Endocrine (E1-E4) Flashcards
This is an endocrine gland that secretes a plethora of hormones that regulate homeostasis; works in concert with input from the brain (hypothalamus) to coordinate many of the body’s endocrine organs
pituitary gland
Blood supply to the pituitary is from these 2 sources
Circle of Willis and internal carotid arteries
what is the other name for the anterior pituitary gland?
adenohypophysis
this part of the pituitary originates from an up-growth of the oral cavity (Rathke’s pouch) and secretes several hormones (TSH, ACTH, LH, FSH, and GH)
anterior pituitary gland
this part of the pituitary originates from a down growth of neural secretory tissue from the hypothalamic floor and releases oxytocin and vasopressin
posterior pituitary
this secretory cell type in the anterior pituitary secretes Growth Hormone (GH) (40-50%)
somatotropes
this secretory cell type in the anterior pituitary secretes ACTH (10-20%)
corticotropes
this secretory cell type in the anterior pituitary secretes TSH (5%)
thyrotropes
this secretory cell type in the anterior pituitary secretes LH and FSH (5-20%)
gonadotropes
this secretory cell type in the anterior pituitary secretes prolactin (10-30%)
lactotropes
this hormone is secreted by the posterior pituitary and acts on the kidney to regulate body fluid homeostasis by affecting water reabsorption
vasopressin
this hormone has direct and indirect actions on growth; protein, carb and fat metabolism; has rapid catabolic actions and slow anabolic effects
growth hormone
Growth Hormone deficiency can lead to this which results from enlargement of Rathke’s pouch or hyperplasia of the anterior pituitary
-animal initially retains puppy coat then develops bilateral symmetrical alopecia/progressive hyperpigmentation
pituitary dwarfism
Growth Hormone excess can lead to this condition which can be due to excess GH production by a pituitary adenoma (cats) or progesterone-induced production of GH by hyperplastic epithelium of mammary glands (dogs)
acromegaly
Blood supply to the adrenal glands comes from branches of these 2 arteries and the aorta
phrenic and renal arteries
this is the inner part of the adrenal gland that secretes catecholamines (adrenaline and noradrenaline)
adrenal medulla
this is the outer part of the adrenal gland that secretes steroid hormones
adrenal cortex
what are the 3 zones of the adrenal cortex of the adrenal gland?
zona glomerulosa (ZG), zona fasciculata (ZF), zona reticularis (ZR)
what is the main product secreted by the zona glomerulosa of the adrenal cortex?
aldosterone
what is the main product secreted by the zona fasciculata of the adrenal cortex?
glucocorticoids
what is the main product secreted by the zona reticularis of the adrenal cortex?
sex hormones
what are the three catecholamines?
adrenaline, noradrenaline, and dopamine
these are released as part of the “fight or flight” response to stress initiated in the hypothalamus and brain stem
catecholamines
the cardiovascular effects of catecholamines on this receptor includes: increased HR, cardiac output, and cardiac contractibility
Beta 1
the cardiovascular effects of catecholamines on this receptor includes: selective arteriolar vasoconstriction and increased systolic BP
Alpha
the cardiovascular effects of catecholamines on this receptor includes: vasodilatory effects
Beta 2
these are hormones of the adrenal cortex with predominate effects on Na+ and K+ excretion; 21-carbon derivatives of cholesterol; ex: aldosterone
mineralocorticoids
these are hormones of the adrenal cortex with predominate effects on glucose and protein metabolism; 21-carbon derivatives of cholesterol; ex: cortisol and corticosterone
glucocorticoids
these are hormones of the adrenal cortex are 19-carbomn derivatives of cholesterol; ex: DHEA and androstenedione
androgenic steroids
these hormones produced by the adrenal cortex play a role in intermediary metabolism to maintain blood glucose levels, are essential for life, and maintain vascular tone
glucocorticoids
this hormone produced by the adrenal cortex increases reabsorption of Na+ from the urine, saliva & colon contents; primary role is ECF volume maintenance
aldosterone
these hormones produced by the adrenal cortex are important for peripheral conversion to testosterone
adrenal androgens
this hormone regulates glucocorticoid secretion (increases GC release) and GCs inhibit its release
ACTH
secretion of this by the adrenal cortex is regulated to a degree by ACTH but more importantly by renin (via angiotensin II and plasma potassium concentration) (RAAS)
aldosterone
this condition is a primary immune-mediated destruction of the adrenal cortex, most common in middle-aged female poodle, NOT common in cats
aka Addison’s-like disease
hypoadrenocorticism
these glands develop from endoderm associated with the pharyngeal gut, they descend to their final location in the anterior part of the neck (lying on either side of the trachea)
thyroid glands
the two lateral lobes of the thyroid gland are connected by this narrow body (humans, sheep, residual in horse)
isthmus
this is the precursor to thyroid hormone that fills the center of each follicle in the thyroid gland
colloid
the 4 parathyroid glands that are closely associated with the thyroid glands secrete this hormone
parathyroid hormone (PTH)
the 4 parathyroid glands receive blood supply from this artery
thyrocervical arteries
parathyroid hormone (PTH) is released in response to decreased this in the blood (and functions to preserve normal blood levels of it)
calcium (and phosphate)
this hormone is released by parafollicular or C cells nestled between thyroid gland follicles and decreases extracellular calcium concentration
Calcitonin hormone
thyroid hormones are generated from these 2 molecules
tyrosines and iodide
this is an enzyme that controls thyroid hormone synthesis
thyroid peroxidase
what are the two principal thyroid hormones?
thyroxine (T4) and triiodotyronine (T3)
the rate of synthesis and release of thyroid hormones is controlled by the level of this hormone (which is released by the anterior pituitary)
thyroid stimulating hormone (TSH)
the anterior pituitary releases thyroid stimulating hormone (TSH) in response to stimulation by this hormone
thyrotropin releasing hormone (TRH)
this thyroid hormone is responsible for most of the actions of the thyroid and has a very short half-life (<1 day)
T3
this thyroid hormone is the principle hormone secreted by the thyroid glands but exerts little action of its own, and has a 7 day half-life
T4
this condition is failure to produce thyroid hormones; leads to decreases MR (weight gain), low body temp, slower HR, lethargy, etc
hypothyroidism
this condition is when there is over production of thyroid hormones; it leads to increased MR (weight loss), increased appetite, high HR, skeletal muscle weakness, etc
hyperthyroidism
which lobe of the pancreas lies close to the descending duodenum?
right lobe
which lobe of the pancreas extends over the caudal surface of the stomach?
left lobe
this type of pancreas tissue functions as a large gland and consists of acini and associated ducts
exocrine
this type of pancreas tissue produces hormones in the Islets of Langerhans that are secreted into the blood stream
endocrine
a lack of insulin or impaired action of insulin can lead to this condition
diabetes mellitus
these cells in the islets of Langerhans are the most abundant and produce insulin
beta cells
this is a large polypeptide produced by alpha cells in the islets of Langerhans, has the opposite effect of insulin (increases glucose availability for organs); released in response to low blood glucose levels
glucagon
this is a short polypeptide with a short half life produced by the delta cells in the islets of Langerhans and in the hypothalamus; suppresses GH secretion; released in response to increased blood glucose levels
somatostatin
this hormone promotes glucose uptake, glycogen synthesis, and amino acid uptake ; and inhibits GNG in the liver and glycogenolysis
insulin
this type of diabetes mellitus is due to insufficient insulin secretion leading to a complete lack of insulin (insulin-dependent, DDM)
type 1
this type of diabetes mellitus develops as a result of insulin resistance in the body, lack of appropriate response to insulin by target tissues (non insulin-dependent, NIDDM)
type 2
this condition occurs when target tissues fail to respond appropriately to insulin, so the insulin demand of the body rises & blood insulin levels are elevated (blood glucose levels eventually become elevated as beta cells become exhausted)
hyperinsulinaemia
this condition is when there are tumors on insulin secreting islet cells causing them to produce increased levels of insulin leading to hypoglycemia
insulinoma
