central nervous system

Question 1

what does the CNS consist of

Answer 1

brain and spinal cord

Question 2

what makes the human brain different to other animals

Answer 2

increased surface area (of cortex) so greater number of cerebral cortex neurons

Question 3

3 layers of brain

Answer 3

cerebrum, brainstem, cerebellum

Question 4

what does the cerebrum consist of

Answer 4

diencephalon and cerebral hemisphere

Question 5

what does the diencephalon consist of

Answer 5

thalamus and hypothalamus

Question 6

what does the brainstem consist of

Answer 6

midbrain, pons, medulla oblongata

Question 7

what does the spinal cord consist of

Answer 7

lies in the vertebral column, consisting of vertebra, in between which are the intervertebral foramen, and is surrounded by 3 membranes (meninges)

Question 8

how many pairs of nerves in the spinal cord and how many vertebra

Answer 8

31 pairs of nerves coming out just below corresponding vertebra, of which there are 30

Question 9

where is the extra nerve

Answer 9

extra cervical nerves from C1 to C8 (only 7 vertebra)

Question 10

spinal cord length vs vertebral colum

Answer 10

spinal cord shorter than vertebral column as horse tail shape (cauda equina from L2 downwards)

Question 11

spinal cord: dorsal to ventral and relative size

Answer 11

cervical (enlargement; 7 vertebra and 8 nerves) → thoracic (12) → lumbar (enlargement; 5) → sacral (5) → coccygeal (1)

Question 12

why is a lumbar puncture conducted between L3 and L4 or L4 and L5 form the lumbar cistern

Answer 12

no nervous tissue just fibres so able to do lumbar puncture for CSF

Question 13

what does each spinal cord segment innervate

Answer 13

a particular skin area (dermatome) and muscle area (myotome)

Question 14

structure of spinal cord

Answer 14

grey matter (butterfly shape; either side are dorsal horns and ventral horns) and white matter

Question 15

what is present in grey matter

Answer 15

motor soma and interneurons

Question 16

what is present in white matter

Answer 16

nerve bundles (axons) with short connections between adjacent segments and long tracts connecting all levels of the spinal cord with the brain

Question 17

what occurs at dorsal horns

Answer 17

sensory neurone make connection (soma in dorsal root ganglion)

Question 18

what occurs at ventral horns

Answer 18

motor somas present

Question 19

diagram of spinal cord cross section

Answer 19

diagram from Medlearn

Question 20

where do nerves exit from the spinal cord

Answer 20

intervertebral foramina

Question 21

where does the brain lie

Answer 21

within cranial cavity of skull

Question 22

what surrounds the brain

Answer 22

meninges

Question 23

what does the brainstem connect

Answer 23

connects cortex to spinal cord via pons

Question 24

significance of where brainstem connects

Answer 24

where nerves cross so left side of brain controls right side of body and vice versa

Question 25

where do some cranial nerves have their origin

Answer 25

medulla oblongata

Question 26

what do cranial nerves in the medulla oblongata do

Answer 26

control basic vital functions like heartbeat, swallowing, breathing, as well as supplying motor, sensory and autonomic innervation to the head

Question 27

what does the cerebral hemisphere consist of

Answer 27

basal ganglia, cerebral cortex and corpus collosum

Question 28

what is present in the basal ganglia

Answer 28

nuclei

Question 29

basal ganglia: what do the caudate and putamen form together

Answer 29

corpus striatum which is connected to cortex, thalamus and substantia nigra

Question 30

basal ganglia: what do the putamen and globus pallidus form together

Answer 30

lentiform nucleus

Question 31

what do the basal ganglia and substantia nigra degenerate to cause

Answer 31

Parkinson’s disease

Question 32

cerebral cortex: what are gyri and sulci

Answer 32

bumps and fissures

Question 33

cerebral cortex: 4 lobes

Answer 33

frontal lobe, parietal lobe, temporal lobes and occipital lobe

Question 34

features of cerebral cortex

Answer 34

laminar (layered) and somatotropic (nerve terminals to range of locations)

Question 35

what does the limbic system consist of

Answer 35

various components of brain (cerebrum and diencephalon)

Question 36

what connects the two cerebellum hemispheres

Answer 36

vermis

Question 37

what is the posterior section of the cerebellum connected to

Answer 37

brainstem; grey cortex (deep parallel folds), deeper white matter, with nuclei

Question 38

what is cerebellum connected to

Answer 38

vestibular system, spinal cord and muscles, and motor cortex and thalamus

Question 39

white matter: corpus callosum function

Answer 39

commissural fibers allowing for association between hemispheres

Question 40

white matter: location of association fibres

Answer 40

within hemispheres

Question 41

white matter: corona radiata function

Answer 41

connects both motor and sensory nerve pathways in brain stem and cortex using projection fibres