Endocrine System

Question 1

endocrine glands

Answer 1

• synthesize and secrete chemical substances called hormones into the circulatory system
• ex: pituitary, hypothalamus, thyroid, parathyroid, adrenals, pancreas, testes, ovaries, pineal gland, kidneys, gastrointestinal glands, heart, and thymus

Question 2

exocrine glands

Answer 2

• secrete substances transported by ducts

- ex: gallbladder

Question 3

adrenal glands

Answer 3

• sit on top of the kidneys

- consist of adrenal cortex and adrenal medulla

Question 4

adrenal cortex

Answer 4

-adrenocoticotropic (ACTH) stimulate the adrenal cortex to produce adrenocortical steroids or corticosteroids

Question 5

corticosteriods

Answer 5

• bound to transport proteins called transcortins

- reduce immune system

Question 6

glucocorticoids (AC)

Answer 6

• cortisol and cortisone
• raise blood glucose levels by promoting the breakdown and gluconeogenesis and decreasing protein synthesis
• anti-inflammatory effects

Question 7

mineralocorticoids (AC)

Answer 7

• aldosterone: active reabsorption of Na and passive reabsorption of water in the nephron, increasing blood volume and pressure
• regulate plasma levels of Na and K and total extracellular water volume

Question 8

cortical sex hormones (AC)

Answer 8

• androgens (male sex hormones)
• testes in men
• in women, overproduction can cause masculinity

Question 9

adrenal medulla

Answer 9

-produces epinephrine and norepinephrine, both with belong to catecholamine (AA derived compounds)

Question 10

epinephrine

Answer 10

• increases conversion of glycogen to glucose, causing increase in blood glucose levels and increase in basal metabolic rate
• increase heartbeat and constrict blood vessels
• “fight or flight”

Question 11

pituitary gland

Answer 11

• hangs below the hypothalamus and is connected to it by a cord known as the infundibulum
• pituitary (hypophysis) is a small, trilled gland at the base of the brain

Question 12

anterior pituitary

Answer 12

-synthesizes direct hormone and tropic hormones (stimulate other endocrine glands to release hormones)

Question 13

direct hormones include

Answer 13

• growth hormone
• prolactin
• endorphins
• melanocyte-stimulating hormone

Question 14

GH (somatotropin)

Answer 14

• promotes muscle and bone growth
• deficiency can lead to dwarfism, overproduction to gigantism
• overproduction in adults leads to acromegaly (disproportionate growth of bones)

Question 15

prolactin

Answer 15

-stimulates milk production

Question 16

endorphins

Answer 16

neurotransmitters with pain-relieving properties

Question 17

melanocyte-stimulating hormone

Answer 17

-releases melanin

Question 18

tropic hormones include

Answer 18

• adrenocorticotropic hormone
• thyroid-stimulating hormone
• luteinizing hormone
• follicle-stimulating hormone

Question 19

adrenocorticotropic hormone

Answer 19

-stimulates adrenal cortex to stnthesize glucocorticoids

Question 20

thyroid-stimualting hormone

Answer 20

-stimulates thyroid to synthesize thyroxine

Question 21

luteinizing hormone

Answer 21

-stimulates ovulation and formation of corpus luteum

Question 22

follicle-stimulating hormone

Answer 22

-causes maturation of follicles that secrete estrogen, maturation of seminiferous tubes and sperm production

Question 23

posterior pituitary

Answer 23

• does not synthesize hormones

- stores and releases peptide hormones oxytocin and antidiuretic hormone

Question 24

oxytocin

Answer 24

-increases strength of uterine muscle contractions

Question 25

antidiuretic hormone (vasopressin)

Answer 25

- increases permeability go collecting duct to water, increases blood volume and pressure - secreted when plasma osmolarity increases

Question 26

hypothalamus

Answer 26

- part of forebrain and located above pituitary gland | - receives transmissions from brain that triggers responses from its neurosecretory cells

Question 27

hypothalamus and anterior pituitary

Answer 27

-hypothalamic-releasing hormones stimulate or inhibit secretions of anterior pituitary

Question 28

hypothalamus and posterior pituitary

Answer 28

-neurosecretory cells synthesize oxytocin and ADH and transport them to the posterior pituitarY

Question 29

thyroid

Answer 29

- hormones in the thyroid are essential for growth and maintenance of metabolic stability - thyroxine and triiodothyronine, formed from thyroglobulin

Question 30

thyroxine (T4)

Answer 30

- transported via plasma proteins | - all is formed and secreted by the thyroid gland

Question 31

triiodothyronine (T3)

Answer 31

- more potent than T4 - 20% is produced by the thyroid gland - majority is produced from the conversion of T4 to T3 by 5'-monodeiodase

Question 32

hypothyroidism

Answer 32

- thyroid hormones are under secreted or not secreted at all | - in infants: cretinism is characterized by intellectual disability

Question 33

hyperthyroidism

Answer 33

-thyroid is overstimulated

Question 34

calcitonin

Answer 34

-decreases plasma Ca2+ by inhibiting the release of | Ca2+ from bone

Question 35

pancreas

Answer 35

- exocrine and endocrine organ - exocrine function performed by cells that secrete digestive enzymes - endocrine function performed by islets of Langerhans, composed of alpha and beta cells

Question 36

glucagon

Answer 36

stimulates protein and fat degradation and conversion of glycogen to glucose, increasing blood glucose levels

Question 37

insulin

Answer 37

secreted in response to high blood glucose concentration, lowers blood glucose levels

Question 38

diabetes mellitus

Answer 38

underproduction of insulin or insensitivity to insulin causes this -characterized by hyperglycemia (high blood glucose levels)

Question 39

parathyroid glands

Answer 39

- 4 pea-shaped structures embedded in the posterior surface of the thyroid - synthesize parathyroid hormones, which regulates plasma Ca2+ concentration

Question 40

kidneys

Answer 40

- produce renin: an enzyme that converts plasma protein angiotensinogen to angiotensin 1 then converted to angiotensin II to stimulate adrenal cortex to produce aldosterone - produces erythropoietin that stimulates RBC production

Question 41

gastrointestinal hormones

Answer 41

- gastrin: stimulates glands to produce HCl - secretin: released by small intestine when acidic food enters stomach, neutralizes chyme - cholecystokinin: released by small intestine in presence of fats and release bile

Question 42

pineal gland

Answer 42

-structure at the base of the brain that secretes melatonin, which plays a role in circadian rhythms- physiological cycles

Question 43

peptide hormones

Answer 43

- first messengers, bind to specific receptors and trigger enzymatic reactions - conversion of ATP to cAMP, which acts as a second messenger (cascade effect)

Question 44

steroid hormones

Answer 44

- class of lipid-derived molecules | - cross the phospholipid bilayer and enter their target cells directly to bind to receptors