Endocrine

Question 1

What is direct communication?

Answer 1

Occurs between 2 cells of same type, exchange of ions/molecules between adjacent cells via gap junctions, rare & specialized

Question 2

What is paracrine communication?

Answer 2

Uses chemical signals to transfer information from cell to cell within single tissue, most common form of intercellular communication

Question 3

What is endocrine communication?

Answer 3

Hormones released into bloodstream, alters metabolic activities of many tissues and organs simultaneously

Question 4

What are functions of hormones?

Answer 4

Stimulates synthesis of enzymes or structural proteins, increases or decreases rates of synthesis, turns existing enzyme or membrane channel “on” or “off”

Question 5

What is a target cell?

Answer 5

Specific cells that possess receptors needed to bind and “read” hormonal messages

Question 6

What are biogenic amines?

Answer 6

Amino acid derivative hormones. Structurally related to amino acids. Synthesized from tyrosine (thyroid, epi, norepi, catecholamines) and tryptophan (melatonin)

Question 7

What are peptide hormones?

Answer 7

1. Glycoproteins: 200+ amino acids long with carbohydrate side chains (TSH, LH, FSH)
2. Short polypeptides (ADH, oxytocin) and small proteins (insulin, GH, PL)

Question 8

What are lipid derivatives?

Answer 8

1. Eicosanoids: paracrine signaling molecules including leukotrienes, prostaglandins, thromboxanes, prostacyclins
2. Steroid hormones: released by reproductive organs, adrenal cortex, kidneys

Question 9

How are hormones inactivated?

Answer 9

1. Diffuse out of bloodstream and bind to receptors on target cells
2. Broken down by liver or kidneys
3. Broken down by enzymes in blood or interstitial fluid

Question 10

What hormones are produced by hypothalamus?

Answer 10

ADH, oxytocin (transported to posterior pituitary gland by axons), regulatory hormones

Question 11

What hormones are produced by pituitary gland?

Answer 11

1. Anterior: ACTH, TSh, GH, PRL, FSH, LH, MSH

2. Posterior: secretes ADH & oxytocin

Question 12

What hormones are produced by Thyroid gland?

Answer 12

T3, T4, calcitonin

Question 13

What hormones are produced by Adrenal glands?

Answer 13

Medulla (Epi, Norepi)

Cortex (cortisol, aldosterone, androgens)

Question 14

What hormones are produced by pancreatic islets?

Answer 14

Insulin, glucagon

Question 15

What hormones are produced by pineal gland?

Answer 15

Melatonin

Question 16

What hormones are produced by parathyroid glands?

Answer 16

PTH

Question 17

What hormones are produced by Heart?

Answer 17

ANP & BNP

Question 18

What hormones are produced by Thymus?

Answer 18

Thymosins

Question 19

What hormones are produced by adipose tissue?

Answer 19

Leptin

Question 20

What hormones are produced by kidneys?

Answer 20

EPO, calcitriol

Question 21

What hormones are produced by gonads?

Answer 21

Androgens, estrogens, progesterone, inhibin

Question 22

What is a portal system?

Answer 22

Blood carried from one capillary bed to another capillary bed.

Question 23

What signals secretion of epinephrine and norepinephrine?

Answer 23

Sympathetic nervous signals to adrenal medulla. (Also controlled by corticotropin releasing hormone and adrenocorticotropic hormone from anterior pituitary)

Question 24

What is FSH pathway?

Answer 24

GnRH – FSH—Follicle cells/Nurse cells—-Estrogen secretion/sperm maturation

Question 25

What is LH pathway?

Answer 25

GnRH---- LH ----Follicle cells/Interstitial cells ---- ovulation/ testosterone secretion

Question 26

What is ACTH pathway?

Answer 26

CRH to ACTH to Adrenal cortex to cortisol secretion. Diurnal pattern (high in morning, low in evening), stimulated by stress

Question 27

What is GH pathway?

Answer 27

GH-RH to GH to all cells. Stimulates growth, protein synthesis, catabolism, opposes action of insulin, stimulates IGF-1

Question 28

What is TSH pathway?

Answer 28

TRH to TSH to Thyroid gland producing T4, converted to T3 by peripheral tissues

Question 29

What does oxytocin do?

Answer 29

1. Uterine contractions during labor 2. Promotes ejection of milk 3. Sexual activity

Question 30

What is function of thyroid gland?

Answer 30

Thyroid produces T4, converted to T3 by peripheral tissues. Many actions ranging from normal growth and development (especially CNS) to effects on energy metabolism in adult. C-cells produce calcitonin (opposes PTH)

Question 31

What is function of parathyroid gland?

Answer 31

Secretes PTH Stimulates calcium reabsorption by osteoclasts in bone and renal tubular calcium reabsorption. Stimulates activation of vitamin D by renal hydroxylation (calcitriol) Calcium regulates PTH by negative feedback.

Question 32

What is produced in zona glomerulosa of adrenal cortex?

Answer 32

Aldosterone. Na+ reabsorption, K + secretion. Works at kidneys, sweat glands, salivary glands, pancreas. Increases salt sensitivity of tongue

Question 33

What is produced at zona fasciculata of adrenal cortex?

Answer 33

Glucocorticoids. Middle cortex layer. Cortisol primarily. Liver increases glucose synthesis & glycogen. Adipose tissue releases fatty acids into blood. Tissues switch to fatty acid/protein metabolism (glucose sparing effect) Also anti-inflammatory.

Question 34

What is produced in zona reticularis of adrenal cortex?

Answer 34

Androgens. Inner cortex. Small quantities of androgens. Some converted into estrogen in bloodstream. In women, promotes muscle mass, RBC formation, libido. Less important for adult males.

Question 35

What is produced in adrenal medulla?

Answer 35

Catecholamines (Epinephrine and Norepinephrine) Continuously secreted at low levels. Increase w/ sympathetic stimulation. Interact w/ alpha and beta cell receptors. Skeletal muscle: utilize glycogen reserves, increase ATP production to increase strength/endurance. Adipose tissue: release fatty acids. Liver: Glycogen break down. Heart: Beta 1 receptors, positive chronotropic and inotropic agent

Question 36

What are complications of pituitary tumor?

Answer 36

Can enlarge out of sella turcica and interrupt optic chiasm. Causes bitemporal hemianopsia (No lateral vision)

Question 37

What is hypothyroidism?

Answer 37

Underactive thyroid or low thyroid, thyroid gland does not produce enough thyroid hormone. Causes fatigue, depression, sensitivity to cold, weight gain

Question 38

What is hyperthyroidism?

Answer 38

Thyroid gland produces too much thyroxine. Accelerate body's metabolism, sudden weight loss, rapid/irregular heart beat, sweating, irritability

Question 39

What is pheochromocytoma?

Answer 39

PCC is a neuroendocrine tumor of medulla of adrenal glands (originating in chromaffin cells) or extra-adrenal chromaffin tissue that failed to involute after birth, secretes high amounts catecholamines, mostly norepinephrine, plus epinephrine. Sympathetic nervous system overactivity.