ENDOCRINE SYSTEM Flashcards
define a hormone
chemical secretion from endocrine gland
how are hormones transported around the body
transported in the body via blood affecting cells
where are receptors located for protein amine hormones ?
attach to receptors in outside of the cell
not able to cross cell membrane
where are receptors located for steroid hormones ?
attach to receptors on inside of the cell
able to cross the cell membrane
which type of hormones alter gene expression
steroid hormones
which type of hormones alter enzyme activity
protein/amine hormones
what are paracrines?
local hormones - released by cells in particular tissues to communicate with adjacent cells in tissue
what is enzyme amplication
1 hormone leads to production of thousands of enzymes
what is hormone clearance
when the hormone has produced its desired effect - needs to be turned off
define negative feedback
response produced by secretions of hormones being opposite to stimulus that caused secretion
(oppose stimulus change)
what are the two lobes of the pituitary gland and where are they located
Anterior Pituitary Gland ( FRONT )
Posterior Pituitary Gland ( BACK )
how is the pituitary gland connected to the hypothalamus?
via the infundibulum
how is the PPG connected to the hypothalamus ?
via nerve cells (neurosecretory cells)
how is the APG connected to the hypothalamus ?
via blood vessels
how does the hypothalamus communicate with the APG
hypothalamus makes release factors for the specific hormone needing to be made
sends it to the APG via blood vessels in the infundibulum
these release factors bind to specific endocrine receptor cells in APG
stimulating it to make/release the hormone into the blood
what hormones are made in the APG?
Growth Hormone
TSH ( thyroid stimulating ) hormone
FSH ( follicle stimulating ) hormone
LH ( luteinising ) hormone
ACTH ( adrenocorticotrophic ) hormone
Prolactin
what hormones are released by the PPG?
Oxytocin
Anti diuretic Hormone
where is the Pineal gland located and what hormone does it secrete ?
located deep inside brain
secretes melatonin involved in regulation of sleep patterns
where is the Thyroid gland located and what hormone does it secrete ?
located in the neck, below larynx
secretes thyroxine and calcitonin
describe the function of thyroxine on the body
thyroxine acts to increase metabolic rate, which increases heat production
describe the function of calcitonin
acts to decrease blood calcium - opposing parathormone
where is the Parathyroid gland located and what hormone does it secrete ?
located in chest, above heart, sternum
secretes parathormone (parathyroid hormone)
4x on THYMUS
what effect does parathormone (parathyroid hormone) have on the body
increases calcium and phosphate levels in the blood
where is the Thymus gland located and what hormone does it secrete ?
located in chest, above heart, sternum
secretes thymosins
what effect do thymosis have on the body?
activates maturation of T cells , increasing immune function