Coordination and response

Question 1

What tissue do electrical impulses travel along?

Answer 1

Neruones.

Question 2

What does the CNS consist of?

Answer 2

The brain and spinal cord

Question 3

What does the PNS consist of?

Answer 3

Nerves, which are outside the brain and spinal cord

Question 4

What is the role of the nervous system?

Answer 4

Coordinaton and regulation of body functions

Question 5

The reflex arc.

Answer 5

Receptor –>Sensory neurone –> relay neurone –> motor neurone –> effector

Question 6

What is a reflex action?

Answer 6

A means of automatically and rapidly integrating and coordinating stimuli with responses of effectors

Question 7

What is a synapse?

Answer 7

A gap between 2 neurones

Question 8

How does an electrical impulse travel from one neurone to the other?

Answer 8

An impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap
The neurotransmitter molecules diffuse across the cap
Neurotransmitter molecules bind with receptor proteins in the next neurone
an impulse us then started in the next neurone

Question 9

What are sense organs?

Answer 9

Groups of receptor cells responding to different stimuli

Question 10

Describe the function of the following:
Cornea
iris
Lens
Retina
Optic Nerve

Answer 10

Cornea - controls the amount of light entering the eye
Iris - regulate the amount of light that can enter the retina
Lens - to transmit and focus light onto the retina
Retina - Contains receptor cells that respond to light
Optic nerve - relay messages from your eyes to the brain to create visual images

Question 11

Explain how the eye reacts to a nearby object and a distant objects

Answer 11

Ciliary muscles and suspensory ligaments are antagonistic to each other
When an object is distant, the ciliary muscles relax and the suspensory ligaments are pulled tight, making the lens appear thinner
When an object is near, The ciliary muscle contracts and and the suspensory ligaments slacken, making the lens more rounded

Question 12

Explain the pupil reflex

Question 13

Describe the distribution of cones and rods

Answer 13

Rods are found on the outer cornea and Cones are found on the inside of the cornea

Question 14

Outline the function of the Rods

Answer 14

They allow us to see in dim light but only in black and white

Question 15

Outline the function of the Cones

Answer 15

They allow us to see a detailed image in colour vision

Question 16

What is the function of the fovea?

Answer 16

Contains receptor cells

Question 17

Define the term hormone

Answer 17

A chemical substance, produce by a gland, and carried by the blod which alters the activity of one or more specific target organs

Question 18

Outline the hormones that the following endocrine glands secrete
Adrenal gland
Pancreas
Testes
Ovaries

Answer 18

Adrenal gland - adrenaline
Pancreas - insulin
Testes - testosterone
Ovaries - Oestrogen

Question 19

Define adrenaline and its effects on the body

Answer 19

Adrenaline - A hormone secreted in “Fight or flight” situations
Effects - Increases breathing rate
Increases heart rate
Dialates the pupil

Question 20

Compare nervous and hormonal systems

Answer 20

-Nervous system uses electrical impulses and the endocrine system uses chemicals
-Nervous system transmits messages much faster than the endocrine system
-Endocrine system lasts longer than nervous system

Question 21

How does adrenaline alter metabolic activity

Answer 21

This causes the liver to release glucose into the blood for energy
Increases the breathing rate of the lungs to supply the body with more oxygen

Question 22

Define Homeostasis

Answer 22

The maintenance of a constant internal environment

Question 23

What is the function of insulin?

Answer 23

To maintain the blood-glucose concentration

Question 24

Explain the concept of homeostatic control by negative feedback

Answer 24

Negative feedback is a mechanism that helps to maintain homeostasis by making changes in the internal environment.
Each condition has a set point and if the conditions are beyond the set point, negative feedback occurs to return the condition back to the set point

Question 25

Describe the control of blood glucose concentration

Answer 25

After having a meal rich in carbs, the blood glucose concentration increases, to lower it to normal, insulin is secreted by the pancreas, to reduce the blood glucose concentration. If the blood glucose concentration is too low, the pancreas detects this and sends glucagon to the liver so that it covers the stored starch into glucose which is then sent through the blood to parts of the body that may need it.

Question 26

Treatment of type 1 diabetes

Answer 26

Insulin shots
Controlled diet

Question 27

Describe what happens when the body temperature rises and falls

Answer 27

The temperature receptors detect the increase in temperature and send electrical impulses to the brain