The Endocrine System Flashcards
What is the endocrine system?
A network of glands throughout the body that manufacture and secrete chemical messages known as hormones.
What are the 4 components of the endocrine system?
Hypothalamus
Pituitary gland
Adrenal glands
Ovaries or Testis
What is the role of the Hypothalamus?
Brain region controlling the pituitary gland
What is the role of the Pituitary gland?
Secretes many different hormones,some of which affect other glands
What is the role of the Adrenal glands?
Help trigger the fight - or - flight response
What is the role of the ovaries + testis?
Ovaries - secrete female sex hormones
Testis - secrete make sex hormones
What do the endocrine glands do?
Produce and secrete hormones that regulate the activity of cells or organs in the body.
What do glands does the endocrine system consist of?
Pituitary glands
Adrenal glands
Reproductive organs
How is the endocrine system regulated?
By feedback
E.g. a signal sent from the hypothalamus to the pituitary gland in the form of a ‘releasing hormone’ which causes the pituitary gland to releases ‘stimulating hormone’ into the bloodstream the hormone then signals the target gland (e.g. the adrenal glands) to secrete it’s hormone.
What are hormones?
The body’s chemical messengers
How do hormones work?
Circulate in the bloodstream and are carried to target sites throughout the body
How do target cells respond to particular hormones?
The target cells have receptors for that particular hormone.
What causes a dysfunction of bodily systems?
when too much or too little of an hormone is released at the wrong time.
E.g. too high a level of cortisol can lead to Cushing’s syndrome.
What is the pituitary gland controlled by?
The hypothalamus
How does the hypothalamus function?
Receives info from many sources about the basic functions of the body, then uses this info to help regulate these functions.
What are the two main parts of the pituitary gland?
the anterior pituitary (front)
the posterior pituitary (back)
Give an example of a hormones that are released by the anterior pituitary + what they’re responsible for.
ACTH as a response to stress - stimulates the adrenal glands to produce cortisol.
Luteinising hormone (LH) + Follicle - stimulating hormone (FSH) - both important in the control of reproductive functioning + sexual characteristics.
Give an example of a hormones that are released by the posterior pituitary + what they’re responsible for.
Oxytocin - stimulates contraction of the uterus during childbirth + is important for mother - infant bonding.
how many adrenal glands are there + where are the adrenal glands located?
2
sit on top of the kidneys
What are the two distinct parts that the adrenal glands are made up of?
The adrenal cortex
The adrenal medulla
What are the main distinctions between the adrenal cortex and the adrenal medulla?
The hormones produced by the adrenal cortex are necessary for life + the hormones produced by the adrenal medulla aren’t.
Give an example of a hormones that are released by the adrenal cortex + what they’re responsible for.
Aldosterone - responsible for maintaining blood volume + blood pressure
Give an example of a hormones that are released by the adrenal medulla + what they’re responsible for.
Adrenaline + noradrenaline - hormones that prepare the body for fight or flight
Adrenaline helps the body respond to a stressful situation e.g. increasing the heart rate + blood flow to the muscles and brain.
Noradrenaline constricts the blood vessels causing blood pressure to increase.
What are the ovaries responsible for?
The production of eggs
What hormones do the ovaries produce?
Oestrogen
Progesterone
What hormones do the testes produce?
Testosterone
