Overview of NS

Question 1

Name the lobes of cerebrum

Answer 1

Frontal, parietal, temporal, occipital, insula

Question 2

Function of frontal lobe

Answer 2

Motor commands and motor planning
thought and personality- coginition
Olfaction (smell)
(last lobe to develop, and make irrational decisions)

Question 3

Function of Parietal Lobe

Answer 3

Somatosensation 
Sensory integration ( interprets sensory info)

Question 4

Function of occipital Lobe

Answer 4

Visual processing

Question 5

Function of temporal Lobe

Answer 5

Auditory information processing (located above ears)

memory in temporary

Question 6

Function of Insula

Answer 6

Taste, Drive, Emotions, Memory

Question 7

what dose broca’s area do and what hemisphere is it in

Answer 7

Production of speech

Located in frontal lobe and in the dominant hemisphere (generally left)

Question 8

What does Wernicke’s area do and where is it located

Answer 8

Lauguage comprehension
located in temporal and parietal lobes–> auditiory association cortex
In the dominant hemisphere–> language is always in the dominant hemisphere (usually left)

Question 9

Name the 5 nuclei of basal ganglia

Answer 9

Caudate Nucleus
Putamen
Globus Pallidus
Subthalamic Nucleus
Substantia Nigra

Question 10

Role of Basal ganglia

Answer 10

Role in modulation of somatic activity (especially willed movement)
Involved in autonomic stereotyped motor activity of a postural and reflex nature
Exerts effects on motor systems via thalamus, motor cortex and motor pathways (descending)
Force, timing, amplitude and tone

Question 11

What makes up the diencephalon

Answer 11

Thalamus
Hypothalamus
Epithalamus
Subthalamus
(all the 'thalamus')

Question 12

Role/Importance of Thalamus

Answer 12

All information (except olfactory) must be processed via the thalamus before reaching the cerebral cortex
It is the gateway to cerebral corte
All thalamic nuclei project to the ipsilateral cerebral cortex (right thalamus communicates w/ right cortex)
Each nucleus of thalamus recieves highly organised info and relays this info to specific areas of the cortex

Question 13

Cerebellum role

Answer 13

Modulates and corrdinated skilled voluntary movements of distal extremities and speech
Compares actual motor output to intended motor output and then adjusts movement as necessary (able to adjust to different surfaces of movement as a result)
maintains posture and balance
Maintains muscle tone

Question 14

What does brainstem consist of

Answer 14

Midbrain–> Thalamus sits above midbrain
Pons
Medulla Oblongata–> merges into spinal cord

Question 15

Where does spinal cord terminate and the structures it forms at the end

Answer 15

SC teriminates between levels L1 and L2 vertebral bodies
Forming conus medullaris
Conus medullaris ends to form the filum terminale–> this anchors the spinal cord to the sacrum
Cauda equina is a formed from the bunch of ventral and dorsal nerve roots that are exiting the spinal cord

Question 16

How many cranial and spinal nerves are there

Answer 16

12 pairs cranial nerves

31 pairs spinal nerves

Question 17

Roman numeral and name of each cranial nerve

Answer 17

I- Olfactory (smell)
II- Optic (vision)
III- Oculomotor (mediates vision)
IV- Trochlear (mediates vision)
V- Trigeminal (muscles of mastification, head and face sensation)
VI- Abducens (mediates vision)
VII- Facial (muscles of facial expression)
VIII- Vestibulocochlear (balance and equilibriu, hearing)
IX- Glossopharyngeal (taste, glands, swallowing)
X- Vagus (phonation, elevation of palate, swallowing/taste)
XI- Accessory (head and shoulder movt- SCM and trapz)
XII- Hypoglossal (tongue movement)

Question 18

Cells of CNS (neurons)

Answer 18

Cells specialised for sending an receiving info
In CNS, neurons occur in laminae or nuclei (in PNS they occur in ganglia)
Principal Cells–> large neurons of a nucleus or comparable region
Interneurons–> Local Circuit neurons (great no of these in CNS)

Question 19

Cells of CNS (Neuroglial/glia cells)

Astrocytes

Answer 19

Function–>insulation and metabolic support, mechanical support (maintenance of blood/brain barrier help in pH balance
surround all capillaries via end feet

Question 20

Cells of CNS (Neuroglial/glia cells)

Microglia

Answer 20

Act as ‘sentinels’ (antigen presenting cells)
Mediation of health of brain
immune response
Phagocytosis

Question 21

Cells of CNS (Neuroglial/glia cells)

Oligodendrocytes

Answer 21

Myelin production in CNS (Schwann cells produes myelin in PNS)

Question 22

Cells of CNS (Neuroglial/glia cells)

Ependymal Cells

Answer 22

Line ventricles and choroid plexus–> produce and secrete CSF

Question 23

White matter fibres

Answer 23

Association (Intracortical) fibres–> communication within the hemisphere (e.g. internal capsule/ optic radiation))
Commussural (intercortical) fibres–> communication between the 2 hemispheres (e.g. corpus callosum)
Projection Fibres–> communication between the cerebral cortex and lower parts of brain and spinal cord (e.g. cerebral pudencle–> coz it attaches to midbrain)

Question 24

Significant Gyri and sulci and what it separates/importance

Answer 24

Longitudinal Fissure–> separates hemisphere
Central Sulcus–> seprates frontal and parietal (never gets to temporal)
Parieto-occipital sulcus–> seprates parietal and occipital (seen medially and laterally)
Calcarine Sulcus–> deep antero-posterior sulcus, starts in temporal and moves towards occipital (only seen on medial view)
Lateral Sulcus–> separates temporal and parietal
Precentral gyrus–> primary motor cortex
Postcenral Gyrus–> primary somatosensory cortex

Question 25

Meninges--> name the 3

Answer 25

Dura--> outermost and hardest layer (under skull) Arachnoid --> middle layer like a spider web due to arachnoid villi which attach to pia mater and through with CSF is reabsorbed Pia Mater--> thinest and innermost layer covering the brain (sometimes arachnoid and pia are joined)

Question 26

Cranial dura real and potential spaces

Answer 26

``` 1 real space: Subarachnoid--> b/t arachnoid and pia 2 Potential spaces: extradural--> b/w dura and skull subdural--> b/w dura and arachnoid ```

Question 27

Spinal dura real and potential spaces

Answer 27

``` 2 real spaces: Subarachnoid--> b/w arachnoid and pia Epidural--> b/w tissues lining VC (vertebral periosteum) and spinal dura 1 Potential space: subdural--> b/w/ dura and arachnoid ```

Question 28

What do the real spaces from meninges contain?

Answer 28

CSF flows through this area

Question 29

Name the layers of dura

Answer 29

Endosteal Layer--> outer layer on skull meningeal layer--> inner layer closer to arachnoid (this is also the only layer that is present in the VC - no endosteal layer)

Question 30

Dural reflections name

Answer 30

Falx cerebri--> separates left and right hemispheres Tentorium cerebelli--> separates cerebellum and brainstem from cerebrum; cerebellum located right under tentorium cerebri hence the flat superior surface of cerebellum

Question 31

Blood supply to meninges

Answer 31

blood supply--> meningeal arteries and veins

Question 32

Dural venous sinuses formation

Answer 32

Formed when the 2 layers of dura separate, resulting in channels called dural venous sinuses ("trapped epidural veins")

Question 33

Dural venous sinus names

Answer 33

Superior sagittal sinus--> lies at superior attached border of falx cerebri Inferior Sagital sinus--> lies at the inferior free border of falx cerebri Straight sinus--> lies at attachment of falx and tentorium cerebri Occipital Sinus--> lies in the attached border of tentorium cerebri (on occipital lobe part of skull and forms a Y shape at the bottom) Transverse Sinus--> runs transversely at the posterolateral margin of tentorium cerebelli Sigmoid Sinus--> 'S' shaped and goes into jugular foramen and continues as internal jugular vein Superior petrosal sinus--> anterolateral attachment of tentorium cerebelli (on temporal bone) Inferior petrosal sinus--> under superior sagittal on temporal bone

Question 34

How are dural reflections formed

Answer 34

Formed by meningeal (inner) layer of dura mater folding in on itself

Question 35

Nerve supply of meninges

Answer 35

Nerve innervation--> trigeminal nerve (mostly) and vagus nerve (for posterior fossa) Due to nerve innervation means that meninges are pain sensitive and have sensory innervation

Question 36

Dural Venous sinus function

Answer 36

Where the cerebral veins empty and are valveless--> hence has bidirectional flow From blood drained into DVS, CSF is reabsorbed through the arachnoid villi mostly in superior sagittal sinus Drainage into DVS then goes into the internal jugular veins

Question 37

Dural venous drainage path

Answer 37

``` Venous blood leaving cerebral cortex Through subarachnoid and subdural spaces Enter Superior sagittal sinus Empty into straight sinus Passes through Sigmoid sinus into internal jugular veins ```

Question 38

What cells line ventricles

Answer 38

Ependymal cells--> forms the choroid plexuses

Question 39

What produces CSF

Answer 39

choroid plexus that lines ventricles

Question 40

Flow path of CSF

Answer 40

``` Lateral ventricles 3rd Ventricle (via interventricular formen) Cerebral Aqueduct 4th Ventricle Median and Lateral aperture of 4th ventricle Cerebellomedullary and pontine cistern Spinal subarachnoid space To lumbar cistern Forward through basal cisterns Upwards and over cerebral hemispheres ```

Question 41

Role of CSF

Answer 41

Suspends brain--> cushioning and shock absorber Regulates composition of fluid bathing glia and neurons of cns Circulates nutrients and chemicals, which need to be distributed in the NS

Question 42

CSF absorbtion

Answer 42

Reabsorbed through arachnoid villi in dural venous sinus (esp. superior sagittal sinus) Reabsorbtion depends on the pressure of CSF being higher than that of blood in dural sinuses

Question 43

What is hydrocephaly

Answer 43

Pathology marked by excessive accumulation of CSF within cranial cavity (hydro=water, cephalus=head) Neural structures can be destroyed by the pressure that accumulates

Question 44

Presentation of Hydrocephalus

Answer 44

Head a=often enlarged | acquired hydrocephalus may occur with head trauma/conditions such as meningitis

Question 45

Communication hydrocephalus

Answer 45

non-obstructive Problems with the production/absorption of CSF free communicating between ventricles/subarachnoid space Lesion usually distal to ventricular system Enlargement of all ventricular cavities and subarachnoid spaces

Question 46

Non-communicating hydrocephalus

Answer 46

obstructive Obstruction within the ventricular system that prevents CSF from flowing/communicating within brain CSF in ventricles cannot reach subarachnoid space due to obstruction Possible lesion sites: cerebral aqueduct, foramen monro Enlargement of ventricles--> dependent on site of lesion