Endocrine System Flashcards
Endocrine system is a collection of?
Ductless Glands
What does the endocrine system produce?
Hormones
What is the control centre of the endocrine system?
The Hypothalamus
What determines the amount of hormone released?
The body’s need for the hormone at any given time
Exocrine Gland?
excretes its essential product by way of duct to external environment. -outside of body or surface of body
Endocrine Gland
secrete their hormones directly into blood, lymph or tissue fluid
Autocrine?
relates to hormone that has effect on original cell that produced it
Paracrine?
Relates to hormone with effect on local cells
Anterior Pituitary Gland is responsible for?
production and release of hormones
Hormones Secreted by anterior pituitary?
FSH - Follicle Stimulating Hormone ACTH - Adrenocorticotrophic Hormone TSH - Thyroid Stimulating Hormone LH - Luteinising Hormone ICSH - Interstitial Cell Stimulating Hormone Prolactin Somatropin/Growth Hormone
Follicle Stimulating Hormone?
Responsible for growth of follicles in ovary, targets Sertoli cells causing maturation of sperm (males).
Adrenocorticotrophic Hormone?
Targets cortex of adrenal glands; increase in ACTH stimulates production of corticosteroids from adrenal glands
Thyroid Stimulating Hormone?
Stimulates thyroid gland to release thyroxine, the function of thyroxine is to control the metabolic rate
Luteinising Hormone?
Females - responsible for maturation of follicles, helps ovulation and development of corpus luteum. Released spontaneously in the bitch, only in response to mating in the queen.
Interstitial Cell Stimulating Hormone?
ICSH targets interstitial (Leydig) cells in testicles and stimulates the release of testosterone and contributes to spermatogenesis.
Prolactin?
targets mammary glands to stimulate development during pregnancy and assist with milk production following parturition. Milk cannot be released until oxytocin is produced at end of gestation period.
Somatropin/Growth Hormone?
Controls rate of growth of young animal. Acts on all tissues of the body stimulating growth by increasing uptake of amino acids and protein production. Fat deposition is also increased, as is the rate of growth at the epiphyses of the bone.
Posterior Pituitary Gland is responsible for?
Releasing hormones directly into bloodstream
Hormones released by Posterior Pituitary Gland?
ADH - Antidiuretic Hormone/Vasopressin
Oxytocin
Antidiuretic Hormone/Vasopressin?
Released in response to increase in osmotic pressure (measured by baroreceptors)
ADH targets collecting ducts in kidneys increasing their permeability, causing an increase in reabsorption of water. Increasing plasma volume and reducing amount of urine produced.
Oxytocin?
Acts during pregnancy and parturition causing contraction of smooth muscle of uterus during labour. Can be used to clinically induce labour. Oxytocin affects milk ejection from mammary glands by stimulating smooth muscle around glandular cells and ducts to contract and eject milk - often referred to as milk let-down reflex.
Pineal Gland produces?
Melatonin
Thyroid Gland secretes?
Thyroxine - T4
Triiodothyronine - T3
Calcitonin - Thyrocalcitonin
How many parathyroid glands are there?
4
What does the parathyroid gland secrete and what does it do?
parathormone - regulates distribution and absorption of calcium, will increase blood calcium levels.
What is the blood calcium phosphorous level ratio?
1-1.5 Calcium : 1 Phosphorous
Adrenal Glands consist of?
Medulla - inner layer
Cortex- outer layer
Connective tissue capsule
What does the adrenal medulla secrete?
Adrenaline and Noradrenaline
What does the adrenal cortex secrete?
Glucorticoids - Cortisol
Mineralocorticoids - Aldosterone
Androgens - adrenal sex hormones
Beta Cells produce?
Insulin - in response to high blood glucose levels, causes decrease in blood glucose concentration
Alpha Cells produce?
Glucagon - in response to low blood glucose levels or stress, increases blood glucose concentration
Delta Cells produce?
Somatostatin - inhibits release glucagon and insulin to prevent fluctuations in blood glucose levels
What fixes low levels of glucose?
Glucagon
