Lecture 18 - Endocrine System 2

Question 1

2 lateral lobes connected by median mass called an isthmus

Answer 1

Thyroid gland

Question 2

The thyroid gland is composed of follicles that produce the glycoprotein ___________________.

Answer 2

Thyroglobulin

Question 3

Colloid (thyroglobulin + iodine) fills lumen of follicles and is a precursor of _________________.

Answer 3

Thyroid hormone

Question 4

Parafollicular cells produce the hormone _________________.

Answer 4

Calcitonin

Question 5

Thyroid hormone is actually 2 related compounds, which are _______ and _________.

Answer 5

T4 (thyroxine)

T3 (triiodothyronine)

Question 6

_______ has 2 tyrosine molecules + 4 bound iodine atoms.

Answer 6

T4

Question 7

_______ has 2 tyrosine molecules + 3 bound iodine atoms.

Answer 7

T3

Question 8

________________ affects virtually every cell in the body; it is the #1 metabolic hormone in the body

Answer 8

Thyroid hormone

Question 9

True or false: Thyroid hormone increases metabolic rate and heat production (calorigenic effect). It also regulates tissue growth and development, and maintains blood pressure.

Answer 9

True

Question 10

The thyroid gland stores TH ___________________.

Answer 10

Extracellularly

Question 11

________________ is necessary for the synthesis of thyroid hormone.

Answer 11

Iodine

Question 12

________ and ________ are transported by thyroxine-binding globulins (TBGs).

Answer 12

T4; T3

Question 13

Both T4 and T3 bind to target receptors, but _____ is 10 times more active than _____.

Answer 13

T3; T4

Question 14

True or false: Peripheral tissues convert T4 to T3.

Answer 14

True

Question 15

Rising TH levels provide negative feedback inhibition on release of __________.

Answer 15

TSH

Question 16

Hypothalamic thyrotropin-releasing hormone can overcome __________________ during pregnancy or exposure to cold (non-human).

Answer 16

Negative feedback

Question 17

___________________ of TH in adults is myxedema; goiter if due to lack of iodine.

Answer 17

Hyposecretion

Question 18

Thyroid swells to maximize surface area to attempt to absorb any trace of iodine present

Answer 18

Goiter

Question 19

True or false: Hyposecretion of TH in infants is cretinism.

Answer 19

True

Question 20

Hypersecretion of TH is ________________ (constant increased metabolism causes patient’s inability to keep weight on)

Answer 20

Graves’ disease

Question 21

___________________ has no known physiological role in humans

Answer 21

Calcitonin

Question 22

Calcitonin is antagonist to _______________

Answer 22

PTH

Question 23

At higher than normal doses, calcitonin ______________ osteoclast activity and release of calcium form bone matrix
*Osteoclasts break down bone

Answer 23

Inhibits

Question 24

4 to 8 tiny glands embedded in posterior aspect of thyroid

Answer 24

Parathyroid glands

Question 25

True or false: Parathyroid glands contain oxyphil cells (function unknown) and parathyroid cells that secrete parathyroid hormone (PTH).

Answer 25

True

Question 26

PTH is most important in __________________ (by releasing calcium from bone).

Answer 26

Calcium homeostasis

Question 27

PTH stimulates _______________ to digest bone matrix and release calcium to blood.

Answer 27

Osteoclasts

Question 28

PTH enhances reabsorption of ____________ and secretion of phosphate by kidneys.

Answer 28

Calcium

Question 29

PTH promotes activation of _______________ (by kidneys); increases absorption of calcium by intestinal mucosa.

Answer 29

Vitamin D

Question 30

Negative feedback control: rising calcium in blood ____________ PTH release

Answer 30

Inhibits

Question 31

_________________ due to tumor: - -> bones soften and deform - -> elevated calcium depresses nervous system and contributes to formation of kidney stones

Answer 31

Hyperparathyroidism

Question 32

Hypoparathyroidism following gland trauma or removal or dietary Mg deficiency: - -> not enough ______ in bloodstream - -> results in tetany, respiratory paralysis, and death

Answer 32

Calcium

Question 33

Paired, pyramid-shaped organs atop kidneys

Answer 33

Adrenal glands

Question 34

Adrenal glands are structurally and functionally 2 glands in one. Name these 2 glands.

Answer 34

Adrenal medulla | Adrenal cortex

Question 35

Nervous tissue; part of sympathetic nervous system

Answer 35

Adrenal medulla

Question 36

3 layers of glandular tissue that synthesize and secrete corticosteroids

Answer 36

Adrenal cortex

Question 37

3 layers of adrenal cortex

Answer 37

1. Zona glomerulosa 2. Zona fasciculata 3. Zona reticularis

Question 38

Superficial layer that produces mineralocorticoids (hormones that help control balance of minerals and water in the blood)

Answer 38

Zona glomerulosa

Question 39

Middle layer that mainly produces the metabolic hormones (glucocorticoids)

Answer 39

Zona fasciculata

Question 40

The innermost layer that produces small amounts of adrenal sex hormones (gonadocorticoids)

Answer 40

Zona reticularis

Question 41

Regulate electrolytes (primarily sodium and potassium) in ECF

Answer 41

Mineralocorticoids

Question 42

Mineralocorticoids are necessary for proper _____________ function.

Answer 42

Nervous system

Question 43

Affects ECF volume, blood volume, blood pressure, levels of other ions

Answer 43

Importance of sodium

Question 44

Sets resting membrane potential of cells

Answer 44

Importance of potassium

Question 45

Most potent mineralocorticoid

Answer 45

Aldosterone

Question 46

True or false: Aldosterone stimulates sodium reabsorption and water retention by kidneys; elimination of potassium

Answer 46

True

Question 47

________________ release is triggered by decreasing blood volume and blood pressure, and rising blood levels of potassium

Answer 47

Aldosterone

Question 48

Hypersecretion due to adrenal tumors - -> hypertension and edema due to excessive sodium - -> excretion of potassium leading to abnormal function of neurons and muscle

Answer 48

Aldosteronism

Question 49

Keep blood glucose levels relatively constant

Answer 49

Glucocorticoids

Question 50

Glucocorticoids maintain blood pressure by increasing action of _________________.

Answer 50

Vasoconstrictors

Question 51

_____________ is the only glucocorticoid present in significant amounts in humans; stress hormone

Answer 51

Cortisol