Topic 7 Homeostasis Flashcards
What do the endocrine glands do
The endocrine system coordinates the body’s response to changes in the environment
What is the pituitary gland
‘Master gland’
Found in the brain and linked to the hypothalamus
releases hormones in response to changes detected by the hypothalamus.
What do the ovaries do
Release oestrogen
One of main hormones in the regulation of the menstrual cycle
What does the pancreas do
Produces insulin which regulates blood glucose levels
What do the adrenal glands do
Located above each kidney
Produces adrenaline which triggers the fight or flight response
What does the thyroid gland do
In our neck and releases thyroxine
Thyroxine regulates our metabolic rate, heart rate and temperature
What are the response for the central nervous system (CNS)
Triggers rapid response
Uses electrical signals that are carried around by neurones
Response is very short
Acts on a very precise part of the body
What are the responses of the endocrine system
. Slower response
Uses chemical messengers that are carried by blood
Response can be long lasting
Can act on large areas of the body
What happens when the the concentration of thyroid hormones such as thyroxine in the blood is low
the hypothalamus (in the brain) produces TRH This causes the pituitary to release TSH
What happens once thyroxine levels go above normal?
TRH secretion is reduced. This reduces TSH and thyroxine levels
How does blood glucose play a part in adrenaline
The liver converts stored glycogen back into glucose, raising the blood sugar levels.
What secondary sex characterises do males experience during puberty
Increase in testosterone which stimulates sperm production
Underarm, facial and pubic hairs
Voice deepens
What secondary sex characteristic do females experience during puberty
The amount of the hormone oestrogen rises and triggers the menstrual cycle.
Underarm and pubic hair grow.
Breasts enlarge.
What is the menstrual cycle
A monthly cycle which involved the maturation and releases of an egg
What four hormones from the endocrine system controls the menstrual cycle
Follicle stimulating hormone (FSH)
Oestrogen
Luteinising hormone (LH)
Progesterone
Once the female reaches puberty, how many eggs mature each month
1
What happens on day one of the menstrual cycle
The uterus lining breaks down
What happens when progesterone levels drop
Triggers the breakdown of the lining
What is the 2nd stage of the menstrual cycle
Days 4-14 -the uterus lining starts to build up again into a thick , spongy layer full of blood vessels
What happens in the 3rd stage of the menstrual cycle
( day 14) Ovulation happens - this is when an egg is released from one of the ovaries
What happens in the 4th stage ( final stage) of the menstrual cycle
Day 15-28 - The uterus lining is maintained, which means that it is now ready for the arrival of a fertilised egg. If no fertilised egg is attached to the uterus lining, the lining breaks down and the cycle begins again.
What is the function of a contraceptive pill
Reduced a women’s fertility to reduce the likelihood of pregnancy
What are the two types of contraceptive pills
Combined pill
Progesterone-only pill
What does the combined pill do
Contains both oestrogen and progesterone
By taking it every day, enough oestrogen builds up in the female body to inhibit the production of FSH so that no eggs mature.
