Structure of the central nervous system

Question 1

how many pairs of nerves do we have?

Answer 1

31 pairs of nerves

Question 2

why do we have a lumbar system?

Answer 2

the spinal cord is shorter than the vertebral column. This means that at in the lumbar region we have fibre and cerebrospinal fluid

Question 3

where do we carry out lumbar punctures?

Answer 3

between L3 and L4 in children and L4 and L5

this enusres there is not risk to the spinal cord

Question 4

what makes up the grey matter in the spinal cord?

Answer 4

the cell bodies

Question 5

what are the dorsal and ventral horns?

Answer 5

dorsal are the 2 top parts of the H where the sensory neurones come into the spinal cord
ventral are the 2 bottom parts of the H where the motor neurones leave the spinal cord

Question 6

what is the white matter in the spinbal cord?

Answer 6

the myelinated axons

Question 7

what are the functions of the spinal cord?

Answer 7

connects the PNS to the ANS
coordinates reflexes
carries sensory info to the brain
carries motor info to the muscles

Question 8

describe the structure of the brain

Answer 8

- the brain stem made up of;
midbrain
pons
medulla
- the cerebrum:
made up of diencephalon which is made up of the thalamus and the hyopthalamus 
the cerebellum 
the cerebral hemisphere- made up of cortex and basal ganglia

Question 9

what is the brain stem responsible for?

Answer 9

control of breathing, heart rate, BP

control of defensive mechanisms e.g. coughing

Question 10

What structure connects the right and left hemispheres?

Answer 10

Corpus Callosum

Question 11

What lies beneath the corpus callosum?

Answer 11

Diencephalon

Question 12

What is the role of the cerebellum?

Answer 12

Fine tuning motor function

Question 13

What are the two parts of the diencephalon?

Answer 13

Thalamus - relay station for information going between the cerebral cortex and other areas of the CNS Hypothalamus - important in coordinating homeostasis (hypothalamo-hypophysial axis)

Question 14

What is the role of the basal ganglia

Answer 14

Regulates voluntary movement

Question 15

what makes up the corpus striatum?

Answer 15

putamen and caudate

diseases in striatum = huntingtons

Question 16

cerebral cortex structure?

Answer 16

3-4 mm layer of grey matter with white matter underneath

Question 17

structure of the cortex

Answer 17

6 layers of cells

Question 18

what is the function of the hippocampus?

Answer 18

responsible for memory formation and is degenerated in alzheimers

Question 19

what are commissural fibres?

Answer 19

they connect the 2 halves of the brain

they forms the corpus collusum

Question 20

what are association fibres?

Answer 20

they connect parts of the same half together

Question 21

what are projection fibres?

Answer 21

they join different parts of the brain together

Question 22

the 3 layers of the meninges are?

Answer 22

dura mater
arachnoid mater
pia mater

Question 23

Describe the ventricular system of the brain.

Answer 23

There are two large C shaped ventricles called lateral ventricles. There is one lateral ventricle for each cerebral hemisphere. The lateral ventricles narrow and form the 3rd ventricle, which is in the diencephalon The 3rd ventricle narrows to form the cerebral aqueduct, which passes down through the midbrain and becomes a tent-shaped structure called the 4th ventricle. The 4th ventricle is behind the pons and medulla and in front of the cerebellum. The 4th ventricle then narrows to form the central canal, which runs down the spinal cord.

Question 24

What are the hole in the vertebral column that spinal nerves pass through called?

Answer 24

Intervertebral Foramina

Question 25

What is the role of CSF?

Answer 25

CSF has a protective role - it is like the foetus being suspended inthe amniotic fluid. It also has a metabolic role in exchanging nutrients and removing waste.

Question 26

Where does CSF leave the ventricles and enter the subarachnoid space?

Answer 26

CSF leaves the ventricles in the 4th ventricle, which has small holes in it

Question 27

Where is cerebrospinal fluid produced?

Answer 27

By the choroid plexus, which is a special type of ependymal cell found in the ventricles.

Question 28

differences between blood and CSF

Answer 28

fewer plasma proteins
lower glucose, calcium and potassium
higher chloride and magnesium