Lec 24

Question 1

Hypophysis

Answer 1

the two parted pituitary:

Anterior and Posterior Pituitary

Question 2

Neurosecretory Neurons

Answer 2

Paraventricular nucleus

Supraoptic nucleus

Question 3

Paraventricular nucleus

Answer 3

located in the hypothalamus, produces oxytocin that is stored in the posterior pituitary.

Question 4

Supraoptic nucleus

Answer 4

located in the hypothalamus, produces vasopressin that is stored in the posterior pituitary.

Question 5

“adenohypophysis”

Answer 5

anterior pituitary that is formed from glandular epithelial tissues.

Question 6

“neurohypophysis”

Answer 6

posterior pituitary - release of hormones is determined by electrical activity from the hypothalamus.

Question 7

During fetal development, the posterior lobe:

Answer 7

comes from neural tissue

Question 8

During fetal development , the anterior lobe:

Answer 8

comes from Rathke’s pouch (as well as intermediate)

Question 9

Hypophysiotropic hormone

Answer 9

a hormone from the hypothalamus that is released into the pituitary stalk and eventually into the hypothalamo-hypophyseal portal system. this controls the release of anterior pituitary hormones.

Question 10

hypothalamohypophyseal portal system

Answer 10

the vascular link that passes hormones from the hypothalamus to the anterior pituitary through systemic arterial inflow.

Question 11

“tropic” hormone

Answer 11

a hormone that regulate the release of another hormone

Question 12

5 Types of hormone-producing cells in the anterior pituitary:

Answer 12

Somatotrophs (30-50%) - Growth Hormone
Corticotrophs (20%) adrenocorticotropic Hormone (ACTH)
next 3 Make up 5% –summed
Thyrotrophs - thyroid stimulating hormone (TSH)
Lactotrophs - prolactin (PRL),
Gonadotrophs - lueteinizing hormone (LH) & Follicle-stimulating Hormone (FSH)

Question 13

Somatotrophs

Answer 13

30-50% - make GH

Question 14

Corticotrophs

Answer 14

20% - make ACTH

Question 15

Thyrotrophs

Answer 15

(summed 5%) - make TSH

Question 16

Lactotrophs

Answer 16

(summed 5%) - make PRL

Question 17

Gonadotrophs

Answer 17

(summed 5%) - make LH & FSH

Question 18

Synonym for GH

Answer 18

somatotropin (STH)

Question 19

GH

Answer 19

general targets - promotes growth by stimulating protein anabolism and fat mobilization

Question 20

PRL

Answer 20

Mammary glands (alveolar secretory glands ) targeted to promote milk secretion

Question 21

TSH

Answer 21

thyroid glands targeted to stimulate development and secretion in the thyroid gland

Question 22

ACTH

Answer 22

adrenal cortex targeted to promote development and secretion in the adrenal cortex.

Question 23

FSH

Answer 23

targets Gonads (primary sex organs)
Female: triggers ovulation; promotes development of corpus luteum
Male: stimulates production of testosterone

Question 24

MSH

Answer 24

targets skin and adrenal glands to possibly stimulate production of melanin pigment in skin. (function unknown)

Question 25

ADH

Answer 25

Targets the kidney to promote water retension by kidney tubules

Question 26

OT

Answer 26

targets uterus and mammary glands to stimulate uterine contractions; stimulates ejection of milk into mammary ducts

Question 27

Peptide hormones

Answer 27

GH & PRL - closely related peptide sequence TSH, FSH, LH - a-subunits are identical! (specificity of their actions is determined by the different B subunits) [most hormones are tropic]

Question 28

Peptide hormones: identical a-subunits

Answer 28

TSH, FSH, LH | specificity of their actions is determined by the different B subunits

Question 29

Peptide hormones: closely related peptide sequence

Answer 29

GH&PRL

Question 30

Functions of the Anterior Pituitary

Answer 30

``` reproduction growth energy metabolism stress response (most hormones are tropic) ```

Question 31

Metabolic rate

Answer 31

determined by TSH --> Thyroid gland --> T3+T4

Question 32

Metabolic actions; Stress Response

Answer 32

determined by ACTH --> adrenal cortex --> cortisol

Question 33

Breast Milk and milk Secretion

Answer 33

determined by PRL --> Mammary glands

Question 34

Growth

Answer 34

determined by GH --> Liver --> Somatomedins --> Bone & soft tissues

Question 35

Sex hormone secretion

Answer 35

determined by LH --> gonads = estrogen and progesterone in females & testosterone in males

Question 36

Gamete production

Answer 36

determined by FSH --> gonads = ova in females & sperm in males

Question 37

Pituitary dwarfism

Answer 37

GH hyposecretion during childhood

Question 38

Gigantism and 3 treatments

Answer 38

GH hypersecretion during childhood - treated by 1.surgery to remove the source of the hormone (tumor) 2. somatostatin analogues, and 3. GH antagonists.

Question 39

Laron Syndrome (dwarfism)

Answer 39

abnormal GH receptors - treated with IGF-1 but only prior to puberty [lower rates of cancer and diabetes]

Question 40

Gh insufficiency treatment

Answer 40

replacement therapy

Question 41

acromegaly

Answer 41

An excess of GH - thickening of bones, the feet, hands, and face, and enlargement of certain organs such as the heart and liver.

Question 42

Inhibits GH

Answer 42

somatostatin

Question 43

PRL inhibition

Answer 43

PRL release is soley inhibitory and that this occurs through release of Dopamine

Question 44

Hypothalamic releasing hormones

Answer 44

Corticotropin-releasing hormone (CRH) Thyrotropin-releasing hormone (TRH) Growth Hormone - releasing hormone (GHRH) Luteinizing hormone - releasing hormone (LHRH or GnRH) Somatostatin , somatotropin releasing hormone (SRIF) Dopamine

Question 45

CRH

Answer 45

stimulates ACTH secretion by corticotrphs; stimulates expressino of POMC gene

Question 46

TRH

Answer 46

stimulates TSH secretion by thyrotrophs; stimulates expression of genes for alpha and Beta subunits of TSH in thyrotrophs; stimulates PRL synthesis by lactotrophs

Question 47

GHRH

Answer 47

Stimulates GH secretion by somatotrophs; stimulates expression of GH gene in somatotrophs

Question 48

LHRH

Answer 48

stimulates FSH and LH secretion by gonadotropin-releasing hormone (GNRH) gonadotrophs (another name for LHRH)

Question 49

SRIF

Answer 49

INHIBITS GH secretion by somatotrophs; inhibits TSH secretion by thyrotrophs

Question 50

Dopamine

Answer 50

inhibits PRL synthesis and secretion by lactotrophs