ANATB - Endocrine Glands II

located in the upper thorax, large in children but shrinks with age, produces hormones that deal with the immune system, posterior to the sternum

thymus

what does the thymus do and what hormone does it produce

controls development of a special group of white blood cells and the immune response, thymosin

2 glands superior to the kidneys, each consists of a medulla and a cortex

adrenal glands

the ____ produces ____ major groups of steroid hormones

adrenal cortex, three

the three steroid hormones secreted by the adrenal cortex are called

corticosteroids

3 types of corticosteroids

1. mineralocorticoids

2. glucocorticoids

3. sex hormones

produced by the outermost cell layer of the adrenal cortex, regulates minerals in the blood

mineralocorticoids (aldosterone)

how do mineralocorticoids work?

they target parts of the kidney that reabsorb minerals or let them get flushed out of the body. they absorb sodium and release potassium into urine when aldosterone levels in blood rise. help regulate water and electrolyte balances in fluids

an enzyme released by the kidneys when blood pressure drops, involved in raising blood pressure, also releases aldosterone by triggering a series of reactions that form angiotensin II

renin

what is angiotensin II

a potent stimulator of aldosterone release

produced by the middle cortical layer of the adrenal glands, helps promote normal cell metabolism and cope with/resist long term stressors, released in response to rising blood levels of ACTH

glucocorticoids

glucocorticoids include _____, and are also called ____

cortisone and cortisol, hyperglycemic hormones

what happens when glucocorticoids in blood levels are high

fats and even proteins are broken down by cells and converted to glucose, which is released into the blood

what else can glucocorticoids do?

can control inflammation and reduce edema, can inhibit pain-causing prostaglandins, can be prescribed as drugs for rheumatoid arthritis

produced by the innermost cortex layer of the adrenal cortex throughout life in relatively small amounts

sex hormones

the majority of sex hormones produced are ____ but some ____ are also formed

androgens (male hormones), estrogens (female hormones)

hyposecretion of the of all the adrenal cortex hormones, characterized by a bronze tone to the skin, low aldosterone causes weak muscles and shock

addison’s disease

hypersecretion of the outermost cortical areas usually caused by a tumor there, where excess sodium ions are retained leading to edema and high blood pressure

hyperaldosteronism

a disease produced by excess secretion of glucocorticoids characterized by weight gain, high blood pressure and osteoporosis, caused by a tumor in the middle cortical area

cushing’s syndrome

hypersecretion of the sex hormones

masculinization

a knot of nervous tissue, stimulated by sympathetic nervous system, releases 2 hormones into bloodstream: epinephrine and nonepinephrine

adrenal medulla

epinephrine and nonepinephrine are ____ and also called

catecholamines, adrenaline and nonadrenaline

the fight or flight response stimulates the

adrenal medulla

what does the fight or flight response do

it pumps hormones directly into the bloodstream to enhance and prolong the effects of the sympathetic nervous system

what do catecholamines do

increase heart rate, blood pressure, blood glucose level, and dilate small passageways of the lungs

glands posterior to the stomach, produces both endocrine and exocrine secretions

pancreas

little masses of endocrine tissue scattered among the exocrine tissue of the pancreas

pancreatic islets (islets of Langerhans)

endocrine tissues produces ____ and exocrine tissue produces ____

hormones, enzymes

the many islets work like organs within an organ, what 2 hormones do the islets produce?

insulin and glucagon

what happens when blood glucose levels are high?

stimulates the release of insulin from beta cells of the islets

what role does insulin have on different parts of the body?

it acts on just about all cells, increasing their ability to import glucose across their plasma membranes and oxidize it for energy

why is insulin said to be hypoglycemic

because it sweeps glucose out of the blood, only hormone that decreases blood glucose level

when insulin is not present, what happens and what is it called? what are symptoms and treatments?

blood level of glucose skyrockets, glucose spills into urine b/c the kidneys can’t absorb it fast enough leading to dehydration. called diabetes mellitus, symptoms are polyuria (excessive urination), polydipsia (excessive thirst), polyphagia (hunger). treatments can be special diets or medications

what is the problem with insulin in type 2 (adult-onset) diabetes? what is it called?

insulin receptors are unable to respond, insulin resistance

what is glucagon and what does it do, what is its primary target organ

regulates blood glucose level to keep it from dropping too low, released by alpha cells, hyperglycemic, target organ is the liver

how does glucagon effect the liver

it stimulates the liver to break down stored glycogen to glucose to release it into the blood

the hormones produced by the ovaries and their specific functions

estrogen: development/growth of reproductive organs & breasts, cyclic changes in uterine lining (menstrual cycle)

progesterone: acts with estrogen to bring about menstrual cycle, helps prepare breast tissue for lactation

what stimulates the release of estrogen and progesterone?

the ovaries

what happens when there is hyposecreation of estrogen and progesterone

it severely hampers a woman’s ability to bear children

hormones produced by the testes:

androgens

role of testosterone in sperm production and development

promotes growth and maturation of reproductive organs, growth of characteristics like facial hair & deeper voice. necessary for continuous production of sperm