Nervous system: The Spinal Cord

Question 1

What is main function of the spinal cord?

Answer 1

It allows information to be transferred from the brain to the periphery and vice versa

Question 2

Where does the spinal cord start?

Answer 2

At the base of the brain

Question 3

Between each vertebrate, what is at each level?

Answer 3

A spinal segmental level

Question 4

Label the diagram

Answer 4

Question 5

What is the range of the cervical enlargement?

Answer 5

C4 - C8

Question 6

What makes the spinal cord enlarged at the cervical enlargement?

Answer 6

This is where the nerves of the ARM join up with all the other nerves so there need to be more space for connections therefore enlarged here

Question 7

Where does the spinal cord terminate? What is this point called?

Answer 7

At L1

at the Conus medullar

Question 8

What makes the spinal cord enlarged at the lumbar enlargement?

Answer 8

This is where the nerves of the LEG join up with all the other nerves so there need to be more space for connections therefore enlarged here

Question 9

How many paired nerves are there in the body?

Answer 9

31 pairs

Question 10

What does the homunculus structure of the brain indicate interns of neuron quantity and sensation?

Answer 10

Where the corresponding parts of the brain are large, there are more nerves going there which means there is more discriminative sensation

Question 11

What is discriminative sensation?

Answer 11

Sensation that is sent to the spinal cord and allow the ability to be able to detect differences

Question 12

What does discriminative sensation on the lips vs the back tell us about the nerves going to these places?

Answer 12

In the lips you can detect two points that are only millimetres apart, on your back can only detect two points within 10cm

This indicates that there is a far higher density of nerves in the lips than in the back

Question 13

Where do the peripheral nerves come INTO the spinal cord?

Answer 13

Though the dorsal root (i.e. a ganglia)

Question 14

What is the white matter made of?

Answer 14

Lots of nerve fibres

Question 15

What is grey matter made of?

Answer 15

Lots of cell bodies

Question 16

What is a ganglia?

Answer 16

A clump of nerve cell bodies

Question 17

What are the two types of capsulated nerves? What do they detect?

Answer 17

Meisner’s corpuscles: touch

Pacinian corpuscle: pressure

Question 18

What is surrounding the corpuscle nerve endings? What does this allow? What does this show about its function?

Answer 18

Myelin, allows rapid info transfer (50ms-1)

Shows that it is used very often

Question 19

What do parisian corpuscles detect? How does their behaviour describe this?

Answer 19

Changes in pressure

They will quickly activate sensing pressure change but then quickly deactivate

Question 20

What do free nerve endings detect?

Answer 20

Pain and temperature

Question 21

What is on the end of a free nerve ending?

Answer 21

Nothing, it is connected directly into the skin

Question 22

Is there myelin along a free nerve? What does this mean for its ability to transmit information and show about its function?

Answer 22

No

It means it transmits information very slowly (~1ms-1)

This indicates that it is not used very often

Question 23

What is the first cervical nerve? Where does it come from?

Answer 23

Atlas, comes from between the first vertebrate and the skull

Question 24

What is the name of this diagram? What does it describe?

Answer 24

Dermatome, it describes the location where the nerves from the spinal cord connect to the skin

Question 25

What is a diagram that shows the location of nerve endings in muscle called?

Answer 25

A Myotome

Question 26

Where do free-nerve endings go into?

Answer 26

The posterior end of the grey matter

Question 27

Label the diagram. What is this showing?

Answer 27

A spinal segment