Repro Flashcards
(95 cards)
hormone
any substance secreted by glandular tissue in the body which stimulate a specific physiological response in cells or activate certain tissues
endocrine
referring to glands that secrete hormones and other substances INTO the body (central circulation)
exocrine
referring to glands that secrete hormones and other substances OUTSIDE the body (into the GI tract, onto the skin)
catecholamine
an organic compound that functions like a neurotransmitter; can occur outside the CNS - specifically EPI, NE, DA
corticosteroid
any steroid type hormone produced by the adrenal cortex; ‘steroids’
Components of the Endocrine System (8)
Hypothalamus/pituitary gland
pineal gland
thyroid
parathyroid
thymus
adrenal glands
pancreas
gonads
Hypothalamus and Pituitary Gland components
anterior and posterior hypophysis
adrenal gland parts
cortical and medullary
Male and female gonads
M - testes
F - ovaries
Pituitary lobe
endocrine extension of hypothalamus: ‘master regulator,’ links the CNS to systemic endocrine function
anterior and posterior lobes
anterior pituitary gland secretions
secretes GH, tropic hormones, prolactin, ACTH, TSH, FSH, and LH
Anterior pituitary regulation
growth rate, sexual maturation, metabolism, stress response, metabolism, fluid balance
Anterior pituitary gland tumor rate
1 in 5 patients with intercranial tumors present with a pituitary tumor
Growth hormone (GH; HGH) primary function
growth regulation during childhood and puberty
GH; HGH
- HGH levels are mediated by hypothalamic signaling
- HGH released daily; metabolically important to growth of peripheral tissues (HGH synthesis increases after 18 mo; greatest levels during puberty, steadily declines > about 40 yrs old)
- HGH essential for normal growth/development (deficiency in childhood/puberty results in growth deficits)
GH; HGH opposes and stimulates what
- opposes activity of insulin
- stimulates gluconeogenesis + glycogenolysis
- acute phase reactant in stress/illness states
ACTH -> adrenocorticotropic hormone primary function
regulates the release of cortisol and other corticosteroids and androgens
ACTH signaled by. . .
the hypothalamus by CRH (corticosteroid releasing hormone)
ACTH -> augmenting metabolism and euvolemic fluid balance. . .
- cortisol and glucocorticoids 1) increase blood sugar, 2) induce catabolism of proteins and fats, 3) cause bone reabsorption
ACTH -> help increase muscle/bone mass, critical role in male secondary sex characteristics. . .
- spermatogeneis and testicular development
- testicular androgen production
Thyroid stimulating hormone (thyrotropin; TSH) primary function
control the release of thyroxine (T4) from the thyroid. helps decrease triiodothyronine (T3) to a lesser degree
TSH
- neg feedback loop btwn TRH, TSH, and T4
- TSH is not an ‘active thyroid hormone;’ T4 and T3 are
- as more TSH binds to TSH receptors in the thyroid, more active thyroid hormone is released (`80% as T4, 20% T3)
- iodine intake and utilization is necessary for normal thyroid and thyrotropic function
Follicle stimulating hormone; FSH
- primarily responsible for the initiation of the menstrual cycle
- stimulates the maturation of follicular oocytes in the ovaries
- men; lower levels of FSH help maintain/control spermatogenesis
Luteinizing hormone -> LH
- LH levels rise in females to stimulate ovarian production of estradiol
- peak after ~14 days in tandem with a surge in FSH -> causes ovulation
- after ovulation; the ovarian follice forms a corpus luteum, can make progesterone if implantation occurs
- men; lower levels of FSH stimulate the testes to produce testosterone