Pituitary And Adrenal Gland Flashcards
What hormones are excreted by the neurohypophysis (posterior pituitary)
ADH (anti diuretic hormone/ vasopressin) and oxytocin
The adenohypophysis (anterior) potion of the pituitary gland is controlled mostly by: Neurohypophysis?
Anterior: hypothalamus
Posterior: nervous tissue
The master gland
The pituitary gland
Where adrenal glands are located
On top of kidneys
ACTH (adrenocorticotropic hormone) controls what portion of the adrenal gland
The cortex: cortex hormones (glucocorticoids, minerlcorticoids, androgens) released based on ACTH levels (feedback loop)
What controls the medulla portion of the adrenal gland
Nervous system
The medulla of the adrenal gland is responsible for producing what
Catecholamines: epinephrine and norepinephrine
Role of glucocorticoids produces by cortex, give example
Ex: cortisol Promotes glycogenesis (production of glucose via breakdown for energy and storage)
What we would give steroids (glucocorticoids) for, what they do
Decreases inflammation, slows healing, inhibits immune system
Give for allergic reactions or swelling
Aldosterone is what kind of cortex hormone, what does it do
Mineralocorticoid: works at kidney level for water and Na retention, and K excretion
What are androgen cortex hormones
Sex hormones like testosterone
What is cushings disease
Hyperadrenocorticism
What is Addison’s disease
Hypoadrenocorticism
Possible causes of hyperadrenocorticism ( cushings)
Adrenal tumor (primary), pituitary tumor (secondary), iatrogenic cause (too many steroid hormones)
Signs of hyperadrenocorticism (cushings)
Pot belly, polyphagia, PU/PD, hair-loss (bi lateral symmetrical), skin changes (too many glucocorticoids, high energy in body)
What is Addison’s disease
Hypoadrenocorticism
Possible causes of hypoadrenocorticism (Addison’s disease)
Tumor, infectious agent, or autoimmune disorder that damages the adrenal gland
Signs of hypoadrenocorticism (Addison’s disease)
Weak, depressed, PU/PD, vomiting, poor hair coat, arrhythmia
(K retained, Na and Cl lost)
What resting cortisol levels can diagnose
Hypoadrenocorticism (low)
Hyperadrenocorticism is not definitive w high levels Bc other things (like physiologic stress) can also increase
What are provocative tests? What ones are used to diagnose hyper/hypoadrenocorticism
Administer drug to provoke a response from feedback loop: ACTH stimulation test or dexamethasone suppression test
How a ACTH stim Test is done
Take baseline blood sample, administer ACTH, take a 2nd sample 1 hr later, measure cortisol samples in both (normally should increase 2-4x)
in an ACTH stim test
What is indicative of hyperadrenocorticism and hypoadrenocorticism
Hyper- second sample v high (4-8x)
Hypo- no change from 1st or 2nd sample, both are low
What is dexamethasone, and how is it used to diagnose hyperadrenocorticism
Synthetic cortisol, injected to suppress release of ACTH and thus suppress cortisol release
Low dose v high dose dexamethasone suppression test (what they diagnose?)
Low dose: hyperadrenocorticism (confirm after resting cortisol test)
High dose: differentiate primary v secondary hyperadrenocorticism)
After dexamethasone is given, the cortisol levels in blood samples should be
Lower than baseline (cortisol in blood tells ACTH to stop, cortisol is suppressed)
What we would see for hyperadrenocorticism on a low dose dexamethasone suppression test
The low is not enough to turn off pituitary or adrenal hormones, all samples have same amounts of cortisol
Primary v secondary hyperadrenocorticism high dose tests
Primary: baseline is high, other samples after dxm also high Bc adrenal gland continues making cortisol (no suppression)
Secondary: baseline high, others suppressed in cortisol (ACTH is suppressed, causing cortisol to be suppressed)
Equine hyperadrenocorticism is also called
Pituitary Pars intermediate dysfunction (PPID) or Equine Cushing’s
When does equine hyperadrenocorticism typically occur
Old horses 18+, usu benign pituitary tumors
Signs of equine hyperadrenocorticism
Lethargy, pot belly, sweating, PU/PD, hirsutism (overgrowth of hair, fails to shed), prone to infections
