B7 HORMONES Flashcards
Hormone
A chemical messenger that changes the way a part of the body works
Important hormones
Insulin Glucagon Adrenalin Oestrogen Progesterone Testosterone Thyroxine LH FSH ACTB Growth hormone
Endocrine
Parts of the body that produce hormones
Important endocrine glands
Pituitary gland, thyroid gland, pancreas
Adrenal glands , ovaries and testes
Target organ
The part of the body affected by a hormone
Sex hormones
Women - oestrogen and progesterone
Men-testosterone
Metabolic rate
The rate at which the bod uses the energy stored in food
Thyroxine
Role- to control your metabolic rate
Endocrine gland- thyroid gland
Target organ- most of the body
Negative feedback
The way the body responds to high levels of something by bringing them down and low levels by bringing them up
Negative feedback and the metabolic
Rate
1) low levels of thyroxine stimulates production of a TRH in hypothalamus
2) this causes the release of TSH from pituitary gland
3) TSH causes the thyroid to produce thyroxine
4)normal levels of thyroxine inhibits
The release of TRH and the production of TSH
Adrenaline
Role is to prepare the body for fight or flight
Endocrine gland : adrenal glands
Target organ
Hearts beats faster and stronger, blood vessels going to muscles get wider, blood vessels going to organ get narrower , liver releases glucose
Menstrual cycles
A roughly 28 day cycle that prepares a woman’s body for pregnancy
Ovulation
The release of an egg cell by an ovary
Fertilisation
When a sperm cell fuses with an egg to form a zygote
Days 1-5
Menstruation: the lining of the uterus breaks down and leaves the body through the vagina
Days 6-12
The uterus lining begins to thicken again
Days 13-15
Ovation happens
Days 16-28
The uterus lining continues to thicken and would be able to accept an embryro if fertilisation happens
Control of the cycle
The menstrual cycle is controlled by the sex hormones : oestrogen
And progesterone
Egg foilie
A layer of tissue surrounding each of the immature eggs in the ovaries
Oestrogen
Causes the release of FSH and the thickening of the uterus lining
High oestrogen levels cause LH release
FSH
Causes one foilicle to develop and mature the egg cell within it
LH
Causes ovulation when the egg is released from the foilicle
Corpus
Luteum
The foilicle becomes a corpus luteum after ovulation and releases progesterone it breaks down over two weeks
Progesterone
Maintains the thickness of the uterus lining inhibits FSH release
Falling progesterone levels trigger ovulation
Contraception
Preventing sexual intercourse from leading to fertilisation and pregnancy
Condom
Worn on the penis they prevent sperm from entering the vagina
Also prevents STDS
Diaphragm or cap
Placed over the cervix at the top of the vagina prevent sperm entering uterus do not prevent STDS
Contraceptive pill/ implant
Uses hormones to prevent ovulation. Does not prevent STDS
Assisted reproductive technology
ART
Using hormones and other methods to increase the chance of pregnancy
Clomifene therapy
Clomifene increases the levels of FSH and LH to make egg successful ovulation more likely
In vitro fertilisation
IVF
Sperm is extracted from a man and eggs from a women
The eggs are fertilised in a laboratory and one or more is placed into the uterus
Homeostasis
Maintaining constant conditions in the body such as temperature or blood glucose concentration
Blood glucose concentration
The concentration (amount) of glucose in the blood Both too high and too low are dangerous
Glycogen
A stored from of glucose made by joining glucose molecules together in long chains
Insulin
Role is to produce blood glucose concentration
endocrine gland - pancreas
Target organ - liver and muscles which convert glucose into glycogen
Glucagon
Role is to increase blood glucose concentration
Endocrine gland - pancreas
Target organ - liver and muscles which convert glycogen back into glucose
Diabetes
A disease in which the body cannot quickly reduce blood glucose concentrations after eating
Type 1 diabetes
Diabetes caused when a persons pancreas can’t produce insulin
Treating type 1 diabetes
Insulin injections
Type 2 diabetes
Diabetes caused when a person does not produce enough insulin or stops responding to insulin
Risk factors for type 2 diabetes
Obesity and inactivity (lack of exercise)
Treating type 2 diabetes
Low sugar diet, increased exercise
Medication to make the body more sensitive to insulin
Measuring obesity
Body mass index above 30:
BMI = mass in kg / height in metre^2
High waist: hip ratio
Waist :hip ratio = waist /hip
