The Adrenal gland 9/3/15

Question 1

Where are the adrenal glands located?

Answer 1

One on top of each kidney

Question 2

What are the 2 portions of the adrenal gland?

Answer 2

Adrenal medulla = inner portion (part of sympathetic autonomic nervous system that controls fight for flight.

Adrenal cortex = outer portion, not part of nervous system. It secretes hormones in response to hormone stimulation.

Question 3

What does the adrenal medulla secrete?

Answer 3

Epinephrine and norepinephrine hormones

Question 4

What does the adrenal cortex secrete?

Answer 4

Steroid hormones

Question 5

What is the Adrenal Medulla derived from?

Answer 5

Neural crest cells

Question 6

What is the Adrenal cortex derived from?

Answer 6

Mesotheial cells

Question 7

____ is a modified sympathetic ganglion

Answer 7

Adrenal medulla
*No postsynaptic neurons with axons in it, instead the postganglionic cells release epinephrine (80%) and norepinephrine (20%) into the blood

Question 8

_____ converts norepinephrine (NE) to epinephrine (E).

Answer 8

Enzyme pheynl-N-methyltransferase

Question 9

Beta receptors have greater affinity for _____ and alpha receptors have greater affinity for _____>

Answer 9

Beta = E
Alpha = NE
*This means neural response to E and NE can vary.

Question 10

What is the response to E and NE in tissues not directly innervated by postganglionic neurons (liver, skeletal muscles and fat)?

Answer 10

E = acts to increase availability of metabolic fuel by stimulating lipolysis, glycogenolysis and gluconeogenesis.

Question 11

In short what does the adrenal medulla do?

Answer 11

Enhances the sympathetic response by releasing hormones that can reach additional target without neural circuits.

Question 12

Because the endocrine (hormone) signal is blood borne, the response is ________.

Answer 12

longer

Question 13

What are the zones of the Adrenal cortex?

Answer 13

Zona Glomerulosa = outermost
Zona Faciculata = middle
Zona Reticularis = innermost, adjacent to the medulla
*Each zone produces a different class of steroid.

Question 14

What are the 5 steroids secreted by the Adrenal cortex zones?

Answer 14

1. Cortisol
2. Corticosterone
3. Aldosterone
4. Anderostenedione
5. Dehydroepiandrosterone (DHEA)

Question 15

In the adrenal cortex, steroid synthesis and secretion is stimulated by_______.

Answer 15

ACTH, Except for aldosterone which is regulated by other signals.

Question 16

Aldosterone is a ______ produced by cells in the _______.

Answer 16

Mineralocorticoid produced in Zona glomerulosa.

Question 17

What is the principal action of Aldosterone?

Answer 17

stimulate Na+ and H2O retention in the kidney in order to maintain blood volume and pressure.

Question 18

The mechanism by which aldosterone helps reabsorb Na+ and H2O in the kidney results in ________.

Answer 18

an increase of K+ and H+ in urine (Important!)

Question 19

How does aldosterone do its job?

Answer 19

The aldosterone-receptor complex binds to DNA and stimulates the synthesis of proteins that act to increase Na+ and H2O reabsorption from the tubular fluid back into the blood.

Question 20

What factors regulate the Secretion go aldosterone? (4)

Answer 20

• Stimulated by increase in plasma K+
• Stimulated by a decrease in plasma pH or Increase in Plasma H+
• Stimulated by a drop in systemic blood pressure
• Inhibited by increased Na+ intake

Question 21

Glucocorticoids _____ and ______ are secreted by the cells of the zone fasciculata.

Answer 21

Cortisol and corticosterone *Cortisol is the important one in humans.

Question 22

What are the major effects of Glucocorticoids (cortisol)?

Answer 22

To increase the availability of glucose: antagonizes the action of insulin.

• increase gluconeogenesis in liver
• Increase proteolysis in muscle
• Increase lipolysis
• decrease glucose uptake in muscle and fat
• decrease immune and inflammatory responses
• decrease growth and reproductive function
• Permissive action on Beta receptors in vascular smooth muscle to regulate blood pressure.

Question 23

Synthesis and secretion of glucocorticoids is stimulated by _______.

Answer 23

ACTH

Question 24

Cortisol has a negative feed back action on ____ and ______.

Answer 24

CRH and ACTH

Question 25

__________ are secreted by the Zona Reticularis.

Answer 25

Sex hormones (androgens) DHEA and androstenedione.

Question 26

_____ Is the precursor of other sex steroids.

Answer 26

DHEA, so it can serve as a circulating reservoir for conservation in peripheral tissues containing steroidogenic enzymes

Question 27

Androstenedione is synthesized by ___________.

Answer 27

enzymatic conversion of DHEA.

Question 28

Which is a stronger androgen, DHEA or Androstenedione?

Answer 28

Androstenedione

Question 29

______ provides a nongonadal source of Testosterone and estradiol.

Answer 29

Androstenedione

Question 30

______ is important source so steroids prior to puberty and in postmenopausal women.

Answer 30

Androstenedione

Question 31

What are adrenal sex steroid important for?

Answer 31

Regulating: - mood - libido - hair growth - erythropoiesis - acne

Question 32

Synthesis and secretion of adrenal androgens is stimulated by _______.

Answer 32

ACTH

Question 33

What is the Stress response?

Answer 33

A response of the stress axis (Hypothalamus- ant. pituitary- adrenal cortex) to a stressor that stimulates hypothalamic CRH neurons and inputs to the SNS.

Question 34

What are the 3 primary goals of the stress response?

Answer 34

1. maintain blood pressure 2. mobilize and increase availability of metabolic fuel 3. inhibit non-essential functions

Question 35

What shuts off the stress response?

Answer 35

Removal of stressor and negative feedback actions of cortisol on CRH and ACTH.

Question 36

What happens when cortisol is elevated for long periods and combined with chronic activation of SNS? 3 things..

Answer 36

- Highly catabolic use of substrates to produce glucose. These tissues can be rebuilt after stress is over, but if it continues to long it can cause problems. - Cortisol inhibits inflammation, cytokines and phagocytosis, this conserves energy in the short term, but is damaging with chronic stress. - Mobilization of metabolic fuels increases lipids in the blood which can increase blood pressure ann cause hypertension

Question 37

What is Addison's disease?

Answer 37

``` Adrenal insufficiency caused by: PRIMARY insufficiency: - disease - Congenital disorder - Autoimmune disorder SECONDARY insufficiency: - pituitary problem - Glucocorticoid therapy * This is important for dentist because patients may have complications with maintaining blood pressure during anesthesia. ```

Question 38

What are the Symptoms of Adrenal insufficiency?

Answer 38

- low cortisol and high ACTH - weakness, lethargy and decreased appetite - low blood pressure - low glucose when fasting - hyper pigmentation due to lack of feedback control of POMC production

Question 39

How do you treat Adrenal insufficiency?

Answer 39

You don't, you're a dentist not a real doctor..........ha ha ha j/k you are supposed to treat with glucocorticoids and/or dietary control.

Question 40

What is Hypercortisolinemia/Cushing's disease?

Answer 40

Typically caused by a pituitary tumor = excess cortisol.

Question 41

What are the symptoms of Cushing's disease?

Answer 41

- excessive tissue catabolism - diabetes like symptoms - impaired immune function - threat of hypertension * In dental patients the primary concern is impairment of immune function after a procedure, but hypertension, osteoporosis and increased bleeding are also a problem.