B11 Hormonal Co-ordination

Question 1

Another word for hormone

Answer 1

Endocrine

Question 2

What is a hormone

Answer 2

Hormones are chemical messages that are located in a gland. They travel through the blood to the targeted organ.

Question 3

Name the 6 main endocrine glands in the body

Answer 3

Testis, ovary, pituitary gland (master gland), thyroid gland, adrenal gland and the pancreas

Question 4

What is the pituitary gland and its function?

Answer 4

The pituitary gland in the brain is a ‘master gland’ which secretes several hormones into the blood in response to body conditions. These hormones in turn act on other glands to stimulate other hormones to be released to bring about effects.

Question 5

Thyroid gland (function)

Answer 5

Controls metabolic rate of the body

Question 6

Pancreas (function)

Answer 6

Controls blood glucose levels

Question 7

Pituitary gland (function)

Answer 7

Control growth in children

Question 8

Adrenal gland (function)

Answer 8

Prepares the flight or fight response

Question 9

High glucose levels

Answer 9

Some hormones only one target organ, but most affect more than one.
The regulation of blood glucose level is an example of negative feedback. The pancreas is stimulated to release insulin. The insulin stimulates the liver to take glucose from the blood and convert inti glycogen, which is stored in the liver.

Question 10

Low blood glucose

Answer 10

Low blood glucose is also an example of negative feedback. The pancreas produces the hormone glucagon. Glucagon stimulates the liver to covert glycogen back to glucose and release the glucose into the bloodstream. Level of glucose will then increase, causing the pancreas to stop producing glucagon.

Question 11

Type 1 diabetes cause

Answer 11

If your pancreas doesn’t make enough (any) insulin, your blood glucose concentration is not controlled. You have type 1 diabetes. Without insulin, blood glucose levels get very high after you eat. Eventually kidney excretes glucose in your urine. You produce lots of urine and feel thirsty all the time. You also feel tired and have a lack of energy because without insulin your glucose cannot be transferred to your cells. Without out insulin your body breaks down fats and protein to use as fuel instead (so lose weight). Type 1 usually begins to occurs in children and teenagers, and has a genetic element involved in it.

Question 12

Type 2 diabetes cause

Answer 12

Type 2 (very common). Becomes more common throughout ageing and linked to obesity, lack of exercise or both. Also a strong genetic inheritance tendency to develop it. In type 2 the pancreas still makes insulin, although it may be less than your body needs. Your body cells stop responding properly to the insulin you make.

Question 13

Treating type 1 diabetes

Answer 13

You need a replacement of insulin before meals. Injecting insulin allows the hormones to convert the glucose into glycogen, so the glucose level isn’t too high. And when the glucose is then needed (later on) it is converted back. This treats diabetes successfully, but doesn’t cure it.

Question 14

Curring type 1 diabetes

Answer 14

Doctors can transplant a pancreas successfully (operation risky and difficult). Furthermore not enough donors and the patient exchanges one medicine (insulin) for another (immunosuppressants). Success rate of transplants, from dead and living donors has been limited. Also the use of embryonic stem cells to specialise them into pancreas cells. This is also being experimented in adult stem cells.

Question 15

What does the menstrual cycle involve the preperation of?

Answer 15

The uterus lining so it is able to develop a fertilised egg

Question 16

How long is the mestrual cycle and how is it controlled

Answer 16

28 days, and controlled by a nukber of sex hormones

Question 17

Follicle stimulating hormone (FSH)

Answer 17

FSH causes the eggs in the ovary to mature (the eggs grow surrounded by cells called the follicle).

Question 18

Luteinising hormone (LH)

Answer 18

LH stimulates the release of the egg at ovulation .

Question 19

Oestrogen

Answer 19

Stimulates the build up of the uterus lining

Question 20

Progesterone

Answer 20

Stimulates the maintaince pf the uterus lining (if egg is fertilised)

Question 21

In which gland are the LH and FSH produced

Answer 21

The pituitary gland

Question 22

In which gland is the oestrogen and progesterone hormones produced

Answer 22

The ovary gland

Question 23

How can you remeber the order of stimulation of the sex hormones, during the mentrual cycle

Answer 23

F.O.L.P

FSH)(Oestrogen)(LH)(Porgesterone

Question 24

Explain stages of the menstrual cycle

Answer 24

Within the beginning of the menstrual cycle FSH is fist stimulated (at the beginning of fist days) to be able to cause the eggs in the ovary to mature (the eggs grow surrounded by cells called the follicle). The process take around 14 days on average. Once the process is completed the LH then become stimulated and is produced rapidly. LH plays out the function of ovulation, in which the matured egg is released out of the ovary into the oviduct. Once LH are stimulated, the FSH is no longer produced. The LH play there role in a short period of time (lasting about a day). Before the egg cell is released the oestrogen hormones stimulate the build of the uterus lining, before day 14. Afterwards the progesterone take action in ensuring the maintenance the uterus lining from day 14 (when the egg is released) to day 28 (period). This occurs just in case the fertilisation of the egg cell, and so results with enough supply of nutrients for the fertilised egg cell to then form into a embryo to then a fetus.

Question 25

What is type 2 diabetes linked to

Answer 25

Obesity, lack of excerise, old age

Question 26

How can you treat type 2 diabetes?

Answer 26

Many people restore a normal blood glucose balance by taking three simple steps eating a balanced diet with carefully controlled amounts of carbohydrates, losing weight and doing regular exercise. If it doesn't work there are drugs that help insulin work better on the body cells, help your pancreas make more insulin, reduce the amount of glucose you absorb from your gut. Type II diabetes usually affects all the people however that it's becoming more and more common in obese young people

Question 27

How can fertility be controlled

Answer 27

Variety of hormonal and non-hormonal methods of contraception

Question 28

Hormone based contraception

Answer 28

Oral contraceptives use female hormones to prevent pregnancy. The mixed pill contains low dosss of oestrogen and progesterone. The hormones inhibit the production and release of FSH by the pituitary gland, affecting the ovaries, so no eggs mature, preventing pregnancy. The pill hormones also stop the uterus lining from developing, preventing implantaion. Also make mucus in the cervix thick to prevent sperm getting through. Contraceptive pilll are easy to use but slight risk of side effects, raised blood pressure, thrombosis and breast cancer. Some pills only contain progesterone. These two pills need to be taken regularly because the artifical hormone levels can drop and allow the body's own hormones to take control- leading to an unexpected baby. Different contraceptive techniques to delivering hormones such as contraceptive implants can last 3 years and contraceptive patches (hirmines go theough the skin into the bloodstream).

Question 29

Chemical methods

Answer 29

Chemicals that kill or disable sperm are known as spermicides. They are readily available but are noth very effective at preventing pregnancy.

Question 30

Intrauterine devices

Answer 30

They are small structures inserted into the uterus by a doctor. Last 3-5 years but can be removed any time if pregnancy is wanted. Some contain copper and prevent any early embroys implanting in the lining of the uterus. Others contain progesterone, releasing it slowly to prevent its build up on the lining and produces mucus in the cervix. They are very effective but could cause infection and period problems.

Question 31

Abstinence

Answer 31

For those who don't believe in using artifical methods of contraception (religious reasons). Use the rythm method were they abstain from intercourse around ovulation (no fertilisation). This method has no side effects but very unreliable. Ovulation indicators makes it more effective.

Question 32

Surgical methods

Answer 32

If don't want children, you can be surgically sterilised, were the sperm duct or oviducts are cut and tied. For men this is called vasectomy.

Question 33

Infertility treatment: lack of ovulation

Answer 33

Some women don't make enougb FSH to stimulate the maturation of the eggs in their ovaries. Luckly artificail FSH an be used as a fertility drug, that stimulates the eggs in the ovary to mature and also trigger oestrogen production. An artfifcal form of LH can then be used to trigger ovulation. Doctors are now careful the doses applied, so the women results with one or two babies only.

Question 34

Infertility treatment: In Vitro Fertilisation

Answer 34

IVF is a form of fertillity treament used if the oviduct have been damaged or blocked by infection, if a donor egg has been used, or if there is no obvious cause for long term infertility. You can't get pregnant nturally in all these casses. Modern infertillity treatments such as these rely on advanced microsopy techniques. Takes a high level of manipulative skill and magnification to work on single eggs and sperm cells, or early embryos without damaging them.

Question 35

Disadvantages of In Vitro Fertilisation

Answer 35

IVF is expensive for society (NHS) and for the individual. It is not always successful. The older the less chance of success Donor sperm and eggs cells can be used to incraese the chance, but the baby then isn't biologically the parents' child. The use of fertility drugs can have some health risks for the mother. The process of IVF is very emotional and physically stressful. IVF incraeses chance of multiple pregnancy (1 in 5 attempts) which could result with the risk for both mother and baby of stillbirths and other problems such as premature births. Costs the hospital a lot of money in keeping a premature small baby alive and if they do survive many will have serve disabilities. The mature eggs produced fertility drugs can be collected and stored, until she wants to get pregnant later, but this raises ethical problems if the women dies, the relationship breaks up, or one of the parents no longer wants the eggs or embryos.

Question 36

Advantages of In Vitro Fertilisation

Answer 36

Can help women whose oviducts have been damaged have children Enables women to concentrate on a career before having babies Is more successful with age

Question 37

Auxins

Answer 37

chemicals which are made in the growing tips of roots and shoots. Transported from back up the shoots and roots by active transport (or sometimes in the phloem sap).

Question 38

Geotropism

Answer 38

root growth down in repsonse to the pull of gravity

Question 39

Positive phototropism

Answer 39

Grows towards the light

Question 40

Gravitropism

Answer 40

Response of a plant to gravity

Question 41

Why do plants produce hormones

Answer 41

coordinate and control growth and responses to light (phototropism) and gravity (gravitropism or geotropism). Unequal distributions of auxin cause unequal growth rates in plant roots and shoots.

Question 42

Where does auxin accumalation occur

Answer 42

more on the opposite side from where the sunlight is entering the plant. Therfore the high amount auxin on the shaded side of the plant cell prelongating the auxin and increasing growth rate on the same side, resulting with the plant to tilt towards the sunlight.

Question 43

What does ethene in a plant control?

Answer 43

Cell division and ripening of fruits

Question 44

Gibberellins are improtant for what?

Answer 44

Initiating seed germination

Question 45

When and where is adrenaline produced, and what impact does it have?

Answer 45

Adrenaline is produced by the adrenal glands in times of fear or stress. It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for ‘flight or fight’.

Question 46

How are thyroxine levels kept stable?

Answer 46

In adults level of thyroxine in the blood are usually stable. This happens because of negative feedback control involving the pituitary gland and the hormone it produces- thyroid. If levels begin to fall, it is detected by sensors in the brain. As a result amount of TSH released from the puritiy gland increases. This work the opposite way for if the level of thyroxine is too high.

Question 47

What does thyroxine from the thyroid gland stimulate, and why is it important, and in what process is it controlled?

Answer 47

Thyroxine from the thyroid gland stimulates the basal metabolic rate (controls it). It plays an important role in growth and development. Thyroxine levels are controlled by negative feedback.

Question 48

Using plant hormones: Auxin (weed killers)

Answer 48

Plant hormones such as auxin can be used to make effective weed killers. Auxin naturally stimulates growth in plants (can kill a plant if sprayed upon). Many crops and grasses are narrow-leaved plants (monocotyledons, or monocots). Crop plants are mainly unaffected by weed killer hormones, but broad leaved weeds go into incontrolable growth and die. Because these chemicals affect one type of plant and another, they are known as selctive herbicides. Farmers use hormine weed killers to kill off the weeds in fields or cereal crops. This removes competition (light and mineral, from soil). Hormone weed killers are one reason why the yield of cereal crops has increased all across Europe, making more food available at cheaper prices.

Question 49

Using plant hormones: Auxin (plant tissue cultures)

Answer 49

Auxins also used in modern plant tissue cultures as part of the plant cloning process. They stimulate growth and cell division in the tissue culture, helps produce many identical plants to help farmers and horticulturists.

Question 50

Using plant hormones (4):

Answer 50

Used in the brewing industry to end seed dormancy, speeding up the germination of the barley seeds used to make malt. Used to promote flowering Used to increase the size of fruit (e.g seeedless grapes would usually grow small, but spraying it with gibberellins to replace the natural hormone, and they grow well). Used to control the ripening of fruit. Warmer temps and ethene added to the atmosphere allows the fruit to rapidly ripen to the perfect stage for sale just when it is needed.