B11 Flashcards
What are examples of hormones?
Adrenaline, insulin, growth hormone and sex hormones.
What is the endocrine system?
It is made up of glands, secreting hormones into the bloodstream, which carries it to its target organ producing an effect.
What is the most powerful endocrine gland and what does it do?
The pituitary gland, found in the brain, which excretes many hormones into the body, in response to changes in body conditions. Examples include ADH and growth hormone.
What does the thyroid do?
Controls the metabolic rate of the body.
What does the pancreas do?
Controls the levels of glucose in the blood.
What does the adrenal gland do?
Prepares the body for stress, adrenaline.
What do the ovaries do?
Controls the development of the female secondary sexual characteristics and is involved in the menstrual cycle.
What do the testes do?
Controls the development of the male secondary sexual characteristics and is involved in the production of sperm.
What is insulin?
It is extracted by the pancreas, controlling the blood glucose concentration with the hormone insulin. if it rises, your pancreas produces insulin allowing glucose to move from the blood into cells. It further stores glycogen in your liver and muscles and can be converted back into glucose when it is needed.
What is glucagon?
If the blood glucose concentration falls below the ideal range, the pancreas secretes another hormone called glucagon, letting your liver break down glycogen, converting it to glucose, releasing it back into your blood.
What happens if your glycogen stores are full?
Any excess glucose is transferred into lipids and stored, so you get obese.
What is type 1 diabetes?
This is when your pancreas doesn’t make enough or any insulin, so your blood glucose concentration is not controlled.
What is type 2 diabetes?
This is when you get older, usually linking to obesity and lack of exercise. However it can also be genetical.
How can you treat type 1 diabetes?
You need replacement insulin before meals, as an injection into your blood. This allows your glucose to be taken into the body and converted to glycogen in the liver, stopping the concentration to become too high.
How can you treat type 2 diabetes?
Eating a balanced diet, losing weight, doing exercise. .
What is negative feedback?
This helps you maintain a steady rate, so for example if a factor in the environment changes, changes take place to return it to the original level.
What is thyroxine?
This controls the basal metabolic rate of your body, acting a large part in growth and development.
What does adrenaline cause?
Heart rate and breathing rate to increase, stored glycogen in the liver to be converted to glucose for respiration, the pupils to dilate, mental awareness to increase, blood to be diverted to limbs.
What is oestrogen?
It is the female reproductive hormone produced by the ovaries, often released in puberty.
What is testosterone?
It is the male reproductive hormone produced by the testes, often released in puberty.
What hormones are involved during the menstrual cycle?
FSH causes the eggs in the ovary to mature, LH stimulates the release of the egg and oestrogen and progesterone stimulate the build-up and maintenance of the uterus lining.
What does FSH do?
It causes the egg to mature and stimulates the ovary to produce oestrogen.
What does LH do?
It triggers ovulation.
What does oestrogen do?
It causes the lining of the uterus to develop, inhibits the release of FSH and stimulates the release of FH.
What does progesterone do?
It maintains the lining of the uterus and inhibits the release of both FSH and LH.
What is contraception?
It is a hormonal or non hormonal way of controlling fertility.
What are 6 methods of contraception?
Hormone based contraception which make no eggs mature. Chemical methods such as spermicides, barrier methods such as a condom. Intrauterine devices which last 3-5 years. Being abstinent. Surgical methods such as a vasectomy.
Why are some people infertile and how can it be avoided?
As they do not make enough FSH to stimulate the maturation of eggs in ovaries. They can take pills to counteract it.
What is IVF?
In vitro fertilisation, which is used when the oviducts have been damaged or blocked.
How does IVF work(4)?
They are given FSH for eggs to mature. The eggs are collected and fertilised with fathers sperm in a lab. Placed into an incubator to grow into embryos. Taken out and inserted into uterus.
What are some disadvantages to IVF?
It can cause a large expense, is not always successful, may have health risks and may be emotionally and physically stressful.
What are plants sensitive to?
Light and gravity.
What is tropism?
The response of the plant.
What is phototropism?
The response of a plant to light.
What is geotropism?
The response of a plant to gravity.
What is auxin?
A hormone that produces growth in a plant released at the tip of the root and shoot of the plant. They dissolve and diffuse backwards along the shoot or the root.
Which direction do roots and shoots grow in response to light and gravity?
Shoots grow towards light and away from gravity, while roots grow away from light and in the direction of the force of gravity.
What are gibberelins?
They are plant hormones that are important in initiating seed germination, triggering the breakdown of the food stores in the seed at the start of germination. They also stimulate the growth of plant hormones.
How is ethene used in plant hormones?
It is used in controlling cell division and can ripen plants. Growers harvest it when it is not ripe, then transport the unripe fruit as they are less likely to be damaged. Then it is added to ethene and can be rapidly ripened for sale.
How can auxins be used?
It naturally stimulates growth in plants and can be used as a weedkiller to send into plants, causing rapid growth killing it. This causes the prices to be cheaper due to increased yeild.
How can you use gibberellins in plant hormones?
They are used to end seed dormancy, speeding up the germination of barley seeds. They are used to promote flowering throughout the year. They are also used to increase the size of fruit.
How do the reproductive hormones interact?
FSH causes ovaries to produce oestrogen. Increase in oestrogen leads to more LH. High progesterone causes high LH and FSH
How do hormonal methods of contraception work?
Oestrogen is used to inhibit the production of FSH, and the progesterone inhibits the production of FSH and LH, of which FSH causes the egg to mature and LH manages the release of the egg.
Where do auxins accumulate on the plant?
In the shoots, on the shady side and on the roots, the lower side.
What do auxins do for growth in a plant?
In the root they inhibit growth and in the shoot they prioritise growth.
Is the endocrine system fast or slow?
Slow as hormones take time but it lasts long.
