Endocrine System: Hormones Flashcards
Hormones
- chemicals produced in one part of body by endocrine system and secreted in circulatory system to affect cells
- acts as regulators (to change speed of body processes)
- Cells have certain receptors for certain hormones
Types of Hormones
- Non-target
- Target
- Tropic
- Non- Tropic
Non target hormones n example
- affect many cells throughout body
ex. insulin causes many cells to absorb glucose
Target hormone and example
- Affect specific cells or tissues only
- ex. gastrin affects stomach only
Tropic hormones n example
- activate other endocrine glands to release hormones
ex. TSH from
pituitary activates thyroid gland to release thyroxine
Non tropic and ex
- Stimulate other tissues that are not endocrine
ex. epinephrine affects heart, blood vessels, diaphragm, airways, etc.
what type of hormones does the pancreas produce
- Somatostatin
- Glucagon
- Insulin
Somatostatin
- control rate at which blood absorbs nutrients
- in pancreas
Glucagon
- produced by alpha cells
- inc blood sugar lvls my stimulating liver to break down glycogen into glucose, which is released into the blood
- in pancreas
Insulin
- Produced by beta cells
- decrease blood glucose lvl by increasing uptake of glucose by cells
- in pancreas
Hormones from adrenal medulla and its functions
- Epinephrine & norepinephrine
- involved in short term stress response
- controlled by sympathetic NS
- causes increased heart rate, breathing rate, blood flow, inc blood sugar, redirects blood to brain from muscles
Hormones from Adrenal Cortex
- long term stress response
- ACTH acts on adrenal cortex to release these steroid hormones: Glucicorticoids, Mineralcorticoids, Sex Hormones
Glucocorticoids (Cortisol)
- inc lvl of amino acids in blood to help body recover from stress
- amino acids convert to glucose by liver which raises lvl of blood sugar to provide greater energy source to help recover cells
- amino acids not converted to glucose are available for protein synthesis to be used to repair damaged cells
- Fats broken down to be used as second source of energy
Mineralocorticoids (Aldosterone)
- Cause inc in reabsorption of sodium from nephron
- Na absorbed > water follows > aldosterone lead water to reabsorption > inc blood pressure
- aldosterone responds when BP is low (due to large loss of bodily fluids)
Sex Hormones
- small amounts of male n female hormones
- Responsible for female sex drive
- at menopause, testosterone can be converted to some estrogen
- assists in prepubertal growth spurt
- assists in early sexual development
Hormones from Thyroid gland
- Thyroxine (T4)
- Triiodothyronine (T3)
- Calcitonin
Thyroxine (T4) n Triiodothyronine (T3)
- Iodine containing hormones
- control rate at which glucose is burned in body
- inc metabolism and heat production and regulates growth
- feedback to anterior pituitary and hypothalamus to stop producing TSH and TRH
Calcitonin
- causes blood calcium lvls to decrease by causing calcium to be deposited in bones
- stimulated by high calcium lvls in blood
- act on: kidneys (to secrete urine), intestines (inhibit absorption of Ca), Bones (promote Ca uptake from blood)
Parathyroid Hormone
- stimulated by low Ca lvls in blood
- Inhibit release of Calcitonin from thyroid gland
- cause ca lvls in blood to increase
- acts on: Kidneys (reabsorb more Ca before secreting and activates vit.D which promotes intestinal uptake of Ca, Intestines (to absorb Ca from food), Bones (release Ca into blood)
Which hormones does the hypothalamus produce
- ADH
- Oxytocin
Releasing Hormones
- aka releasing factors
- peptides produced by hypothalamus that stimulate anterior pituitary to release its hormones
Inhibiting Hormones/factors
- produced in hypothalamus
- Stop pituitary secretions and inhibit production of anterior pituitary hormones
- factors travel from hypothalamus to pituitary by blood vessels
ADH (antidiuretic, vasopressin)
- stimulate water reabsorption in nephron bcs of dehydration
- released from posterior pituitary, but made in hypothalamus
- water removed from urine to conserve body water>less urine> more water in blood> high BP
- sensory receptors called osmoreceptor in hypothalamus detect osmotic pressure
- make collecting duct of nephron more permeable to water
Oxytocin
- released from posterior pituitary, made in hypothalamus
- stimulates contraction of uterus and milk “let down” reflex
Growth Hormone (somatotropin)
- stimulates growth (mostly bone n muscles)
- inc protein synthesis n cell division
- important in young children
- associated w/ diet, stress lvls, sleep
- affected by insulin, androgens, and thyroid hormones
Thyroid Stimulating Hormone (TSH)
- stimulate thyroid to release its hormones (thyroxine)
- type of tropic hormone
- produced in anterior pituitary
Adrenocorticotropic Hormone (ACTH)
- Stimulate adrenal cortex to release its hormones (Aldosterone n cortisol)
- type of tropic hormone
- produced in anterior pituitary
Prolactin
Stimulates production of breast milk after child birth
- produced in anterior pituitary
What are Gonadotropic Hormones
- classified as tropic hormones
- Follicle Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
Follicle Stimulating Hormone (FSH)
- Females: stimulates development of follicles in ovary which stimulates production of estrogen
- Male: stimulates production and maturation of sperm
Luteinizing Hormone (LH)
- Females: Stimulates ovulation and production of corpus luteum which produces proestrogen and some estrogen
- Males: aka interstitial cell stimulating hormone (ICSH) bcs it stimulates interstital cells to produce testosterone
2 Classifications of hormones
- steroid hormone
- protein hormone
Steroid hormone
- made from cholesterol
- fat (lipid) soluble
- longer lasting effect
- act inside cell
- can be orally taken (not digested in stomach)
- ex. thyroxine, testosterone, estrogen
Protein Hormones
- made of proteins, peptides, or amino acids
- water soluble
- act outside of cell > activates enzymes in cytoplasm
- cannot be orally taken (digested)
- ex. ADH, insulin, GH
Prostaglandins
- Group of hormones that do not move to other sites in body
- Act directly on cells that produce them
- tissue cells release prostaglandins when tissue is damaged (stressed)
- stimulate inflammination > inc. blood flow > stimulare platelets to form clots
- Role in producing fever
- inc perception of pain
BP and Aldosterone
- Juxtaglomerular appartus near glomerulus (in kidneys) has BP pressure receptors called baroreceptors
- When BP is low, baroreceptors detect change and stimulate JGA to release enzyme called renin
- renin converts angiotensinogen into angiotension
Renin
- renin converts angiotensinogen into angiotensin
- released when JGA is stimulated
Angiotensin
- constricts blood vessels > inc BP
- Stimulates release of aldosterone > carried to kidneys to act on cells of distal tubule and collecting duct to inc Na absorption > osmotic pressure inc. > more water move out of nephron and into blood > inc BP and blood volume
Aspirin
- Effective reducer of pain, fever, inflammination
- Blocks enzymes involved w/ prostaglandin production
- reduce prostaglandin, blood dont clot easily
- possible danger bcs you can bleed profusely
