Topic 2: Body Balance

Question 1

What does the endocrine system do?

Answer 1

• maintains balance in the body through the
  action of hormones

Question 2

What is the endocrine system?

Answer 2

The endocrine system is made up of endocrine glands that secrete hormones which travel through the bloodstream to cells everywhere in the body. This allows for the maintenance of the internal environment in the body, or internal homeostasis

Question 3

What does the endocrine system do?

Answer 3

It regulates, coordinates and controls:
1. growth and development
2. male and female development
3. how your body uses energy
4. Appetite

Question 4

What is an endocrine gland?

Answer 4

A gland that secretes hormones into the bloodstream for transport around the body.
- same in males and females, except for the ovaries and testes.

Question 5

What is a hormone?

Answer 5

proteins that are secreted from the endocrine glands and into the bloodstream that affects cells in another part of the body

Question 6

How do hormones “know” which cells are their target cells?

Answer 6

It is because target cells have special receptors that recognise the hormones and allow them to influence that cell. The target cell and the receptor have the same size and shape.

Question 7

What controls internal signalling?

Answer 7

Nerve Cells - are short acting but send a message quickly
Hormones - are long-acting but slower to be received.

Question 8

What is external stimuli?

Answer 8

via nerves from the sensory organs into the nervous system

Question 9

What is internal stimuli?

Answer 9

via nerves and other hormones from inside the body

Question 10

List 2 Examples of External Stimuli

Answer 10

1. Hearing a loud noise
2. A large dog runs towards you, growling and barking

Question 11

List 2 Examples of Internal Stimuli

Answer 11

1. You have not eaten in 6 hours
2. You are sick and develop a fever.

Question 12

What are target cells?

Answer 12

have receptors on the cell membrane of a cell that recognise receptors to initiate a response.

Question 13

Role of the hypothalamus

Answer 13

• monitors the body for temperature, pH, and other conditions.
• signals the pituitary gland if conditions need to be corrected.

Question 14

Role of the pituitary gland

Answer 14

• signals other glands to produce their hormones when needed
• found in the brain and receives signals from the hypothalamus.

Question 15

Hormones released: pituitary gland

Answer 15

1. Growth Hormone
   - Too much - gigantism
   - Too little - dwarfism
2. Antidiuretic hormone - stimulates kidneys to keep water

Question 16

Role of the thyroid gland

Answer 16

• regulates metabolism and energy balance

Question 17

Hormones released: thyroid gland

Answer 17

1. Thyroxine - regulates body energy usage
2. Calcitonin - regulates calcium and phosphate in the blood.

Question 18

What does the thyroxine do?

Answer 18

• controls the rate of metabolic processes in the body and influences physical development.
  -people who don’t produce enough of these hormones have hypothyroidism.

Question 19

Role of Adrenal Glands

Answer 19

• releases hormones that help your body deal with stress. It increases heart rate and blood pressure in times of fright, increasing amount of energy available to muscles

Question 20

Hormone Released: Adrenal Glands

Answer 20

1. Adrenaline - stimulates heart rate, increases blood pressure, and dilates pupils (acts on multiple tissues).
2. Cortisol: increases mental stimulation, and breaks down fat and protein to glucose. Involved in response to stress and anxiety

Question 21

Role of Pancreas

Answer 21

• regulates blood sugar levels in the blood.

Question 22

Hormones Released: Pancreas

Answer 22

1. Insulin - allows cells throughout the body to take glucose from the blood (acts on the liver, muscle, and fat tissue)
2. Glucagon - controls the amount of glucose released from the liver into the blood.

Question 23

Role of Ovary

Answer 23

• normal reproductive development and fertility
• releases hormones that control the menstrual cycle, pregnancy, and the development of the female sexual features

Question 24

Hormone Released: Ovary

Answer 24

Oestrogen - stimulates the development of female sexual characteristics
Progesterone - controls menstruation in women and plays a role in pregnancy

Question 25

Role of testes

Answer 25

• responsible for making testosterone, the primary male sex hormone, and for producing sperm.

Question 26

Hormone released: Testes

Answer 26

1. Testosterone - stimulates development of male sexual characteristics

Question 27

Role of pineal gland

Answer 27

• controls sleeping and waking patterns

Question 28

Hormone released:

Answer 28

Melatonin - varies in 24-hour cycles and is controlled by the body clock.
- production reduced in bright light
- levels increase at night.

Question 29

Define homeostasis

Answer 29

The body’s ability to regulate and maintain a stable condition inside your body, regardless of changes to the external environment

Question 30

Name the 2 body systems that coordinate all the functions of the body

Answer 30

• the nervous system
• the endocrine system

Question 31

3 Examples of homeostasis:

Answer 31

• body temperature at 37ºC
• the amount of water inside our body
• blood sugar levels

Question 32

Why is it so important to maintain temperature?

Answer 32

The human enzymes work best at 37ºC, so if the body temperature changes too much, it could result in:
- heat stroke
- hyperthermia
- dehydration
- death

Question 33

Why is it so important to maintain water levels?

Answer 33

If the amount of water in the body is wrong, cells can be damaged because too much water enters and leaves them, affecting their ability to function properly.

Question 34

Why is it so important to maintain carbon dioxide levels?

Answer 34

increased CO2 levels would alter the concentration of CO2 and O2 and the cells wouldn’t receive enough oxygen which means they wouldn’t function properly.

Question 35

SRBERN

Answer 35

Stimulus - what has happened?
Receptors - name the type of receptor
Brain - hypothalamus
Effector - fixes the problem
Response - counter-acts the problem
Negative Feedback - don’t want it to keep happening

Question 36

What happens if body temperature is too low?

Question 37

What happens if body temperature is too high?

Question 38

What happens is blood-sugar levels are too high?