B9- Coordination and response

Question 1

Define Hormone

Answer 1

-A chemical substance,
-produced by a gland
-carried by the blood,
-alters the activity of one +specific target organs

Question 2

Describe adrenaline

Answer 2

The hormone secreted in ‘fight or flight’ situations.

Question 3

Name some effects of adrenaline

Answer 3

• Increased pulse rate
• Increased breathing depth and rate
• Pupil dilation
• Increase blood glucose concentration

Question 4

Why is the blood glucose concentration increased when adrenaline is secreted?

Answer 4

• To provide energy to the muscles for respiration for ‘fight or flight’

Question 5

What is a nerve impulse?

Answer 5

An electrical signal
that passes along nerve cells called neurones

Question 6

Describe a voluntary action

Answer 6

An action made by the brain, conscious

Question 7

Describe an involuntrary action

Answer 7

An automatic response made without conscious decisions

Question 8

What is the order of an arc reflex?

Answer 8

Receptor, sensory neuron, relay neuron, motor neuron and effector

Question 9

Describe a reflex action

Answer 9

Automatically and rapidly integrating and coordinating stimuli with the responses of
effectors (muscles and glands)

Question 10

What is the function of the cornea?

Answer 10

Refracts light

Question 11

What is the function of the Iris?

Answer 11

controls how much light enters the pupil

Question 12

What is the function of the retina?

Answer 12

Contains light receptors, some sensitive to light of different colours.

Question 13

What is the function of the optic nerve?

Answer 13

carries impulses to the brain

Question 14

Define homeostasis

Answer 14

The maintenance of a
constant internal environment

Question 15

How do the muscles make the pupil smaller? (circular + radial)

Answer 15

Circular muscles- contract
Radial muscles - relax

Question 16

More adrenaline is produced by the adrenal gland when a person is frightened. Blood glucose concentration decreases when adrenaline is secreted. True or false?

Answer 16

False

Blood glucose concentration increases to provide energy to muscles for respiration

Question 17

Is the change in pupil size due to light intensity voluntary or involuntary?

Answer 17

Involuntary

Question 18

The lens in the eye changes shape during accommodation.
Voluntary or Involuntary?

Answer 18

Voluntary

Question 19

In a plant shoot, where is auxin made and what is its effect? [2]

Answer 19

Shoot tip
Promotes cell elongation

Question 20

When the environment is too hot what happens to the arterioles?

Answer 20

They vasodilate

In vasodilation to reduce temperature and to allow radiation

Question 21

Where is the blind spot found in the eye?

Answer 21

In the retina, in front of the optic nerve

Question 22

A person changes their focus from a near object to a distant object.
Describe the changes in terms of the ciliary muscle, suspensory ligaments and the lens.

Answer 22

Ciliary muscle- relax

Suspensory ligaments- contract/tighten

Lens- becomes tall and thin

Question 23

Explain the importance of the pupil reflex

Answer 23

To protect the eye from being blinded by bright light

Question 24

State the name of the hormone released to reduce the glucose levels in the blood

Answer 24

Insulin

Question 25

Suggest one way that the blood glucose concentration could be reduced other than by insulin

Answer 25

Exersice

Question 26

Describe how the liver and pancreas work together to cause changes in blood glucose levels. [3]

Answer 26

• Pancreas releases glucagon
• Glycogen (stored) in liver
• Glycogen converted to glucose

Question 27

State a term that can be used to describe the control of blood glucose concentration.

Answer 27

Negative feedback

Question 28

State 3 differences between the hormonal and nervous systems.

Answer 28

Hormonal- chemical hormones, slow information transfer time, long-lasting action

Nervous- Electrical impulses, very fast information transfer time, short-lived action

Question 29

Describe how adrenaline is transported.

Answer 29

Through the blood