module 6 endocrine system Flashcards
Which system works closely with the endocrine and coordinates various activities of the body
nervous
In nervous what do neurons release that influence excitability of other neuron
neurotransmitters
How does endocrine system interact with the rest of the body
hormones released into blood stream
Does the nervous system act faster than endocrine
yes
What allows cells to react to hormones
have specific receptors
“lock and key”
What is a hormone
organic chemical produced by 1 set of cells affect different set of cell
What are some characteristics of hormones
chemical messenger influence metabolism of recipiant
have specific organ/action
proteins coded for by gene and synthesized within cytoplasm at ribosome
eventually packaged into vesicles at golgi apparatus and secreted @ plasma membrane
What are 2 categories of hormones
peptide
steroid
What is a peptide hormone and function
derived from protein, peptides, catecholamines
activate existing enzymes in cell
react quickly for short period of time
What is a steroid hormone and function
derived from cholesterol by series of metabolic reaction
act more slowly
stored in fat-> until released in plasma membrane
enter cell and nucleus freely instead of needing to interact w/cell- surface receptor
once in nucleus, steroid hormone binds with receptor-> hormone receptor complex-> activate gene lead to protein synthesis
has more sustained affect on cell because of new protein
What are hormones secreted by
glands:
endocrine( ductless, secrete contents into blood stream for distribution)
exocrine( have ducts, secrete contents into epithelial surface: salivary-> secrete amylase)
What is a primary endocrine organ
secretes hormones chemically to regulate body functions
What are the primary endocrine organs
Hypothalamus, pituitary, pineal, thyroid, parathyroid, adrenal, pancreas
Which 3 primary endocrine organs are found in the brain
hypothalamus, pituitary, pineal
Where can the adrenals, thyroid, parathyroid and pancreas be found
adrenals: lie superior to each kidney
thyroid: attach to trachea below larynx
parathyroid: imbedded into surface of thyroid
pancreas: long organ lie transversely in abdomen between kidneys and duodenum of sm. intestine
What is the function of secondary endocrine organs and what is included
secrete hormone as secondary function
includes: heart, gonads, thymus( lobular in upper thorax)
What is the negative feedback system
controls most hormones
the way for the body to maintain homeostasis
has specific set point: thermostat
once body detect sufficient hormone turns off that specific hormone production, if low levels increases or turn on hormone production
what is the positive feedback system
increases amount of hormone regulated
example: oxytocin: causes uterus to contract and as uterus contracts more oxytocin is produced increasing contractions until baby born and uterus stop contracting which then stops the production of oxytocin
What is the function of the hypothalamus
regulate internal environment and homeostasis
controls: HR, body temp, H20 balance, glandular secretion of pituitary
Where does the pituitary gland lie and how many sections
lie just below hypothalamus
2 sections: anterior and posterior
What is structure and function of posterior pituitary
connected to hypothalamus by stalk like structures
stores and releases ADH and Oxytocin
What are neurosecretory neurons
neurons in hypothalamus that respond to neurotransmitters and produce hormones
What is the function of ADH and Oxytocin
ADH( Antidiuretic hormone)- promote reabsorption of H20 from ducts which receive urine
Oxytocin: increases contractions of uterus for childbirth: can be given artificially to induce labor: stimulate release of milk from mammary gland
What is function of anterior pituitary gland
secretes following hormones: GH, Prolactin, MSH, TSH, ACTH, FSH, LH
What is the function of the Growth Hormone( GH)
“Somatropic” hormone: affect physical appearance: ht and wt and bone structure
cause cell growth, division, protein sythesis
impact change on skeletal muscle, liver, bones
How does GH influence bones
promote growth of cartilaginous plate- cause osteoblast to form new bone
What is it called when there is too much GH in childhood and too little
too little: pituitary dwarf
too much: pituitary giant
What is acromeatly
overproduction of GH in adults
specifically seen in feet, hands, face( chin, nose and eyebrows)
what is the function of prolactin
produced only during pregnancy/childbirth nursing
cause mammary gland in breast to develop and produce milk
plays role in carb and fat metabolism
What is function Melanocyte stimulating hormone( MSH)
stimulate malanocytes ( skin) to increase synthesis of melanin
what is melanin
dark pigment release when exposed to sun
What is function of Thyroid stimulating hormone( TSH)
stimulate thyroid to produce T3 and T4
What is function of Adrenocorticotropic hormone( ACTH)
stimulate adrenals to produce cortisol
What is function of Gonadotropic hormones FSH and LH
stimulate gonads: testes and ovaries
What does TSH stimulate thyroid to produce
Thyroxin: T4
What do both T3 and T4 contain
Iodine
How is iodine transported
actively into thyroid- reach concentration of 25x greater than in blood
What is Goiter
enlarged thyroid- lack of iodine
low levels of thyroxin in blood, anterior pituitary cont to produce TSH-> increased thyroid in size which is ineffective because active thyroxin can’t be produced without enough iodine
What is the function of thryoxin
increased metabolic rate in cells-> Increased O2, # of respiratory enzymes
What is congenital hypothyroidism
individuals who have had decreased thyroid- hypothyroidism
What are symptoms of congenital hypothyroidism
reduced skeletal growth, sexual immaturity, abnormal protein metabolism- lead to intellectual disability
What other hormone does thyroid produce
calcitonin: decreases levels of calcium in blood and deposit Ca into bone; opposes action of parathyroid hormone
What is function of parathyroid gland
produce parathyroid hormone( PTH)
What is the interaction between PTH and Ca
PTH increase CA level in blood and decrease P
When appropriate Ca level reach parathyroid stop production through negative feedback
What are the actions that increase Ca
PTH cause increased Ca absorption from intestine
retain Ca through excrete P @ kidneys
in bones: promote osteoclasts: demineralize bone-> increase Ca in blood
What happens if PTH not produced in response to decrease Ca
Tetany- body shakes from continuous muscle contraction
Ca plays a role in nervous conduction and muscle contraction
Decreased blood Ca cause increased excitability of nerves: fire spontaneously w/o rest
What are the inner and outer portions of the adrenal glands called and which can be removed
inner: medulla- can be removed
outer: cortex- essential to life
What is the function of adrenal medulla
secrete epinephrine and norepinephrine into blood stream under stress
response: fight/flight
Increases blood glucose, metabolic rate, increased Breath and HR
blood vessel in intestine constrict, muscles dilate-> more dilate-more stamina
Which hormone is used to stimulate a patient in cardiac arrest
epinephrine
What is function of adrenal cortex
secrete 2 classe of hormones: glucocorticoids, mineralocorticoid
secrete sm. amount male sex hormone, very small female sex hormone
What is the function of glucocorticoids
most active is cortisol: under control by ACTH
promote hydrolysis protein( muscle) to amino acids that enter blood stream-> lead to increase level of glucose
favors fatty acid metabolism than carbs
in opposition to insulin, cortisol increase blood sugar
counteract inflammatory response
What is the function of minercorticoids
most active aldosterone: not under ACTH control regulate Na and K+ ion in blood primary target is kidney promotes: renal absorption of Na promotes renal excrete K+
What is important to maintenance of BP and indirectly regulate secretion of aldosterone
Na
Where is pineal gland found
3rd ventricle of the brain
What is function of pineal gland
produce melatonin: @ night
receives nerve impulse from eyes by optic tract
what makes the circadian rhythm
pineal gland and melatonin
person grow sleepy melatonin is high at night
awake in am when daylight and melatonin is low
shift worker and travel disrupt circadian rhythm
What are 2 types of tissue in the pancreas
exocrine: produce and secrete digestive juices by duct into small intestine
endocrine: panreacti islet of langerhan: produce and secrete hormone: insulin and glucagon into blood
When is insulin secreted and by what
beta cells; when increased blood glucose level: after meal
What are functions of insulin
1.stimulate liver, fat and muscle to take and metabolic glucose
2. stimulate liver and muscle to store glucose as glycogen
3. promote buildup of fate and protein: inhibit their use as energy source
promotes storage of nutrients on hand during time of decreased blood glucose
What is glucagon
secreted from pancreas by alpha cells
between eating: effects are opposite to insulin
stimulate breakdown of nutrients and cause blood glucose to rise
what is function of kidney
produce erythropoietin- acts on bone marrow to increase release RBC to blood
w/o RBC patient has anemia
What are the organs of female and male gonads: primary
male: testes in scrotum: produce androgens: testosterone
female: ovaries in abdominal cavity: produce estrogen and progesterone
What is function of testosterone
essential normal development and function of sex organ in males
sperm production
stimulate growth of penis and testes
cause growth of hard, beard, puberty, change voice
muscle strength
cause oil and sweat glands to secrete- body odor/acne
influence sex drive
What is function of FSH and LH
FSH: cause follicle on ovary to mature before ovulation-> increased estrogen production
LH: cause ovulation-> cause progesterone release to help potential fertilization of the egg and pregnancy
what is key to maintain pregnancy
progesterone
What is function of estrogen
stimulate growth uterus and vagina
necessary for egg maturation
secondary sex characteristic: body hair, fat distribution, breast development, regulate uterine cycle
Do both female and males produce all hormones
yes: varying degrees of each
males have higher testosterone
adrenals responsible for production of hormones
What is structure and function of thymus
lg size: most active in childhood
w/age organ gets smaller and fatty
produces thymosin which aids development of T-cells which aid immunes system.
