Endocrine Organs

Question 1

Name 6 endocrine glands

Answer 1

Pineal, pituitary, thyroid/parathyroid, adrenal, ovaries/testes, and placenta

Question 2

Part of the brain that is not a gland but still secretes hormones?

Answer 2

Hypothalamus

Question 3

Function of the pineal gland

Answer 3

To secrete melatonin

Question 4

List the 3 components of the 3 tiered chain of command or “axis”; Aka name the order in which the hormones go

Answer 4

Hypothalamic neurons, pituitary gland, and endocrine glands

Question 5

Name the 3 specific axes

Answer 5

1. Hypothalamic-pituitary-thyroid axis
2. Hypothalamic-pituitary-adrenal axis
3. Hypothalamic-pituitary-gonadal axis

Question 6

Path of hypothalamic-pituitary-thyroid axis

What does it regulate

Answer 6

Hypothalamus releases thyrotropin releasing hormone to pituitary which secretes TSH to activate thyroid gland to secrete thyroxine.
Thyroxine regulates metabolic rate and temperature

Question 7

Path of hypothalamic-pituitary-adrenal axis

What does it regulate

Answer 7

Hypothalamus releases CRH to pituitary which secretes ACTH which activates adrenal glands

Regulates secretion of cortisol

Question 8

Path of hypothalamic-pituitary-gonadal axis

Answer 8

Hypothalamus releases GnRH to pituitary which secretes FSH and LH into circulation to reach ovaries/testes

Question 9

Name an organ that is part of the growth axis

Explain

Answer 9

Liver

Hypothalamus releases somatostatin to regulate pituitary secretion of somatotropin (GH) which stimulates liver secretion of somatomedin (another growth hormone)

Question 10

What part of the thyroid gland is midline

Answer 10

Isthmus

Question 11

Thyroid gland synthesizes, stores, and secretes what two things?

Function (3)

Answer 11

T3 (triiodothyronine) and T4 (thyroxine)

Increase metabolic rate, stimulating mitochondrial function and mitochondrial proliferation

Question 12

What other hormone does thyroid gland synthesize, store and secrete?

Function?

Answer 12

Calcitonin

Promotes calcium storage in bone by inhibiting bone resorption

Question 13

1. Thyroid gland consists of which type of tissue when in store mode?
2. When in secretory phase?

Answer 13

1. Simple cuboidal epithelium

2. Simple columnar epithelium

Question 14

Two principal endocrine cell types?

Answer 14

Follicular cells (thyrocytes) and parafollicular cells (clara or C cells)

Question 15

1. Two functions of follicular cells?

2. Function of parafollicular cells?

Answer 15

1. Form the simple epithelium and synthesize/release thyroid hormone
2. Synthesize/release calcitonin

Question 16

Location of parafollicular and follicular cells in relation to each other?

Answer 16

Parafollicular cells are deep to follicular cells

Question 17

1. T3 is composed of what 2 things?

2. T4?

Answer 17

1. Monoiodotyrosine + diiodotyrosine

2. Diiodotyrosine + diiodotyrosine

Question 18

Polymerized form of tyrosine

Then post transitionally modified via __ and __

Answer 18

Thryoglobin

RER and golgi (then secreted into lumen)

Question 19

Iodide is transported through ___ to be converted to iodine

Tyrosine residues are iodinated to form?

Answer 19

Thryocyte

MIT or DIT ~ then further conversion to form T3 and T4

Question 20

How does thyroxine (thyroid hormones) signal?

Answer 20

By binding to an intracellular receptor (THR)

Question 21

How does THR regulate gene expression?

Answer 21

THR dimerizes with retinoid X receptor and binds to a specific promotor region DNA sequence

Question 22

What inhibits the hypothalamic-pituitary-thyroid axis?

Answer 22

Elevates T3/T4 levels (negative feedback inhibition)

Question 23

Natural activator and 2 natural inhibitors of the thyroid

Answer 23

Cold activates it; heat and stress inhibit it

Question 24

Does sympathetic innervation stimulate or inhibit the thyroid? How?

Answer 24

Stimulates; by increasing blood flow or by noradrenergic stimulation of follicular cells to secrete T3 and T4

Question 25

Calcitonin has what effect on blood levels of calcium

Answer 25

Reduces blood levels of calcium by inhibiting bone resorption and decreasing retention by kidney

Question 26

Function of parathyroid hormone

Answer 26

Increases blood levels of calcium by activating bone resorption, increasing calcium retention by kidney and increasing absorption from GI

Question 27

Where are the parathyroid glands located

Answer 27

Posterior side of thyroid gland usually but could also be on lateral surface

Question 28

Another name for hyperthyroidism

Answer 28

Graves disease

Question 29

What is graves disease Hallmark symptoms? Other symptoms

Answer 29

Autoimmune disease that binds and activates TSH Esophthalmos (protruding eyes), myxedema (puffy skin) and goiter Fatigue, weight loss, increase appetite, heat intolerance (using a lot more energy)

Question 30

People with graves disease have an increase in TSH because ?

Answer 30

They have deficient thyroxine production (which means less inhibition, so more TSH released)

Question 31

Adrenal glands from outer to inner (3)

Answer 31

Capsule, adrenal cortex, adrenal medulla

Question 32

3 zones of the adrenal cortex from outer to inner

Answer 32

Zona glomerulosa, zona fasciculata, and zona reticularis

Question 33

What type of cells are in the adrenal medulla? Function

Answer 33

Chromaffin cells Post-ganglionic sympathetic neurons that secrete epinephrine/norepinephrine into the blood

Question 34

Main function of the zona glomerulosa

Answer 34

Synthesizes mineralcorticoids (aldosterone)

Question 35

Function of the zona fasciculata and reticulata?

Answer 35

Synthesizes glucocorticoids (cortisol)

Question 36

What has the ability to increase expression of the enzyme that converts NE to E?

Answer 36

Glucocorticoids (secreted by cortex, can diffuse into medulla)

Question 37

Two main functions of ACTH

Answer 37

Stimulates adrenal cortex to synthesize/secrete glucocorticoids and can also act as a growth factor to induce adrenal hypertrophy

Question 38

Elevated glucocorticoids promotes what two things

Answer 38

Gluconeogenesis and glycogeneolysis

Question 39

Name two other ways that glucocorticoids act in the body

Answer 39

Suppress growth and can be used to help some immune system responses

Question 40

Steroid hormones and glucocorticoids act as transcription factors. What does that mean

Answer 40

They bind promoter regions on DNA and regulate gene expression

Question 41

Cushing syndrome 1. Caused by 2. What does it cause

Answer 41

1. excess ACTH (secondary to pituitary tumor) | 2. Adrenal hyperplasia, inappropriate hair growth in females/masculinization, obesity, and osteoporosis

Question 42

Addisons disease 1. Caused by 2. Hallmark symptoms

Answer 42

1. Adrenal hypofunction, autoimmune resulting in adrenal cortex degeneration/failure 2. Weakness, hypotension, hypoglycemia, Na+ wasting and K+ elevation

Question 43

Pheochromocytoma 1. Originate from 2. Hyperfunction syndrome is? 3. What does it cause 4. Where else can it occur

Answer 43

1. Chromaffin cells 2. Excess production of NE or E 3. Hyperglycemia, hypertension, arrhythmias 4. Prevertebral/paravertebral sites due to ectopic sites of chromaffin cells in sympathetic ganglia

Question 44

1. Adrenal medulla originates from? | 2. Adrenal cortex originates from

Answer 44

1. Neural crest cells | 2. Mesoderm that initially lies lateral to the dorsal aorta