CHAPTER 9: Endocrine System Flashcards
(38 cards)
in charge of creating and releasing of hormones to maintain bodily functions
endocrine system
chemical substances secreted by endocrine cells
hormones
two classifications of hormones
- amino acid-based derived by proteins, peptides, & amines
- steroids derived by cholesterol
certain issue cells or organs affected by hormones
target cells or target organs
two mechanisms by which hormones trigger changes in cells
- direct gene activation
- second message system
explain direct gene activation
a type of mechanism where certain hormones can directly influence gene expression (can cross plasma membrane & binds with the receptors within the cell)
explain secondary messenger system
a type of mechanism that relays signals from outside of the cell to trigger responses inside the cell (cannot enter cell membrane, attach to the proteins on the surface of cell membrane)
secretion of hormones is triggered by the release of hormones from other glands
hormonal stimuli
example of hormonal stimuli
hypothalamus -> releasing & inhibiting hormones -> glands -> hormones
changes in blood levels of nutrients/ion that trigger the release or inhibition of a hormone
humoral stimuli
example of humoral stimuli
blood contains low concentration of calcium which stimulates secretion of parathyroid hormone by parathyroid glands
the nervous systen stimulates endocrine glands to secrete hormones
neural stimuli
example of neural stimuli
adrenal gland releases norepinephrine & epinephrine which provides bursts of energy required for the body to respond
major endocrine organs
- pineal gland
- hypothalamus
- pituitary gland
- thyroid gland
- parathyroid gland
- thymus
- adrenal gland
- pancreas
- gonads (sex glands)
location of pituitary gland
hangs by a stalk from the inferior surface of the hypothalamus
approximate size of pituitary gland
pea
does not make the hormone it releases (pituitary); acts as storage area
posterior pituitary gland
hormones made by hypothalamic neurons + functions
- Oxytocin: stimulates contractions of the uterine muscle during sexual relations, labor, & bread. it also cause milk ejection
- antidiuretic hormone: inhibits urine production
why is ADH being released
low blood volume -> low blood pressure -> dehydration -> release of ADH (reabsorbs H²O) -> increased blood volume -> increased blood pressure
master gland; releases hormones that control other glands
anterior pituitary gland
hormones released by the anterior pituitary gland & its functions
- growth hormone: growth of muscles & long bones
- prolactin: stimulates & maintains milk PRODUCTION
- gonadotropin follicle stimulating hormones: stimulates follicle development in the ovaries + stimulates sperm development in the testes
- luteinizing hormone: produce progesterone & estrogen + stimulates testosterone production
- thyrotropic hormone: influences the growth & activity of the thyroid gland
- adrenocorticotropic hormone: regulates endocrine activity of the cortex portion of the adrenal gland
small-cone shaped gland that hangs from the roof of the third ventricle of the brain
pineal gland
hormones released by pineal gland
melatonin: plays an important role in establishing the body’s sleep-wake cycle (high at night & low at morning)
