Topic 7: Coordination & Control Flashcards
What are endocrine glands?
Glands that secrete chemical messengers (hormones) directly into the bloodstream which carries them to the target organ
What are all of the glands in the endocrine system?
- Pituitary gland
- Thyroid gland
- Adrenal gland
- Pancreas
- Ovaries
- Testes
PeeTeaAPOT
What gland is adrenaline released from?
Adrenal gland
What are the 2 main effects of adrenaline on the body?
- Liver converts glycogen into glucose - increases blood glucose levels - more glucose is transported to cells for respiration
- Heart contracts more frequently with force - higher heart rate and blood pressure - increases blood flow to muscles so more oxygen is produced
What does adrenaline prepare your body for?
A fight or flight response
What does thyroxine do?
Regulates metabolic rate
What gland produces thyroxine?
Thyroid gland
What is metabolic rate?
The rate at which energy stored in food is transferred by all the reactions in your body to keep you alive
What happens when the body detects blood thyroxine levels are too low?
- The hypothalamus release TRH
- TRH stimulates pituitary gland to secrete TSH
- TSH stimulates the thyroid gland to secrete thyroxine
- Thyroxine levels return to normal
What happens when the body detects blood thyroxine levels are too high?
- The secretion of TRH and TSH are inhibited
- Thyroxine levels return to normal
What type of feedback are thyroxine levels controlled by?
Negative feedback
How to remember what hormones are involved in the menstrual cycle and what gland they’re secreted from?
FSH Pituitary
Oestrogen Ovaries
LH Pituitary
Progesterone Ovaries
FOLP POPO
What happens on day 1 of the menstrual cycle?
Uterus lining begins to break down and menstruation starts
(FSH levels cause an egg to mature in an ovary)
What happens on day 4 of the menstrual cycle?
Uterus lining is prepared - builds up into a thick spongy layer full of blood vessels ready to receive a fertilised egg
(Oestrogen causes the uterus lining to thicken)
What happens on day 14 of the menstrual cycle?
Ovulation - the egg develops and is released from the ovary
(LH stimulates the release of the egg or ovulation)
What happens on day 28 of the menstrual cycle?
Lining of the uterus is maintained BUT if no fertilised egg lands on the wall, the lining breaks down again and the cycle starts again
(Progesterone maintains uterus lining)
What is the role of FSH?
Matures the egg
What is the role of oestrogen?
Thicken the uterus lining
What is the role of LH?
Causes the egg to be released
What is the role of progesterone?
Maintains the uterus lining
What is the hormone feedback in the menstrual cycle if someone isnt pregnant?
- FSH stimulates the release of oestrogen
- Oestrogen stimulates the release of LH
- LH will stimulate the development of the corpus luteum
- The corpus luteum will release progesterone
What is the hormone feedback in the menstrual cycle if someone is pregnant?
- Oestrogen will inhibit the release of FSH
- Progesterone will inhibit the release of LH and FSH
- Levels of progesterone will stay high during pregnancy
What does ART stand for?
Assisted Reproductive Technology
What does IVF stand for?
In Vitro Fertilisation
What are examples of ART?
IVF
Clomifene therapy
What is IVF?
When eggs are handled and fertilised outside of the body
What is the process of IVF?
- The woman is given FSH and LH to stimulate egg production
- The eggs are then collected from the woman’s ovaries
- The eggs are then fertilised in a lab using the man’s sperm
- The fertilised eggs are grown into embryos
- Once the embryos are tiny balls of cells, one or two of them are transferred to the woman’s uterus
Advantages of IVF?
Gives a woman a natural birth
Allows infertile couples to have a child
Disadvantages of IVF?
Expensive
There a limited number of times you can have them for free
Risk of having multiple births e.g. octomum
What is the process of clomifene therapy?
- A woman who doesn’t ovulate or doesn’t ovulate regularly may take clomifene
- More FSH and LH are released
- Egg maturation and ovulation is stimulated
- Woman can have intercourse when she knows she’s ovulating
- Increased chance of pregnancy
What is contraception?
Methods of reducing the likelihood of sperm reaching an ovulated egg
What are the 2 types of contraception?
- Hormonal
- Barrier
Examples of hormonal methods of contraception?
Pill
Injection
Patch
Advantages of hormonal methods of contraception?
When used correctly, more effective than barrier methods
Can reduce risks of cancer
Disadvantages of hormonal methods of contraception?
There are side effects - changes in weight, mood swings, high blood pressure etc.
Don’t protect against STIs
Examples of barrier methods of contraception?
Condom - have spermicidal agents on them, kill sperm
Diaphragm
Sterilisation
IUDs
Advantages of barrier methods of contraception?
Fewer side effects than hormonal methods
They protect against STIs - prevent sperm and egg meeting
IUDs last long - 10 years
Disadvantages of barrier methods of contraception?
Condoms can tear or rip
Sterilisation is irreversible
IUDs can cause an ectopic pregnancy