1.1 Introduction to NS and Topography Flashcards Preview

Yr 2 Sem 2 NSNP > 1.1 Introduction to NS and Topography > Flashcards

Flashcards in 1.1 Introduction to NS and Topography Deck (64):
1

What makes up the CNS? And what do they develop from?

Brain and Spinal Cord
Develop from the neural tube

2

What makes up the PNS?

Dorsal and ventral roots
Spinral nerves
Peripheral nerves
Ganglia

3

What makes up the caudal equina?

Dorsal and ventral roots

4

Define ganglia

Collections of cell bodies in PNS

5

What is grey matter comprised of?

Cell bodies and dendrites

6

How is grey matter adapted for its computational role?

It is highly vascularised to provide for its high metabolic demands

7

Why is grey matter grey?

Not much fat
Highly vascularised

8

What is white matter composed of?

Axons (with their supporting cells)

9

Why is white matter white?

Presence of fatty myelin

10

What is the PNS equivalent of grey matter?

A ganglion

11

What is the PNS equivalent of white matter?

Peripheral nerve

12

How many segments is the SC composed of?

31

13

Describe the structure of the cord

Central core of grey matter and outer shell of white matter

14

Where does the SC extend from and to?

Foramen magnum -> L1

15

Is white matter homogenous?

No
It has different regions with different functions

16

Define funiculus

A segment of white matter containing multiple distinct tracts
Impulse travel in multiple directions

(Large block of white matter with axons going up and down in SC)

Dorsal, lateral, ventral

17

Define tract

An anatomically and functionally defined white matter pathway connecting two distinct regions of grey matter
Impulses travel in one direction

18

Define fasciculus

A subdivision of a tract supplying a distinct region of the body

19

Give an example of fasciculi

Gracilis (lower body) and cuneatus (upper body) in the dorsal column tract

20

How is grey matter organised?

Into cell columns
(Rexed laminae)

Functional segregation

21

What is a nucleus formed from?

The motor neurones supplying a given muscle arise from multiple segments and forma distinct population of neurones in the CNS

22

Define nucleus (grey matter)

A collection of functionally related cell bodies

23

Define cortex (grey matter)

A folded sheet of cell bodies found on the surface of a brain structure

24

How thick is the cortex usually?

1-5mm

25

Define fibre (white matter)

A term relating to an axon in association with its supporting cells
(also called an axon)

26

What do association fibres do?

Connect cortical regions within the same hemisphere

27

What do commissural fibres do?

Connect left and right hemispheres or cord halves

28

What do projection fibres do?

Connect the cerebral hemispheres with the cord/brainstem and vice versa

29

What is another name for the midbrain?

Mesencephalon

30

What is another name for the pons?

Metencephalon

31

What is another name for the medulla oblongata?

Myelencephalon

32

What are the roles of the midbrain?

Eye movements
Reflex responses to sound and vision

33

What are the roles of the pons?

Feeding (and suckling)
Sleep

34

What are the roles of the medulla?

Cardiovascular and respiratory centres
Contains a major motor pathway (medullary pyramids)

35

How can the central sulcus be identified?

Sits in the coronal plane
Goes from the temporal line laterally to the midline unimpeded

36

What does the pre-central gyrus contain?

The primary motor cortex

37

What does the post-central gyrus contain?

Primary sensory cortex

38

What does the lateral fissure do? and what is its other name?

Separates the temporal from frontal/parietal lobes
Sylvian fissure

39

What does the parieto-occipital sulcus do?

Separates parietal from occipital lobe

40

What surrounds the calcarine sulcus?

Primary visual cortex

41

What is the optic chasm?

A site where fibres in the visual system cross over

42

What is the uncus?

Part of the temporal lobe that can herniate, compressing the midbrain
Has an important olfactory role

43

What is located in the medullary pyramids?

Descending motor fibres

44

What is the parahippocampal gyrus?

Key cortical region for memory encoding

45

What does the corpus callosum contain?

Fibres connecting the two cerebral hemispheres

46

What is the thalamus?

Sensory relay station projecting to sensory cortex

47

What is the cingulate gyrus?

Cortical area important for emotion and memory
Part of the limbic system for emotional processing

48

What is the hypothalamus?

Essential centre for homeostasis

49

What is the fornix?

Major output pathway from the hippocampus

50

What is the tectum?

Dorsal part of the midbrain involved in involuntary responses to auditory and visual stimuli

51

What is the cerebellar tonsil?

Part of the cerebellum that can herniate and compress the medulla

52

What are cavities in the brain called and why do they develop?

Ventricles
Because the brain is hollow as it developed from a hollow tube (neural tube)

53

What do the ventricles contain?

Choroid plexus (highly vascularised) which make 600-700ml in total of CSF a day

54

What two groups of functions does CSF have?

Metabolic and mechanical

55

Describe the movement of CSF

CSF circulates through the ventricular system and subarachnoid space before being reabsorbed

56

Where is CSF reabsorbed?

At the arachnoid granulations

57

Where do the two lateral ventricles join?

At the inter ventricular foramen

58

Why is the third ventricle flattened?

It is sandwiched between the two halves of the thalamus

59

What shape is the fourth ventricle?

Pyramid

60

What is the 4th ventricle continuous caudally with?

Central canal of SC

61

Why does not much CSF go into the cord?

Because the central canal is very narrow

62

How does CSF get to the subarachnoid space?

2x lateral apertures
Midline apertures

63

What happens to CSF once it leaves the subarachnoid space?

Drains into the venous blood through granulations in the superior saggital sinus

64

What happens if a child is born with a congenital stenosis of the cerebral aqueduct?

Build up of CSF leading to hydrocephalus