B7: Animal Coordination Flashcards
(27 cards)
What does the endocrine system consist of?
A series of glands which secrete chemicals (hormones) which are transported into the bloodstream by the body
What glands make up the endocrine system?
Pituitary gland, thyroid gland, adrenal gland, pancreas, testes, ovaries
What is the difference between the endocrine system and the nervous system?
- nervous system uses electrical impulses vs endocrine system uses chemical signals
- transmission happens through nerve cells in nervous system whereas endocrine system transmission happens in the bloodstream
- nervous system is very rapid and short duration whereas endocrine system is slow and longer duration.
Where is the pituitary gland located?
Below the centre of the brain
What is the role of the pituitary gland?
It is known as the master gland as it produces and secretes many hormones in the bloodstream.
-it controls growth
-stimulates thyroid gland to produce thyroxine
-stimulates ovaries to produce and release eggs and making oestrogen
-it stimulates testes to make sperm and testosterone
Where is the thyroid gland located?
In the neck
What is the role of the thyroid gland?
It produces thyroxine, controls metabolic rate of body
What process does the boy to produce thyroxine?
The pituitary gland produces TSH hormone which STIMULATES thyroid gland to produce thyroxine, thyroxine then INHIBITS the production of TSH from the pituitary.
What happens if thyroxine levels are too high?
Thyroxine will inhibit then pituitary gland from producing TSH. Less TSH means thyroid wont release as much thyroxine, therefore levels fall back to normal.
What happens if thyroxine levels are too low?
The pituitary gland will release TSH, which stimulates thyroid to release more thyroxine, therefore levels increase back to norma.
How iss controlling thyroxine levels an example of negative feedback?
It adjusts hormone release to maintain stable blood levels.
Where is the adrenal gland located?
Located on top of the kidneys
What does adrenal gland produce?
Adrenaline
What is the role of adrenal gland?
-It produces adrenaline, which are produced in “flight of fight” situations, like when your scared or exercise
What does the production of adrenal glands cause?
- increased heart rate to increase ( by binding to receptors on the cardiac muscle to increase rate of force of contraction) along with blood pressure, blood flow to muscles and increases blood sugar levels.
- it stimulates liver to breakdown stored glycogen to increase blood glucose (for respiration)
Where are the ovaries located?
In the uterus
What is the role of the ovaries?
-they produce and secrete oestrogen and progesterone
What is the role of oestrogen?
-it causes uterus lining to thicken and high levels and causes another hormone to release from pituitary gland and causes an egg to be released
What is the role of progesterone?
It maintains the uterus lining
What does FSH stand for?
Follicle stimulating hormone which stimulates eggs to mature in the ovaries
What does LH stand for?
Luteinising hormone which stimulates the release of a mature egg
How long is the menstrual cycle (AVERAGE)?
28 days?
What is ovulation?
When a mature egg is released
What happens during stage one of the menstrual cycle?
Menstruation happens, the uterus lining breaks down (bleeding), which lasts around 4 days
