Week 6 (Sadie)

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

he goals of emergency therapy for an addisonian crisis are to (5)

1. Correct hypovolemia, 2. Correct electrolyte abnormalities (particularly hyperkalemia), 3. Correct hypoglycemia (if present), 4. Correct acid-base abnormalities (acidosis), 5. Correct glucocorticoid and mineralocorticoid deficiencies

Angiotensin II has three major functions:

1. Initiating vasoconstriction of the arterioles, decreasing blood flow 2. Stimulating kidney tubules to reabsorb NaCl and water, increasing blood volume 3. Signaling the adrenal cortex to secrete aldosterone, the effects of which further contribute to fluid retention, restoring blood pressure and blood volume

At high concentrations, cortisol is immunosuppressive. 3 methods

1. It inhibits prostaglandin production produced by damaged tissues 2. reduces secretion of histamine by mast cells 3. Cortisol decreases phagocytosis and suppresses antibody formation

RAAS (renin-angiotensin-aldosterone system)

1. Renin is released by kidneys in response to decreased blood volume; causes angiotensinogen (from liver) to split & produce angiotensin I 2. lungs convert angiotensin I to angiotensin II via ACE 3. angiotensin II stimulates adrenal gland to release aldosterone & causes an increase in peripheral vasoconstriction

3 main clinical signs of Addisonian Crisis

1. Severe dehydration 2. Hypovolemic shock 3. Bradycardia

What would the plasma profile in a patient with hyperadrenocorticism typically include? (4)

1. hyperglycemia 2. increased hepatic enzymes 3. decreased insulin 4. hypercholesterolemia

Zones of Adrenal Cortex (outer to inner)

1. zona glomerulosa 2. zona fasciculata 3. zona reticularis

Zona Glomerulosa _____ % of cortex Zona Fasciculata ____% of cortex Zona Reticularis ____% of cortex

15, 80, 5

Normal ______ ratio Cortex to Medulla

2:1

Which liver enzyme is frequently elevated in the serum during hyperadrencorticism?

ALP- increases are associated with cortisol

3rd types of cell locate din the pars distalis of the anterior pituitary (what do they secrete)

Acidophils: secrete GH, PRL Basophils: secrete ACTH, TSH, FSH, LH chromophobes

If both adrenal glands are removed, which hormone concentration is most likely to be elevated?

Adrenocorticotropin (ACTH)

Which hormone is a significant regulator of sodium absorption and potassium excretion in the colon?

Aldosterone

________ is the major mineralocorticoid. It is released in response to elevated blood _____, low blood , ______ blood pressure or blood volume.

Aldosterone K+, Na+, low

______ hypoadrenocorticism is the destruction of fasciculata and reticularis. Leads to high levels of _______ b/c there is no negative feedback from cortisol

Atypical, ACTH

A 7-year-old miniature Schnauzer presents with signs of hypothyroidism that is confirmed with laboratory diagnostic assays. The dog was diagnosed with hypoadrenocorticism eight months ago. The presentation of both diseases in the same dog is suggestive of what process?

Autoimmune polyglandular syndrome

How are glucocorticoids and mineralocorticoids similar?

Both are produced from cholesterol

glucocorticoids reduce inflammation by inhibition of genes regulating expression of _____ and __________

COX2, most inflammatory cytokines

In response to long-term stressors, the hypothalamus secretes _______, which in turn triggers the release of ________ by the anterior pituitary which triggers the release of the __________ by the adrenal cortex

CRH ( corticotropin- releasing hormone), ACTH (Adrenocorticotropic hormone), glucocorticoids (cortisol)

Iatrogenic Cushing's Disease: The HPA axis is normal but prolonged excessive administration of glucocorticoids leads to suppresses ______ and ______ causing bilateral adrenocortical ______

CRH and ACTH, atrophy

iatrogenic cushings suppress ______ and _______ concentrations causing __________

CRH, ACTH, bilateral adrenocortical atrophy

In a dog with pituitary dependent hyperadrenocorticism which of the following hormones would be expected to be decreased?

CRH- Since CRH is 'upstream' from the pituitary gland, hyperactivity of the pituitary gland should cause a decrease in CRH production since the excessive cortisol production (triggered by the ACTH coming from the pituitary) should be negatively feeding back to decrease CRH production at the level of the hypothalamus.

During ultrasonographic evaluation of the right adrenal gland in the dog, which is the first major vessel found medial to the gland?

Caudal vena cava

Which adrenal cells are functionally equivalent to postganglionic sympathetic neurons?

Chromaffin cells

Where is the unbound glucocorticoid receptor located?

Cytosol

What activates RAAS?

Decrease in renal perfusion (blood volume/pressure)

Replacement of glucocorticoids and mineralocorticoids in the acute setting can help improve clinical signs and clinicopathologic abnormalities in dogs, if primary hypoadrenocorticism is suspected and especially if hyperkalemia is documented. Which of the following drugs would meet this need specifically.

Desoxycorticosterone pivalate (DOCP)

what is seen in ACTH stimulation test of a dog with Cushings

Expectant to see dramatic increase in cortisol level following synthetic ACTH administration. (this test can confirm the diagnosis of Cushing's disease but not the origin)

Dogs in an acute hypoadrenocortical crisis may present with severe hypoglycemia and plasma volume depletion. Which of the following would be a targeted and recommended treatment for these findings?

Fifty percent dextrose added to isotonic intravenous fluids to produce a 5% dextrose solution

explain Iatrogenic Cushing's Disease

From exogenous administration of corticosteroids for prolonged periods of time (allergies/ autoimmune)

Glucocorticoids play a role in water diuresis(increased or excessive production of urine) by increasing the _______.

GFR

Anti insulin effect of glucocorticoids (Chronic administration of glucocorticoids can lead to development of steroid diabetes)

Glucocorticoids inhibit glucose uptake and metabolism in peripheral tissues

What lesion is typically associated with Histoplasma capsulatum infection in dogs and resulting insufficiency of the adrenal gland cortex?

Granuloma

_______ adrenalitis is caused by Histoplasma capsulatum, Coccidioides immitis, or Cryptococcus neoformans

Granulomatous

The Adenohypophysis produces these are 6 hormones:

Growth (Somatotropic) hormone STH Follicle-stimulating hormone FSH Luteinizing hormone LH Adrenocorticotropic hormone ACTH Thyroid-stimulating hormone TSH Prolactin

2 reasons why dogs with hyperadrenocorticism develop pendulous abdomens?

Hepatomegaly- Caused by increased deposits of lipid and glycogen from catabolic affects of cortisol Muscle wasting- Is a result of increased catabolism of structural protein combined with decreased protein synthesis in skeletal myocytes under influence of long term excessive cortisol

__________ decreases pacemaker tissue activity causing bradycardia

Hyperkalemia

Electrolyte imbalances associated with Hypoadrenocorticism

Hyperkalemia, hyponatremia, Hypochloremia

why can we see hyperpigmentation in dogs with addisons

Hyperpigmentation due to too much MSH as a response to the decrease in negative feedback cause no cortisol Lacking cortisol-->so no cortical is having an inhibitory effect on CRH--> CRH from the hypothalamus stimulates the anterior pituitary to produce MSH-->get hyperpigmentation

To which region of the brain is the hypophysis directly attached?

Hypothalamus

3 parts of the neurohypophysis (posterior lobe)

INFUNDIBULUM : proximal portion suspending from the hypothalamus (specifically tuber cinereum of hypothalamus) PARS NERVOSA: modest expansion from the infundibulum and major portion of neurohypophysis PARS CAVA : recess formed in infundibulum from invagination of the third ventricle

Low dose dex suppression test results in pituitary vs adrenal cushings

In Pituitary origin Cushing's disease- it is expected to see a small decrease in cortisol levels over the 4 and 8 hour post-injection samples compared to the pre-injection sample. This is because the negative feedback loop is diminished but not lost in pituitary origins. In cases of adrenal origin Cushing's disease, it is expected to see no decrease in cortisol levels over the 4 and 8 hour post-injection samples compared to the pre-injection sample. This is because the negative feedback loop is lost entirely in adrenal origins.

two major arteries supplying the pituitary gland

Internal carotid arteries Caudal communicating arteries

what is a normal urinalysis finding associated with hypoadrenocorticism

Isosthenuria- Cannot concentrate urine properly b/c aldosterone isn't working to absorb water and NA

aldosterone increases the excretion of ______ and the retention of , which in turn ______- blood volume and blood pressure.

K+, Na+, increases

The ______- adrenal gland is the larger of the two glands

Left

Which vessel provides direct venous drainage of the left adrenal gland in the dog?

Left renal vein

Which abnormality is RARELY seen in patients with hypoadrenocorticism?

Lymphopenia (an ill dog should have lymphopenia secondary to cortisol release- stress leukogram; but no cortisol is being produced)

ACTH binds to ___ receptor; signal transduction is mediated through ______ and _______

MC2 (g protein coupled receptor) , adenylate cyclase and intracellular CAMP

Which of the following tests is the optimal way to monitor effectiveness of fludrocortisone or desoxycorticosterone pivalate treatment in a canine patient with hypoadrenocorticism?

Measurement of serum sodium and potassium concentrations

how do we monitor hypoadrenocorticism? Would ACTH stimulation test help?

Monitor electrolytes No ACTH will not help, unless iatrogenic.

What is the embryonic origin of the adenohypophysis (anterior lobe)?

Mouth (stomodeum)

What is the embryonic origin of the neurohypophysis (posterior lobe)?

Neural ectoderm

what does ACTH stimulation test look like in a normal dog compared to a dog w Addison's

Normal dog: synthetic ACTH is given cortisol levels should increase Addison's dog: synthetic ACTH is given cortisol levels are remain low (same for primary and secondary)

4 parts of the adenohypophysis (anterior lobe)

PARS INTERMEDIA (intermediate lobe) : dorsal portion of adenohypophysis Caudal to the hypophysial cleft Hormone produced: α-melanocyte-stimulating hormone PARS DISTALIS : largest portion of the adenohypophysis; separated by the hypophyseal cavity from the pars intermedia PARS NERVOSA: axons from neurons of supraoptic and paraventricular nuclei of hypothalamus PARS TUBERALIS : the part of the adenohypophysis that extends as a cuff or collar around the infundibulum

________-dependent Cushing disease accounts for 80-85% of spontaneous hyperadrenocorticism _________ tumors account for remaining 15-20% of cases of spontaneous

Pituitary, Adrenocortical

___________ sympathetic fibers innervate the adrenal cortex

Postganglionic

__________ sympathetic fibers synapse inside the adrenal medulla

Preganglionic- This is an exception usually synapse outside organ on ganglia but the medullary tissue is neural in origin

What is the interpretation of an ACTH Stimulation Test in a dog: (Cortisol Serial 2) - Pre test: 0.7 μg/dL (normal 1.0-5.0 μg/dL) - 1 Hour Post test: 0.8 μg/dL (normal 8.0-17.0 μg/dL) (Normal resting or baseline cortisol concentration: 1-4 μg/dL)

Primary hypoadrenocorticism

how does endogenous ACTH help differentiate primary from secondary hypoadrenocorticism

Primary= Lack neg feedback, ACTH will be high Secondary= Pituitary Gland: ATCH will be low because not producing it

Which property of neutrophils is LEAST likely to be negatively affected by the administration of prednisone?

Release of mature neutrophils from bone marrow

Functionally, medullary cells of the adrenal gland are equivalent to which type of neuronal cell bodies?

Secondary sympathetic neurons

Which of the dog breeds is known to present with inherited hypoadrenocorticism?

Standard poodle

What statement best describes the mechanism by which glucocorticoids influence target cells?

They freely pass through the cell membrane and then bind to intracellular glucocorticoid receptors

why use the high dose dexamethasone suppression test for cushings testing

This is used to definitively determine the origin of Cushing's disease if there is no reduction in the cortisol levels seen during low dose testing. This is because a pituitary origin may exhibit resistance to the effects of dexamethasone. If the high cortisol levels persist after administration of high-dose dexamethasone over a 4 and 8 hour time period, then it can be definitively determined to be adrenal origin Cushing's disease.

what is the purpose of ACTH stimulation test

Trying to find out functional capacity of adrenal gland; fasciculata and reticularis layers- cortisol production

Histopathology of the adrenal glands of a dog that died with severe electrolyte imbalances reveals bilateral cortical atrophy with a lymphocytic infiltrate, characterized by special staining as CD4+ and CD8+ T cells. Assuming that cytotoxic T cells are effectors of the disease, what type of hypersensitivity reaction is most likely involved?

Type IV (Cell Mediated/ Delayed- Type)

how is baseline cortisol useful in ruling out hypoadrenocorticism

Wondering if a dog is dealing with renal disease or addisons disease Resting cortisol can help rule OUT addisons-->if cortisol is normal then you can rule out Addisons

cortical _______ are usually single, unilateral, well demarcated Often functional; producing excess corticosteroids

adenoma

_________ Accounts for 80-85% of spontaneous hyperadrenocorticism

adenomas in the pituitary (pituitary dependent cushings)

explain pituitary dependent cushings

adenomatous enlargement of the pituitary gland, resulting in excessive ACTH production which leads to excessive cortisol levels. Normal negative feedback inhibition of ACTH secretion by increased cortisol levels is missing

A measurement of endogenous ACTH can often distinguish between _____ or _______ origin

adrenal (primary) or pituitary (secondary)

Primary mineralocorticoid is ___________ which functions in the control of _________

aldosterone, blood pressure.

The overall effect of glucocorticoids is to inhibit ________ while stimulating the __________ to maintain adequate fuel supplies.

anabolism ( tissue building) ,catabolism (breakdown of stored nutrients)

what major vessel is bound to the medial border of the left adrenal gland

aorta

increased concentrations of exogenous cortisol result in notable ______ of the adrenal cortex (especially ACTH dependent zona fasiculata and reticularis)

atrophy

Occasionally a dog may experience two or more autoimmune endocrine disorders simultaneously called ___________, but this is very uncommon.

autoimmune polyglandular syndrome (Results suggested that the occurrence of multiple endocrine disorders was uncommon in dogs. The most common combinations of endocrine disorders in this population of dogs were diabetes mellitus and hyperadrenocorticism, followed by hypoadrenocorticism and hypothyroidism.)

The Hypophysis sits in a depression, the hypophysial fossa of the __________ bone

basisphenoid

Cortical ______- cells resemble adenoma but more mitoses and less well differentiated cells; necrosis common- invade adjacent adrenal cortex Extension into vena cava may occurs; can also metastasize to lungs

carcinoma

When nerve impulses carried by the sympathetic fibers reach the ___________- secreting chromaffin cells, they release their secretory products. Therefore, chromaffin cells are considered the equivalent of _________

catecholamine, postsynaptic neurons.

2 branches of phrenicoabdominal artery and what they supply

caudal phrenic artery- more cranial supplies caudal aspect of diaphragm cranial abdominal artery- more caudal supplies cranial aspect of abdomen

Often the capsule of the right adrenal gland is continuous with the tunica externa/adventitia of the _______ (vessel)

caudal vena cava

The adrenal veins of each gland terminate differently because of their position relative to the caudal vena cava: The right adrenal vein joins directly with the _________ The left adrenal vein enters the ________

caudal vena cava, left renal vein

adenohypophysis drains into the __________

cavernous sinus

A ____________ on each side of the hypophysis allows connection with the ophthalmic plexus (veins of the face) rostrally and the external jugular vein and vertebral venous plexus caudally

cavernous sinus (large venous channel)

histochemically the catecholamines _______ and __________secreted by the chromaffin cells are produced by different cell types

cell w/ dense core vesicles= norepinephrine cells w/ smaller less dense vesicles= epinephrine

Adrenal corticoids are synthesized from __________ The synthesis of catecholamines is from ________

cholesterol, tyrosine

Cells of the zona glomerulosa are relatively small and ________ or __________

columnar or pyramidal

The adrenal _______ Is a major steroid-producing organ The adrenal ________ augments together with the nervous system the general adaptation of the body to stress

cortex, medulla

The main activator of the HPA axis is ________ hromone

corticotropin-releasing hormone (CRH)

why do animals with hyperadrenocorticism heal poorly

cortisol suppress both inflammation and immune response- reduced resistance to bacteria, fungi, viruses disrupts would healing due to inhibition of fibroblast & collagen synthesis (scar tissue)

Sympathetic axons from the _________ ganglion pass branches to the hypophysis by way of the tunica externa of the _________ artery

cranial cervical, internal carotid

The adrenal gland is located near the __________ border of the kidney

craniomedial

Adrenal Gland: Robust capsule of __________ connective tissue envelops the cortex, and delicate connective tissue envelope separates the cortex and medulla.

dense irregular collagenous,

Phrenicoabdominal artery lies ______ to adrenal gland

dorsal underneath

The medulla is the heart of the adrenal gland it is darker and of ________ origin, originating from _______ tissue

ectodermal, sympathetic

The principal role of mineralocorticoids is to maintain _______ and _______ homeostasis. These actions are carried out at the level of the ________ in the kidney.

electrolyte balance and blood pressure, distal tubules

What is the first physiological increase during the stress response?

epinephrine

After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands. These glands respond by pumping the hormone ________ into the bloodstream.

epinephrine (also known as adrenaline) (As the initial surge of epinephrine subsides, the hypothalamus activates the second component of the stress response system — known as the HPA axis. T)

T/F Mineralocorticoid treatment is essential for treating an Addisonian crisis.

false- its not but idk why?

Zona ________ Is the largest zone of the cortex It typically composes 50% or more of the cortex

fasiculata

how to distinguish nodular hyperplasia from adenoma in adrenal gland

functional adenomas usually larger and contain many cells with foamy cytoplasm and lipid vacuoles

Zona ________ the outermost zone and constitutes 25% of the adrenal cortex

glomerulosa

_________ secreted in the cortex induce the enzyme that catalyzes the methylation of norepinephrine to produce epinephrine in chromaffin cells.

glucocorticoids

The principal secretion of the zona fasciculata is _________ that regulate glucose and fatty acid metabolism.

glucocorticoids (cortisol)

The zona reticularis produces _________ and __________

glucocorticoids and androgens.

Specific effects of glucocorticoids is stimulation of hepatic _________

gluconeogenesis

cortisol favors _______; raises level of blood glucose which increases _______ in the liver

gluconeogensis, glycogen

Cortisol acts on many different cells and tissues to increase the metabolic availability of ______ and ________ both of which are immediate sources of energy.

glucose and fatty acids

In conditions of long-term stress cortisol promotes: the catabolism of glycogen to ________ the catabolism of stored triglycerides into ______ and _______ the catabolism of muscle proteins into ________.

glucose, fatty acids and glycerol, amino acids

Neurohypophysis (posterior pituitary) contains ______ bodies which secretes _____ and ______

herring, ADH (vasopressin) and Oxytocin

Hyperadrenocorticism caused by a functional adenoma of the pituitary gland (ACTH-secreting)results in bilateral adrenal cortical ________ and ________

hypertrophy and hyperplasia.

Iatrogenic Cushing's Disease: in these animals ACTH stimulation test results are consistent with spontaneous _________ despite clinical signs of __________

hypoadrenocorticism, hyperadrenocorticism

Overall, we would expect to see hypoosmolality in patients with Addison's due to _______ and _________

hyponatremia and hypoglycemia.

Neurohypophysis is primarily composed of axons from the _________ regions

hypothalamic

Hypoadrenocorticism is the most common initial endocrinopathy observed in polyendocrine gland failure in dogs and is usually followed by the development of _________.

hypothyroidism

Cortisol also depress the ________ and ________ responses and, as a result of the latter, inhibit ______ healing.

immune and inflammatory, wound

fight or flight response on various body systems

increase heart rate, increase blood pressure, reduce blood flow to viscera and skin stimulate conversion of glycogen to glucose increase sweating induce dilation of bronchioles increase rate of respiration decrease digestion; decrease enzyme production by digestive system glands; decrease urine production

what is the immediate effects of ACTH

increase steroidogenesis by increasing cholesterol availability

A ________ serum cortisol concentration inhibits the release of more CRH and ACTH.

increased

explain adrenal dependent cushings

increased cortisol production due to adrenal cortical adenoma/ carcinoma (functional adrenal cortical neoplasms)

A common adverse effect of the chronic use of supraphysiologic steroid dosages, is atrophy of the adrenal gland. This has been attributed to which of the following mechanisms?

induced negative feedback on the hypothalamic adrenal axis.

primary hypoadrenocorticism is commonly a results of _______ disease or _______ destruction of the adrenal cortex

infectious, autoimmune (genetic)

Cortisol also decreases sensitivity of adipose and lymphoid tissue to _______ so less glucose is removed from the blood by these tissues, which leaves glucose for the brain and muscles

insulin

Glucocorticoids and ________ have similar effects on liver glycogen metabolism

insulin

Another effective method to rapidly decrease the plasma potassium concentration is administration of regular _______

insulin (Insulin helps drive the Na K ATPase pump so K goes into the cells)

In the pancreas, cortisol decreases _______ and increases _______

insulin, glucagon (Glucagon is a peptide hormone secreted by pancreatic cells to increase lipolysis and liver gluconeogenesis)

PU/PD mechanisms in hypoadrenocorticism

less aldosterone being produced, RAAS system isnt working so your body can't reabsorb Na+ as well, so it doesn't reabsorb as much water either so you drink and pee more because you aren't retaining any water

Glucocorticoids on fat metabolism: The effect on adipose tissue is to increase rate of _______ and to redistribute fat into the _______ and _______

lipolysis, liver and abdomen

Mechanism of adrenal hormone is similar to ________ hormones as they are able to penetrate through the cell membrane

lipophilic

the lymphatic vessels of the adrenal gland drain into the _______ lymph nodes

lumbar aortic

what are characteristic blood values in Addison in relation with lack of cortisol (3) and aldosterone(3)

lymphocytosis, eosinophilia, hypoglycemia, hyponatremia, hypochloremia, hyperkalemia

4 factors of stress leukogram

lymphopenia, neutrophilia, Monocytosis, eosinopenia

Epinephrine release results in a different pattern, known as physiologic leukocytosis or excitement leukocytosis, characterized by _________ (like the glucocorticoid response) and ________ (unlike the glucocorticoid response).

mature neutrophilia, lymphocytosis

The chromaffin cells are locate din the adrenal _________

medulla, neurons

Pars intermedia of the anterior pituitary secretes _________

melanocyte stimulating hormone (MSH)

The cortex is lighter in color, and radially striated It originates from ________ cells of the _________

mesenchymal, mesoderm

The cells of the zona glomerulosa secrete _________ compounds that function in the regulation of ______ and ________ (ions) homeostasis and water balance.

mineralocorticoids, sodium and potassium

Cortisol has ______ feedback action on both the hypothalamic release of CRH and the pituitary release of ACTH.

negative

_______ small nodules of hyperplastic cells within and outside of adrenal capsule; well defined spherical nodules in cortex or attached to capsule

nodular hyperplasia (usually multiple, bilateral, yellow)

N- methylating enzyme converts _______ to ________ and is _________ hormone dependent

norepinephrine to epinephrine, corticosteroid

Hyperkalemia is life threatening in the acute Addisonian crisis but can be reliably treated with aggressive intravenous fluid therapy using ________

normal saline (0.9% sodium chloride) -

Glucocorticoid receptors have to be bound to glucocorticoids in order for them to be translocated into the ________.

nucleus

_______ is the most frequent tumor of the adrenal medulla in animals; arise from ______ cells and resembles them

pheochromocytoma, chromaffin

Cranial adrenal branches from the __________ artery Middle adrenal branches from the _________ Caudal adrenal branches from the _______ and ________ arteries

phrenicoabdominal, abdominal aorta, lumbar and renal

The cells of the zona fasciculata are large and ________. _________ cells are common in this zone

polyhedral, Binucleated

the _______ lobe is formed by a downgrowth of hypothalamus

posterior lobe

The adrenal medulla is considered a specialized ________ sympathetic neuron devoid of an axon. The chromaffin cells of the medulla secrete stored catecholamines in response to cholinergic stimulation by __________ sympathetic fibers.

postganglionic, preganglionic (review this)

______ hypoadrenocorticism is the destruction of all layers of adrenal cortex; primarily _______ mediated

primary , immune (the disease has a genetic basis in several breeds of dogs)

First step in steroid hormone synthesis is to form _________ from cholesterol. These function as precursors to all other corticosteriods

progestogens (pregneneolone and progesterone) ;

The dorsal border of the right kidney is formed by the _______ muscle and the ________

psoas minor, crus of the diaphragm

The dorsal border of the left adrenal gland Is applied closely to the body of the ______ muscle and the transverse process of the ______ lumbar vertebra

psoas minor, second

Primary hypoadrenocorticism: Pre-renal azotemia results from decreased _______ and ________

renal perfusion and decreased glomerular filtration rate (GFR)

The zona glomerulosa is under feedback control of the ________ system.

renin-angiotensin-aldosterone

The cells of the zona ________ are noticeably smaller than those of the zona fasciculata, and their nuclei are more deeply stained.

reticularis

Zona ________ composes the innermost 25% of the cortex and appears as the darker zone of the cortex

reticularis

Both adrenal glands lie in a generous bed of _________

retroperitoneal fat

which adrenal gland is more cranial in position

right

The cranial two thirds of the right adrenal gland Is covered by the caudal extension of the __________ hepatic lobe of the liver

right lateral

________ hypoadrenocorticism is related to a pituitary problem; lack of ______ production

secondary, ACTH

what would the ACTH stimulation test look like in a dog with iatrogenic hypoadrenocorticism

should be high because there is a lack of cortisol for negative feedback

Osmolality is directly associated with ________ (ion)

sodium All animals that are hypernatremic are also hyperosmolal Hypoosmolality is always is associated with hyponatremia

Primary hypoadrenocorticism: Inability to retain _____ and ______ reduces extracellular fluid volume, leading to progressive development of hypovolemia, hypotension, a reduced cardiac output, an decreased perfusion of the kidneys and other tissues

sodium and chloride

Primary hypoadrenocorticism: Loss of aldosterone secretion results in impaired renal conservation of_____ and ______ and the excretion of ______

sodium and chloride , potassium (leading to the development of hyponatremia, hypochloremia, and hyperkalemia)

without aldosterone cells cannot hold on to _____ and _______ or excrete _______

sodium, chloride, potassium

explain endocrine alopecia

symmetrical on dorsal aspect- hair stuck in telogen phase

Innervation to the adrenal gland is predominantly ________ by way of the _________ plexus, which communicates with the major and minor ________ nerve, and the __________ plexus

sympathetic, suprarenal, splanchnic, celiacomesenteric

Glucocorticoids on proteins: Protein _______ is inhibited by glucocorticoids; causes increased protein _______

synthesis, catabolism (to release energy)

T/F Adrenocortical adenoma and carcinoma occur with equal frequency

true

T/F Unlike the cortex, the parenchyma of the medulla cannot be partitioned into zones according to cellular or tissue morphologic characteristics

true!

T/F The negative feedback of glucocorticoids occurs at all levels of the HPA axis, this includes the hypothalamus (TRH neurons) the anterior pituitary (corticotroph cells), and the adrenal gland (Zonas reticularis and fasciculata)

true!!!

Glucocorticoids inhibit _______ activity which leads to enhanced exertion of water

vasopressin

Phrenicoabdominal vein lies _________ to adrenal gland

ventral (lies on top of and across gland)

At the interface of the outer and inner cortices, there is a narrow band, the ___________ of small undifferentiated cells that make up the blastemic stem cells, which generate replacement parenchyma for both the inner and outer cortex

zona intermedia,


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