B11
Endocrine gland - The glands that produce the hormones that control many aspects of development and metabolism of the body and the hormones they produce
Pituitary gland
Controls growth in children
Stimulates the thyroid gland to make thyroxine to control the rate of metabolism
In women - stimulates the ovaries to produce and release eggs and make the female sex hormone oestrogen
In men - stimulates the testes to make sperm and the males sex hormone testosterone
Thyroid
controls the metabolic rate of the body
Pancreas
They make insulin
controls levels of glucose in the blood
Adrenal
makes Adrenalin
Prepares the body for stressful situations - 'fight of flight' response
Ovaries
makes Oestrogen
controls the development of the female secondary sexual characteristics and is involved in the menstrual cycle
Testes
Makes Testosterone
Controls the development of the male secondary sexual characteristics and is involved in the production of sperm
Pancreas
It constantly monitors and controls your body glucose concentration using 2 hormones
Insulin
When your blood glucose concentration rises after eaten a meal, the pancreas produces insulin.
Insulin allows glucose to move from the blood into your cells where it is used
Glucagon
The control of your blood glucose doesn't involve insulin
When your blood glucose level falls below the ideal range the pancreas secretes another hormone called glucagon
Glucagon makes your liver break down glucagon, converting it back into glucose this way the glucose can be put back into your blood so it raises the level
Type 1 diabetes
This is when your pancreas does not make enough or no insulin, so the glucose concentration is not controlled
without insulin your blood glucose levels get very high after you eat
eventually, your kidneys excrete glucose and you become very thirsty
without insulin glucose cannot get into the cells of your body, so lack energy within the body and feel tired
Loose alot of weight with this disease as it used a lot of the bodies fat and protein as fuel instead.
Type 2 diabetes
Is very common type of diabetes, it gets more common as people get older and is often linked to obesity, lack of exercise or both
There is also strong genetic tendency to develop type 2
In type 2 diabetes the pancreas still makes insulin although it may make less than your body needs
Most importantly, your body cells stop responding properly to the insulin your make.
Ovaries
Menstrual cycle
Each month, girl goes through the menstrual cycle
The main reproductive hormone is oestrogen
Between the ages of 8-14 we change - hair under our arms, the breast develop, the external gentials grow and the skin darkens, brain changes and matures, mature eggs start to form every month
eggs begin to mature in the ovary. At the same time the uterus produces a thickened lining ready for a pregnancy.
Every 28 days a mature egg is released this is called ovulation, if the egg is not fertilized around 14 days later the lining of the uterus is shed along with the egg
Hormones involved
FSH - causes the eggs in the ovary to mature (the eggs grow surrounded by cells called the follicle)
LH - stimulates the release of the egg at ovulation
Oestrogen and progesterone - stimulate the build - up and maintenance of the uterus lining
35 - 40 years the eggs run out and women go though a time of menopause which means they don't have periods and they are less fertile
Testes
The main male reproductive hormone is testosterone
As levels of testosterone rise all kinds of changes are triggered and the male secondary sexual characteristics develop, pubic hair, underarm hair and facial hair, larynx gets bigger and voice begins to break, brain matures, testes become more active
IVF process
- Fertility drugs are used to make lots of eggs mature at the same time for collection
- the eggs are collected and placed in a special solution in a petri dish
- A sample of semen is collected and the sperm and eggs are mixed in the petri dish
- The eggs are checked to make sure they have been fertilized and the early embryos are developing properly
When the fertilized eggs have formed tiny balls of cells, 1 or 2 of the tiny embryos are placed in the womb of the mother. Then if all goes well, at least one baby will grow and develop successfully.