Chapter 64: Assessment of the Endocrine System Flashcards
Posterior pituitary hormones
Vasopressin/antidiuretic hormone ADH: kidney: water reabsorption
oxytocin: uterus and mammary: contractions, milk ejection
Anterior pituitary hormones
Thyroid stimulating hormone/thyrotropin TSH: target thyroid: synthesis and release of thyroid hormone
adrenocorticotropic hormone ACTH: target adrenal cortex: corticosteroids and adrenocortical growth
luteinizing hormone LH: ovary testes: ovulation and progesterone; testosterone secretion
follicle-stimulating hormone FSH: ovary testes: estrogen and follicle maturation; spermatogenesis
prolactin: mammary glands: breast milk production
growth hormone: bone and soft tissue: growth
Melanocyte stimulating hormone: melanocytes: pigmentation
Thyroid hormones
T3 triiodothyronine
T4 thyroxine
calcitonin
Adrenal cortex hormones
Glucocorticoids/cortisol
mineralocorticoids/aldosterone
Ovary hormones
Estrogen
progesterone
Pancreas hormones
Insulin
glucagon
somatostatin
hypothalamic-hypophysial portal system
The small, closed circulatory system that the hypothalamus shares with the anterior pituitary gland, which allows hormones produced in the hypothalamus to travel directly to the anterior pituitary gland.
Hypothalmus
The endocrine function is to produce regulatory hormones to stimulate or inhibit the release of anterior pituitary hormones.
Pituitary gland
Located in the sella turcica. Has two lobes, the anterior-adenohypophysis is the larger. The posterior lobe is the neurohypophysis. The posterior stores hormones produced in the hypothalamus. They are released when needed. Drugs, diet, lifestyle, and conditions can increase or decrease the secretion.
The anterior secretes tropic hormones (that stimulate other glands), and other hormones.
Gonads
The male and female reproductive endocrine glands.
Male puberty: increased secretion of gonadotropins which include luteinizing hormone & follicle-stimulating hormone from the anterior pituitary gland stimulates maturation of the testes, production of testosterone, maturation of external genitalia.
Female puberty: same hormones stimulate maturation of ovaries, estrogen production, ovulation, and external genitalia.
Adrenal glands
top of the kidneys. Outer is the cortex, inner is the medulla.
Cortex: 3 layers. Often called adrenal steroids or corticosteroids
Mineralcorticoids in the zona glomerulosa (Na and K). Control body fluids and electrolytes. Aldosterone
Glucocorticoids, androgens, and estrogens in the zona fasiculata and zona reticularis
Aldosterone
mineralocorticoid, adrenal cortex, maintains ECF.
NA and H2O reabsorption, K excretion in kidney tubules.
Regulated by renin-angiotensin system, rise in K concentration, and ACTH.
Renin is released by a decreased ECF (blood or NA loss, posture changes). It converts angiotensin in the liver to angiotensin I, which is converted to angiotensin II, which stimulates the secretion of aldosterone.
Cortisol
glucocorticoid from adrenal cortex
Carbohydrate, protein, and fat metabolism
Body’s response to stress
Emotional stability
Immune function
Regulated by directly by ACTH, and indirectly by CRH. These are affected by sleep wake cycle, and stress. Peaks in the morning with a low 12 hrs later. Stress increases the release.
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Sex hormones
Androgens and estrogens
Adrenal cortex
The gonads also secrete these hormones in larger amounts. However in women the adrenal gland is the major source of androgens.
Functions of glucocorticoid hormones
Maintain blood glucose.
Increase lipolysis, releasing glycerol and free fatty acids.
Increase protein catabolism.
Decreased collagen and connective tissue.
Increase the number of polymorphonuclear leukocytes released from the bone marrow.
Exert anti-inflammatory effects that decrease the migration of inflammatory cells to sign of injury.
Maintain behavior cognitive functions.
Adrenal medulla
Stimulation of SNS releases catecholamines epinephrine and norepinephrine. Play a role in stress response. Fight or flight response.
Thyroid gland
T3 and T4 Increase metabolism which increases oxygen use and heat production. the hypothalamus secretes thyroid releasing hormone>anterior pituitary to release TSH. Cold and stress will cause release.
Need protein and iodine to produce them.
Calcitonin Helps control the calcium and phosphorus balance. It lowers serum calcium and serum phosphorus levels by reducing bone resorption/breakdown. Low calcium levels inhibit the release.
Parathyroid
Four small glands behind the thyroid. Parathyroid hormone. It regulates calcium and phosphorus metabolism by acting on the phone comment kidney, and intestinal tract. Parathyroid hormone increases bone resorption which is the release of calcium into the blood from bone storage site.
Pancreas
Is located behind the stomach and islets of Langerhans produce hormones. Alpha secrete glucagon. Beta cells secrete insulin. Delta cells secrete somatostatin. Somatostatin inhibits the release of glucagon & insulin.
The main function is to regulate blood glucose. Glucagon increases blood glucose levels. It targets the liver to convert glycogen to glucose. It enhances amino acids from muscle to convert to glucose. Targets fats to convert to ketones. Insulin helps move glucose into cells
Endocrine changes with aging
Decreased ADH which increases the risk for dehydration. Decrease ovarian production of estrogen which decreases bone density, thinner dryer skin, vaginal dryness. And decreased glucose tolerance which leads to Increased weight and possible diabetes. Decreased general metabolism so they are less tolerant of cold, decreased appetite, decreased heart rate and blood pressure.
