endocrine system Flashcards
what is an exocrine gland
least one duct and secrete their product on surface or in the lumen of a hollow organ
what is an endocrine gland
ductless glands which secrete hormones directly into the bloodstream
what does the endocrine system regulate
- growth
- development
- metabolism
- adaptive of body in stressful situations producing hormones
what carry hormones to target organs
blood and lymph
what are the central regulatory formations of the endocrine system
- hypothalamus
- hypophysis- pituitary gland
- pineal gland
what are the peripheral endocrine organs
- thyroid
- parathyroid
- adrenal glands
what organs have endocrine and nonendocrine functions
- gonads
- pancreas
- placenta
what are isolated endocrine cells
- secrete steroids and other hormones
what does the hypothalamus secrete
- oxytocin and antidiuretic hormone
- simulate or inhibit secretion of pituitary hormones
what do the axons of neurosecretory cells do
form hypothalamo-hypophyseal tract terminate in posterior pituitary as accumulations of herring bodies
what does the supraoptic nucleus secrete
vasopressin - ADH
what does ADH do
- increases permeability of water in distal convoluted tubules and collecting tubules making urine hypertonic
- contract smooth muscle tissue of small arteries and increase blood pressure
what does the paraventricular nuclei create
oxytocin
what does oxytocin do
- stimulates contraction of smooth muscle tissue in uterine during child birth
- myoepithelial cells of mammary glands during nursing
what do parvocelluar neucliei secrete
- Liberians and statins
what are statins
inhibit the production of relevant pituitary hormones
what are Liberins
stimulate the production of specific pituitary hormones
where are hypothalamic releasing hormones released
median eminence from neurosecretory terminals of neurones into the primary capillary plexus of the hypothalamo - hypophyseal portal system
what does the portal system do
carries hormones to secondary capillary plexus in the adenohypophysis
where is the pituitary gland/ hypophysis found
sella turcica of sphenoid bone
what are the two parts of the hypophysis
- adenohypophysis - pars distalis, para tubercles and para intermedia
- neurohypophysis
where does the adenohypophysis arise from
invagination from ectodermal roof or primitive mouth cavity forming rathke pouch
where does the neurohypophysis arise from
neuro-ectoderm from evagination from the floor of the diencephalon
what is the pituitary gland composed of
- glandular tissue - secretes hormones
- neural tissue - stories oxytocin and ADH