones controlled by?

Answer 27

hypothlamus

Question 28

how many hormones are released from the pituitary gland?

Answer 28

6

Question 29

how many of these hormones are tropic hormones that are releaased from anterior pituitary gland?

Answer 29

5/6

Question 30

what are the anterior pituitary hormones?

Answer 30

Thyroid Stimulating Hormone (TSH) aka thyrotropin Adrenocorticotrophic Hormone (ACTH) aka corticotropin Follicle Stimulating Hormone (FSH) Luteinising Hormone (LH) Growth Hormone (GH) Prolactin

Question 31

which of the anterior pituitary hormones are not tropic hormones?

Answer 31

prolactin

Question 32

what does prolactin do?

Answer 32

directly stimulates milk production from the breast during lactation

Question 33

action of prolactin

Answer 33

breast --> lactation (direct)

Question 34

action of thyeoid-stimulating hormone

Answer 34

thyroid --> TH release (tropic)

Question 35

action of adrenocorticotropic hormone?

Answer 35

ad. cortex --> cortisol release (tropic)

Question 36

action of the growth hormone

Answer 36

liver --> IGF-1 release (tropic) and tissue metabolism (direct)

Question 37

action of the follicle-stimulating hormone luteinising hormone?

Answer 37

gonads --> regulation of reproductive function (direct) and sex hormone release (tropic)

Question 38

what are the integration centres that control the anterior pituitary feedback control?

Answer 38

hypothalamus anterior pituitary target endocrine cell

Question 39

how does the anterior pituitary feedback control work?

Answer 39

hormones themselves act as negative feedback signal each hormone feeds back to inhibit hormone secretion by integrating centres earlier in the reflex feedback from endocrine target = long-loop feedback feedback from anterior pituitary to hypothalamus = short-loop feedback

Question 40

what are the peptide hormones that the posterior pituitary stores and releases?

Answer 40

vasopressin (ADH) | oxytocin

Question 41

where are the posterior pituitary neurohormones synthesised?

Answer 41

magnocellular neurons which have their cell bodies in specific areas of the hypothalamus

Question 42

how do the axons get to the posterior pituitary?

Answer 42

project down the infundibulum

Question 43

what type of hormones do oxytocin and vasopressin behave like?

Answer 43

typical peptide hormones

Question 44

what is vasopressins main function?

Answer 44

regulates water balance

Question 45

the release of vasopressin is triggered by?

Answer 45

increase plasma osmolarity and decrease plasma volume/blood pressure

Question 46

what is the site/mode of action of vasopressin?

Answer 46

kidney collecting ducts increases water absorption vascular smooth muscle increase blood pressure

Question 47

what is the function of oxytocin?

Answer 47

milk ejection and urine contraction

Question 48

the release of oxytocin is triggered by?

Answer 48

labour | suckling

Question 49

site/mode of action of oxytocin?

Answer 49

milk duct smooth muscle contracts muscle- ejecting milk urine smooth muscle child birth

Question 50

what is hyposecretion?

Answer 50

too little hormone secreted

Question 51

hypersecretion

Answer 51

too much hormone secreted

Question 52

hyporesponsiveness

Answer 52

reduced response of the target cell

Question 53

hyperreponsiveness

Answer 53

increased response of the target cell

Question 54

what does hyporesponsiveness relate to?

Answer 54

relates to alterations in receptor for hormone, disordered post-receptor events or failure of metabolic activation of hormone, (where this is required for function).

Question 55

what does hyperresponsiveness relate to?

Answer 55

could be due to permissive effects e.g. Thyroid hormone ++ adrenaline mediated lipolysis.

Question 56

what are 1st disorders?

Answer 56

are those in which the defect is in the cells that secrete the hormone

Question 57

what are 2nd disorders?

Answer 57

are those in which there is too little or too much trophic hormone from pituitary

Question 58

what are 3rd disorders?

Answer 58

relate to hypothalamic defects

Question 59

what kind of neurons does the posterior pituitary contain?

Answer 59

magnocellular neurons which have their cell bodies in the hypothalamu

Question 60

magnocellular neurons store and releases 2 peptide neurohormones. What are they?

Answer 60

vasopressin | Oxytocin

Question 61

how do vasopressin and oxytocin behave?

Answer 61

as typical peptide hormones

Question 62

how is anterior pituitary connected to hypothalamus?

Answer 62

Connected to hypothalamus via hypothalamic-hypophyseal portal system