Adrenal Gland Pathology

Question 1

Primary regulatory control and secretory products of zona glomerulosa

Answer 1

Renin-angiotension, aldosterone (Na^+, H2O retention, K^+ secretion)

Question 2

Primary regulatory control and secretory products of zona fasciculata

Answer 2

ACTH, CRH (corticotrophin-releasing hormone), cortisol secreted

Question 3

Primary regulatory control and secretory products of zona reticularis

Answer 3

ACTH, CRH, sex hormones (e.g. androgens) secreted

Question 4

Primary regulatory control and secretory products of chromaffin cells

Answer 4

Preganglionic sympathetic fibres, catecholamines (epinephrine (adrenaline), norepinephrine)

Question 5

Summary of layers of adrenal gland and hormones secreted

Answer 5

Question 6

Outline the hypothalamic-pituitary-adrenal (HPA) axis feedback loops

Answer 6

Question 7

Where are the adrenal glands located?

Answer 7

Adjacent to kidneys + close to blood vv., hard for tumour removal surgery + can be occluded

Question 8

Degenerative changes of the adrenal cortex (2)

Answer 8

• Amyloidosis
• Mineralisation

Question 9

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Question 10

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Question 11

Types of amyloidosis (not examinable)

Answer 11

Question 12

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Question 13

Types of circulatory disturbances of adrenal cortex (2)

Answer 13

• Haemorrhage
• Infarction

Question 14

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Question 15

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Question 16

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Question 17

Mechanisms of toxicity of the adrenal cortex (3)

Answer 17

Question 18

Disorders of growth of the adrenal cortex (4)

Answer 18

• Developmental malformations
• Atrophy
• Nodular hyperplasia
• Neoplasia - adenoma, carcinoma

Question 19

Developmental findings of the adrenal cortex (3)

Answer 19

Question 20

Answer 20

Grossly, adrenal cortex to medulla ratio should be 1:1

Question 21

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Question 22

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Question 23

Compare and contrast nodular hyperplasia and adenomas (6)

Answer 23

Question 24

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Question 25

What are the types of hyperadrenocorticism? (4)

Answer 25

Question 26

Pituitary-dependent hyperadrenocorticism - adrenal gland gross pathology

Answer 26

Bilateral adrenocortical hyperplasia (+ mass) - ACTH in bloodstream - both glands

Question 27

Adrenal-dependent hyperadrenocorticism - adrenal gland gross pathology

Answer 27

Bilateral adrenocortical atrophy (+ mass) - compensation

Question 28

Iatrogenic hyperadrenocorticism - adrenal gland gross pathology

Answer 28

Bilateral adrenocortical atrophy (+ history of corticosteroid use), no tumour

Question 29

Ectopic ACTH secretion - adrenal gland gross pathology

Answer 29

Bilateral adrenocortical hyperplasia, no tumour

Question 30

Answer 30

Pituitary-dependent hyperadrenocorticism

Question 31

Answer 31

Adrenal-dependent hyperadrenocorticism

Question 32

Answer 32

Iatrogenic hyperadrenocorticism

Question 33

Answer 33

Ectopic ACTH secretion

Question 34

Answer 34

Question 35

Clinical signs of hyperadrenocorticism (8)

Answer 35

* Excess cortisol -\> inc stress * Common in middle-aged dogs * Poodles and Boston terriers predisposed * Immunosuppressed * Pot-belled/get fat - inc protein catabolism, glycolysis + glucose production * 5 Ps!

Question 36

Answer 36

Question 37

What is calcinosis cutis?

Answer 37

Accumulation of calcium salt crystals in skin - calcification of degenerate collagen, localised (dystrophic)

Question 38

Answer 38

Question 39

Difference between dystrophic and metastatic calcification

Answer 39

Question 40

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Question 41

What clinical pathological changes are induced by corticosteroid release? (6)

Answer 41

* Stress leucogram ('LEMoN', LE = dec leucocytes, N = inc neutrophils) - lymphopoenia, eosinopenia, neutrophilia + monocytosis (dogs) * Stress hyperglycaemia * Hypercortisolism * Inc ALP (alkaline phosphotase) * Lipaemia + hypercholestrolaemia * Hypercoagulable state

Question 42

Diagnostic tests that differentiate pituitary and adrenal-dependent hyperadrenocorticism (4)

Answer 42

* LDDS = low-dose dexamethasone suppression testing * HDDS = high-dose dexamethasone suppression

Question 43

What are the pathogenic mechanisms of cortisol excess in dogs? (5)

Answer 43

Question 44

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Question 45

Answer 45

Rare in cats, mostly pituitary-dependent, thin fragile skin, curling of tips of ear pinna

Question 46

Answer 46

* Excess glucocorticosteroid production + excess sex steroids * Functional adrenal gland hyperplasia, adenomas or adenocarcinomas * May be related to neutering at an early age * Middle age (3-4 years) * Hair loss - begins in tail and progresses toward front to completely bald * Swollen vulva in spayed females * Straining to urinate (enlarged prostate) * Thinning of skin, muscle wasting + pot-bellied appearance in long-term disease

Question 47

What are the different types of hypoadrenocorticism and which part of the adrenal gland is affect? (3)

Answer 47

Question 48

What are the non-specific clinical findings of hypoadrenocorticism? (5)

Answer 48

Question 49

Function of mineralocorticoids in the body

Answer 49

Aldosterone (goes to kidneys) - Na^+ + H2O retention, K^+ secretion (-ive feedback loop), H^+ secretion

Question 50

Hypoadrenocorticism pathogenesis (1^y + 2^y)

Answer 50

Question 51

Additional diagnostic tests for hypoadrenocorticism (3)

Answer 51

Question 52

What is hyperaldosteronism? (2)

Answer 52

Question 53

Renin-angiotensin-aldosterone system

Answer 53

Question 54

What are phaeochromocytomas? (4)

Answer 54

* Neoplasm of the adrenal medullary secretory cells * Rare; mostly seen in dogs and cattle * May be benign or malignant - invasion of adjacent vessels - vena cava common with malignant form * May secrete catecholamines (adrenaline and noradrenaline) * Hypertension - spontaneous haemorrhage, glomerulopathy * Tachycardia * Anxiety, restlessness

Question 55

Answer 55

Question 56

Answer 56

Malignant - invasion of the caudal vena cava