L1 - intro

Question 1

Components of the CNS

Answer 1

• spinal cord
• brainstem
• cerebellum
• cerebral hemisphere

Question 2

PNS

Answer 2

• spinal nerves
• cranial nerves
• ANS
• peripheral nerves
• dorsal and ventral roots
• cauda equina

Question 3

Difference between the CNS and PNS

Answer 3

CNS:

• can’t regenerate
• myelinated by oligodendrocytes
• grey matter
• white matter

PNS:

• regenerates well
• myelinated by Schwann cells
• ganglion
• peripheral nerves = white matter equivalent

Question 4

Grey matter

Answer 4

• Collection of cell bodies with dendrites in the CNS
• Also contains axons but less than the white matter
• highly vascular

Question 5

White matter

Answer 5

• mainly axons in the CNS

- contains myelin which makes it white

Question 6

Difference between the brain and spinal cord

Answer 6

The brain has an extra layer of grey matter surrounding the white matter caller the cerebral cortex

The spine has central grey matter and outer white matter. Spinal nerves are connected to a segment of the spinal cord by ventral and dorsal roots

Question 7

Where does the spinal cord terminate

Answer 7

L2

Continues as the cauda equina

Question 8

Parts of white matter

Answer 8

• funiculus
• tracts
• fasciculus

Question 9

Funiculus

Answer 9

A segment of white matter containing multiple distinct tracts travelling in different directions

• dorsal, lateral and ventral funiculi

Question 10

Tracts

Answer 10

Anatomically and functionally distinct pathways of white matter connecting two regions of grey matter travelling in one direction only.

Therefore either motor or sensory

Question 11

Fasciculus

Answer 11

An aspect of a tract supplying a distinct region of the body

Question 12

Organisation of grey matter

Answer 12

Organised in cell columns - rexed laminae

Question 13

Nucleus

Answer 13

A collection of cell bodies that are functionally related
Surrounded by white matter

Tracts connect nuclei

Question 14

Cortex

Answer 14

Folded sheet of cell bodies found on the surface of the brain
(1 - 5 mm thick)

Question 15

Fibre

Answer 15

Axon with its supporting cells e.g. oligodendrocytes

Question 16

Types of fibre

Answer 16

Association
Projection
Commissural

Question 17

Association fibres

Answer 17

Connect adjacent gyri in the same hemisphere

Question 18

Projection fibres

Answer 18

Connects the cerebral hemisphere in the brain with the spinal cord or brainstem and vice versa

Question 19

Commissural fibres

Answer 19

Connect the left and right hemispheres

Question 20

Purpose of the midbrain

Answer 20

Eye movements

Reflex responses to sound and vision

Question 21

Role of pons

Answer 21

Feeding

Sleeping

Question 22

Role of the medulla

Answer 22

Cardiovascular and respiratory centres

Contain major motor pathways in the medullary pyramids

Question 23

Precentral gyrus

Answer 23

Contains the primary motor cortex

Question 24

Postcentral gyrus

Answer 24

Contains the primary sensory cortex

Question 25

Lateral (Sylvian) fissure

Answer 25

Separates the temporal lobe from the frontal and parietal lobe

Question 26

Parieto- occipital sulcus

Answer 26

Separates the occipital lobe and parietal lobe

Question 27

Calcarine sulcus

Answer 27

The primary visual cortex surrounds this

Question 28

Optic chiasm

Answer 28

Site where the optic fibres cross over

Question 29

Uncus

Answer 29

- Part of the temporal lobe that can herniate, compressing the midbrain and occulomotor nerve - olfactory role

Question 30

Medullary pyramids

Answer 30

Location of descending motor fibres (corticospinal tracts)

Question 31

Parahippocampal gyrus

Answer 31

Memory encoding

Question 32

Corpus callosum

Answer 32

Fibres connecting the 2 cerebral hemispheres

Question 33

Thalamus

Answer 33

Sensory relay station projecting to the sensory cortex Conscious awareness Inferior to fornix

Question 34

Cingulate gyrus

Answer 34

Surround the corpus callosum Emotion and memory

Question 35

Hypothalamus

Answer 35

Inferior to the thalamus Homeostasis

Question 36

Fornix

Answer 36

Inferior to the corpus callosum | Output pathway of the hippocampus

Question 37

Tectum

Answer 37

Dorsal part of the midbrain Responsible for involuntary responses to auditory and visual stimuli Superior colliculus - visual Inferior colliculus - auditory

Question 38

Cerebellar tonsil

Answer 38

Part of the cerebellum that can herniate and compress the medulla if intracranial pressure is raised - coning

Question 39

Ventricles

Answer 39

Cavities in the brain filled with CSF | Contain choroid plexus which produce CSF

Question 40

How much CSF is produced per day

Answer 40

600-700ml

Question 41

Ventricular system

Answer 41

1. 1st and 2nd ventricle - lateral ventricles 2. Connected by the intervertebral foramen 3. 3rd ventricle compressed by the thalamus either side 4. Cerebral aqueduct 5. 4th ventricle which is diamond shaped

Question 42

Cerebral aqueduct

Answer 42

Connects the third and fourth ventricle | Very narrow therefore most susceptible to occlusion

Question 43

CSF leaving the ventricular system

Answer 43

Leaves the 4th ventricle via - central canal (minimal) - foramen of Luschka laterally - foramen of magendie medially Drains into the subarachnoid space where it is reabsorbed by arachnoid granulations

Question 44

CSF

Answer 44

Metabolic function Contains immune cells Acts as buoyancy mechanism for brain

Question 45

Lateral ventricles

Answer 45

Where most CSF made | Biggest ventricles