The Adrenal

Question 1

Where is the adrenal gland?

Answer 1

Lie superior to each kidney, like a hat

Have a fibrous capsule and are surrounded by fat; are retroperitoneal

Question 2

What are the two parts of the adrenal gland?

Answer 2

The cortex (outer) and the medulla (inner)

Question 3

How is the adrenal cortex formed?

Answer 3

In embryo, mesoderm (a cell type) form posterior abdominal wall, which becomes the outer area, or cortex of the adrenal

Question 4

How is the adrenal medulla formed?

Answer 4

Neural crest cells

Question 5

How many, and what kinds, of hormone are produced by the adrenal gland?

Answer 5

There are over 2 dozen steroid hormones produced in the adrenal cortex

Question 6

Physically describe the adrenal cortex

Answer 6

This is the biggest of the two tissues that make up the adrenal gland
It comprises 80-90% of the two, and is yellowish in color
It is essential for life, without it you would die in 2 days-week

Question 7

What three zones make up the adrenal?

Answer 7

Zona glomerulosa
Zona fasciculata
Zona reticularis

Question 8

Where is the zona glomerulosa?

Answer 8

Just underneath the capsule; just deep to the capsule

Question 9

How are cells in the zona glomerulosa arranged?

Answer 9

The cells are arranged in arched loops or round balls

Question 10

What do the cells of the zona glomerulosa secrete?

Answer 10

They secrete mineralocorticoids

Question 11

What is an example of a mineralocorticoids? What do these secretions effect?

Answer 11

They affect water and electrolyte homeostasis

Aldosterone

Question 12

What organ does aldosterone affect?

Answer 12

The kidney

Question 13

Chemically speaking, what does aldosterone do?

Answer 13

↑ Na+ reabsorption, brings it back into the body from filtrate
↑ K+ excretion, sends it out of the body

Question 14

What does an increase in aldosterone do?

Answer 14

↑ reabsorption of Na+ and water follows Na+

Question 15

What two things happen due to a high aldosterone level?

Answer 15

1- Elevated blood Na levels

2- Lower blood K levels

Question 16

What does an elevated blood Na level mean?

Answer 16

So greater than normal amounts of Na+ in the blood

So greater amount of water retained in blood (water follows Na+)

Question 17

What are the sx of elevated blood Na level?

Answer 17

↑ BP, hypertension, and edema

Question 18

What does a lower blood K level mean?

Answer 18

So, ↓ K+ in extracellular fluid
So, a greater tendency for K+ to diffuse out of the cell
So, hyperpolarize the neural membrane
Therefore, need greater stimulus to depolarize the membrane

Question 19

What are the sx of lower blood K levels?

Answer 19

Muscle weakness (lethargy) or paralysis

Question 20

What happens with a low aldosterone level?

Answer 20

Lower blood Na levels

Higher blood K levels

Question 21

What happens due to lower blood Na levels?

Answer 21

Less Na+ absorbed from the kidney

As water follows Na+ , when water goes into the filtrate to be peed out, Na+ follows

Question 22

What are the sx of low blood Na levels?

Answer 22

↓BP

Question 23

What happens with elevated blood K levels?

Answer 23

K+ diffuses into cells, especially neurons
Therefore, the cell membrane potential is more +
Therefore, spontaneous action potentials in response to small stimuli

Question 24

What are the sx of elevated blood K levels?

Answer 24

Muscle spasms, tetany

Question 25

How are cells arranged in the zona fasciculata?

Answer 25

Cells arranged in long, straight cords

Question 26

Which adrenal zone is the widest?

Answer 26

The zona fasciculata

Question 27

What is secreted in the zone fasciculata? (generally, and specifically?)

Answer 27

Glucocorticoids

Cortisol

Question 28

What do glucocorticoids do?

Answer 28

Influence the metabolism of most body cells

Question 29

What does cortisol do?

Answer 29

Affects glucose homeostasis, promotes natural development

Helps the body cope with stress, so there are numerous targets for cortisol

Question 30

What is Cushing’s disease?

Answer 30

A disease of trouble with adrenal secretions

Fat deposits on face/neck; “buffalo hump” of fat deposit on neck

Question 31

Where is the zona reticularis?

Answer 31

Deepest of the three zones, next to the medulla

Question 32

How are the cells of the zone reticularis arranged?

Answer 32

Cells arranged in freely-branching cords

Question 33

What do the cells of the zona reticularis secrete? And what are they?

Answer 33

Secrete gonadocorticoids (weak androgens [general term for male hormones])

Question 34

What is DHEA?

Answer 34

Assists in prepubertal growth spurt, and axillary and pubic hair development
These androgens can be converted into estrogen by other body tissues, so this could help during menopause

Question 35

What is the mnemonic for the zones of the adrenal?

Answer 35

Go Find Rex, Make Good Sex: Glomerulosa, Fasciculata, Reticularis, Mineralocorticoids, glucocorticoids, gonadocorticoides (sex)

Question 36

Describe the adrenal medulla

Answer 36

Not essential for life
Smaller area in the center, completely surrounded by cortex
10-20% of gland, colored gray to dark red
Cells if no particular design

Question 37

What kinds of cells are produced by the adrenal medulla?

Answer 37

Chromaffin cells

Question 38

What is a chromaffin cell?

Answer 38

Are actually modified neurons (no dendrites/axons) from embryonic neural crest cells
Receive direct innervation from preganglionic neurons from the sympathetic ANS
Thus: They are sympathetic, post-ganglionic cells (pass thru both ganglia go to medulla)

Question 39

What do Chromaffin cells secrete? In what percentages?

Answer 39

epinephrine and norepinephrine 80/20%

Question 40

Chromaffin cells _____ glucose levels by breaking down ______ in liver.

Answer 40

Boost

Glycogen