4.5 Response and Regulation

Question 1

What is the function of the nervous system?

Answer 1

transmits signals between different parts of the body

Question 2

How is information sent through the nervous system?

Answer 2

As a series of small electrical signals

Question 3

What are the sense organs for the following stimulus:
light 
sound 
temperature 
touch 
chemicals

Answer 3

eyes 
ears 
skin 
skin 
tongue/nose

Question 4

What is a receptor?

Answer 4

a group of specialised cells that detects a stimulus

Question 5

What is a reflex?

Answer 5

a fast, automatic response to a stimulus

Question 6

What is the function of a reflex action?

Answer 6

protect the body

Question 7

Name the 3 neurones that are involved in a reflex arc

Answer 7

sensory neurone
relay neurone
motor neurone

Question 8

What is a reflex arc?

Answer 8

the nerve pathway that makes such an automatic response possible

Question 9

What is the central nervous system made up of?

Answer 9

spinal cord and brain

Question 10

EXAM STYLE
Each reflex reaction follows a series of steps
What is the order to show the nerve pathway of a reflex arc? (potential 6 marker)

Answer 10

STIMULUS is picked up by a RECEPTOR which transmits an electrical impulse to a SENSORY NEURONE
SENSORY NEURONE passes the electrical impulse to the RELAY NEURONE in the SPINAL CORD via a SYNAPSE
RELAY NEURONE passes the electrical impulse on to a MOTOR NEURONE
which carries the response back to the effector organ
the response is carried out by the effector organ e.g muscle contracts

Question 11

What does sense organ mean?

Answer 11

an organ that has receptors sensitive to a particular kind of stimulus

Question 12

What are the 3 properties of a reflex action?

Answer 12

fast
automatic
protective

Question 13

Explain what happens to hairs when we are cold?

Answer 13

The hair erector muscle contracts which cause the hair to raise
the hair traps a thicker layer of air above the skin
the air insulates the skin against heat loss

Question 14

Explain what happens to hairs when we are warm?

Answer 14

The hair erector muscle relaxes which causes the hair to lower
a thin insulating layer of air is trapped above the skin
more heat is lost to the environment

Question 15

What does vasoconstriction mean?

Answer 15

a response to being too cold
the process involves the narrowing of blood vessels at the skin surface to reduce heat loss through the surface of the skin

Question 16

What does Vasodilation mean?

Answer 16

a response to being too hot

process includes the widening of blood vessels at the skin surface to increase heat loss through the surface of the skin

Question 17

State two internal conditions that need to be controlled in the human body

Answer 17

temperature

level of glucose in blood

Question 18

State one factor that can cause blood glucose levels to:
decrease
increase

Answer 18

decrease- after exercise

increase- eaten a meal

Question 19

Name the two hormones released as part of glucose regulation

Answer 19

insulin

glucagon

Question 20

Name the two organs involved in glucose regulation and describe its function

Answer 20

pancreas- releases the hormones

liver- responds to the hormones

Question 21

When blood glucose levels increase

a) which hormone is released?
b) what affect does this have on the liver?

Answer 21

a) insulin

b) liver takes in excess glucose from the blood and stores as glycogen

Question 22

When blood glucose levels decrease

a) which hormone is released?
b) what affect does this have on the liver?

Answer 22

a) glucagon

b) liver breaks down glycogen and releases glucose into the blood

Question 23

Explain what happens if there’s an increase in blood glucose levels? (6 mark)

Answer 23

Blood glucose levels can rise after eating carbohydrates/sugar
The PANCREAS produces the hormone INSULIN
The insulin travels in the bloodstream to the LIVER and muscles.
Insulin makes glucose move from the BLOOD into the liver and muscles
Glucose is stored in the liver and muscles as GLYCOGEN
This decreases the blood glucose levels back down to normal

Question 24

Explain what happens if there’s a decrease in blood glucose levels? (6mark)

Answer 24

Blood glucose levels can fall after exercising
The PANCREAS produces the hormone GLUCAGON and stops producing insulin
The GLUCAGON travels in the bloodstream to the LIVER and muscles.
The liver converts the GLYCOGEN into glucose which is released into the blood
This increases the blood glucose levels back up to normal

Question 25

What does homeostasis mean?

Answer 25

maintaining a constant internal environment in the body

Question 26

What is diabetes?

Answer 26

When you’re unable to control your blood glucose levels

Question 27

What is type 1 diabetes?

Answer 27

Occurs when the body does not produce sufficient insulin

Question 28

What is type 2 diabetes?

Answer 28

Occurs when body cells do not correctly respond to the insulin that is produced

Question 29

What does negative feedback mean?

Answer 29

A change from optimal internal conditions resulting in the body compensating and restoring normal conditions

Question 30

What impact do depressant drugs have on the body?

Answer 30

slows down signals in the nerves and brain

Question 31

Why is it important to impose legal limits for drivers (alcohol)?

Answer 31

because alcohol increases reaction times so this impairs the ability to control the vehicle

Question 32

How do you test for diabetes?

Answer 32

urine sample for the presence of glucose
Benedict’s solution and heat
it will change blue to red

Question 33

State two feature of hormones

Answer 33

chemical messengers

controls body function