Nervous system and brain

Question 1

What is the nervous system made up of?

Answer 1

The nervous system is made up of the brain, spinal cord, and many nerve cells.

Question 2

What is the Central Nervous System?

Answer 2

It is all the nerves in your brain and spinal cord.

Question 3

What is the Peripheral Nervous System?

Answer 3

It is all the nerves going to and from the CNS.

Question 4

What are the different types of sensory receptors?

Answer 4

1. Light-sensitive receptor cells
2. Touch receptor cells
   3.Temperature receptors cells

Question 5

What do Light-sensitive receptor cells do?

Answer 5

Light-sensitive receptor cells in the retina of the eye detect light and
pass this to the central nervous system for processing

Question 6

What do Touch receptor receptor cells do?

Answer 6

Touch receptor cells in the skin detect pressure on the skin and pass this to the CNS for processing

Question 7

What do Temperature receptors cells do?

Answer 7

Temperature receptor cells in the skin detect temperature changes and pass this to the brain for processing

Question 8

What are the different types of neurones?

Answer 8

1. Sensory Neurones
2. Relay Neurones
3. Motor Neurones

Question 8

What does the sensory neurones do?

Answer 8

The sensory neurons carry information as electrical impulses from sensory receptors to the CNS

Question 8

What does the relay neurones do?

Answer 8

The relay neurones collect electrical impulses from sensory neurones to motor neurones. They are found in the CNS.

Question 8

What does the motor neurones do?

Answer 8

The motor neurones carry electrical impulses from the CNS to the effectors.

Question 9

Why are some axons covered in myelin sheath?

Answer 9

The myelin sheath acts as an electrical insulator, speeding up the electrical impulse.

Question 10

What do dendrites and dendrons do?

Answer 10

Dendrites and dendrons carry nerve impulses toward the cell body.

Question 11

What do axons do?

Answer 11

Axons carry nerve impulses away from the cell body.

Question 12

What is a synapse?

Answer 12

The connection between two neurones

Question 13

What are neurotransmitters?

Answer 13

Neurotransmitters are chemicals involved in passing nerve impulses from one nerve cell to the next across a synapse.

Question 14

What is the process of responding to stimuli?

Answer 14

stimulus > receptor > sensory neurone > CNS > motor
neurone > effector (muscle of gland) > response

Question 15

What are reflexes?

Answer 15

Reflexes are fast, automatic responses to certain stimuli.

Question 16

What is a reflex arc?

Answer 16

A reflex arc is the passage of information in a reflex (from receptor to effector). The function is to provide a quick and automatic response to potentially harmful stimuli, allowing the body to quickly protect itself.

Question 17

What is a withdrawal reflex?

Answer 17

The withdrawal reflex acts to quickly remove a limb from a painful stimulus

Question 18

What is the reflex which responds to light?

Answer 18

This is the iris reflex.

Question 19

Which two muscles control the size of the pupil?

Answer 19

The circular muscles and radial muscles.

Question 20

Which eye muscle contracts to make the pupil smaller?

Answer 20

The circular muscles.

Question 21

Which eye muscle contracts to make the pupil bigger?

Answer 21

The radial muscles.

Question 22

What is the brain?

Answer 22

The brain is part of the central nervous system (CNS).
It’s made up of billions of interconnected neurones (nerve cells that are connected).
The brain is in charge of all of our complex behaviours. It controls and coordinates everything you do - running, breathing etc

Question 23

What are the four main regions of the brain?

Answer 23

1. Cerebrum
2. Cerebellum
3. Medulla
4. Spinal Cord

Question 24

What is the Cerebrum?

Answer 24

The largest part of the brain. Divided into two halves called cerebral hemispheres.
The right hemisphere controls muscles on the left side of the body and the left hemisphere controls muscles on the right side of the body.
Different parts of the cerebrum are responsible for different things, including movement, intelligence, memory, language, and vision.

Question 25

What is the Cerebellum?

Answer 25

The cerebellum (little brain) is found at the back of the brain.
It’s responsible for muscle coordination, posture, and balance. It helps you stand upright and move properly.
It also coordinates the timing and fine control of muscle activity, making sure that movements are smooth.

Question 26

What is the Medulla Oblongata?

Answer 26

The medulla oblongata is at the base of the brain, at the top of the spinal cord.
It controls unconscious activities (things you don’t have to think about doing) like breathing and your heart rate.
It is also responsible for reflexes such as vomiting, sneezing, and swallowing.

Question 27

What is the Spinal Cord?

Answer 27

The spinal cord is a long column of neurones (nerve cells) that run from the base of the brain down the spine.
The spinal cord relays information between the brain and the rest of the body.

Question 28

What is a CT scan?

Answer 28

A CT scanner uses X-rays to produce an image of the brain.
It shows the main structures in the brain, but not what they do.
However, the function of parts of the brain can sometimes be worked out with a CT scan.
E.g. if an area of the brain is damaged and the patient can’t see, then you know that area is involved in vision.

Question 29

What is a PET scan?

Answer 29

A PET scan shows brain activity.
Before a person has a PET scan they are injected with a radioactive chemical (called a tracer). Radioactive glucose is often used.
Your cells need glucose for respiration. The more active they are, the more glucose they need.
Regions of your brain that are more active will take up more of the radioactive glucose and appear brighter on a scanner.

Question 30

What are the difficulties in treating CNS problems?

Answer 30

It’s hard to repair damage to the nervous system - neurones in the CNS don’t readily repair themselves and as of yet scientists haven’t developed a way to repair nervous tissue in the CNS.
If a problem occurs in a part of the nervous system that’s not easy to access it can be hard to treat, e.g. it’s not possible to surgically remove tumours growing in certain parts of the brain.
Treatment for problems in the nervous system may lead to permanent damage. For example, a person who has injured their spinal cord may need surgery on their spine near the injury. There is a risk that the spinal cord could be damaged further during the operation, leading to permanent damage.