Adrenal Cortex

Question 1

Adrenal also known as

Answer 1

Suprarenal glands

Question 2

Adrenal (Suprarenal)

Shape
Location
Weight

Answer 2

Glands paired, pyramid-shaped organs atop the kidneys weighs 4 to 6 grams

Question 3

2 parts of adrenal gland

Answer 3

Adrenal cortex
Adrenal medulla

Question 4

Adrenal Cortex

____%
glandular tissue derived from_____

Answer 4

80-90%

embryonic mesoderm (mesenchymal)

Question 5

Adrenal Medulla

______%
formed from_______, can be considered a modified sympathetic ganglion

Answer 5

10-20

neural ectoderm

Question 6

synthesizes and releases steroid hormones (corticosteroids)

Answer 6

Adrenal Cortex

Question 7

Adrenal Cortex

Zona Glomerulosa

Classification and Hormones

Answer 7

Mineralocorticoids

Aldosterone
Corticosterone

Question 8

Adrenal cortex

Zona Fasciculata

Classification

Hormone

Answer 8

Glucocorticoids

Cortisol

Question 9

Adrenal cortex

Zona Reticularis

Classification and Hormones

Answer 9

Gonadocorticoids/ Sex Steroids

Androgens

Question 10

is the parent compound for all steroid hormones.

Answer 10

Cholesterol

Question 11

Steroid Hormones: Synthesis

Steroids are derivatives of_____

____is from the lipid droplets in cortical cells (cholesterol esters in LDL)

Removed cholesterol is replenished by
cholesterol in LDL in blood or synthesized from acetate

Answer 11

cholesterol

Cholesterol

Question 12

• The first and rate-limiting step in steroid hormone synthesis is the conversion of cholesterol into pregnenolone. This step is regulated by the enzyme___________, also known as______ ____enzyme (P450scc).
• Location: This reaction occurs in the mitochondria.

•	The product,\_\_\_\_\_\_, is the precursor for all steroid hormones, including glucocorticoids, mineralocorticoids, androgens, estrogens, and progestogens.

Answer 12

cholesterol desmolase

cytochrome P450 side-chain cleavage

pregnenolone

Question 13

Unlike peptide hormones,______ hormones are not stored in vesicles because they are lipophilic (fat-soluble) and can freely diffuse across membranes.

Answer 13

steroid

Question 14

• Newly synthesized hormones are not stored in the cell but are released as soon as they are formed.

•	Once synthesized in the mitochondria and smooth endoplasmic reticulum, steroid hormones passively diffuse through the cell membrane due to their lipophilic nature.

Question 15

After secretion into the bloodstream, steroid hormones are transported in a bound form:
• _________(CBG): Specifically binds glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone).

•	\_\_\_\_\_\_\_: A nonspecific plasma protein that binds most steroid hormones to a lesser extent.

Answer 15

Corticosteroid-binding globulin

Albumin

Question 16

Mineralocorticoids
synthesized in zona______
regulate the electrolyte concentration of
extracellular fluids

Answer 16

glomerulosa

Question 17

– most important mineralocorticoid

Answer 17

Aldosterone

Question 18

Maintains Na+ balance by reducing excretion of sodium from
the body

Stimulates ¥reabsorption of Na* by the kidneys and K+ excretion

Increases transcription of Na/K pump
Increases the expression of apical Na channels and an Na/K/Cl cotransporter

Expands ECF volume

Answer 18

Aldosterone

Question 19

Aldosterone is synthesized in the _______of the adrenal cortex.

•	Its primary function is to regulate\_\_\_\_\_\_ and \_\_\_\_\_\_

Answer 19

zona glomerulosa

electrolyte balance and maintain extracellular fluid (ECF) volume.

Question 20

stimulates the reabsorption of sodium (Na⁺) in the kidneys, specifically in the distal convoluted tubule and collecting ducts:

1.	Increases transcription of the Na⁺/K⁺ ATPase pump:
•	This pump moves Na⁺ from the renal tubular cells into the blood and pumps K⁺ into the cells.
2.	Upregulates apical Na⁺ channels (ENaC):
•	These channels increase Na⁺ reabsorption from the filtrate into tubular cells.

Answer 20

Aldosterone

Question 21

Aldosterone promotes the_______ of K⁺ into the urine by

Answer 21

excretion

Question 22

Sodium reabsorption by aldosterone leads to water retention (via osmosis), which:
• (2)

Answer 22

Increases blood volume.
Raises blood pressure.

Question 23

The renin-angiotensin system is the primary regulator of aldosterone secretion:

1.	Decreased blood volume or pressure:
•	Low blood pressure or volume stimulates\_\_\_\_\_ release from the kidneys.
•	Renin converts angiotensinogen (produced by the liver) into angiotensin I, which is converted to angiotensin II by ACE (angiotensin-converting enzyme) in the lungs.
•	Angiotensin II directly stimulates the adrenal cortex to release\_\_\_\_\_.

Answer 23

renin

aldosterone

Question 24

Blood Sodium and Potassium Levels

• Low blood Na⁺:
• Signals the need for sodium conservation, stimulating_____ secretion.

• High blood K⁺:
• Aldosterone secretion increases to promote ____excretion, maintaining electrolyte balance.

Answer 24

aldosterone

K⁺

Question 25

The________ is the most important pathway for aldosterone regulation

Answer 25

renin-angiotensin-aldosterone system (RAAS)

Question 26

Renin-angiotensin mechanism
– kidneys release renin, which is converted into_____ that in turn stimulates aldosterone release

Answer 26

angiotensin II

Question 27

Plasma concentration of sodium and potassium
– directly influences the______

Answer 27

zona glomerulosa

Question 28

High potassium (hyperkalemia):
• Stimulates______ release to promote K⁺ excretion by the kidneys, maintaining potassium homeostasis.
• ________:
• Triggers aldosterone secretion to conserve Na⁺ by increasing reabsorption in the kidneys.
• Effect:
• This mechanism ensures the balance of electrolytes and proper nerve and muscle function.

Answer 28

aldosterone

Low sodium (hyponatremia)

Question 29

Mineralocorticoids
synthesized in zona_______
regulate the electrolyte concentration of
extracellular fluids

Answer 29

glomerulosa