The Brain and Spinal Cord

Question 1

What is the CNS made up of

Answer 1

brain and spinal cord

Question 2

what is the brain made out of

Answer 2

• 2 cerebral hemispheres
• the cerebellum
• the brain stem

Question 3

what does the transerves cerebral fissure separate

Answer 3

separates the occipital lobe and temporal lobe from the cerebellum

Question 4

what is the brain stem made out of

Answer 4

• midbrain
• medulla oblongata
• pons

Question 5

what are the ventricles in the brain

Answer 5

2 lateral ventricles
1 third ventricle
1 fourth ventricle

Question 6

what is each hemisphere divided into

Answer 6

• its divided into 4 lobes
• frontal
• parietal
• temporal
• occipital lobes

Question 7

what are the sulci

Answer 7

• price central glares
• central sulcus
• post central gyrus
• lateral sulcus

Question 8

what is the spinal cord protected by

Answer 8

• bone
• meninges
• cerbrospinal fluid

Question 9

label the spinal cord

Answer 9

label it

Question 10

what makes up the grey matter

Answer 10

• grey matter is made up of cell bodies

Question 11

what makes up the white matter

Answer 11

• white matter is made up of myelinated axons

Question 12

How many pairs of spinal nerves are there

Answer 12

• there are 31 pairs of spinal nerves which attach to the spinal cord by paired roots
• each nerve exits from the vertebral column and travel to the segment region of the body that is serves

Question 13

describe sensory neurones

Answer 13

• afferent fibres form the dorsal roots which fan out as dorsal rootlets before they end the spinal cord
• cell bodies found in Dorsal root ganglion
• on entering the cord the primary sensory axon synapse in the dorsal horn of the grey matter
• the second order of neurones may synapse with interneurones in the grey matter
• may travel to different areas of the cord or enter the white matter and travel up to the Brain

Question 14

describe motor neurones

Answer 14

• efferent impulses travel down primary motor neurones from the brain to the level of the spinal cord in
  descending tracts
• they end in the ventral horn of grey matter
• the efferent nerve which innervates the skeletal muscle starts in the ventral horn and then leaves the spinal cord via ventral rootlets which joint to become the ventral root
• the ventral root joins the dorsal root in the spinal nerve

Question 15

sensory neurones are

Answer 15

afferent

Question 16

motor neurones are

Answer 16

efferent

Question 17

what is white mater

Answer 17

• this is the tissue through which messages pass between different areas of grey matter within the CNS
• it is white because of the type of fat called myelin that surrounds axons

Question 18

what are TRACTS

Answer 18

the white matter funicular contain collections of fibres called TRACTS

Question 19

ascending tract =

Answer 19

sensory neurone

Question 20

descending tract =

Answer 20

motor neurone

Question 21

describe ascending tracts

Answer 21

• sensory tracts
• the first order neurone conducts impulses from a peripheral receptor to the spinal cord or brainstem
• axons entering the brain stem are in cranial nerves
• axons entering the spinal cord are in spinal nerves
• the cell Body is in the dorsal root ganglion
• ti synapses with the second order neurone in the grey matter either in the dorsal horn or brainstem
• ascending pathways conduct sensory impulses up to the brain
• there tertiary neurone passes to the sensory cortex

Question 22

describe descending tracts

Answer 22

the first order neurone (upper motor neurone) descends from the brain to the spinal cord or brainstem

• they synapse with the second order neurones in the grey matter of either the brain stem or spinal cord
• the lower motor neurones travel to the skeletal muscle
• axons leaving the brainstem are in cranial nerves
• axons leaving the spinal cord are in spinal nerves