Endocrine System Flashcards
What does the hypothalamus do
- regulate body temp., water balance, heart rate, releases releasing and inhibiting factors
What hormones does the hypothalamus release
Releasing & inhibiting factors, oxytocin and ADH
What hormones does the anterior pituitary release
FSH, LH, growth, Adrenocorticotropin, thyroid stimulating , prolactin, parathyroid stimulating
What hormone does the pineal gland release
Melatonin
What hormones does the pancreas secrete
Insulin & glucagon
What hormones do the adrenal glands secrete
Cortisol, adrenaline, epinephrine, norepinephrine
What hormones does the thyroid produce
Thyroxine, calcitonin, triiodothyronine
What hormones does the parathyroid release
Parathyroid hormone
What hormone does the thymus make
Thymosin
What hormones do the ovaries secrete
Oestrogen & progesterone
What hormone does the testes secrete
Testosterone
Prolactin target tissue and effects
Mammary glands - milk production
Adrenocorticotropin target tissue and effect
Adrenal cortex, stimulate cortisol production
Growth hormone
Growth and protein synthesis in all cells
Gonadotrophins
Ovaries & testes, produce sperm and ova
Ocytocin
Uterus, mammary glands - uterine cintractions, lactation
ADH
Kidney tubules - water reabsorbtion
Melatonin
Various tissues - circadian rhythm, sleep
Thyroxine
Digestive system & muscle - metabolic rate
Calcitonin
Bone, decrease calcium levels
Triiodothyronine
Digestive & muscle - metabolic rate
Parathyroid hormone
Bones - increase calcium levels
Epinephrine, adrenaline, norepinephrine, cortisol
Stress, fight or flight, autonomic response
Insulin
Blood - decrease blood sugar
Glucagon
Liver - increase blood sugar
3 ways endocrine glands are prompted to release/not release hormones
-hormonal
- neural
- Humoral
Whats hormonal stimuli
Promotes release of another hormone
Eg. Hypothalamus- pituitary
Whats humoral stimuli
Changing in blood levels of certain ions and nutrients in turn stimulating hormone release
Eg. Parathyroid prompted by low calcium levels
Neural Stimuli
Directly innervated glands
Eg. Adrenal medulla stimulated by action potential to release adrenaline and noradrenalin during stress
What enables hormones to take action
Specific Protein receptors on target cell membranes/interior to which the hormone can attatch
What do hormones effect
Cell membrane permiability or electrical state, synthesis of proteins, activation/inactivation of enzymes, stimulation of mitosis, promote secretory activity
Things about steroid hormones
Lipid soluble, diffuse into cell, binds to receptor in cytoplasm, enters nucleus, promot biochemical action
Steps of steroid hormone action
1 diffusion through cell membrane
2 enters cytoplasm
3 binds to specific receptor protein
4 hormone receptor complex binds to sites on DNA
5 transcription of mRNA
6 mRNA translated in cytoplasm - protein synthesis
Things about peptide hormones
Water soluble, unable to enter target cells, bind to receptors on plasma membrane and utilise a second messenger system
Steps for peptide hormone action
1 hormone binds to membrane receptor
2 activated receptor sets off a series of reactions - activating an enzyme
3 enzyme catalyses reactions that produce second messenger molecules (cAMP)
4 intracellular changes take place that promote the typical response of the target cell to the hormone
Compare nervous system with endocrine
N - electrochemical message, high specificity of message, fast speed of response, some consious control, targeted response location
E - chemical message, less specific message, slow speed of response, involuntary response, widespread response location
What hormone does the thymus produce
Thymosin
What does Thymosin do
Maturation of T lymphocytes
Effects of steroid hormones
Slow to take effect but lasts long
Effects of protein hormones
Quick response but short lasting
Characteristics of protein receptors
-specific (lock and key)
- only a certain amount on each cell - can lead to saturation
How does the hypothalamus effect anterior and posterior pituitary glands
Anterior - blood vessels
Posterior - nerves (stores and releases hormones - oxytocin & ADH)
What does follicle stimulating hormone do?
Stimulates growth of follicles and production of sperm
Luitenising hormone effects
Stimulates ovulation
Stimulates secretion of testosterone
Thyroid stimulating hormone
Secretion of thyroid hormones
Prolactin
Milk production
Examples of protein hormones
Insulin, glucagon, thyrocalcitonin, pituitary hormones, and hypothalamic hormones
Examples of steroid hormones
Testosterone, progesterone, cortisol, aldosterone
