Endocrine System; The Glands Flashcards
(45 cards)
Function of the hypothalamus
Maintain homeostasis and act as a control centre. Stimulates/inhibits body function. Links NS to endocrine
What Happens when Hypothalamus Receives Signal?
Will secrete neurohormones that control pituitary gland secretion
Corticotrophin Releasing Hormone (CRH)
Sends message to anterior pituitary gland stimulating adrenal gland to release corticosteroids which regulate metabolism/immune response
Gonadotrophin Releasing Hormone (GnRH)
stimulates anterior pituitary gland to release follicle stimulating hormone (FSH) and luteinizing hormone (LH) which work together to ensure function of ovaries/testes
Growth hormone-releasing hormone (GHRH) OR growth hormone-inhibiting hormone (GHIH)
also known as somatostatin. prompts anterior pituitary gland to release growth hormone. GH is essential to children’s healthy body composition. In adults, it aids healthy bone’s, muscle mass and fat distribution
Prolactin Releasing Hormone (PRH) OR Prolactin - Inhibiting Hormone (PIH)
prompts the anterior pituitary gland to stimulate breast milk production through the production of prolactin. PIH inhibits prolactin thus stopping breast milk production
Thyrotropin Releasing Hormone (TRH)
triggers the release of thyroid stimulating hormone that regulates metabolism, energy and growth/development
What does the Pineal Gland do?
Secretes Melatonin that controls circadian rhythm and inhibits some reproductive hormones. Also, its secretion is controlled by light levels
Circadian Rythm = when the body decides when it is time to go to sleep and be awake
Why is the Pituitary Gland Called the ‘Master Gland’?
Because its hormones control other parts of the endocrine system
How is it Connected to the Hypothalamus?
- It’s connected by the pituitary stalk (infundibulum)
How is the Pituitary Gland Connected to the Hypothalamus?
It’s connected by the pituitary stalk (infundibulum)
When and How does the Pituitary Gland Act?
It acts when the hypothalamus tells it to by sending hormones to other organs of the endocrine system instructing them to increase/decrease or inhibit hormone production
What are the Two Lobes of the Pineal Gland, and What do they do?
Anterior - produces and releases certain hormones when instructed via vessels from the hypothalamus
Posterior - releases different hormones when instructed via nerves from the hypothalamus
Adrenocorticotropic Hormone (ACTH)
stimulates the adrenal gland
Follicle Stimulating Hormone (FSH)
works with LH to ensure normal function of ovaries/testes
Growth Hormone (GH)
Essential in early years to maintain healthy body composition, muscle mass and fat distribution
Prolactin
stimulates breast milk production
Thyroid Stimulating Hormone (TSH)
stimulates the thyroid gland to produce hormones
The Posterior Lobe
It has many nerve endings coming from the hypothalamus so it can send hormones directly to the posterior lobe via these nerves and then the pituitary gland releases them
The Posterior Lobe Hormones
ADH - tells the kidneys to increase water absorption in the blood
Oxytocin - A variety of processing including contraction of the uterus during childbirth and stimulating breast milk production
What does the Thyroid Gland do?
Secretes metabolism hormones - all cells rely on the thyroid hormones for their metabolism regulation
What are the Two Main Hormones the Thyroid Makes?
It uses iodine to produce tri-iodothyronine (T3) and thyroxine (T4)
What Happens when Thyroid Hormone Levels are Low?
The hypothalamus releases thyroid releasing hormones (TRH) which signals to the pituitary gland to release thyroid stimulating hormone (TSH) causing the thyroid to produce more T3 and T4
What is a Normal Balance of T3 and T4?
20% T3 and 80% T4