4 - Endocrine System Flashcards
Describe the structure and function of the endocrine system
Endocrine glands produce and secrete hormones into the bloodstream which are required to regulate many bodily functions.
The major glands of the endocrine system include the pituitary gland and the adrenal glands.
What are target cells?
Hormones only affect a limited number of cells, known as target cells.
They respond to a particular hormone because they have receptors for that hormone.
Describe the structure and function of the pituitary gland
Located in the brain.
Produces hormones which influence the release of other hormones from other glands.
Controlled by the hypothalamus, a region of the brain just above the pituitary gland
Describe the structure and function of the hypothalamus and how it works with the pituitary gland
A region of the brain just above the pituitary gland.
Receives information from many sources about the basic functions of the body. Then sends a signal to the pituitary gland in the form of a releasing hormone.
This causes the pituitary gland to send a stimulating hormone into the bloodstream to tell the target gland to release its hormone.
As levels of this hormone rise in the bloodstream the hypothalamus shuts down production of the releasing hormone and the pituitary gland shuts down secretion of the stimulating hormone.
Describe the two divisions of the pituitary gland
1) The anterior pituitary gland - releases ACTH - prepares body for fight/flight response which occurs when someone is stressed.
2) The posterior pituitary gland - releases oxytocin - crucial for infant/mother bonding
What are the two parts of the adrenal glands?
Adrenal Medulla
Adrenal Cortex
Describe the adrenal cortex
Outer section of adrenal gland.
Produces cortisol which is produced in high amounts when someone is stressed. Cortisol is also responsible for the cardiovascular system (increase blood pressure and cause blood vessels to contract)
Describe the adrenal medulla
Inner section of the adrenal gland.
Produces adrenaline and nor-adrenaline, the hormones that are needed for the fight or flight response which is activated when someone is stressed. Adrenaline is responsible for increasing heart rate, dilating pupils and stopping digestion. Noradrenaline is responsible for constricting blood vessels, causing blood pressure to increase.
