Topic 7 - Hormones

Question 1

What are hormones?

Answer 1

Hormones are chemical messengers produced by endocrine glands and released directly into the blood. The organ or tissue affected by a hormones is called a target organ.
Hormones control things in organs and cells that need constant adjustment.

Question 2

Pituitary gland?

Answer 2

• Attached to the brain

* Growth hormone

Question 3

Thyroid gland?

Answer 3

• In our necks
• Releases thyroxine
• Thyroxine regulates rate of metabolism
• Controls how quickly chemical reactions happen in the body
• Target organ: all tissues and bones

Question 4

Adrenal glands?

Answer 4

• Sit on top of our kidneys
• Produces adrenaline
• Gets body ready for ‘Fight or flight’ response
• Target organ: all tissues and kidneys

Question 5

Pancreas?

Answer 5

• In front of the kidneys
• Produces insulin and glucagon
• Controls blood glucose levels
• Target organ: liver and muscles

Question 6

Testes?

Answer 6

• Produce testosterone

* Controls male development during puberty

Question 7

Ovaries?

Answer 7

• Produce oestrogen and progesterone

* Controls female development during puberty

Question 8

What are the features of the endocrine system?

Answer 8

• Relies on hormones secreted by glands
• Transported in the blood
• Spread more slowly
• Effects last longer
• Act more generally - spreads through the entire body

Question 9

What are the features of the nervous system?

Answer 9

• Relies on electrical impulses which are transferred along nerve cells
• Very fast
• Effects don’t last long
• Go to one specific area - precise

Question 10

What are the effects of adrenaline?

Answer 10

• Increased heart rate —> increased blood flow
• Increased blood pressure
• Blood vessels to the digestive system narrow but blood vessels to the muscles and the heart widen so that the muscles can receive more oxygen and glucose for increased respiration
• Stimulates liver to convert glycogen to glucose which increases blood glucose level, so there’s raised blood sugar levels

Question 11

What is negative feedback?

Answer 11

When the body detects that the level of a substance has gone above or below the normal level, it triggers a response to bring the level back to normal again.

Question 12

What is metabolic rate?

Answer 12

The rate at which we can extract energy from food.

Question 13

How does thyroxine control metabolic rate?

Answer 13

• When thyroxine level is lower than normal the hypothalamus is stimulated to release TRH
• TRH stimulates the pituitary gland to release TSH
• TSH stimulates the thyroid gland to release thyroxine, so the thyroxine levels rise back to normal.
• When the thyroxine levels get higher than normal, the release of TRH from the hypothalamus is inhibited, which reduces the production of TSH, so thyroxine levels fall.

Question 14

What are the effects of thyroxine?

Answer 14

• Causes heart cells to contract more

* Causes proteins and carbohydrates to break down more quickly

Question 15

What is homeostasis?

Answer 15

The maintenance of the internal environment.

Question 16

What happens when blood glucose levels are too high?

Answer 16

• Pancreas (gland) detects + releases insulin (hormone)
• Insulin diffuses into the blood and travels to the liver (target organ)
• At the liver glucose is stored as glycogen
• Blood glucose levels decrease

Question 17

What happens when blood glucose levels are too low?

Answer 17

• Pancreas (gland) detects and releases glucagon (hormone)
• Glucagon diffuses into the blood and travels to the liver (target organ)
• At the liver it stimulates the liver to break down glycogen into glucose
• Blood glucose levels increase

Question 18

What is type 1 diabetes?

Answer 18

A condition where the pancreas doesn’t produce any insulin.

The result is that a person’s blood glucose can rise to a level that can kill them.

Question 19

What is the cause of type 1 diabetes?

Answer 19

Genetics

Diagnosed in childhood and is lifelong

Question 20

What is the treatment for type 1 diabetes?

Answer 20

Inject insulin. This is often done at meal times to make sure that glucose is removed from the blood quickly once the food has been digested.
They also can:
• Limit the intake of foods rich in simple carbohydrates
• Take regular exercise - helps to remove excess glucose from the blood

Question 21

What is type 2 diabetes?

Answer 21

When a person becomes resistant to insulin.

Question 22

What are the causes of type 2 diabetes?

Answer 22

Obesity
Lack of exercise
Old age

Question 23

What are the treatments for type 2 diabetes?

Answer 23

• More exercise
• Healthy low sugar diet
• Loosing weight

Question 24

How to calculate BMI?

Answer 24

Mass (kg) / height (m) 2

Question 25

How to calculated waist-to-hip ratio?

Answer 25

Waist circumference (cm) / hip circumference (cm)

Question 26

What are the hormones and their location involved in the menstrual cycle?

Answer 26

Hormone - Gland 1) FSH - Pituitary 2) Oestrogen - Ovaries 3) LH - Pituitary 4) Progesterone - Ovaries

Question 27

What is the first stage of the menstrual cycle?

Answer 27

``` 1) FSH • Released from the pituitary gland • Travels to the ovaries • Stimulates the ovaries to mature an egg • Stimulates the production of oestrogen ```

Question 28

What is the second stage of the menstrual cycle?

Answer 28

``` 2) Oestrogen • Released from the ovaries • Travels to the uterus • Stimulates building of uterus lining/thickens uterus lining • Stops the production of FSH ```

Question 29

What is the third stage of the menstrual cycle?

Answer 29

3) At day 14 LH levels spike • It is released from pituitary • This causes ovulation (egg is released)

Question 30

What is the fourth stage of the menstrual cycle?

Answer 30

4) Progesterone • Released from the ovaries • Maintains the uterus lining • If a woman is pregnant progesterone levels stay high, if she is not pregnant the uterus lining sheds because progesterone levels fall

Question 31

What is a hormonal method of contraception?

Answer 31

Use hormones to reduce female fertility (by preventing the release of an egg and thickening cervical mucus.

Question 32

What are the hormonal methods of contraception?

Answer 32

1) The pill 2) Injection 3) Vaginal ring 4) Implant 5) Coil

Question 33

What are barrier methods of contraception?

Answer 33

Methods of contraception that aim to stop the sperm and egg meeting.

Question 34

What are some barrier methods?

Answer 34

* Condom | * Caps or diaphragms

Question 35

Advantages and disadvantages of the coil?

Answer 35

- Doesn’t protect against STI’s, side effects (less likely) but still include mood swings, can be painful to get inserted. + Very reliable, last for 5 years, lighter/no periods

Question 36

Advantages and disadvantages of the patch?

Answer 36

- Side effects include weight gain, mood swings or an increased risk of blood clots. Does not protect against STI’s + Very reliable and not affected by digestive problems

Question 37

Advantages and disadvantages of the pill?

Answer 37

- Females need to remember to take it daily. Side effects include weight gain, mood swings or an increased risk of blood clots. Does not protect against STI’s + Very reliable

Question 38

Advantages and disadvantages of the condom?

Answer 38

- Unreliable if not used properly | + Easily obtained. Protects against STI’s

Question 39

Adavantages and disadvantages of sterilisation?

Answer 39

- Doesn’t protect against STI’s, very difficult to reverse. | + Virtually 100% effective. Long term affects are rare, doesn’t impact sex drives

Question 40

Advantages and disadvantages of diaphragm?

Answer 40

- Can take time to learn how to insert, not reliable against STI’s. Can lead to a bladder infection + No serious associated health risks, quite effective.

Question 41

General advantages and disadvantages of hormonal and barrier methods?

Answer 41

+ Hormonal methods are more effective + Hormonal methods mean couple don’t have to stop and think contraception each time they have intercourse - Hormonal methods can have unpleasant side effects - Hormonal methods don’t protect against STI’s

Question 42

How do hormonal contraceptives work?

Answer 42

An example of a hormonal contraceptive is the pill. Hormonal contraceptives release oestrogen and progesterone. Oestrogen stops the release of an egg (it inhibits FSH) Progesterone thickens cervical mucus. This stops the sperm entering the uterus and reaching the egg.

Question 43

What are the 2 types of treatments for infertility?

Answer 43

Clomifene therapy | IVF

Question 44

What is Clomifene therapy and how does it work?

Answer 44

Clomifene is a drug It causes more FSH and LH to be released by the blood which stimulate egg maturation and ovulation. By knowing when the woman will be ovulating, the couple can have intercourse during this time period to increase the chance of becoming pregnant.

Question 45

What is IVF and how does it work?

Answer 45

It involves collecting eggs from the woman’s ovaries and fertilising them in a lab using the man’s sperm. These are then grown into embryos. Once the embryos are tiny balls of cells, one or two of them are transferred to the woman’s uterus to improve the chance of pregnancy. FSH and LH are given before egg collection to stimulate egg production. IVF is an example of assisted reproductive technology (a fertility treatment that involves egg being handled outside of the body)