Endocrine Histology Col 3

Front 1

Pituitary gland is directly attached to the hypothalamus region of the brain by a stalk called?

Back 1

infundibulum

Front 2

Pituitary gland consists of three sections

Back 2

anterior lobe, intermediate lobe and posterior lobe.

Front 3

anterior and intermediate lobe orgin is

Back 3

rathkes pouch, from oral ectoderm

Front 4

posterior lobe orgin is

Back 4

neuroectoderm

Front 5

Adenohypophysis consists of?

Back 5

Pars distalis, Pars intermedia pars tuberalis (anterior pituitary)

Front 6

Neurohypophysis consists of?

Back 6

Median eminence, Infundibulum, Pars nervosa (posterior pituitary)

Front 7

The neurohypophysis is functionally and structurally connected with?

Back 7

Diencephalon

Front 8

Cell types present in the pars distalis of adenohypophysis:

Back 8

Chromophiles, divided into acidophiles and basophiles. Chromophobes

Front 9

What are the precentage and characteristics of cell types in the pars distalis?

Back 9

Acidophils – 40% red or pinkish, Basophils – 10% blue or purple. Chromophobes – 50% of all cells, pale inactive froms of secretory pituitary cells, do not stain clearly.

Front 10

What are the type and products of acidophilic chromophils and structure?

Back 10

Somatotrophs -growth hormone (peptide), Mammotrophs – prolaction (protein)

Front 11

What are the type and products of basophilic chromophils and structure?

Back 11

Corticotrophs – ACTH (glycoprotein). Thyrotrophs – TSH (glycoprotein) thee are also smallest % of cells, less than 10%. Gonadotrophs – FSH, LH (Glycoproteins)

Front 12

Gonadotropins are secreted at the same time although in different amounts, under the influence of

Back 12

GnRH, gonadotropin-releasing hormone.

Front 13

cell bodies which secrete vasopressin (ADH) are located in the?

Back 13

supraoptic nucleus of the hypothalamus

Front 14

cell bodies which secrete oxytocin are located in the?

Back 14

paraventricular nucleus of the hypothalamus

Front 15

Dilated endings of the hypothalamic axons that contain ADH and oxytocin

Back 15

herring bodies

Front 16

Proteins that carry hormones from perikaryons of the hypothalamic neurons along their axons to hypophysis

Back 16

Neurophysins

Front 17

primary capillary plexus is located in the

Back 17

upper infundibulum

Front 18

secondary capillary plexus is located in the

Back 18

pars distalis

Front 19

what controls secretion of all pituitary hormones?

Back 19

diencephalon

Front 20

a stimulus (e.g low body temperature) causes the hypothalamus to secrete ___ which acts on the ___. (complete sentence)

Back 20

thyrotropin-releasing hormone (TRH), anterior pituitary.

Front 21

Thyrotropic cells in the anterior pituitary release?

Back 21

thyrod-stimulating hormone (TSH)

Front 22

TSH stimulates follicular cells of the thyroid gland to release?

Back 22

thyroid hormone (TH)

Front 23

TH function?

Back 23

stimulates target cells to increase metabolic activites, resulting in an increase in basal body temperature

Front 24

Increased body temperature is detected by and what does it do?

Back 24

hypothalamus, and secretion of TRH by the hypothalamus is inhibited., TH also block TRH receptors on the thyrotropic cells, inhibiting synthesis and release of TSH. Both effects indirectly dampen TH production in the thyroid.

Front 25

describe the typical negative feedback loop

Back 25

increase in the blood concentration of hormone decreases release of the trophic hormone from the anterior pituitary (short loop), and decreases releases of the respective liberin (long loop)

Front 26

adrenal cortex is embryologically derived from?

Back 26

embryonic mesodermal cells

Front 27

adrenal medulla is embryologically derived from?

Back 27

neural crest cells

Front 28

Adrenal cortex secrete?

Back 28

steroid hormones

Front 29

steroid hormones are structurally related to the common precursor:

Back 29

cholesterol

Front 30

steriod hormones are regulated by?

Back 30

ACTH

Front 31

there are three structural and functional groups:

Back 31

mineralocorticoids (aldosterone), Glucocorticoids (cortisol), sex hormones

Front 32

outer layer of adrenal cortex

Back 32

Zona glomerulosa

Front 33

middle layer of adrenal cortex

Back 33

Zona fasciculata

Front 34

inner layer of adrenal cortex

Back 34

Zona reticularis

Front 35

Zona glomerulosa synthesize and secrete the

Back 35

mineralocorticoid hormones

Front 36

Zona fasciculata synsthesize and secrete the

Back 36

glucocorticoid hormones, androgens

Front 37

Zona reticularis synthesize and secrete the

Back 37

cortisol and week androgens

Front 38

ACTH comes from and function?

Back 38

the pars distalis of the pituitary. Is the trophic hormone that stimulates secretion of the suprarenal cortex hormones.

Front 39

Adrenal medulla secretory cells release:

Back 39

catecholamine hormones: adrenaline and noradrenaline

Front 40

describe adrenaline structure

Back 40

epinephrine with N-methyl group

Front 41

describe noradrenalin structure

Back 41

norepinephrine lacking methyl group

Front 42

adrenal medulla has what cells

Back 42

chromaffin cells, post-ganglionic neuroendocrine cells innervated by pre-ganglionic sympathetic neurons.

Front 43

Thyroid peroxidase, TPO, catalyzes two sequential reactions:

Back 43

Iodination of tyrosines on thyroglobulin, Synthesis of throxine or triiodothyronine from two iodotyrosines.

Front 44

Functions of the thyreocyte, synthesis and secretion of:

Back 44

T3, T4 and thyroglobulin (Tg), protein of the colloid which binds and stores iodothyrnines inside the follicule

Front 45

Functions of the thyreocyte, endoytosis of

Back 45

Tg

Front 46

Describe the sodium-iodide symporter

Back 46

simultaneously transports both Na and I ions from the extracellular fluid (blood) into the thyroid epithelial cell. This process is an example of secondary active transport. Energy is provided by the electrochmical gradient of Na acros the cell membrane. The low intracellular concentraion of Na i maintained by sodium pumps

Front 47

Follicular cells produce two iodine containing hormones

Back 47

Tetraiodothronine=T4=thyroxine, contains 4 iodine atoms. T4 is converted to T3 in blood and tissues. Triiodothyronine=T3 contains 3 iodine atoms, far more potent than T4

Front 48

four steps of how threocyres synthesize and release hormones

Back 48

1. They concentrate iodine from blood by Na/I symporter located in basal plasma membrane 2. Iodide is oxidized to iodine by thyroid peroxidase and transported into follicular lumen. 3. Iodine is combined inside follicular lumen with thyroxine residue of thyroglobulin (glycoprotein synthesized by threocytes, major component of the colloid) 4. The cells endocytose thyroglobulin, digest it in lysosomes and release T4 and T3 into blood vessels.

Front 49

Thyreocytes are stimulated by

Back 49

thyroid stimulating hormone=TSH=thyrotropin. Secreted by basophilic cells of adenohypophysis.

Front 50

TSH promotes

Back 50

synthesis, endocytosis and breakdown of the colloid.

Front 51

C-cells=

Back 51

parafollicular cells, clear cells

Front 52

describe C-cell

Back 52

adjacent to follicles epithelium but OUTSIDE its basal lamina. Prodce calcitonin which decreases concentration of Ca in blood

Front 53

how does calcitonin lower blood calcium?

Back 53

by inhibiting bone resorption by osteoclasts and by stimulating activity of osteoblasts.

Front 54

Synthesis and release of calcitonin are regulated by?

Back 54

blood Ca levels through C-cell plasma membrane calcium receptor

Front 55

Parathyroid has 2 types of secretory cells.

Back 55

chief cells, oxyphil cells

Front 56

describe chief cells

Back 56

secrete parathyroid hormone, PTH, apicolateral pole – surface that faces bloodstream

Front 57

describe oxyphil cells

Back 57

larger then chief cells, less numerous. Strongly eosinophilic cytoplasm with fine granules, increase in number after puberty, function unknown

Front 58

Parathyroidhormone=PTH function?

Back 58

raise blood calcium level indirectly, increases rate of osteoclastic resorption, increases renal tubular reabsorpton of calcium ions AND inhibits reabsorption of phosphate in renal tubules, promotes aborption of calcium by small intestine, (similary to vit D3)

Front 59

So shortly, low concentration of calcium in blood what happens?

Back 59

release of parathroid hormone, efflux of calcium from bone, decreased loss of calcium in urine, enchanced absorption of calcium from intestine

Front 60

Pineal gland=

Back 60

epiphysis

Front 61

what is pineal sand?

Back 61

basophilic extracellular bodies, concentric layers of calcium and magnesium phosphate within an organic matrix.

Front 62

The four major islet hormones and the cells secreting them

Back 62

alpha cells making glucagon, beta cells making insulin, d cells making somatostatin, F cells making pancreatic polypeptide.

Front 63

1. What are the regions of the posterior lobe of the pituitary gland?
1-median eminence, 2-pars distalis, 3-pars intermedia, 4-pars
nervosa, 5-pars tuberalis, 6-infundibulum
A. 1,2,3
B 4,5,6
C 2,3,4
D 1,4,6
E 1,4,5

Back 63

D

Front 64

2. Which hormones regulate blood calcium level and how? Choose
the correct set. First describes increase second describes decrease.
A. PTH, Cortisol
B. Calcitonin, PTH
C. Calcitonin, TSH
D. PTH, Calcitonin
E. ACTH, Androgens

Back 64

D

Front 65

3. Which pairs of hormones are connected by one regulating
mechanism? Choose correct set.
1-calcitonin, 2-TSH, 3-PTH, 4-thyroxine, 5-oxytocin, 6-ACTH, 7-ADH,
8-LH, 9-ICTH
A. 1-7, 6-4
B. 8-9, 1-3
C. 1-3, 2-4
D. 1-5, 2-4
E. 6-7, 1-3

Back 65

C

Front 66

4. Which of these are the functions of thyroxine?
1-increase metabolism, 2-increase growth rate, 3-facilitate mental
processes, 4-increase endocrine gland activity, 5-decerase
cholesterol, 6-decrease body weight, 7-increase heart rate
A. all of these
B. only 1,2,3
C. only 4,5,6,7
D. only 2,3,4
E. only 5,6

Back 66

A

Front 67

5. Where the thyroid peroxidase oxidizes iodide?
A. in the basal lamina
B. at the basal cell membrane – colloid interface
C. in the sodium/iodide symporter
D. in the cytosol
E. at the apical cell membrane – colloid interface

Back 67

E

Front 68

3. Which paires of hormones are connected by one regulating mechanism? Choose correct set.
1-calcitonin, 2-TSH, 3-PTH, 4-thyroxine, 5-progesterone, 6-ACTH, 7-ADH, 8-LH, 9-ICTH
A.
1-7, 6-4
B.
8-9, 1-3
C.
5-8, 2-4
D.
1-5, 2-4
E.
6-7, 1-3

Back 68

C

Front 69

What is the main function of melatonin? Which cells secrete it (gland and cell type?)

Back 69

function is to inhibit the release of growth hormone and gonadotropin by the hypophysis and the hypothalamus respectively. Pinealocytes secretes it and its from the pineal gland

Front 70

What is neurophysin and what is its function?

Back 70

Proteins that carry hormones from perikaryon of the hypothalamic neurons along their axons to hypophysis

Front 71

What is the morphology of thyroid follicular cells in states of low and high demand for T3/T4

Back 71

During great demand for thyroid hormone, follicuar cells extend pseudopods into the follicles to envelop and absorb the colloid. When demand for the hormone declines the amount of colloid in the follicle lumen increases

Front 72

How is aldosteron secretion regulated?

Back 72

By ACTH from the anterior pituitary gland

Front 73

In which way is the thyroxie secretion regulated?

Back 73

by the negative feed back loop

Front 74

What is the activity of chief cells, how is it regulated?

Back 74

they secrete parathyroid hormone, PTH. There is a feedback mechanism with calcitonin

Front 75

What is the structure of adrenal glands?

Back 75

Capsule, Zona glomerulosa, Zona fasciculata, Zona reticularis, Medulla

Front 76

What is the structure of the pituitary gland? What are the parts of adenohypophysis and neurohypophysis?

Back 76

Adenohypophysis contains: pars distalis, Pars intermedia, Pars tuberalis. Neurohypophysis: Median eminence, Infundibulum, Pars nervosa

Front 77

What is the hormonal regulation of aldosterone secretion?

Back 77

ACTH

Front 78

what is the function of aldosterone

Back 78

stimulate sodium absorption and regulation of water balances