ANA Exam 4 Study Guide Flashcards
What are hormones?
Chemical messengers secreted into the bloodstream which stimulate physiological responses in distant organs
Once a hormone enters blood stream, it goes wherever the blood goes, only receptors for that hormone will pick it up
Most familiar hormone source is the endocrine glands
What are the endocrine glands?
A ductless gland that secretes hormones into the bloodstream
High density of blood capillaries (fenestrated capillaries), which pick up/ carry away hormones
I.e. pituitary, thyroid, adrenal glands and more
Define the endocrine system.
A system of internal chemical communication composed of all endocrine glands and the hormone-secreting cells found in other tissues and organs
Neuroendocrine cells: Act like neurons but release their secretions (like oxytocin)
What are target cells?
A cell acted upon by a nerve fiber or by a chemical messenger such as a hormone.
The target organ of corticotropin-releasing hormone, and oxytocin.
CRH: Targets adrenal cortex (growth of adrenal cortex, secretion of glucocorticoids)
Oxytocin: Uterus, mammary glands, brain (labor contractions, milk release, possibly involved in ejaculation, sperm transport in female, sexual affection, and parent-offspring bonding)
The location and anatomy of the adrenal glands and their position to the rest of endocrine glands.
The adrenal glands are attached to the superior aspect of each kidney.
2 distinct portions: the adrenal cortex and the adrenal medulla.
Adrenal medulla is essentially a sympathetic ganglion consisting of chromaffin cells, modified neurons devoid of dendrites and axons. The medulla responds to sympathetic stimulation by secreting catecholamines (a subgroup of monoamines), including epinephrine, norepinephrine, and a small amount of dopamine. The secretion occurs in response to stress.
Adrenal cortex synthesizes more than 31 corticosteroids (corticoids). All are synthesized from cholesterol.
The cortex has three tissue layers:
1. Zona glomerulosa
- The outermost, thin layer of the cortex consists of cells arranged in small, round clusters. Mineralocorticoids secreted by the zona glomerulosa control electrolyte balance. The main mineralocorticoid is aldosterone. Aldosterone targets kidney cells and causes sodium retention and potassium excretion, which affects blood volume and blood pressure.
2. Zona fasciculata
- In this thick middle layer, cells called spongiocytes are arranged in parallel cords perpendicular to the adrenal surface. The zona fasciculata produces glucocorticoids in response to ACTH. Glucocorticoids stimulate fat and protein catabolism, and release glucose and fatty acids to the blood. The principal glucocorticoid is cortisol, which helps the body respond to stress and tissue damage.
3. Zona reticularis
- Weak androgens and small amounts of estrogen are secreted by the zona
What hormones have effect on blood pressure?
Angiotensin II, natriuretic peptides, Aldosterone, Vasopressin/ADH (antidiuretic hormone), Norepi/Epi
The location and anatomy of the thymus and its
position to the rest of endocrine glands.
Located in the mediastinum superior to the heart and is larger in children than in adults.
It plays a role in the endocrine, lymphatic, and immune systems.
It is the site of maturation for white blood cells, the T lymphocytes (T for thymus) that play a critical role in immune response.
Secretes a number of hormones that stimulate the development of other lymph organs and regulate the development and activity of T lymphocytes.
What glands regressed after childhood? And hormones they released.
Adrenal: epinephrine, norepi, aldosterone, cortisol, corticosterone, androgens
Thymus: thymopoietin, thymosin, thymulin to T lymphocytes
Pineal gland: releases melatonin to the brain
The origin and function of insulin.
Released by beta/insulin cells in the pancreatic islets
Insulin is secreted during and immediately after a meal in response to rising blood-borne nutrients levels (glucose and amino acids)
Stimulates most body tissues to absorb these nutrients and store or metabolize them
Lowers blood glucose levels, promotes glycogen, fat, and protein synthesis
What are secreted by adrenal cortex, pineal gland, parathyroid gland, and neurohypophysis?
Adrenal cortex: Aldosterone, cortisol, corticosterone, androgens
Pineal gland:
Melatonin
Parathyroid gland:
Parathyroid hormone (PTH)
Neurohypophysis (posterior pituitary):
Antidiuretic hormone (ADH), Oxytocin (OT)
What are the effects of thyroid hormones, glucagon, and thyroid hormone?
Thyroid hormone (T4 and T3):
Stimulate prenatal and childhood brain development and bone growth, promotes pituitary secretion of growth hormone, quicker somatic reflexes, raises heart rate and metabolic rate, promote intestinal absorption of carbs, lowers plasma cholesterol levels, stimulate metabolic rate, heat production
Glucagon:
Secreted between meals when blood glucose level falls, stimulate release of stored glucose from liver and fatty acids from adipose tissue, provide body with blood-borne fuel until next meal
Label the pineal gland
Label the suprarenal gland
Label the upper respiratory tract
Label the parts of the larynx (posterior)
Label the parts of the stomach
Label the parts of the liver
Label the kidney anatomy
Label the lower male urinary tract
Label the parts of the Epididymis
Label the parts of the Uterus