Lecture 2 - Nervous System I

Question 0

What is the CNS surrounded by?

Answer 0

Bone

Question 1

What is the major division of the nervous system?

Answer 1

CNS

PNS

Question 2

Describe the difference in the neuraxis of quadrupeds and humans

Answer 2

Quadrupeds: neuraxis runs horizontally

Humans: neuraxis is vertical and curved at the head

Question 3

What is the neuraxis?

Answer 3

Rostro - Caudal axis

Rostro: head
Caudal: tail

Question 4

What is the dorsal ventral axis?

What is the more common term for humans?

Answer 4

Dorsal: stomach
Ventral: back

More common is anterior and posterior

Question 5

Describe the different terms for the sections that can be taken of the brain, and of the body more generally

Answer 5

Coronal

Sagittal

Horizontal

Question 6

Ganglia (such as dorsal root, chain etc. ) belong to which division of the nervous system?

Answer 6

Peripheral

Question 7

What are the meninges?

Answer 7

Protective layers over the brain

Question 8

What are the three meninges?

Answer 8

Dura mater
Arachnoid mater
Pia mater

Question 9

What type of tissue are the meninges?

Answer 9

Connective

Question 10

What is CSF?

Where is it located?

Answer 10

Cerebrospinal fluid - protects the brain

Lies in the sub arachnoid space

Question 11

How does CSF return to circulation?

Answer 11

It drains out of the subarachnoid space through arachnoid granulations into the superior sagittal sinus, which is located within the dura mater.

This blood then goes back into venous return

Question 12

Where and how is CSF made?

How much per day?

Answer 12

Made in the ventricles by specialised vasculature called the choroid plexus

1/2 L per day

Question 13

What are the four ventricles in the body?

Answer 13

Two lateral ventricles
Third ventricle
Fourth ventricle

Question 14

What happens if CSF isn’t properly returned to circulation?

Answer 14

Babies: hydrocephalus

Increase in intra-cranial pressure –> cerebro vascular accident

Question 15

How is hydrocephalus treated in babies?

Answer 15

Catheter drains the fluid

Question 16

What is a haematoma?

Answer 16

Pooling of blood in the brain

Question 17

What is the difference between white and grey matter?

Answer 17

White: axons are myelinated

Question 18

What are the locations where a haematoma can occur in the brain?

Answer 18

Intracerebral: within brain tissue
Subdural - venous blood
Epidural - dura peeled away from skull, arterial blood

Question 19

Where is white matter found?

Answer 19

Interior of brain

Exterior of spinal cord

Question 22

Differentiate between the two types of transmission that occur within neurons and between neurons

Answer 22

Within neurons: electrical, fast

Between neurons: chemical, slower

Question 23

What is a nerve?

Answer 23

Bundle of thousands of axons in the PNS surrounded by connective tissue

Question 24

What are e connective tissue layers in nerves?

Answer 24

Epineurium
Perineurium
Endoneurium

Question 25

What is a fascicle?

Answer 25

Sub-group of axons within a nerve, surrounded by the perineurium

Question 26

What does the endoneurium surround?

Answer 26

A single axon

Question 27

What is the role of astrocytes?

Answer 27

* Recycle neurotransmitters * Maintain ionic composition of ECF * Blood brain barrier

Question 28

What type of cells are astrocytes?

Answer 28

Glial

Question 29

What is the structure of the blood brain barrier?

Answer 29

* Many tight junctions | * Foot processes of the astrocytes

Question 30

What is the blood brain barrier? | What does it do?

Answer 30

It is the largely impenetrable endothelium of the vasculature in the CNS It lets only certain molecules into the interstitial fluid of the brain

Question 31

What are the various types of nerve present in the body? | How many of each?

Answer 31

Cranial: 12 Spinal: 31

Question 32

What are nerve plexes?

Answer 32

These are the nerves that supply the limbs in the cervical and lumar-sacral regions of the spinal cord

Question 33

What are the different nerve plexes?

Answer 33

Cervical Brachial Lumbar Sacral

Question 34

What is the role of the cranial nerves?

Answer 34

* Sensory * Motor * Autonomic of head and neck

Question 35

Which nerves are in the thoracic segments of the spinal cord?

Answer 35

Intercostal nerves

Question 36

Differentiate between afferent and efferent | Where do they enter and exit the CNS?

Answer 36

Afferent: towards CNS, Dorsal horn of spinal cord Efferent: away from CNS, ventral horn

Question 37

Where do the myelin sheaths come from? | Compare in CNS and PNS

Answer 37

CNS: Oligodendrocytes PNS: Schwann cells

Question 38

How is neuronal action potential conduction sped up?

Answer 38

Saltatory conduction, myelin sheaths around the axon

Question 39

What situations could lead to an increase in intracranial pressure?

Answer 39

Haematoma Tumour growth Too much CSF

Question 40

What is the difference between astroglia and astrocytes?

Answer 40

No difference

Question 41

What are plexuses and where are they found?

Answer 41

Complex arrangements of nerve roots Supply the limbs

Question 42

Where do the cranial nerves leave the CNS?

Answer 42

11: brain stem Cranial nerve I leaves from brain