ENDOCRINE SYSTEM Flashcards
branch of physiology dealing with coordination of various body tissues by chemical mediators produced by restricted ares of the body and transported the circulatory system to the organ or tissue on which they exert their effects.
ENDOCRINOLOGY
substance or chemical mediator produced by the endocrine glandsand secreted into the bloodstream
HORMONE
Classification of hormones according to composition:
- polypeptides
- glycoproteins
- amines
- steroids
each less than 100 amino acids long
ex. insulin - helps control glucose levels in the blood
- polypeptides
a polypeptide chain, longer than 100 amino acids;
attached to carbohydrate
ex. FSH and LH
- glycoproteins
hormones derived from amino acids tyrosine and tryptophan
- amines
lipids derived from cholesterol
ex. corticosteroids secretes from adrenal glands
- steroids
essential component of endocrine system
hypothalamus
functions of hypothalamus
- control of autonomic NS
- reception of sensory impulses from viscera
- intermediary between NS and ES
- control of body temp.
- regulation of body intake
- thirst center
- part of limbic system - emotios such as rage and agression
- part of reticular formation
3 lobes of pituitary gland or hypophysis
- anterior -
- intermediate -
- posterior -
- anterior - adenohypophysis
- intermediate - pars intermedia
- posterior - neurohypophysis
with two lobes connected by isthmus, bridge of tissues; maintains levels metabolism in the tissues optimal for the normal function;
secretes T4 and T3
thyroid gland
T4
thyroxine
T3
triiodothyronine
increases the basal metabolic rate of an individual
T4 thyroxine
stimulates the oxygen consumption and most of cells in the body, and helps regulate lipid and carbohydrates metabolism
T3 triiodothyronine
body wasting, nervousness, excess heat production
excess thyroid secretion
caused by thyroid stimulating immunoglobulins (TSI)
grave’s disease (exopthalamic disorder)
simple goiter; lack of thyroxine secretion due to iodine deficiency in the diet
hypothyroidism
located near the thyroid gland
produces paratyhroid hormone (PTH)
stimulates tha calcitonin secretion in the thyroid gland in response to the increasing Ca level in the blood.
parathyroid gland
increases the level of Ca in the blood by mobilization of Ca from the bones, and enhancement of Ca and P absorption from intestinal tract ( urinary phospahate exretion)
(PTH) Parathyroid hormone
lowers Ca level
calcitonin
2 division of adrenal gland
- adrenal cortex
2. adrenal medulla
located at the anterior part of the kidney
adrenal gland
hormones of adrenal cortex
1, glucocorticoids - cortisol
- cortisone
- corticosterone 2. aldosterone
hormones of adrenal medulla
1, epinephrine (adrenalin)
2. noephinephrine
secreted by zona fasciculate and zona reticularis
stimulates glycogenolysisand gluconeogenesis
glucocorticoids
secreted by zona glomerulosa
regulates mineral metabolism and water balance;
regulates soduim metabolism by reabsorbing sodium from kidney tubules
aldosterone
emergency hormone, increase heart rate, vasoconstriction
epinephrine (adrenalin)
maintenance of blood pressure
noephinephrine
located at the duodenal loop of small intestine
pancreas
function of pancreas as exocrine gland:
acinar cells secrete pancreatic juices w/ digestive enzymes
function of pancreas as edocrine gland:
islets of langerhans alpha and beta cells produce 2 diffrent hormones
produces insulin w/c stimulates entry of glucose into the cells for metabolism
anabolic process: lowering blood glucose levels
increasing storage of glucose, fatty acids and amino acids.
beta cells
excess insulin
hypoglycemia
lack of insulin
diabetes mellitus
produces glucagon w/c stimulates glycogenolysis
catabolic process: increasing blood glucose levels
mobilizing glucose, fatty acids and amino acids into the bloodstream
alpha cells
excess glucagon
worsens diabetes
lack of glucagon
can also cause hypoglycemia
male gonad
testes
produce nale gametes w/c is sperm
produces hormone testosterone for the devt of male chracteristics
testes
female gonad
ovary
produces female gametes w/c is ova
ovary
produces estrogen, progesterone, relaxin
ovary
produces hormone testosterone for the devt of male chracteristics
testes
to enhance female receptivity during estrus, development of accessory esx glands (mammary gland)
estrogen
from corpus luteum to maintain pregnancy and to develop alveoli of mammary gland
progesterone
for the relaxation of the cervix during parturition
relaxin
