Adrenal Glands

Question 1

What are the two regions of the adrenal gland?

Answer 1

Cortex (outer) and Medulla (inner)

Question 2

What is the function of the cortex?

Answer 2

Responds to long-term stress

Question 3

What hormones does the cortex secrete?

Answer 3

Cortisol
Aldosterone
Androgens

Question 4

What is the function of the medulla?

Answer 4

Responds to short-term stress

Question 5

What hormones does the medulla secrete?

Answer 5

Catecholamines (epi/nor)
Enkephalins and other peptides

Question 6

What are examples of long term stress responses?

Answer 6

Retention of water/salt by the kidneys
Increased BP/blood volume
Increased blood glucose/proteolysis/lipolysis
Suppress immune response
Maintain/promote anabolic growth

Question 7

What are examples of short term stress responses?

Answer 7

Increase HR/BP
Bronchodilation
Glycogenolysis + increase in plasma glucose
Blood diverted from GI to heart, CNS, + muscles
Increase metabolism

Question 8

The adrenal medulla is a functional “____________” of the _____________ nervous system

Answer 8

“extension” ; sympathetic

Question 9

Short term stress signaling starts in the _____________, which then signals the ______________, which sends action potentials to the adrenal _____________ via the sympathetic division of the _______________ nervous system

Answer 9

Hypothalamus
Brainstem/Spinal Cord
Medulla
Autonomic

Question 10

What are catecholamines?

Answer 10

Epinephrine (adrenaline)
Norepinephrine (noradrenaline)

Question 11

What are the percentages of catecholamines released by the adrenal medulla?

Answer 11

80% Epinephrine
20% Norepinephrine

Question 12

What responses do enkephalins stimulate?

Answer 12

Analgesic

Question 13

What stimulates the adrenal medulla and what is the response?

Answer 13

Stressor or threats to survival
(think adrenaline related)
Fight or flight response

Question 14

What happens in a fight or flight response?

Answer 14

HR/BP/TPR increase
Ventilation increases
Metabolism increases
Glycogenolysis/lipolysis
CNS “alertness” increases
GI function decreases

Question 15

What tissues does the adrenal medulla target?

Answer 15

Heart
Blood vessels
Bronchioles
Liver
Adipose
Intestines
Kidneys
CNS

Question 16

How do sympathetic stimuli affect the kidneys?

Answer 16

Decrease GFR and RBF (think long term stress response)

Question 17

How are catecholamines removed from circulation?

Answer 17

Metabolized by enzymes in the kidneys and excreted via kidneys

Question 18

What are the layers of the adrenal cortex?

Answer 18

Zona Glomerulosa (outer)
Zona Fasiculata (middle)
Zona Reticularis (inner)

Question 19

What does the zona glomerulosa contain?

Answer 19

Enzymes that synthesize aldosterone

Question 20

What does the zona fasiculata contain?

Answer 20

Enzymes that synthesize cortisol

Question 21

What does the zona reticularis contain?

Answer 21

Enzymes that synthesize adrenal androgens

Question 22

What is the precursor/stimuli to adrenal cortex hormones?

Answer 22

Cholesterol

Question 23

______ binds to receptors and delivers cholesterol into the adrenal ___________

Answer 23

LDL
Cortex

Question 24

_______ stimulates the adrenal cortex to convert cholesterol into ______________

Answer 24

ACTH
Pregnenolone

Question 25

What is pregnenolone used for?

Answer 25

To synthesize aldosterone, cortisol, and adrenal androgens

Question 26

What can cause adrenal pathologies?

Answer 26

Enzyme deficiencies

Question 27

What does cortisol do?

Answer 27

Enhances enzyme activity to allow metabolism to occur more efficiently "Gas pedal, not the ignition"

Question 28

What can excess cortisol cause?

Answer 28

Suppressive effects (Think negative feedback loop)

Question 29

What does cortisol influence?

Answer 29

Plasma glucose Immune response CV function Kidney function CNS function Fetal growth and surfactant

Question 30

What is the target tissue of cortisol?

Answer 30

Heart Blood vessels Kidneys Liver Adipose Muscles Immune system CNS CT (bone, ligaments, tendons)

Question 31

Cortisol effect on heart and blood vessels

Answer 31

Vasoconstriction Increase HR and stroke volume

Question 32

Cortisol effect on kidneys

Answer 32

Increase GFR and RBF Increase salt/water retention Increase potassium excretion

Question 33

How does cortisol affect the immune system?

Answer 33

Enhance anti-inflammatory response

Question 34

How does excess cortisol affect the immune system?

Answer 34

Impairs immune system Reduces both cellular and humoral immunity (Poor wound healing/immune defenses)

Question 35

How does cortisol affect the CNS?

Answer 35

Increases excitability Increases attention and memory formation but may impair recall Alters mood and perception

Question 36

How does excess cortisol affect the CNS?

Answer 36

Can cause neuronal death and impair CNS function (depression/dementia)

Question 37

How does cortisol effect bone? What can excess cortisol cause?

Answer 37

Stimulates osteoclasts/calcium resorption Excess can cause osteoporosis

Question 38

How does cortisol affect muscle? What can excess cortisol cause?

Answer 38

Stimulate proteolysis Excess can cause muscle wasting/weakness and loss of lean body mass

Question 39

How does cortisol affect tendons/ligaments/CT? What can excess cortisol cause?

Answer 39

Inhibits fibroblasts/collagen production (weakens CT) Excess can cause ligament/tendon failure

Question 40

What stimulates cortisol?

Answer 40

Circadian rhythm Stress

Question 41

When is most cortisol released and when does it peak?

Answer 41

Released between midnight and 8am, peaks right before waking

Question 42

What inhibits cortisol?

Answer 42

Negative feedback loops Elevated levels of cortisol inhibit ACTH and CRH (which stimulate cortisol)

Question 43

What is the function of aldosterone?

Answer 43

Influence renal regulation of salt, water, and potassium

Question 44

What tissues does aldosterone target?

Answer 44

Kidneys and blood vessels

Question 45

How does aldosterone affect the kidneys?

Answer 45

Increases Na reabsorption promoting water resorption Increases potassium excretion

Question 46

What is the function result of aldosterone's affect on the kidneys?

Answer 46

Increase BP/BV Decrease plasma potassium Increase pH

Question 47

How does potassium affect pH?

Answer 47

Potassium excretion is coupled with hydrogen excretion in the kidneys The loss of hydrogen promotes alkalosis in the plasma

Question 48

What stimulates aldosterone?

Answer 48

Angiotensin II Hyperkalemia

Question 49

What inhibits aldosterone?

Answer 49

Negative feedback loops Atrial natriuretic peptide (ANP) Beta Blockers

Question 50

What are androgens responsible for?

Answer 50

Development and maintenance of male characteristics Role in reproductive activity Precursor to estrogen

Question 51

What are examples of active androgens and what is their MOA?

Answer 51

Dihydrotestosterone (DHT) Testosterone (precursor to DHT) MOA: bind to androgen receptors and exert androgenic effects on target tissue

Question 52

What are examples of inactive androgens and what is their MOA?

Answer 52

DHEAS/DHEA Androstenedione MOA: Converted to active androgen (testosterone) which does on to exert androgenic effects

Question 53

The adrenal glands release which androgens?

Answer 53

Inactive (DHEAs/DHEA and androstenedione)

Question 54

What other organs secrete androgens?

Answer 54

Gonads (testes and ovaries)

Question 55

What is the most abundant androgen?

Answer 55

DHEAS/DHEA

Question 56

Testosterone is synthesized in which organs?

Answer 56

Mostly in gonads but small amount in peripheral tissues

Question 57

What is the difference between males and females regarding testosterone production and release?

Answer 57

Males' testes release testosterone into bloodstream/circulation Females' ovaries convert most testosterone into estrogen w/ small amount of testosterone released into circulation

Question 58

Where are inactive androgens converted into testosterone?

Answer 58

Peripheral tissues

Question 59

The conversion of testosterone into DHT requires?

Answer 59

5 alpha reductase

Question 60

DHT is the most __________ androgen

Answer 60

Potent

Question 61

What is the approximate ratio of DHT:Testosterone in the body?

Answer 61

1:10

Question 62

What is the difference between females and males in regards to DHT synthesis?

Answer 62

Females have less 5 alpha reductase than males which results in less DHT synthesis

Question 63

Androgens and pre-puberty

Answer 63

Play important role in development of axillary hair, pubic hair, muscle mass, sebaceous glands (acne)

Question 64

Adrenal excess during pre-puberty in males causes?

Answer 64

Significant androgenic effects Isosexual precocious puberty

Question 65

What is isosexual precocious puberty?

Answer 65

Early development of male secondary sexual characteristics before the age of 9

Question 66

Adrenal excess during pre-puberty in females causes?

Answer 66

Significant androgenic effects Heterosexual precocious puberty

Question 67

What is heterosexual precocious puberty?

Answer 67

Early development of male secondary sexual characteristics before the age of 8

Question 68

Androgens and post-puberty in males

Answer 68

Limited role in maintenance of male sex characteristics Testosterone plays the dominant role instead

Question 69

Androgens and post-puberty in females

Answer 69

Significant role in maintenance of axillary/pubic hair growth, muscle mass, libido Since ovaries produce such a small amount of testosterone

Question 70

What is the difference in having adrenal excess post-puberty in males vs. females?

Answer 70

Adrenal excess will have no/minimal androgenic effect in males but a significant androgenic effect in females

Question 71

Excess androgens post-puberty in females

Answer 71

Development of male sexual characteristics cystic acne, male type baldness, infertility