Endocrine Glands

Question 0

Properties of endocrine glands

Answer 0

• most endocrine glands consist of epithelial tissues
• some derived from NCC or neurons
• no ducts are present
• highly vascular
• hormones may be stored in intracellular secretory granules

Question 1

Hormones

Answer 1

• act long distance
• distributed by circulation
• released into the bloodstream of interstitial fluid

Question 2

Hydrophilic hormones

Answer 2

• can’t permeate membrane
• receptors on cell surface and act through secondary messengers
• peptides, glycoproteins, modified amino acids

Question 3

Membrane permeable hormones

Answer 3

• receptors are intracellular DNA binding proteins that affect transcription
• steroid and thyroid hormones

Question 4

Cells producing peptide hormones

Answer 4

Abundant RER
Prominent Golgi
Hormones stored in secretory granules

Question 5

Cells producing steroid hormones

Answer 5

Centrally located nucleus
Lipid droplets in cytoplasm
Abundant smooth ER for cholesterol synthesis
Spherical mitochondria with tubular or vesicular cristae

Question 6

Hypophysis

Answer 6

Pea sized gland that hangs by a stalk from hypothalamus
Dual embryonic origin-anterior from oral ectoderm and consists of epi
Post from neuroectoderm

Question 7

Anterior pit

Answer 7

From oral ectoderm
Andenohypophysis
Produces a variety of hormones that regulate body growth, milk production, and functions of other endocrine glands
Pars tuberalis, pars distalis, pars intermedia

Question 8

Posterior pit

Answer 8

Neuro hypophysis
Contains no secretory cells
Stores and releases hormones produced in the hypothalamus

Question 9

Histological features of ant pit

Answer 9

Chromophils or chopromophobes

-chromophils divided into basophils and acidophils

Question 10

Chromophobes

Answer 10

Stem cells or cells that already secreted their granules

Question 11

Acidophils

Answer 11

GPA-GH, prolactin

Question 12

Basophils cells

Answer 12

BFLAT
-FSH, LH, ACTH, TSH
ACTH is small polypeptide hormone, others are glycoproteins

Question 13

Somatotropic cell

Answer 13

Acidophilic
50% of cells
Secretes somatotropin (GH)
Growth of long bones and other growth processes

Question 14

Lactotropic cell

Answer 14

Acidophilic
15-20% of cells
Prolactin
Stimulates secretion of milk

Question 15

Gonadotropic cell

Answer 15

Basophilic
10% of cells
FSH LH
Gametogenesis (FSH) and regulation of estrogen and androgens, promotes ovulation

Question 16

Thyrotropic cell

Answer 16

Basophilic
5% of cells
TSH
stimulates thyroid

Question 17

Corticotropic cell

Answer 17

Basophilic
15-20% of cells
ACTH and beta-lipotropin
Stim adrenal cortical secretion and promotes utilization of fat

Question 18

Pars distalis and tuberalis

Answer 18

Each cell type secretes one hormone type
Except gonadotropic and corticotropic (2)

Cells can be distinguished by immunostaining for specific hormones or by electron microscopy because their granules are different sizes

Question 19

Pars intermedia

Answer 19

Largely inactive in adult

Colloid filled follicles and rathkes cysts

Question 20

Post pit 2

Answer 20

No secretory cells
Neurons and glial cells called pituicytes
Cell bodies in hypothalamus
Hormones are vasopressin and oxytocin
Hormones are stored in dilated axons called herring bodies

Question 21

ADH

Answer 21

Regulation of blood osmolarity

Increases water reabsorption in kidney collecting ducts

Question 22

Oxytocin

Answer 22

Stimulation of uterine contraction during childbirth and contraction of myoepithelial cells of mammary glands during nursing

Question 23

Hypopthalamo-hypophyseal portal system

Answer 23

Hypothal regulates functions of adenohypophysis via releasing and inhibiting hormones
No neural connections
Hormones produced in hypothal get to pit via specialized blood system
Portal system

Question 24

Adrenal glands

Answer 24

Located above each kidney | Cortex and medulla

Question 25

Cortex of adrenal gland

Answer 25

Epithelial origin 3 concentric zones Zonal glomerulosa, fasciculata, reticularis Have features of steroid producing cell:central nucleus acidophilic cyto with lipid droplets, smooth ER, spherical mito

Question 26

Medulla of adrenal gland

Answer 26

Neuronal origin Cells contain electron dense secretory granules that react with chromium and silver Produces catechols

Question 27

Zona glomerulosa

Answer 27

``` Rounded cords of cells Steroid producing cells-foaming Mineralocorticoids-aldosterone produced Salt Regulation of salt balance Regulated by angiotensin II ```

Question 28

Zona fasciculata

Answer 28

``` Long cords Steroid producing cells-extra foamy Glucocorticoids-cortisol produced Sugar,stress Regulation of glucose metabolism Regulated by ACTH ```

Question 29

Zona reticularis

Answer 29

``` Irregular mesh work Steroid producing cells Produces cortisol and weak androgen Glucose regulation and testosterone production Regulated ACTH Sex ```

Question 30

Medulla 2

Answer 30

``` Cords or clumps Cells react with chrome or salts Secretes catechols Fight or flight response Regulated by sns ```

Question 31

Pancreas

Answer 31

Compact masses of endocrine tissue embedded within the exocrine tissue Polygonal or round cells arranged in cords Typical protein secreting cells Lightly stained Cells contain secretory granules Produce polypeptide hormones

Question 32

Alpha cells

Answer 32

20% Periphery of islets Glucagon Increases blood glucose by promoting conversion of glycogen

Question 33

Beta cells

Answer 33

70% Centrally located Insulin Lowers blood glucose by promoting glucose storage

Question 34

Delta cells

Answer 34

5-10% Somatostatin Inhibits release of other islet cell hormones-local paracrine effect Inhibits release of GH and TSH by pit and HCl secretion by gastric parietal cells

Question 35

F or pp cells

Answer 35

Rare Pancreatic polypeptide Stimulates activity of gastric chief cells, inhibits bile and pancreatic enzyme secretion

Question 36

Thyroid

Answer 36

Located anterior to trachea Consists of follicles-spherical structures lined by simple epithelium filled with colloid Colloid consists of storage form of thyroid hormones, thyroglobulin

Question 37

Follicular cells

Answer 37

Vary in shape from cuboidal to low columnar Have features characteristic of protein secreting cells Regulated by TSH Thyroid hormone (3,4) regulate basal metabolic rate, body growth and development, heat production

Question 38

Parafollicular cells | C cells

Answer 38

``` Larger in size than follicular cells Appear pale in h and e preps Located within the basal lamina of the follicles or between follicles Can be shiny Produce calcitonin Regulated by blood calcium levels ```

Question 39

Parathyroid glands

Answer 39

Four small oval glands located on the back of the thyroid Chief cells Oxyphil cells

Question 40

Chief cells

Answer 40

``` Small polygonal cells Pale staining, slightly acidophilic Product PTH Increases ca by regulating osteoclasts, kidney excretion and intestinal absorption Abundant Regulated by calcium level in plasma ```

Question 41

Oxyphil cells

Answer 41

Large Highly acidophilic Less abundant Unknown function

Question 42

Endocrine functions of non-endocrine organs

Answer 42

Heart- atrial natriuretic peptide Kidney- erythropoietin, renin Stomach and small intestine-enteric hormones Adipose tissue-leptin regulates appetite and metabolism, adiponectin-regulates fatty acid and glucose metabolism and modifies sensitivity to insulin Steroid hormones