Endocrine glands I Flashcards Preview

Year 1 Cell Biology > Endocrine glands I > Flashcards

Flashcards in Endocrine glands I Deck (59):
1

Which pituitary lobe is neural?

Posterior

2

Which pituitary lobe is glandular?

Anterior

3

What are the anterior pituitary secretory cells?

1. Chromophils2. Chromophobes

4

Where are the hypothalamic neurosecretory hormones synthesized?

Neurons in the hypothalamus

5

Where are the hypothalamic neurosecretory hormones stored?

Axons of neurons in hypothalamus, which terminate at median eminence

6

What is the direction of flow of hypothalamic neurosecretory hormones after being released at median eminence?

1. Primary capillary plexus (fenestrated capillaries)2. Hypophyseal portal veins in infundibulum3. Secondary capillary plexus (sinusoidal with fenestrated endothelium - anterior lobe)4. Parenchyma of anterior lobe

7

What are housed in the supraoptic and paraventricular nuclei of the hypothalamus?

Cell bodies of neurosecretory cells

8

Where are the cell bodies of neurosecretory cells housed?

Supraoptic and paraventricular nuclei of hypothalamus

9

What makes up the hypothalamohypophyseal tract?

The unmyelinated axons of neurosecretory cells in the supraoptic and paraventricular nuclei

10

Where does the hypothalamohypophyseal tract terminate?

Capillaries in the posterior lobe of pituitary

11

What does the hypothalamohypophyseal tract release into the capillaries of the posterior pituitary?

ADH and oxytocin

12

The anterior pituitary has what kind of capillaries?

Fenestrated sinudoidal

13

What are the chromophils of the anterior pituitary?

1. Acidophils2. Basophils

14

What are the different types of acidophils?

1. Somatotropes2. Lactotropes

15

What stimulates somatotrope production?

GHRH

16

What inhibits somatotropes?

Somatostatin

17

What do somatotropes secrete?

Growth hormone

18

What is the role of growth hormone?

Increases metabolic rate and influences long bone growth

19

What stimulates lactotrope production?

PRH

20

What inhibits lactotropes?

PIF

21

What do lactotropes secrete?

Prolactin which promotes mamary gland growth during pregnancy and lactation after birth

22

What are the types of basophils?

1. Corticotropes2. Thyrotropes3. Gonadotropes

23

What stimulates corticotrope production?

CRH

24

What do corticotropes secrete?

ACTH which stimulates adrenal cortex

25

What stimulates thyrotrope production?

TRH

26

What do thyrotropes secrete?

TSH (thyrotropin)

27

What inhibits thyrotropes?

T3 and T4 in blood

28

What stimulates gonadotrope production?

GnRH

29

What do gonadotropes secrete?

FSH and LH which function in male and female reproduction

30

What are chromophobes?

May be degranulated chromophils

31

What are Herring bodies?

Accumulations of neurosecretory granules int he axons and axon terminals of the hypothalamohyophyseal tract

32

Where are Herring bodies released?

Fenestrated capillary plexus

33

What is contained in Herring bodies?

Either ADH or oxytocin

34

What is the target of ADH?

Distal tubules and collecting ducts of kidney

35

What is the function of ADH?

Lower urine volume

36

What is the target of oxytocin?

Uterine myometrium and myoepithelial cells of mammary gland

37

What is the function of oxytocin?

Stimulate smooth muscle contraction of uterus and mammary gland

38

Where are pituicytes located?

Posterior lobe of pituitary

39

What are pituicytes?

Glia-like local cells that cover and support axons and their terminals

40

Diabetes insipidus can be caused by damage to what endocrine system components?

Hypothalamus or posterior pituitary

41

What is the derivation of the thyroid capsule?

Deep cervical fascia

42

What kind of CT makes up the thyroid capsule?

Dense irregular collagenous

43

What hormones are synthesized by the thyroid gland?

1. T32. T43. Calcitonin

44

What is the structural and functional unit of the thyroid gland?

Follicle

45

From low to high activity, what kind of epithelium is found in the follicle?

1. Simple squamous2. Simple cuboidal3. Simple columnar

46

What surround the thyroid follicle?

1. Basal lamina2. Reticular fibers3. Fenestrated capillary plexus

47

What is the difference between the thyroid follicle and the functional units of other endocrine glands?

The follicle stores glandular secretory product in the lumen (extracellularly) as opposed to accumulating it in the parenchyma

48

What are contained in the secretory granules of parafollicular cells?

Calcitonin

49

What are the characteristics of calcitonin?

1. Peptide hormone2. Released when blood calcium levels are high3. Inhibits bone breakdown by osteoclasts4. Promotes calcium deposition in bones (osteoid calcification)

50

What is contained in the follicular lumen?

Colloid

51

What comprises colloid?

Thyroglobulin

52

Where is thyroglobulin synthesized?

Follicular cells (rER)

53

Where is iodide oxidized in the follicular cells?

Apical cell membrane facing colloid. Iodine is active form and stored in lumen

54

Where is thyroglobulin glycosylated?

Golgi

55

What enzyme oxidizes iodide?

Thyroid peroxidase

56

What enzyme carries out the iodination of thyroglobulin's tyrosine residues?

Thyroid peroxidase - where luminal aspect of follicular cell contacts the colloid

57

Are thyroid hormone active or inactive in the blood stream?

Inactive

58

How is most of the T3 synthesized?

From T4, in kidney, liver, and heart

59

What are the physiological effects of T3 and T4?

1. Increase cellular metabolism, growth rate, mental activity2. Stimulate endocrine gland functions and carbohydrate metabolism3. Decrease formation of phospholipids and triglycerides4. Enhance synthesis of cholesterol5. Increase formation of fatty acids