Endocrine System

Question 1

endocrine glands synthesize and secrete ____ directly into the ___ ____

Answer 1

endocrine glands synthesize and secrete HORMONES directly into the CIRCULATORY SYSTEM

Question 2

list the endocrine glands or organs that secrete hormones

Answer 2

1. pituitary
2. hypothalamus
3. thyroid
4. parathyroids
5. adrenals
6. pancreas
7. testes
8. ovaries
9. pineal gland
10. kidneys
11. gastrointestinal glands
12. heart
13. thymus

Question 3

Where are the adrenal glands located? What do they consist of?

Answer 3

on top of the kidneys. They consist of the ADRENAL CORTEX and the ADRENAL MEDULLA

Question 4

where is adrenocorticotropic hormone (ACTH) produced and what does it stimulate?

Answer 4

ACTH is produced by the anterior pituitary gland in response to STRESS.
It stimulates the ADRENAL CORTEX to produce CORTICOSTEROIDS

Question 5

3 major classes of corticosteroids:

Answer 5

1. GLUCOCORTICOIDS (e.g., cortisol and cortisone)
2. MINERALOCORTICOIDS (e.g., ,aldosterone)
3. CORTICAL SEX HORMONES (e.g., androgens)

Question 6

what are glucocorticoids involved in?

Answer 6

glucocorticoids, such as CORTISOL and CORTISONE, are involved in GLUCOSE REGULATION and PROTEIN METABOLISM.
Glucocorticoids RAISE BLOOD GLC LEVELS by promoting PROTEIN BRAKDOWN and GLUCONEOGENESIS and decreasing protein synthesis.
Antagonistic to effects of insulin

Question 7

role of mineralocorticoids?

Answer 7

mineralocorticoids, like ALDOSTERONE, regulate plasma levels of SODIUM and POTASSIUM and the TOTAL ECF VOLUME.
Aldosterone causes active reabsorption of sodium and passive reabsorption of water in the NEPHRON of the KIDNEY. This results in an increase in BLOOD VOLUME and BP.

Question 8

What happens when there is an excess production of aldosterone?

Answer 8

this results in an excess retention of water and resulting high blood pressure

Question 9

Overproduction of androgens in females may lead to

Answer 9

masculinizing effects, such as excessive facial hair

Question 10

What does the adrenal medulla produce?

Answer 10

epinephrine and norepinephrine (i.e. catecholamines)

Question 11

name the slender cord which connects the pituitary gland to the hypothalamus

Answer 11

infundibulum

Question 12

direct vs tropic hormones

Answer 12

direct hormones = act directly on their target organ

tropic hormones = stimulate other endocrine glands to release hormones

Question 13

Tropic hormones of the ANTERIOR PITUITARY:

Answer 13

1. Follicle-stimulating hormone (FSH)
2. Luteinizing hormone (LH)
3. Adrenocorticotropic hormone (ACTH)
4. Thyroid-stimulating hormone (TSH)

Question 14

Direct hormones of the ANTERIOR PITUITARY

Answer 14

1. Prolactin
2. Endorphins
3. Growth hormone (GH)
4. Melanocyte-stimulating hormone (MSH)

Question 15

role of FSH

Answer 15

in women, FSH causes MATURATION OF OVARIAN FOLLICLES, which in turn secrete ESTROGEN.
in men, FSH stimulates MATURATION OF THE SEMINIFEROUS TUBULES and SPERM PRODUCTION

Question 16

role of LH

Answer 16

In women, LH stimulates OVULATION and maintenance of the CORPUS LUTEUM. Also responsible for regulating progesterone secretion in women.
In men, LH stimulates the interstitial cells of the testes to synthesize testosterone

Question 17

ACTH role

Answer 17

ACTH stimulates the ADRENAL CORTEX to synthesize and secrete GLUCOCORTICOIDS and is regulated by CRF

Question 18

TSH role

Answer 18

TSH stimulates the THYROID GLAND to synthesize and release thyroid hormones

Question 19

prolactin role

Answer 19

stimulates milk production in female mammary glands

Question 20

GH role

Answer 20

growth hormone promotes bone andmuscle growth, protein synthesis, and lipid metabolism/catabolism.

Question 21

does the posterior pituitary sunthesize hormones? What does it do?

Answer 21

no, it stores and releases OXYTOCIN and ANTIDIURETIC HORMONE. Hormone secretion is stimulated by APs descending the hypothalamus

Question 22

where are oxytocin and antidiuretic hormone produced?

Answer 22

in the neurosecretory cells of the HYPOTHALAMUS

Question 23

role of oxytocin

Answer 23

oxytocin is secreted at childbirth. Its role is to increase the strength and frequency of uterine muscle contractions.
Oxytocin is also induced by suckling; it stimulates milk secretion in the mammary glands

Question 24

Antidiuretic hormone is aka

Answer 24

ADH or vasopressin

Question 25

role of ADH

Answer 25

increases the permeabilitt of the nephron’s collecting duct to water,, thereby promoting WATER REABSORPTION and increasing blood volume, which subsequently increases blood pressure.

Question 26

when is ADH secreted?

Answer 26

when osmoreceptors in the hypothalamus sense an increase of plasma osmomolarity, or when baroreceptors sense a decrease in blood volume

Question 27

The hypothalamus is part of the ____ and is located directly above the ___ ___

Answer 27

The hypothalamus is part of the FOREBRAIN and is located directly above the PITUITARY GLAND

Question 28

thyroid hormones:

Answer 28

1. thyroxine (T4)

2. triiodothyronine (T3)

Question 29

T4 and T3 are formed by ____

Answer 29

thyroglobulin (a glycoprotein)

Question 30

calcitonin

Answer 30

decreases plasma Ca++ concentration by inhibiting the release of Ca++ from bone.
This is regulated by plasma Ca++ levels.
Calcitonin is antagonistic to parathyroid hormone

Question 31

The pancreas is both an ___ organ and an ___ organ

Answer 31

The pancreas is both an EXOCRINE organ and an ENDOCRINE organ

Question 32

the endocrine function of the pancreas is performed by:

Answer 32

small glandular structures called the ISLETS OF LANGERHANS, which are composed of alpha and beta cells

Question 33

Alpha cells in the islets of Langerhans of the pancreas produce and secrete ____, ,while beta cells produce and secrete ____

Answer 33

Alpha cells in the islets of Langerhans of the pancreas produce and secrete GLUCAGON,while beta cells produce and secrete INSULIN

Question 34

role of glucagon

Answer 34

stimulates protein and fat degradation, conversion of glycogen to glucose, and gluconeogenesis, all which serve to increase blood glc levels

Question 35

role of insulin

Answer 35

protein hormone secreted in response to high blood glc.
It stimulates the uptake of glc by muscle and adipose cells and the storage of glc as glycogen in muscle and liver cells, thus lowering blood glc levels.
Also stimulates synthesis of fats from glucose and the uptake of aa’s.

Question 36

insulin’s actions are antagonistic to those of ___ and ____

Answer 36

glucagon and glucocorticids

Question 37

Where are the parathyroid glands located?

Answer 37

in the posterior surface of the thyroid

Question 38

what do the 4 parathyroid glands synthesize and secrete?

Answer 38

parathyroid hormone (PTH)

Question 39

role of PTH?

Answer 39

to regulate plasma Ca++ concentration.

Raises Ca++ conc by stimulating Ca++ release from the bone and decreasing Ca++ excretion in the kidneys

Question 40

When blood volume falls the kidneys produce ____

Answer 40

renin.
Renin is an enxyme that converts angiotensinogen to angiotensin I. Angiotensin I is converted to angiotensin II, whch stimulates the adrnal cortex to secrete ALDOSTERONE

Question 41

erythropoietin (EPO)

Answer 41

released by the KIDNEYS.

stimulates RBC production

Question 42

Role of gastrin

Answer 42

Gastrin is released by the stomach and carried to the gastric glands where it stimulates the secretion of HCl in response to food in the stomach.

Question 43

Secretin

Answer 43

hormone which is secreted by the small intestine when acidic chyme enters from the stomach.
It stimulates the secretion of bicarbonate solution from the pancreas to neutralize acidity

Question 44

cholecystokinin

Answer 44

hormone released by small intestine in response to presence of fats. Causes contraction of the gallbladder and release of bile into the small intestine

Question 45

What is the pinea gland? what does it secrete?

Answer 45

the pineal gland is a tiny structure at the base of the brain that secretes the hormone MELATONIN

Question 46

which hormone is thought to play a role in the regulation of circadian rhythm?

Answer 46

melatonin

Question 47

hormones are classified into two main groups:

Answer 47

peptide hormones

steroid hormones

Question 48

2 ways in which hormones affect the activities of their taget cells: via _____ receptors or _____ receptors

Answer 48

extracellular and intracellular

Question 49

peptide hormones act as ___ ____, which bind to specific receptors on the ___ of the target cell and trigger…

Answer 49

peptide hormones act as FIRST MESSENGERS, whih bind to specific receptors on the SURFACE of the target cell and trigger a AERIES OF ENZYMATIC REACTIONS (e.g., ATP –> cyclic AMP first step in chain of reactions)