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.
What is each adrenal gland made up of?
2 distinct parts - outer part is the adrenal cortex and inner region is the adrenal medulla.
Which part of the adrenal gland releases hormones that are necessary for life?
Adrenal cortex.
What is the difference in function between the adrenal cortex and the adrenal medulla?
The hormone released by the adrenal cortex are necessary for life whereas those released by the adrenal medulla are not.
What hormones does the adrenal cortex produce?
Cortisol.
Aldosterone.
What does cortisol do?
Regulates/supports a variety of important bodily functions including cardiovascular and anti-inflammatory functions.
When is cortisol production increased?
In response to stress.
What are the consequences of the level of cortisol being too low?
The individual has low bp, poor immune function and an inability to deal with stress.
What does aldosterone do?
Maintains blood volume and bp.
What hormones does the adrenal medulla release?
Adrenaline and noradrenaline.
What are the ovaries responsible for?
The production of eggs and for the hormones oestrogen and progesterone.
What has progesterone been associated with?
Heightened sensitivity to social cues that indicate the presence of social opportunity or threat that would be significant in the case of pregnancy (Maner and Miller, 2014).
What does testosterone cause?
The development of male characteristics such as growth of facial hair, deepening of the voice and the growth spurt that takes place during puberty.
Also plays a role in sex drive, sperm production and maintenance of muscle strength, and is associated with overall health and well-being in men.
What is testosterone production controlled by?
The hypothalamus and the pituitary gland.
How is testosterone production controlled by the hypothalamus and the pituitary gland?
The hypothalamus instructs the pituitary gland on how much testosterone to produce, and the pituitary gland passes this message on to the testes.
Define endocrine glands
Special groups of cells within the endocrine system, whose function is to produce and secrete hormones.
What is the endocrine system?
A network of glands throughout the body that manufacture and secrete chemical messengers known as hormones.
Define hormones
The body’s chemical messengers. They travel through the bloodstream, influencing many different processes including mood, the stress response and bonding between mother and newborn baby.
What is the pituitary gland?
The ‘master gland’, whose primary function is to influence the release of hormones from other glands.
