Bio 461 Exam 1 flashcards

Exocrine gland

have ducts

Endocrine glands

no ducts

endocrine glands

pituitary, thyroid, parathyroid, adrenal, and pineal glands

hypothalamus

neuroendocrine organ

endocrine system controls and regulates

• reproduction,

• growth and development,

• maintenance of electrolyte water and nutrient balance of blood

• regulation of cellular metabolism and energy balance

• mobilization of body defenses

amino acid based hormones

• cannot enter the cell body directly

• water based

• receptors are outside of the cell

• second messenger system

steroids

• enter the cell directly

• synthesized from cholesterol

• receptor is free floating and is located within cell or attached to the nuclear membrane

• direct access to DNA so it can make the cell react to the drug or hormone

Up regulation

more receptors in response to low hormone levels

Down regulation

lose receptors in response to high hormone levels

negative feedback system

blood levels of hormones controlled by what system?

half life

time required for hormone blood levels to decrease by half

target cells

tissues with receptors for specific hormone

amino acid based hormones

• act on plasma membrane receptors

• act via g protein second messengers

• cannot enter the cell

steroid and thyroid hormones

• can act on intracellular receptors that directly activate genes

• can enter cell

g protein

activates adenylate cyclase

adenylate cyclase

converts ATP to cAMP(secondary messenger)

cAMP

adenylate cyclase converts ATP to ——

phosphodiesterase

rapidly degrades cAMP

Humoral stimuli

changing blood levels of ions (body fluids)

Neural stimuli

nerve fibers stimulate hormone relasea

hormonal stimuli

hormones stimulate other endocrine organs to release their hormones

nervous system

—- Can override normal endocrine controls

antagonism

one or more hormones oppose actions of another hormone

parasympathetic nervous system

rest and digest

sympathetic nervous system

fight or flight

posterior pituitary lobe

stores and secretes * does not make anything

posterior pituitary and anterior pituitary

pituitary gland two major lobes

anterior pituitary

store makes and releases hormones

oxytocin and antidiuretic hormone (ADH)

posterior pituitary hormones

Rathke's pouch deformity

newborn presents with a large head and is growing quickly, labs results show an abundance of anterior pituitary hormones

oxytocin

uterine contraction and milk EJECTION

Antidiuretic hormone (ADH)

inhibits/prevents urine formation

regulates water balance

targets kidney tubules so they reabsorb more water\

creates aquaporins

alcohol and diuretics

inhibit ADH

vasoconstriction

high concentrations of ADH lead to—

growth hormone(GH), Thyroid stimulating hormone(TSH), Adrenocorticotropic hormone (ACTH), follicle stimulating hormone(FSH), luteinizing hormone(LH), prolactin (PRL)

anterior pituitary hormones

bone and skeletal muscle

growth hormone major targets

growth hormone releasing hormone (GHRH)

stimulates growth hormone release

growth hormone inhibiting hormone (GHIH)

inhibits growth hormone release

gigantism and acromegaly

hypersecretion of GH

gigantism

affects children because their growth plates are still open, leads to excessive abnormal body size

acromegaly

affects adults because growth plates are closed, large head, and shoe size (normally cause by pituitary tumor)

pituitary dwarfism

hyposecretion of GH

thyroid stimulating hormone

• stimulates normal development and secretory activity of the thyroid

• release triggered by thyrotropin-releasing hormone from the hypothalamus

• inhibited by rising blood levels of thyroid hormones (negative feedback)

adrenocorticotropic hormone

stimulates adrenal cortex to release corticosteroids

gonadotropins

FSH and LH

FSH

gamete (egg or sperm) production

LH

promotes gonadal hormones (ex. testosterone)

prolactin (PRL)

stimulates milk PRODUCTION

prolactin inhibiting hormone (PIH) (dopamine)

primarily controls prolactin

parafollicular cells

produce calcitonin

Thyroxine (T4)

has 2 tyrosine molecules and 4 bound iodine atoms

triiodothyronine (t3)

has 2 tyrosine’s and 3 bound iodine atoms

thyroid hormone

• major metabolic hormone

too little TH

intolerance to cold and new hair

too much TH

can’t handle heat and hair falling out

t3

ten times more active than t4

TRH

overcomes negative feedback during pregnancy or exposure to cold. rising levels provide negative feedback inhibition on release of TSH

hyposecretion of TH in adults

myxedema; goiter, protruding eyes, mustache, intolerance to cold

myxedema

swelling of shins

calcitonin

produced by parafollicular cells, storese ca2+ in bone, lowers ca2+ concentration in the blood

parathyroid hormone (PTH)

most important hormone in ca2+ homeostasis

chief cells

secrete PTH

Parathyroid hormone

increase ca2+ concentration in blood

hypoparathyroidism

causes tetany, respiratory paralysis, and death due to inability to control muscles due to lack of ca2+ in blood (cant contract muscles)

signs of hypoparathyroidism

chvostek’s sign and trousseau’s sign

Chvostek’s sign

tapping along the course of the facial nerve causes contractions of the muscles of the eye mouth or nose (over reaction of muscles)

trousseau’s sign

inflating a blood pressure cuff about the arm for several minutes induces carpal spasm within seconds, which goes away after cuff is deflated (over reaction of muscles)

adrenal medulla

nervous tissue; part of sympathetic nervous system

adrenal cortex

three layers of glandular tissue that synthesize and secrete corticosteroids

zona glomerulosa

produces mineralocorticoids

zona fasciculata

glucocorticoids

zona reticularis

gonadocorticoids

mineralocorticoids

regulates electrolytes

aldosterone

most potent mineralocorticoid, stimulates Na+ reabsorption and water retention by kidneys

alcohol

blocks aldosterone

atrial natriuretic peptide (ANP)

blocks renin and aldosterone secretion to decrease blood pressure. Comes from right atrium

right atrium

where atrial natriuretic peptide (ANP) comes from

glucocorticoids

keeps blood glucose levels relatively constant. Maintains blood pressure—- stress response will cause this to save glucose for the brain

cortisol (hydrocortisone

only major glucocorticoid in humans

hypersecretions of glucocorticoids

cushings syndrome

hyposecretion of glucocorticoids

addison’s disease

cushing’s syndrome

• caused my hypersecretion of glucocorticoids

• trunk obesity and wiry arms and legs

• depresses cartilage and bone formation

• inhibits inflammation

• depresses immune system

• disrupts cardiovascular, neural, and GI function

• buffalo hump

Addison’s disease

• hyposecretion of glucocorticoids

• bronze skin

• decrease in glucose and NA+ levels

• weight loss, severe dehydration, hypotension

gonadocorticoids hypersecretion

adrenogenital syndrome (masculinization)

adrenogenital syndrome

only noticeable in females and prepubertal males.

boys: reproductive organs mature; secondary sex characteristics emerge early

females: beard, masculine pattern of body hair; clitoris resembles a small penis

medullary chromaffin cells

synthesize epinephrine

catecholamines

epinephrine and norepinephrine hormone class

adrenal medulla hypersecretion

• hyperglycemia

• increased metabolic rate

• rapid heartbeat and palpitation

• hypertension

• intense nervousness

• sweating

adrenal medulla hyposecretion

not problematic because adrenal catecholamines not essential to life

pinealocytes

secretes melatonin derived from serotonin

alpha cells

produce glucagon

beta cells

produce insulin

glucagon

increase blood sugar

insulin

lowers blood sugar by moving sugar into the cell

acinar cells

produce enzyme rich juice for digestion

pancreatic islets (islets of langerhans)

contain endocrine cells

glycogenolysis

breakdown of glycogen into glucose

gluconeogenesis

synthesis of glucose from lactic acid and non carbohydrates

diabetes mellitus signs

large urine output, ,excessive thirst, excessive hunger

hypoglycemia

hyperinsulinism causes