hormonal communication Flashcards
list the 9 major glands of the body
hypothalamus
pituitary gland
parathyroid gland
thyroid gland
thymus gland
adrenal glands
pancreas
ovaries
testes
where is the hypothalamus located
it is the region at the base of the brain
what hormones does the hypothalamus secrete
various hormones which stimulate the pituitary gland
where is the pituitary gland located
located at the base of the brain below the hypothalamus
what hormones does the pituitary gland secrete
anterior pituitary secretes TSH - thyroid stimulating
FSH + LH - menstrual regulation
ACTH - stimulates adrenal cortex
posterior pituitary secretes oxytocin - antistress + reproduction + birth contractions
ADH - water control
pituitary gland regulates other glands and hormones, and influences growth + metabolism + reproduction + water balance
where is the parathyroid gland located
in the neck, behind the thyroid gland
- it works alongside the thyroid gland for some functions
what hormones does the parathyroid gland secrete
it produces parathyroid hormone PTH - this regulates Ca levels in the blood by stimulating release of Ca from bones or reabsorption of Ca by kidneys
where is the thyroid gland located
located in the neck consisting of 2 lobes around the trachea
what hormones does the thyroid gland secrete
thyroxine and triiodothyronine - responsible for regulating metabolism + growth + development in the body
calcitonin which works antagonistically with PTH
function of the thymus gland
a lymphatic organ
it is involved in the maturation and regulation of T-cells, and is prominent in childhood development, its size decreases with age
where are the adrenal glands located
there are 2, each located above each kidney
what hormones do the adrenal glands secrete
consists of 2 parts
adrenal cortex secretes steroid hormones - cortisol, aldosterone, androgens
adrenal medulla secretes peptide hormones - adrenaline, noradrenaline
these hormones impact metabolism + blood pressure + stress response
what gland secretes aldosterone + what does it do
secreted by adrenal cortex
it regulates salt levels and water balance of blood, therefore impacting volume and pressure
what gland secretes cortisol + what does it do
secreted by adrenal cortex
it is the primary stress hormone, regulates metabolism of glucose + proteins + fats to release useable energy
what gland secretes adrenaline + what does it do
secretes by adrenal medulla
it is produced at times of stress or excitement that affects many organs in the body, preparing the body to respond to emergency situations - fight or flight
where is the pancreas located
located in the upper abdomen, by the stomach
what hormones does the pancreas secrete
insulin + glucagon - used to regulate blood glucose concentration
where are the ovaries located
located on either side of the uterus in females
what hormones do the ovaries secrete
oestrogen + progesterone + small amounts of testosterone - these regulate the menstrual cycle + reproductive system + development of secondary sexual characteristics in puberty
where are the testes located
located in the scrotum
what hormones do the testes secrete
testosterone - the primary male sex hormone, responsible for developing secondary sexual characteristics in puberty + regulating sperm production + reproductive tissues in males
what is an essential feature of endocrine glands
they must have a good blood supply
why do endocrine glands have good blood supplies
this allows them to secrete hormones directly into the blood stream (specifically blood plasma)
how do hormones work
they are transported around the body via the blood stream to target cells and tissues, which have complementary receptors on cell surface membrane, allowing them to interact with the hormone to bring about a response
what kind of response is achieved by hormones + why
slower and longer lasting responses (compared to nervous system)
- transmission is slower as it takes longer for hormones to reach target cells
- effect lasts longer as it takes time before hormone has been completely removed from the blood or be broken down so no longer binding to target cells
what are the 2 types of hormone
steroid - derived from cholesterol and insoluble in blood, activates cell internally as it can move through membrane - e.g. testosterone, oestrogen, cortisol
peptide - globular proteins made of amino acid chains, soluble in blood, activates cell externally via glycoprotein receptors - e.g. adrenaline