Endocrine system Flashcards
What controls the endocrine system?
the hypothalamus
do endocrine glands have a duct?
no
what is a hormone?
chemicals that travel through the blood stream to a target organ and cause and effect
what does autocrine mean?
a hormone that has an effect on the original cell that produced it (insulin)
what does endocrine mean?
a hormone transported in the blood to a target organ
what does exocrine mean?
a substance, that is not a hormone, released by a duct (pancreas and digestive enzymes)
what does paracrine mean?
a hormone that has an effect on local cells (testosterone/oestrogen)
what are the seven main endocrine glands?
-pineal
-pituitary
-adrenal
-ovaries
-testes
-thyroid
-pancreas
-parathyroid
what are three hormone organs that secrete hormones but this is not their main purpose?
stomach - gastrin
kidneys - erythropoeitin
small intestine - secretin
what is the pineal gland?
- in the brain
- produces melatonin (wake/sleep patterns and photoperiodic functions)
what is the hypothalamus?
- control centre of endocrine system
what is the pituitary gland?
- control over many endocrine gland
- ventral to forebrain
- two lobes (anterior and posterior)
- anterior lobe - adeno-hypophysis
- posterior lobe - neuro-hypophysis
what hormones does the anterior pituitary gland secrete?
- somatotrophic/growth hormone
- thyroid stimulating hormone
- adrenocorticotrophic hormone
- follicle stimulating hormone
- luteinising hormone
- luteotropic/prolactin hormone
- interstitial cell stimulating hormone
what is the somatotrophic hormone?
- influences growth of bones and soft tissues by increasing the uptake of amino acids and protein production and increasing fat deposits
what is the overgrowth of soft tissue when an animal has finished growing in terms of somatotrophic hormones called?
acromegaly
what is the thyroid stimulating hormone?
- stimulates the growth of the thyroid gland
- hormones T3 and T4
- stimulates the release of thyroxine which controls the metabolic rate
- controlled by negative feedback
what is the adrenocorticotrophic hormone?
- stimulates hormonal production from the adrenal cortex
- stimulates the release of corticosteroids and mineralcorticoids
- hypothalamus releases corticotropin-releasing hormone stimulating ACTH release
what is the follicle stimulating hormone stimulate in females?
- stimulates development of follicles on the ovary in females
what is the luteinising hormone responsible for?
- responsible for release of ova from the mature ovarian follicle and inital formation of corpus luteum in the female and targets the Leydig cells stimulating testosterone production in the male
what is the luteotrophic hormone?
- prolactin
- stimulates corpus luteum to produce progesterine
- stimulate milk let down
what is the interstitial cell stimulating hormone?
- stimulates secretion of testosterone from the interstitial cells in the testis
what hormones are in the posterior pituitary gland?
- oxytocin
- anti-diurectic hormone
what is oxytocin?
- causes uterine contractions and milk let down by acting on the smooth muscle of the uterus and mammary glands
what does an anti-diuretic hormone do?
- vasopressin
- regulates absorption of water from the distal convoluted tubule in the kidneys, so increases the reabsorption of water and decreases the volume of urine produced