Flashcards in Topic 7 - Hormones, Fertility and Homeostasis Deck (52):
Role of glucagon in blood glucose control?
If the blood glucose levels are too low, glucagon is added and it makes the liver turn glycogen into glucose. Glucose is then released into the blood by the liver and blood glucose increases.
How do hormonal contraception methods prevent pregnancy?
The pill or implant placed under the skin releases hormones to prevent ovulation and thicken cervix mucus, making it difficult for sperm to pass through.
Role of FSH in the menstrual cycle?
Causes a follicle to mature in one of the ovaries.
Stimulates oestrogen production.
Gland that FSH is released from?
Role of progesterone in the menstrual cycle?
Inhibits the release of LH and FSH.
Maintains uterus lining.
When the level of progesterone falls and there's a low oestrogen level, the uterus lining breaks down.
A low progesterone level allows FSH to increase and the cycle starts again.
Gland that progesterone is released from?
Corpus luteum (after ovulation)
The maintenance of a constant internal environment.
Role of oestrogen in the menstrual cycle?
Causes the uterus lining to thicken. A high level also stimulates an LH surge.
Gland that oestrogen is released from?
Where are hormones produced?
They are produced and secreted in/by endocrine glands..
How are hormones transported?
They are transported in the bloodstream.
Which gland releases LH?
Which 2 hormones are inhibited by increasing progesterone levels?
LH and FSH
The control of the balance of water and mineral salts in the body.
Which 3 hormones control metabolic rate?
Thyroxine, TSH, TRH
2 barrier methods for contraception?
- female condom/femidom
- cervical cap
Role of LH in the menstrual cycle?
Stimulates ovulation at day 14, meaning the follicle ruptures and the egg is released. It also stimulates the remains of the follicle to develop into a corpus luteum, secreting progesterone.
What is the effect of adrenaline on the body?
Adrenaline prepares the body in the face of threat:
It binds to specific receptors in the heart, causing the muscles to contract more frequently and with more force.
Blood pressure increases and blood flow to muscles is increased. This means that cells receive more oxygen and glucose for increased respiration. Adrenaline also binds to receptors in the liver, causing the liver to break down glycogen stores to release glucose. Blood glucose levels increase and more glucose transports to cells.
Cause of type 2 diabetes?
Pancreas doesn't produce enough insulin or has become resistant to insulin. (Usually due to an unhealthy diet/lifestyle)
How is type 2 diabetes controlled?
Eating a healthy diet, regular exercise and losing weight.
Cause of type 1 diabetes?
Pancreas produces little or no insulin meaning that their blood glucose levels can rise to a level that can kill them.
How is type 1 diabetes controlled?
It is controlled with insulin injections into the blood, stopping the level of glucose in the blood getting too high.
Give the BMI equation.
BMI = Mass(kg) ÷ Height(m)2
Process allowing your body to maintain its core internal temperature.
Define the term hormone.
Chemical messenger produced by glands that travel in the bloodstream to target organs.
Where is insulin released from and what is its role in blood glucose control?
It is released from the pancreas and reduces blood glucose as it causes it to be stored in the liver.
2 target tissues of growth hormone?
Gland which produces growth hormones?
2 symptoms of diabetes?
- excessive thirst
- excessive urination
- unexplained weight loss
- dry mouth
- blurred vision
- excessive hunger
What hormone does a corpus luteum secrete?
What is another word for the lining of the uterus?
What does a high level of oestrogen stimulate?
A rapid increase of LH/LH surge.
What does IVF stand for?
In vitro fertilisation
What is Clomifene therapy?
Clomifene is a drug that can be taken to cause more FSH and LH to be released by the body, which stimulate egg maturation and ovulation.
When is insulin added?
When blood glucose concentration gets too high.
When is glucagon added?
When blood glucose concentration gets too low.
What is negative feedback?
A reaction that ensures that, in any control system, changes are reversed and returned back to the set level.
Give the waist-to-hip ratio calculation.
Waist-to-hip ratio =
Waist circumference(cm) ÷ Hip circumference(cm)
How does your body cool you down when you're too hot?
- Errector muscles relax, hairs lie flat
- Sweat is produced in the dermis. The sweat is released onto the surface of the skin through pores in the epidermis. When the sweat evaporates, it transfers energy from your skin to the environment and cools you down.
- Blood vessels close to the surface of the skin dilate allowing more blood to flow near the surface, which transfers more energy into the surroundings. (vasodilation)
How does your body reduce heat released from your body when you're too cold?
- Errector muscles contract - hairs stand on end to trap an insulating layer of air near the surface of the skin.
- Blood vessels near the surface of the skin constrict, meaning less blood flows near the surface so that less energy is transferred to the surroundings.
- You shiver (muscles contract automatically), increasing rate of respiration, which transfers more energy to warm the body.
What 3 main roles do the kidneys have?
- Removal of urea from the blood.
- Adjustment of ion levels in the blood.
- Adjustment of water content in the blood.
What are nephrons?
Filtration units in the kidneys.
What is the function of the glomerulus?
The glomerulus filters blood and produces glomerular filtrate. This filtrate contains water, glucose, salts and urea. Large molecules such as protein are too large to fit through the blood capillary walls.
Function of the Bowman's capsule?
The Bowman's capsule collects the filtrate and it enters the tubules. All glucose is reabsorbed immediately into the blood capillaries.
3 processes that take place in the nephron?
- Selective reabsorbtion
- Excretion of waste
Where is testosterone produced?
How does a negative feedback system work in the body?
A negative feedback control system responds when conditions change from the ideal or set point and returns conditions to this set point.
Who might need to use clomofene therapy?
Women who don't ovulate or don't ovulate regularly.
How is IVF carried out?
Eggs are collected from a woman's ovaries and fertilised in a lab using the man's sperm. They are grown into embryos in the lab and then are transferred back into the woman's uterus.
What waste product is removed in urine?
List the main structures in the urinary system.
- Left and right kidney