2j Coordination and responses (continued...)

Question 1

What temperature is a human body temperature at?

Answer 1

37°C

Question 2

What are the two systems that control the body?

Answer 2

• endocrine system

- nervous system

Question 3

What does the endocrine system consist of?

Answer 3

• glands that secrete hormones

Question 4

What are hormones?

Answer 4

• hormones are chemical substances which produced by endocrine glands which are directly released in the bloodstream and are carried in the blood plasma around the body

Question 5

Why do hormones only act on certain cells or organs?

Answer 5

• the cells or organs must have the correct receptors (target organs)

Question 6

Which system is faster?

Answer 6

Nervous system

Question 7

Which system is chemical and which is electrical?

Answer 7

• endocrine system is chemical

- nervous system is electrical

Question 8

Which system uses impulses that travel along neurones?

Answer 8

Nervous system

Question 9

Which system uses hormones secreted by glands?

Answer 9

Endocrine system

Question 10

Which system controls reactions to body surroundings?

Answer 10

Nervous system

Question 11

Which system controls processes inside the body?

Answer 11

Endocrine system

Question 12

Which system is longer lasting?

Answer 12

Endocrine system

Question 13

Which system is shorter lasting?

Answer 13

Nervous system

Question 14

Which system is slower?

Answer 14

Endocrine system

Question 15

Which 3 endocrine glands are male?

Answer 15

• pituitary gland
• adrenal gland
• testes

Question 16

Which 2 endocrine glands are female?

Answer 16

• pancreas

- ovaries

Question 17

What does the pituitary gland do?

Answer 17

• makes hormones that control other endocrine glands

- makes growth hormones

Question 18

What does the adrenal gland do?

Answer 18

• makes adrenaline

- gets the body ready for action in the ‘flight or fight’ response

Question 19

What do the testes do?

Answer 19

• make testosterone

- this controls the development of male characteristics in puberty

Question 20

What does the pancreas do?

Answer 20

• makes hormones called insulin and glucagon

- these control the amount of sugar in the body

Question 21

What do the ovaries do?

Answer 21

• make female hormones called oestrogen and progesterone

- cause the development of female characteristics during puberty and control the menstrual cycle

Question 22

What is adrenaline’s target organ?

Answer 22

• vital organs (heart, ect.)

Question 23

What is insulin’s target organ?

Answer 23

Liver

Question 24

What is testosterone’s target organ?

Answer 24

Male reproductive organs

Question 25

What is progesterone's target organ?

Answer 25

Female reproductive organs

Question 26

What is oestrogen's target organ?

Answer 26

Female reproductive organs

Question 27

What is homeostasis?

Answer 27

- the ability to maintain a constant internal environment

Question 28

What does homeostasis involve?

Answer 28

- keeping certain physiological variables within a normal range, to allow cells to function at optimal conditions

Question 29

What are 5 examples of homeostasis?

Answer 29

- body temperature - water balance - blood pH - carbon dioxide concentration - blood glucose levels

Question 30

What is negative feedback?

Answer 30

When a deviation from the ‘norm’ is detected, it will initiate a response to return the system to its ‘norm’.

Question 31

What is thermoregulation?

Answer 31

Control of body temperature to ensure optimum temperature for enzymes

Question 32

What are the dangers if the body temperature becomes too low?

Answer 32

- the reactions become too slow for cells to survive | - hypothermia

Question 33

What are the dangers if the body temperature becomes too high?

Answer 33

- the body's enzymes are at risk of denaturing

Question 34

What is the hypothalamus?

Answer 34

The hypothalamus is the area of the brain responsible for controlling temperature, and in that area the thermoregulatory centre detects changes in the blood temperature

Question 35

How is a rise in temperature detected?

Answer 35

Rise in temperature is detected by the warm skin thermoreceptors and the thermoregulatory centre

Question 36

What are the 3 cooling mechanisms?

Answer 36

- sweating - vasodilation - behaviours

Question 37

How is a reduction in temperature detected?

Answer 37

Reduced temperature is detected by the cold skin thermoreceptors and thermoregulatory centre

Question 38

What are the 4 warming mechanisms?

Answer 38

- increase rate of metabolism - constriction of arterioles (vasocontriction) in the skin - contraction of arrector pili muscles - behaviours

Question 39

What is vasodilation?

Answer 39

- control the size of the blood vessels (arterioles) near the surface of the skin

Question 40

What happens if you are too hot (vasodilation)?

Answer 40

If you are too hot, more blood vessels are opened so more blood flows near the skin’s surface and radiates heat to the environment. This results in more heat being lost so the body cools down.

Question 41

What happens if you are too hot (sweating)?

Answer 41

- sweat is made up of water and salts from the body - sweat glands open ensuring that water is lost to the skin - evaporation of this water from the skin uses heat energy which causes a cooling effect on the body

Question 42

What happens if you are too hot (behaviours)?

Answer 42

- Removing excess clothing, limiting excess movement, air conditioning

Question 43

What happens if you are too cold (increased rate of metabolism)?

Answer 43

- start to shiver when cold - shivering is caused by muscle contractions - this uses respiration which generates heat as a by-product

Question 44

What happens when you are too cold (vasoconstriction)?

Answer 44

- close blood vessels so the blood does not flow near the skin and does not lose heat energy - results in less blood being transferred to the skin and more blood transferred to internal organs - less heat is lost by radiation

Question 45

What happens when you are too cold (contraction of arrector pili muscles)?

Answer 45

- hairs can stand on end (up) | - traps a layer of air around the skin which is a very good insulator, this stops you losing too much heat

Question 46

What happens when you are too cold (behaviours)?

Answer 46

- increased movement, huddling, reduction of exposed surfaces.