| What is the regulation of the internal conditions? | Homeostasis is the regulation of the internal conditions of a cell or organism. This is to maintain optimum conditions for function in response to internal and external changes. |
| What internal changes happen to the body during exericse? | During exercise, homeostasis keeps the blood glucose concentration, body temperature and water levels constant. Glucose is used in respiration to produce energy. This causes the blood glucose concentration to drop, so increased glucose is supplied from the liver and kidneys. During exercise body temperature also rises, so to keep the body's internal temperature constant, heat is lost through sweating. And as water is lost water levels are kept constant by the kidneys that conserve water to prevent dehydration. |
| How does homeostasis make sure these internal conditions are constant? | Homeostasis makes sure internal conditions are constant through automatic control systems. |
| What is the endocrine system made up of? | The endocrine system is made up of glands that secrete hormones directly into the bloodstream, which the blood will then carry around the body. |
| Where are the key glands in the endocrine system? | Key glands in the the endocrine system are the ovaries and testiest which release hormones involved in puberty and in reproduction.
And the thyroid gland, that produces hormones involved in growth and in regulating the body’s basic metabolic rate. |
| What does the pituitary gland do? | The pituitary gland is in the brain. It releases a number of different hormones into the blood, depending on the conditions. They act on other glands and cause other hormones to be released. By acting on other glands the pituitary hormones can trigger a range of different effects in the body. |
| Why is the concentration of glucose in the blood important? | Glucose is needed by every cell to releases energy by respiration so it’s important that the concentration of glucose in the blood is kept as constant as possible. |
| What happens when we eat carbohydrates? | When we eat carbohydrates the concentration of glucose in the blood increases which the pancreas senses so it produces the hormone insulin. |
| How does insulin reduce the level the of glucose the blood? | Insulin travels in the blood stream all around the body and triggers body cells to intake glucose from the blood. Insulin also triggers liver and muscle cells to store excess glucose as a storage molecule called glycogen. Therefore insulin reduces the level of glucose in the blood because when glucose is taken out of the blood, and stored, the concentration of glucose return to its normal level. |
| Why does the concentration of glucose in the blood in someone who has type 1and type 2 diabetes remain at a high level? | After eating carbohydrates, a person with type 1 diabetes’ blood glucose concentration level rises and maintains a high level. This is because their pancreas cannot produce sufficient insulin.
And a person with type 2 diabetes blood glucose concentration maintains a high level because their body cells stop responding to insulin produced by the pancreas. |
| How do people with type 1 and type 2 diabetes control their blood glucose concentration? | People with type 1 diabetes monitor their blood glucose concentration and inject themselves with insulin which returns the glucose concentration level to normal. While type 2 diabetes is often treated with a diet containing a controlled level of carbohydrates to prevent blood glucose concentration from rising too high. People with type 2 diabetes are also advised to do exercise. |
| What happens when someone’s blood glucose concentration is too low? | If the blood glucose concentration is too low the pancreas secretes the hormone glucagon into the bloodstream. Glucagon triggers liver cells to convert glycogen stores back to glucose which is then released into the blood. |
| Why do glucagon and insulin form a negative feedback cycle? | Because insulin and glucagon have opposite effects on the blood glucose insulin, they forma negative feedback cycle. |
| Give one hormon that men produce and one that women produce. | In men, the testes produce the hormone testosterone which stimulates the tests to produce sperm.
While, in women, the ovaries produce the hormone oestrogen. |
| What is ovulation? | Ovulation is the once puberty begins eggs in the ovaries starts to mature and every 28 days an egg is released. |
| What does the uterus do to prepare for release an egg | In preparation for releasing an egg the uterus lining becomes thick and spongy. |
| What does follicle stimulating hormone and the liturgising hormone do? | Follicle stimulating hormone causes an egg to mature in the ovary.
And the liturgising hormone causes the egg to be released, ovulation. |
| What do oestrogen and progesterone do? | Oestrogen and progesterone maintain the uterus lining if the egg is fertilised and maintain implants. |
| Describe the process of the menstrual cycle | In the first stage of the menstrual cycle FSH is released by the pituitary gland. It then travels in the blood to the ovaries where it matures an egg and triggers the ovaries to make oestrogen.
Oestrogen causes the lining of the uterus to thicken and stops the pituitary gland from releasing anymore FSH, instead it will release LH.
LH triggers ovulation, and once the ovary has released an egg, the ovary produces the hormone progesterone.
Progesterone stops the pituitary gland from releasing LH to prevent more eggs maturing or being released, and it keeps the lining of the uterus thick in case of a fertilised egg being implanted. |
| What is a fertility drug and what are there affects? | A fertility drug is an infertility treatment made of the combination of FSH and LH. Fertility drugs cause women to have increased ovulation and increase her chance of becoming pregnant through sexual intercourse. |
| What is in vitro fertilisation? | In-verto fertilisation is an infertility treatment where fertilisation takes place outside of the body. |
| Describe the process of IVF | Firstly, during IVF the mother is treated with FSH and LH which cause several eggs to mature.
After the eggs have matured, they are collected from the mother to be fertilised in a laboratory with sperm collected from the father. Then the fertilised eggs develop into embryos and once they are tiny balls of cells they are inserted into the mother's uterus (womb) to grow into a foetus. |
| What is a benefit and problems of IVF? | A benefit of IVF is that it gives women the chance to have their own children. However possible problems of IVF are success rates are low and it can be emotionally stressful for both partners. IVF is also physically demanding on the mother in the treatment with fertility drugs and in the collection of eggs. And IVF can lead to multiple births which are risky for the babies and the mother. |
| What happens to the embryos that are not transferred into the mother? | Due to not all embryos being transferred into the mother, the remaining embryos are destroyed which some people consider unethical. |
| What do people believe the money for IVF should be spent on? | Some people believe because IVF is very expensive, the money should be spent on other medical issues that are yet to be solved such as cancer. |
| Where is are the adrenal glands located? | The adrenal glands are located at the top of the kidneys. |
| What do the adrenal glands do in times of fear or stress? | During times of fear or stress, the adrenal glands produce the hormone adrenaline in the blood. The effect of this adrenaline is to increase the heart rate. Because the heart is beating faster more oxygen and glucose are delivered in the blood to the brain and muscles. |
| How does the body prepare from this released oxygen and glucose? | Both oxygen and glucose are needed for respiration which prepare the body to fight or run away, which is referred to as fight or flight. |
| Where is the thyroid gland located and what hormones does it release? | The thyroid gland is located in the base of the neck, and it releases the hormone thyroxine. The effects of Thyroxine are it stimulates the body’s basal metabolic rate. And as metabolism the sum of all the reactions of a cell or the body, thyroxine makes the body’s chemical reactions occur at a faster rate. |
| What does negative feedback control? | Negative feedback controls the level of thyroxine in the blood. |
| In detail describe what happens in the thyroid negative feedback cycle | In the negative feedback cycle for the thyroid, the level of thyroxine in the blood is monitored by the brain and when this level falls the pituitary gland in the brain, releases the hormone TSH into the bloodstream. TSH tiggers the thyroid gland to release more thyroxine into the blood. This increased level of thyroxine is detected by the brain which prevents the pituitary gland form releasing any more TSH. And as the TSH level falls the thyroid gland releases less thyroxine. |
| Briefly describe the negative feedback cycle for thyroxine | The negative feedback cycle for thyroxine is If the level of thyroxine falls events are triggered which cause the level of thyroxine to increase and if the level of thyroxine becomes too high events are triggers to bring it back down |
