Central Nervous System

Question 1

What 3 parts is the brain compromised of

Answer 1

Forebrain-cerebral hemispheres and diencephalon

Midbrain

Hindbrain-pons,medulla,cerebellum

Question 2

Brain stem contains

Answer 2

Midbrain
Pons
Medulla

Question 3

Frontal lobe

Answer 3

Language
Congnitive functions eg planning attention and memory
Regulating and initiating motor function

Question 4

Parietal

Answer 4

Sensation
Sensory aspects of language
Spatial orientation
Self perception

Question 5

Temporal and occipital

Answer 5

Auditory info
Visual info

Question 6

Limbic lobe contains

Answer 6

Amygdala
Hippocampus
Mamillary body
Cingulate gyrus
Involved in learning memory emotion and motivation

Question 7

Insular cortex location

Answer 7

Deep within lateral fissure

Question 8

What is insular cortex involved in

Answer 8

Visceral sensation, autonomic control and interoception, auditory processing, visual vestibular integration

Question 9

Where is cerebrospinal fluid produced and where does it circulate

Answer 9

Choroid plexus of lateral 3rd and 4th ventricles
Occupies ventricular system and sub arachnoid space
125ml needed and 500ml made everyday

Question 10

Where is CSF reabsorbed

Answer 10

Arachnoid villi (granulations) into superior Sagittal sinus

Question 11

CSF VS PLASMA

Answer 11

CSF has lower pH,less glucose,protein and potassium

Question 12

Function of CSF

Answer 12

• Shock absorbing- protection of brain/CNS
• Removes waste products from cellular metabolism
• Supplies neurones with nutrients (secondary to blood) & transports nutrients
• Contains immune cells

Question 13

What do spinal nerves emerge through

Answer 13

Intervertebral foramina

Question 14

Which spinal nerves emerge above vertebrae

Answer 14

C1-C7

Question 15

Which spinal nerves emerge below the vertebrae?

Answer 15

C8 - Co1

Question 16

Spinal chord enlargements

Answer 16

• Cervical enlargement at upper part of cord because of the huge amount of innervation of upper limbs both going in an out
• Lumbar enlargement at lower part of cord because of increase in innervation of lower limbs
• Shape also changes

Question 17

What are the 2 major ascending pathways for sensation/sensory?

Answer 17

Dorsal column pathway
Spinothalmic tract

Question 18

Dorsal column pathway detects

Answer 18

fine touch, vibration and proprioception

Question 19

Dorsal column pathway

Answer 19

1) First order neurons have cell bodies in dorsal root ganglion ,fibres enter via dorsal horn. Info from lower limbs (below T6) travel ipsilaterally along gracile tract. Info from upper limbs (above T6) travel ipsilateraly along the cuneate tract. synapse in medulla

2)second order neurons have cell bodies in the medulla which synapse into thalamus

3( third order neurones from thalamus project to somatosensory cortex

Question 20

What tract do these second order neurons then form once they have crossed?

Answer 20

Contralateral medial lemniscus tract

Question 21

Spinothalamic (anterolateral) tract- which sensations does it detect

Answer 21

Pain and temperature
Anterior spinothalmic tract detects crude touch

Question 22

Spinothalmic tract pathway

Answer 22

1) first order neurons in dorsal root ganglion

2)second order neurons decussate immediately in the spinal cord

3)third order neurons from the thalamus project to the somatosensory cortex

Question 23

Major descending pathway for voluntary movement

Answer 23

Corticospinal tract

Question 24

What is the corticospinal tract composed of

Answer 24

Upper motor neurons in primary motor cortex and lower motor neurons in brainstem

Question 25

How do the lateral and anterior/ventral corticospinal tracts differ in decussation, and what muscles do each of these tracts supply?

Answer 25

• The lateral corticospinal tract decussates in the medulla (this makes up 85% of fibres), supplies limb muscles
• The anterior (ventral) corticospinal tract doesn’t decussate- they stay on the same side as the side the upper motor neurones have come from, supplies trunk muscles

Question 26

Corticobulbar tract

Answer 26

Pathway from primary motor cortex to muscles of face

Question 27

Extrapyramidal tracts

Answer 27

Supply muscles that are more automated in their response

Vestibulospinal- provides info about head movement and position and mediated posture

Tectospinal-orientation of head and neck during eye movement

Reticulospinal-controls breathing and emotional motor function

Rubrospinal-innervate lower motor neurons of upper limb and becomes more active is corticospinal tract is injured