lecture7: organisation of the CNS Flashcards Preview

neuroscience and mental health LCRS > lecture7: organisation of the CNS > Flashcards

Flashcards in lecture7: organisation of the CNS Deck (62)
Loading flashcards...
1
Q

*draw a diagram to explain the relationship between the following divisions of the CNS

A

insert the pic

2
Q

what are the three main components of the brain stem?

A
  • the midbrain - the pons - the medulla
3
Q

what are the main functions of the brain stem?

A
  • contains a lot of nuclei which control vital things like respiration and cardiac control - ascending pathways to the brain - descending pathways to spinal cord - cranial nerves which provide sensory and motor innervation for the head region - the reticular activating system controls the level of consciousness
4
Q

* show a diagram of where the diencephalon is?

A

INSERT PIC

5
Q

what are the two main structures in the diencephalon?

A
  • thalamus - hypothalamus
6
Q

what is the function of the thalamus?

A

it is a relay station for info going between the cerebral correct and other parts of the CNS (bi directional)

7
Q

where is the thalamus found?

A

in the upper area of the diencephalon

8
Q

what is the function of the hypothalamus ?

A

controls homeostasis

9
Q

where is the hypothalamus found?

A
  • found below the thalamus
10
Q

where is the basal ganglia found?

A
  • found deep inside the cerebral cortex and is one of the main nuclei
11
Q

what is the function of the basal ganglia?

A
  • needed for movement control - group of nuclei which produce the pattern of movement and work together with the motor cortex
12
Q

* where is the cerebellum found?

A

INSERT PIC - found towards the back of the head

13
Q

what is the function of the cerebellum?

A
  • it doesn’t initiate movement but it coordinates the movement and is important for learning new motor skills
14
Q

* show a diagram of a brain with the following labelled: - cerebral hemisphere - diencephalon - midbrain - pons - medulla - cerebellum

A

insert the pic

15
Q

what are the three main parts of the brain and what do they split into?

A

the forebrain - cerebral hemispheres and diencephalon the midbrain - the hindbrain- pons medulla and cerebellum

16
Q

* identify on a digram the cortical lobes and the primary cortical areas:

A
17
Q

what are the two main types of cortex?

A
  1. primary cortical areas - the basic functions happen here - discrete parts of the brain 2. association cortex - the rest of the brain - higher functions happen here
18
Q

what are the four main cortex’s?

A
  • primary motor cortex - primary somatosensory cortex - primary auditory cortex - primary visual cortex
19
Q

what do the following cortex’s do? - primary motor cortex - primary somatosensory cortex - primary auditory cortex - primary visual cortex

A
  • the motor cortex sends axons down a descending pathway to stimulate motor neurones in the spinal cord - the somatosensory cortex receives general sensory information - the primary auditory cortex receives information from the ears - the primary visual cortex receives information from the ears
20
Q

what is the corpus callous for?

A

connecting the right and left hemisphere across the midline

21
Q

what is wernickes area for?

A
  • important for understanding language
22
Q

what is brocas area for?

A
  • important for speech
23
Q

* show a diagram of the brain highlighting the different lobes:

A

INSERT PIC

24
Q

* show a diagram showing the different parts of the cranial fosse

A

INSERT PIC

25
Q

what ventricles are there in the brain?

A
  • there are two main ventricles - they are C shaped - they are called lateral ventricles - they join up in the middle by a midline ventricle called the 3rd ventricle - the 3rd ventricle is located in the middle of the diencephalon - at the base of the third ventricle there is a narrowing which makes a fine channel called the cerebral aqueduct - the aqueduct passes through the midbrain and opens up into the fourth ventricle - the fourth ventricle then lowers again to make a very fine channel called the central canal
26
Q

what is the composition of the cerebrospinal fluid?

A
  • produced by the ependymal cells which are found in the ventricles called the choroid plexus - the choroid plexus filters the blood and secretes it
27
Q

what is the difference between blood and CSF fluid?

A

the CSF fluid has - fewer cells, - less protein and - reduced concentrations of sodium and potassium - higher concentration of magnesium and chloride ions

28
Q

how is the CSF fluid circulated?

A
  • circulates through the ventricular system - gets to the 4th ventricle where it can exit and move across the brain - the CSF then circulates again in the sub arachnoid space between the meninges - it is then reabsorbed into the venous system by arachnoid villi
29
Q

what is the function of the CSF fluid?

A
  • to cushion the brain and acts as a shock absorber - to circulate nutrients and filter chemicals from the blood - to remove waste products from the blood
30
Q

what is the average total volume of the CSF?

A

150 ml

31
Q

what is the average flow rate of the CSF?

A

500 ml a day

32
Q

what is a epidural haemorrhage?

A

this is a bleed which is between the skull and the dura - the is caused by the rupture of the middle meningeal artery

33
Q

what is a subdural haemorrhage?

A

between the inside of the dura and the brain itself

34
Q

what is the hydrocephalus?

A

this is a blockage of the sub arachnoid space caused by the build up of the CSF can lead to stroke if there is bleeding

35
Q

what are the two types of stroke and what do they mean?

A
  • communicating presents with headaches - non communicating presents with blackouts
36
Q

how is hydrocephalus treated?

A

it is treated by using a stunt to divert the CSF or by removing the cause

37
Q

what are the three membranes which enclose the brain and the spinal cord?

A
  1. the dura mater - tough membrane attached to the bone with folds and venous sinuses in the margins 2. the arachnoid membrane - thin membrane attached to the underside of the dura 3. pia mater delicate membrane which is closely adherent to the surface of the brain and the spinal cord
38
Q

where is the sub arachnoid space?

A
  • this is located between the arachnoid and the pia where the CSF circulates
39
Q

what is the structure of the spinal cord?

A
  • the spinal cord is a column of neural tissue which is segmental - each segment has one pair of spinal nerves - the core consists of grey matter - there is a wrapping around of white matter - they grey matter is divided into sensory and motor areas
40
Q

*show a diagram of the cross section of a spinal cord:

A

insert pic

41
Q

what are dorsal horns?

A

dorsal horns of grey matter are sensory centres

42
Q

where does the soma of the sensory axon lie?

A

the dorsal root ganglion

43
Q

where does the axon continue?

A

the axon continues via the dorsal root and enters the dorsal horn

44
Q

where is the sensory information carried after the dorsal horn?

A

the sensory information is then carried up ascending pathways in the white matter to the brain for analysis

45
Q

what is the ventral horn?

A

the ventral horn is the motor centre

46
Q

where do the axons of motor neurones go?

A

the axons of the motor neurones go out via the ventral roots and to the muscles

47
Q

what is towards and away from the CNS dorsal ventral

A
  • dorsal - towards the CNS - ventral - away from the CNS
48
Q

where does the spinal cord lie?

A
  • the spinal cord lies in the vertebral canal in the vertebral column
49
Q

what are the intervertebral foramina?

A

along the sides of the vertebral column there are a series of holes called the intervertebral foramina

50
Q

what are the cervical levels?

A

C1- C7

51
Q

what are the thoracic levels?

A

T1 - T12

52
Q

what are the lumbar levels?

A

L1 -L5

53
Q

what are the sacral levels?

A

S1 - S5

54
Q

what is the number of nerves and vertebrae compared to each other?

A

there is an equal number of nerves and vertebrae except there is an extra nerve above C1 so there are 8 cervical nerves not 7

55
Q

what is shorter the spinal cord or the vertebral column?

A
  • the spinal cord is much shorter than the vertebral column - this is because the spinal cord finishes growing much earlier in development compared to the vertebral column - the cervical and thoracic segments of the spinal cord are corresponding to the vertebral column levels
56
Q

what is the lumbar cistern?

A

this is the area with no spinal cord - it contains CSF fluid and a needle can be inserted to take a sample of the fluid

57
Q

where are lumbar punctures taken from?

A

between L3 and L4

58
Q

where is the area with no spinal cord but many nerves?

A
  • cauda equina
59
Q

what is the function of the cerebellum?

A

motor function

  • coordinated movement
60
Q

the function of the brains stem?

A
  • contains nuclei which control our vital functions
  • lots of ascending and descending pathways that go through the brain stem
  • ascending goes up to the brain stem
  • descending goes down from motor cortical regions to the spinal cord to produce movement
61
Q

function of the diencephalon?

A
  • thalamus is the higher region of the diencephalon
  • this is a relay station for info which goes between the cerebral cortex and other parts of the CNS
  • the hypothalamus is found inferior to the thalamus and is needed for homeostasis
62
Q

function of the cerebral cortex?

A
  • lots of nuclei present
  • one of the main nuclei is the basal ganglion
  • the basal ganglia are the group of nuclei which produce a pattern of movement and work together with the motor cortex.