The Endocrine System II Flashcards
What are the parathyroid glands?
- 4 or 5 are present
- located at the posterior lobes of the thyroid gland
- secretes the parathyroid hormone
What is the function of the parathyroid hormone ( PTH) ?
- it antagonizes calcitonins effects on the blood calcium
- therefore it increases the blood calcium by increasing the activity of osteoblasts
- it activates vitamin D in the intestines which aids in the uptake and reabsorption of calcium from food in the GI tract
What are the disorders of the PTH? (2)
1) Hypersecretion - increase in blood calcium
- causes muscle and nerve irritability to decrease
2) Hyposecretion- decrease in calcium levels
- increase in muscle irritability
- can cause muscle spasms or convulsions
What is the Adrenal gland?
found on the superior surface of the kidney
- 2 layers ( the medulla and the cortex)
What is the adrenal cortex composed of ?
regular endocrine tissue
What is produced in the adrenal cortex?
steroid hormones, specifically in the corticosteroids
What are the zones of the adrenal cortex?
1) zona glomerulosa (outer)
2) zona fasciculata ( middle)
3) zona reticularis ( inner)
What are the hormones of the zona glomerulosa?
mineralocoricoids including aldoesterone
What is the function of aldosterone?
stimulates the kidneys to conserve Na+ via the exchange of Na+ for K+ and H+ ions
- this causes the release of ADH by the neruohypophysis
- this also decreases blood volume
What does a decline in BP cause ?
the kidneys to produce and release renin
What is renin
secreted by kidneys
-catalyzes the conversion of angiotensionogen to angiotension 2 which then stimulates the adrenal cortex to release aldosterone
What hormones comes from zona fasciculata?
glucocorticoids such as cortisol ( hydrocortisone)
What is cortisol?
has an antiinflammatory effect when released in high concentrations
- it also breaks down proteins and lipids and contributes to the production of glucose
- can depress the human immune function
What hormones are in the zona reticularis?
secretes gonadocorticoids ( small amounts)
- which produce testosterone and adrogens
- some estrogen
What is hyposecretion of aldosterone?
hypertension/edema + excessive secretion of K+
What is Addison’s disease?
- involves hypersecretion of aldosterone and cortisol
- patient will suffer weight loss, low glucose and Na+ levels in the blood, increase K+ in blood, dehydration and hypotension
What is cushioning disease?
hypersecretion of cortisol
caused by glucocoritcoid drugs or problems with the pituitary tumors
-hyperglycemia - loss of protien in muscle, increased bruising and a fatty face
What is the adrenal medulla?
- composed of neurosecretory tissue
- secretes additional norepinephrine and epinephrine CNS stimulates the adrenal gland itself
- this helps to prolong sympathetic stimulation
What is the pancreas
- found behind the stomach
- acts as an endocrine and an exocrine gland
What are the endocrine cells in the pancreas?
-pancreatic islet cells
What is the pancreas exocrine?
the pancreatic acini tissue is exocrine nature
- secretes digestive juices
What are the types of endocrine cells?
1) Alpha
2) Beta
3) Delta
4) PP or F cells
What are alpha cells?
- secrete insulin
- decrease blood glucose
- antagonizes the effects of glycogen
- BLOOD GLUCOSE LOWERING HORMONE
What are delta cells?
- secrete pancreatic polypeptides
- influences digestion and the distribution of food molecules
What is they thymus gland?
- large in childhood, smaller in adults
- located in the mediastium
- a lymphatic organ
- produces thymosins and thymopetins
- helps differentiate between WBC’s and mature T- cells
- serves an immune function
What do the testes secrete?
testosterone
What do the ovaries secrete?
estrogens and progesterones
What does the placenta secrete?
hCG - choronic gonadotropin
- stimulates the development of the maternal ovarian tissues that help maintain a pregnancu
- measured in pregnancy tests
What does the heart produce?a
atrial naturetic peptide ( ANP)
What does the GI tract produce?
various peptide hormones with digestive functions
What do the kidneys produce?
erythropoietin
stimulates the formation of eurthrocytes
What does the skin produce?
- cholencalciferol
- inactive form of vit. D
What does adipose tissue produce?
- leptin
- involved with appetite control
