Bio - The endocrine system Flashcards
What do the endocrine and nervous systems work very closely together to do?
Regulate the physiological processes of the human body.
How does the endocrine system send its signals?
Uses blood vessels to deliver hormones to their target sites in the body.
What is the hypothalamus and what does it do?
Brain region controlling the pituitary gland.
What does the pituitary gland do?
Secretes many different hormones, some of which affect other glands.
Where is the pituitary gland?
Below the hypothalamus.
What do the adrenal glands do?
Help trigger the fight or flight response by producing adrenaline.
Where are the adrenal glands?
On top of the kidneys.
What do the testes do?
Secrete male sex hormone - testosterone.
What do the ovaries do?
Secrete female sex hormones - oestrogen and progesterone.
What do hormones do?
Regulate the activity of cells or organs in the body.
What are the major glands of the endocrine system?
Pituitary gland, adrenal glands and reproductive organs (ovaries and testes).
What is the endocrine system regulated by?
Feedback.
What do hormones act on?
Target cells.
What is critical for normal functioning?
Timing of hormone release.
What can too high level of cortisol lead to?
Cushing’s syndrome.
What is Cushing’s syndrome caused by?
Too high level of cortisol.
What is Cushing’s syndrome characterised by?
High BP and depression.
What is the most common cause of excess cortisol?
A tumour in the pituitary gland which makes too much of a hormone called adrenocorticotropic hormone (ACTH) which stimulates the adrenal glands to make too much cortisol.
What is the primary function of the pituitary gland?
To influence the release of hormones from other glands and regulate many of the body’s functions.
What is the pituitary gland controlled by?
The hypothalamus.
What are the 2 main parts of the pituitary gland?
The anterior (front) pituitary and the posterior (back) pituitary.
What does the anterior pituitary release?
ACTH as a response to stress. This stimulates the adrenal glands to produce cortisol.
LH (luteinising hormone).
FSH (follicle-stimulating hormone).
What does the posterior pituitary release?
Oxytocin which stimulates contraction of the uterus during childbirth and is important for mother-infant bonding.
Why do target cells only respond to a particular hormone?
Because they have receptor cells for that hormone - cells without these specific receptor cells are not affected.