Unit 4 Endocrine

Question 1

divisions of adenohypophysis

Answer 1

pars distalis
pars intermedia
pars tuberalis

Question 2

neurohypophysis

Answer 2

pars nervosa

infundibulum

Question 3

origins of adenohypophysis

Answer 3

Rathke’s pouch
oral ectoderm
loses attachment with oral cavity

Question 4

organs of neurohypophysis

Answer 4

neuroectoderm
outgrowth from floor of diencephalon
remains attached to brain via infundibulum

Question 5

major cell types

adenohypophysis

Answer 5

chromophobes

chromophils

Question 6

chromophils

Answer 6

acidophils

basophils

Question 7

acidophils

Answer 7

somatotropes

mammotropes

Question 8

somatotropes

Answer 8

secrete somatotropin (hGH); affects 
epiphyseal plate of long bones

Question 9

mammotropes

Answer 9

secrete prolactin; stimulates milk secretion

Question 10

basophils

Answer 10

thyrotropes
gonadotropes
corticotropes

Question 11

thyrotropes

Answer 11

secrete TSH; causes secretion of thyroid 
hormones

Question 12

gonadotropes

Answer 12

1. secrete FSH – in females stimulates development of ovarian follicles; in males stimulates Sertoli cells to secrete androgen-binding protein
2. secrete LH – in females promotes maturation of follicle and ovulation and maintains corpus luteum; in males called interstitial cell secreting hormone (ICSH) promotes secretion of testosterone by Leydig cells

Question 13

corticotropes

Answer 13

secrete ACTH; promotes growth of adrenal cortex and secretion of glucocorticoids and gonadocorticoids

Question 14

hypothalamohypophyseal tract

Answer 14

axons of neurons of supraoptic and paraventricular nuclei
herring bodies
pituicytes

Question 15

neurohypophyseal hormones

Answer 15

oxytocin

vasopressin (ADH)

Question 16

oxytocin

Answer 16

made in paraventricular nucleus of the hypothalamus; stimulates smooth muscle of uterus and myoepithelial cells of mammary gland

Question 17

vasopressin

Answer 17

made in supraoptic nucleus of the hypothalamus; acts on distal tubules and collecting tubules of kidney making them more permeable to water;
generates hypertonic urine

Question 18

pituicytes

Answer 18

glial-like cells

Question 19

pituitary blood supply

Answer 19

inferior hypophyseal arteries to neurohypophysis

hypothalamohypophyseal portal system

Question 20

hypothalamohypophyseal portal system

Answer 20

1. delivers hypothalamic regulating hormones to adenohypophysis
2. superior hypophyseal arteries, primary capillary plexus around 
stalk and median eminence of hypothalamus
3. secondary capillary plexus in adenohypophysis

Question 21

thyroid gland structure

Answer 21

two lobes
isthmus
connective tissue capsule

Question 22

thyroid follicles

Answer 22

1. follicular cells – simple cuboidal epithelium
2. colloid – precursor to thyroid hormones, thyroxine (T4) and triiodothyronine (T3)
   thyroglobulin
3. only endocrine gland to store its secretions; storage is extracellular
4. regulated by TSH

Question 23

parafollicular cells

Answer 23

1. produce calcitonin

2. regulated by blood calcium levels

Question 24

thyroid hormones

Answer 24

1. follicular hormones thyroxine and triiodothyronine stimulate metabolic rate
2. calcitonin – lowers blood calcium levels by inhibiting bone resorption

Question 25

parathyroid gland structure

Answer 25

1. two pair 2. embedded on posterior of thyroid gland 3. cords of cells: chief cells, oxyphil cells

Question 26

parathyroid function

Answer 26

1. increases blood level of calcium by increasing number and activity of osteoclasts 2. decreases blood level of phosphate by decreasing resorption in kidney tubules, promoting its excretion

Question 27

adrenal origins

Answer 27

cortex - mesoderm | medulla - neural crest

Question 28

adrenal cortex zones

Answer 28

zona glomerulosa zona fasciculata zona reticularis

Question 29

zona glomerulosa

Answer 29

1. secretes mineralocorticoids – aldosterone 2. maintains electrolyte and water balance 3. regulated by renin-angiotensin system 4. unaffected by ACTH

Question 30

zone fasciculata

Answer 30

1. secrete glucocorticoids -- cortisol 2. prepares body for maximal immediate energy demands; part of 
“fight or flight” stress response 3. depresses immune function and inflammatory response 4. regulated by ACTH

Question 31

zona reticularis

Answer 31

1. secretes gonadocorticoids – dehydroepiandrosterone (DHEA) 2. negligible amount compared with testis 3. regulated by ACTH

Question 32

adrenal medulla

Answer 32

1. modified sympathetic ganglion 2. chromaffin cells – modified post-ganglionic neurons 3. secretes epinephrine (80%) and norepinephrine (20%) 4. regulated by preganglionic sympathetic neurons

Question 33

adrenal blood supply

Answer 33

1. capsular arteries 2. medullary arteries 3. cortical capillaries

Question 34

medullary arteries

Answer 34

1. travel through cortex to medulla | 2. arterial blood delivered to medullary sinusoidal capillaries

Question 35

cortical capillaries

Answer 35

1. cortical sinusoidal capillaries | 2. drain into medullary capillaries

Question 36

dual blood supply medulla

Answer 36

1. arterial blood 2. venous blood from cortex 3. portal system 4. allows glucocorticoids from cortex to convert 
norepinephrine to epinephrine in medulla

Question 37

pineal gland

Answer 37

epiphysis cerebri or pineal body

Question 38

pinealocytes

Answer 38

1. secret melatonin 2. diurnal rhythms 3. innervated by neurons of the ANS

Question 39

brain sand

Answer 39

crystallized calcium carbonates and calcium phosphates (pineal)