Endocrine Shstem Flashcards
What is the endocrine system
The endocrine system provides a chemical system of communication in the body via the blood stream, working alongside the nervous system. Endocrine glands produce and secrete hormones into the bloodstream which are needed to regulate many bodily functions, the major glands of the endocrine system are the pituitary gland and adrenal gland, each producing hormones which regulate activity of organs/tissues in the body
What do hormones affect
Despite hormones coming into contact with most cells, they only affect a very limited amount, known as target cells. These cells respond to a particular hormone because they have receptors for that hormone. When enough receptor sites are stimulated by that hormone, there is a physiological reaction
What is the role of the pituitary gland
Located in the brain and it produces hormones whose primary function is to influence the release of other hormones from other glands in the body. It is controlled by the hypothalamus, a region of the brain just above the pituitary
How does the hypothalamus control the pituitary gland?
The hypothalamus reviews information from many sources about the basic functions of the body. The hypothalamus the sends a signal to the pituitary gland in the form of a releasing hormone, causing the pituitary gland to send a stimulating hormone into the bloodstream to tell the target gland to release its hormone. As the levels of this hormone rises in the bloodstream, the hypothalamus shuts down the production of the releasing hormone and the pituitary glands shuts down the release of the stimulating hormone
What are the two divisions of the pituitary gland?
1) The anterior pituitary gland: releases hormone ACTH which regulates the hormone cortisol, TSH, high stimulates the thyroid gland to release thyroxine, growth hormone, promotes cell growth
2) The posterior pituitary gland: responsible for releasing the hormone oxytocin which is crucial for infant/mother bonding and the release of ADH which regulates water balance of the body
How many adrenal glands do we have?
Two: situated on top of the kidney, made up of two distinct parts.
The adrenal cortex and the adrenal medulla
What does the adrenal cortex do?
It is the outer section of the adrenal gland and it produces the hormone cortisol which is produced in high amounts when someone is experiencing chronic stress. Cortisol s also responsible for cardiovascular system, e.g. it can increase blood pressure and cause blood vessels to constrict
What does adrenal medulla do?
Inner section of the adrenal gland and it produces adrenaline, the hormone needed in fight, a response that gets activated when suddenly stressed. Adrenaline increases heart rate, dilates pupils and stops digestion
