Introduction To Brain, Cranial Meninges And Blood Supply Flashcards
4 main parts of the brain
Cerebrum
Cerebellum
Diencephalon
Brainstem
Where is the cerebrum
Largest part covering the superior and lateral aspects of the brain, covered in folds of tissue
Division of cerebrum
Made up of 2 hemispheres each divided into 4 lobes
Where is the cerebellum
Smaller, bolbous structure underneath the posterior part of the cerebrum
What is the location of the Diencephalon
Area is deep within the brain, beneath the cerebrum but above the brain stem
Where is the brain stem
Connects the cerebrum and Diencephalon to the spinal cord
Function of the frontal lobe
Contains the primary motor cortex involved in planning and executing conscious movement
Contains the prefrontal cortex involved in behaviour, personality and decision making
Function of the primary motor cortex
Planning and executing conscious movement
Function of the prefrontal cortex
Behaviour, personality and decision making
Function of the temporal lobe
Contains the primary auditory cortex responsible for processing auditory information
Contains the hippocampus involved in formation of memories
Function of the hippocampus
Formation of memories
Function of the parietal lobes
Contain the primary somatosensory cortex involved in processing sensory information
Function of the primary somatosensory cortex
Processing sensory information
Function of the primary auditory cortex
Processing auditory information
Function of the occipital lobe
Contains the primary visual cortex responsible for processing visual information
Function of the primary visual cortex
Processing visual information
Function of the cerebellum
Helps maintain posture, balance and corrects fine movements
Function of the brain stem
Connects the rest of the brain to the spinal cord
Contains the nuclei of cranial nerves and vital centres for regulation of breathing and cardiovascular function
Gyri
Folds/ridges of the exterior aspect of the brain
SuIci
Furrows/grooves in between the gyri
Central sulcus
Large sulcus in the coronal plane separating the frontal and parietal lobes
One on both hemispheres
Lateral sulcus (Sylvian fissure)
Large sulcus in the transverse plane separating the temporal lobe from the frontal and parietal lobes
One on both hemispheres
Insula
Part of the cerebral cortex that can only be seen by opening the lateral sulcus
Opercula
The parts of the frontal, parietal and temporal lobes that cover the insula
Longitudinal fissure
Large groove separating the two hemispheres
Corpus callosum
A large bundle of white matter that connects the two hemispheres
Olfactory tracts
Nerve fibres carrying information about smell from the nasal cavity
Run along the inferior surface of the frontal lobes on each side of the
Optic nerve
Carry visual information from the retina
On inferior surface of frontal lobe and pass posteriorly and medially to a point where they party cross over each other (optic chiasm)
Optic chiasm
Point where 2 optic nerves partly cross over each other
Mammillary bodies
Rounded structures found behind the optic chiasm and pituitary gland
Part of Diencephalon
Hypothalamus
Part of Diencephalon
Only just visible behind the optic chiasm
Mammillary bodies located on its inferior surface
What is the hypothalamus part of
Diencephalon
Crus cerebri
Pillars of white matter next to the mammillary bodies that connect the brain to the brain stem
Form part of the cerebral peduncles (part of the midbrain)
Interpeduncal fossa
Fossa between the cerebral peduncles
May have a layer of arachnoid matter overlying it
Parts of the brain stem
Midbrain
Pons
Medulla oblongata
Location of the midbrain
Most superior part of brain stem where the crus cerebri are located
Location of the pons
Large, bulbous, central part of brain stem
Location of the medulla oblongata
Most inferior part of the brain stem that tapers down to become the spinal cord inferiorly
Cerebellum
Lined with many small fissures and is made up of 2 hemispheres connected by a central vermis
Connects to the brainstem
What connects the 2 hemispheres of the cerebellum
A central vermis
Functional areas of the frontal lobe
Primary motor cortex
Pre motor cortex
Prefrontal cortex
Broca’s area
Functional areas of the parietal lobe
Primary somatosensory cortex
Functional areas of the temporal lobe
Primary auditory cortex
Hippocampus
Amygdala
Wernicke’s area
Functional areas of the occipital lobe
Primary visual cortex
Location of the primary motor cortex
Most posteriorly in the frontal lobe
Immediately anterior to the central sulcus
Location of Broca’s area
Inferior frontal lobe of the dominant hemisphere (usually left0
Which hemisphere is usually dominant
Left
Anterior to posterior frontal lobe functional areas
Prefrontal cortex
Premotor cortex
Primary motor cortex
Function of the primary motor cortex
Execution of motor function
Function of the premotor cortex
Planning and preparation of movements
Function of the prefrontal cortex
Personality, behaviour, problem solving, impulse control and inhibition, social and sexual behaviour
Function of Broca’s area
Spoken language production
Location of the parietal lobe
Central sulcus to the parietooccipital fissure
Location of the primary somatosensory cortex
Immediately posterior to the central sulcus
Role of the dominant parietal lobe (left)
Perception and mathematical and language operations
Role of the non-dominant parietal lobe (right)
Visuospatial function
Location of the primary auditory cortex
Immediately below the lateral sulcus
Location of the hippocampus
Inferior and medially in the temporal lobe
Location of the amygdala
Deep within the temporal lobe
Role of amygdala
Perception of fear
Location of wernicke’s area
Most superior and posterior part of dominant temporal lobe
Function of wernicke’s area
Understanding and coordination spoken language
Location of the occipital lobe
Most posterior part of cerebrum
Limbic system contains
Group of structures found in the medial margins of the hemispheres, including the hippocampus, amygdala and parts of the cortex
Also contains the Diencephalon
Function of limbic system
Involved in emotion, memory and behaviour
Influence over the endocrine function of the body
Parts are specifically related to sensations of fear, pleasure and rewarding behaviours
Homunculus
Mapping of specific parts of the body to parts of the cortex (the gyri)
There is a motor and sensory cortices
Where are the face and mouth represented in the homunculus
On the lateral aspects of the primary motor and somatosensory cortices
Where are the upper limb and torso represented in the homunculus
Most superior part of the cortex
Where are the feet represented in the homunculus
Most medial part of the cortices
Cranial meninges
3 layers of tissue that envelop the brain and spinal cord
3 layers of cranial meninges
Dura mater
Arachnoid mater
Pia mater
Dura mater
Most external, lying against the skull
It is fibrous, thick and does not stretch
Arachnoid mater
Intermediate layer
It is much thinner and more flexible
Resembles a spider’s web
Pia mater
Most internal- lies on surface of the brain
It is very thin (cannot be seen with the naked eye)
Layers of matter from skin to cerebral cortex
Skin
Aponeurosis
Periosteum
Skull
Dura mater (endosteal layer and meningeal layer)
Arachnoid mater
Subarachnoid space
Pia mater
Cerebral cortex
2 layers of dura mater
Outer Endosteal layer
Inner Meningeal layer
Outer endosteal layer
Layer of dura
Adherent to interior of the skull
Inner meningeal layer
Layer of dura
Completely envelops the brain and spinal cord
Peels away from the endosteal layer in certain places and folds down into the brain to form a double layer of dura that separates certain parts of the brain
Falx cerebri
A double layer of folded dura lying in the longitudinal fissure that separates the 2 hemispheres
Tentorium cerebelli
A double layer of folded dura that separates the occipital lobe and cerebellum
Falx cerebelli
Separates the 2 lobes of the cerebellum
Dural venous sinuses
Channels between the outer endosteal layer and inner meningeal layer filled with venous blood
What separates the cerebellum and occipital lobe
Tentorium cerebelli
Superior sagittal sinus
Formed in the space between the 2 layers of dura
Located superiorly and runs along the top of the brain in the sagittal plane
Inferior sagittal sinus
A smaller version of the superior sagittal sinus
Runs in same direction but is located inferior to it
Lies on top of the corpus callosum
Formed as the meningeal layer of dura that forms the Falx cerebri folds back on itself in the longitudinal fissure
Which dural venous sinus lies on top of the corpus callosum
Inferior sagittal sinus
Straight sinus
Found where the Falx cerebri connects to the Tentorium cerebelli posteriorly
Allows venous blood to drain backwards from the inferior sagittal sinus
Which dural venous sinus is found where the Falx cerebri and Tentorium cerebelli connect
Straight sinus
Transverse sinuses
Found on both lateral aspects extending from the Tentorium cerebelli around the side of the skull
Sigmoid sinuses
S-shaped sinuses that connect the transverse sinuses to the internal jugular veins outside the skull to drain venous blood from the brain
Which sinus connects the transverse sinus and internal jugular vein
Sigmoid sinus
Confluence of sinuses
Where the straight sinus meets the transverse sinuses and superior sagittal sinus
Found at most posterior aspect of skull
Cavernous sinuses
Found anteriorly either side of the sella turcica of the sphenoid bone
Internal carotid passes through it
Arachnoid mater
Single layer that loosely follows the contours of the meningeal layer of the dura
Subarachnoid space
A thin space between the arachnoid and pia
Contains cerebrospinal fluid
Cisterns
A sealed space between gyri filled with CSF formed by arachnoid covering over the sulcus
Pia mater
Tightly adhered to the brain and spinal cord
Forms blood-brain barrier
Where are the arteries that supply the brain located
Subarachnoid space
What forms the blood-brain barrier
Pia fuses with the endothelial cells of the capillaries
Function of blood-brain barrier
Limits passage of certain molecules into the brain and spinal cord protecting them from harmful substances
4 features of the blood-brain barrier
Tightly bonded endothelial cells to prevent molecules passing between them
Basement membrane of capillaries lacks fenestrations
Pericytes wrap around endothelial cells to regulate blood flow and permeability
Astrocytes have specialised projections (end feet) that wrap around capillaries to restrict flow of certain molecules
Astrocytes
have specialised projections (end feet) that wrap around capillaries to restrict flow of certain molecules in blood-brain barrier
Meningitis
Inflammation of the meningeal layers
Often caused by viral or bacterial infection
Symptoms of meningitis
Headache, stiffness of the neck, photophobia (bright lights causing discomfort)
Diagnosing meningitis
A sample of CSF is tested
A small needle is inserted into the subarachnoid space in the lumbar region of the spine (lumbar puncture/spinal tap)
Which is more serious viral or bacterial meningitis
Bacterial= requires intravenous antibiotics
(Viral usually resolves on its own)
3 main types of intrameningeal bleeding
Extradural haemorrhage
Subdural haematoma
Subarachnoid haemorrhage
Extradural haemorrhage
blood is located outside the dura, but inside the skull. The characteristic pattern on a CT scan is that of an oval or convex shape, often located at the lateral aspect of the brain. The reason the blood forms this shape is because the endosteal layer of the dura is tightly stuck to the inside of the skull, meaning blood trapped outside of it bulges inwards and cannot spread around the side of the brain. Extradural blood is arterial, and a common cause of an extradural haemorrhage is traumatic damage to the middle meningeal artery located on the lateral aspects of the skull. This region is sometimes referred to as the ‘temple’.
Subdural haematoma
blood is located deep to the dura, but superficial to the arachnoid. The characteristic pattern on a CT scan is that of a crescent or concave shape, often located at the lateral aspect of the brain. Unlike in the extradural space, the arachnoid and dura are not adherent to each other, so blood can easily spread around the sides of the brain causing the crescent appearance. Subdural blood is venous, and bleeding is often caused because of stretching of bridging veins that are carrying venous blood from the brain to the dural venous sinuses. Any process or illness that causes the brain to shrink in size causes these bridging veins to become stretched, which is why subdural haematomas are more common in the elderly or patients suffering from alcoholism.
Subarachnoid haemorrhage
blood is located deep to the arachnoid, but superficial to the pia. Blood leaks into the subarachnoid cisterns, mixing with the CSF, sometimes causing a white star-shaped pattern on a CT scan. Subarachnoid blood is usually arterial and may be caused by a traumatic head injury or rupture of an aneurysm of one of the cerebral arteries. The classic symptom at presentation of spontaneous subarachnoid haemorrhage is sudden-onset severe headache, often termed a ‘thunderclap’ headache. Diagnosis may be confirmed by CT scan or by the presence of blood in the CSF. This can be sampled with a lumbar puncture.
Difference between a haemorrhage and haematoma
Haemorrhage- active bleed
Haematoma - collection of blood without an active bleed
Coning
Herniation of parts of the brain due to an increase in intracranial pressure and compression of the brain
Restricts blood supply to the compressed parts and is often fatal if not treated promptly
Tonsillar herniation
Tonsils (part of cerebellum) may be forced out of the Foramen magnum
Uncal herniation
Uncus (part of temporal lobe) may be forced under the Tentorium cerebelli
Which 2 pairs of arteries supply the brain
Internal carotid arteries
Vertebral arteries
What percentage of blood do the vertebral arteries supply the brain with
20%
What percentage of blood do the internal carotid arteries supply the brain with
80%
Which area of the brain do the vertebral arteries supply
Mainly the posterior parts such as the occipital lobe, cerebellum and brainstem
Which areas of the brain do the internal carotid arteries supply
Cerebrum (not occipital lobe) and Diencephalon
Arteries of the Circle of Willis
Internal carotid arteries
Vertebral arteries
Basilar artery
Posterior cerebral arteries
Middle cerebral arteries
Anterior cerebral arteries
Posterior communicating arteries
Anterior communicating arteries
Cerebellar arteries
Basilar artery
A singular artery formed by the unison of the 2 vertebral arteries
Gives off small pontine arteries to supply the brain stem as it travels along its surface
Pontine arteries
Branches of the basilar artery
Supply the brain stem
Posterior cerebral arteries
Formed by the bifurcation of the basilar artery
Pass posteriorly
Middle cerebral arteries
Continuation of the internal carotid arteries after they have entered the skull
Pass into the lateral sulcus and give off branches to superficial and deep brain tisuse
Anterior cerebral arteries
Branches of the internal carotid arteries as they enter the skull
Pass anteriorly then wrap backwards over the corpus callosum
Which arteries pass over the corpus callosum
Anterior cerebral arteries
Which arteries are formed from the internal carotid arteries
Middle and anterior cerebral arteries
Posterior communicating arteries
Join the posterior cerebral to the middle cerebral arteries
Anterior communicating arteries
Joins the left and right anterior cerebral arteries
3 pairs of cerebellar arteries
Anterior inferior cerebellar arteries
Posterior inferior cerebellar arteries
Superior cerebellar arteries
What does the anterior cerebral artery supply
Medial aspects of frontal and parietal lobes
Strip of cortex on superior aspect - includes motor and somatosensory cortex responsible for lower limbs
Some anterior structures of Diencephalon
What does the middle cerebral artery supply
Majority of lateral aspects and deep parts of hemispheres-includes motor and somatosensory cortices responsible for face, arm and trunk
Internal capsule
Some structures of the Diencephalon
Internal capsule
Transmits all fibres to and form the cortices
What does the posterior cerebral artery supply
Mainly the occipital lobe
Small portion of inferior temporal lobe
What does the basilar artery supply
Carries blood from vertebral arteries to circle of Willis
Supplies the pons
What do the cerebellar arteries supply
Cerebellum
Parts of the brain stem
Anterior circulation
Includes anterior and middle cerebral arteries
Posterior circulation
Includes posterior cerebral, basilar and cerebellar arteries
Stroke
interruption to the blood supply of part of the brain leading to a neurological deficit that lasts longer than 24 hours. Strokes may be ischaemic (caused by obstruction of a vessel by a thrombus or embolus and subsequent downstream ischaemia) or haemorrhagic (caused by rupture of a blood vessel leading to compression of nearby structures by the accumulation of blood).
By knowing the function of specific areas of the brain and knowing which areas of the brain are supplied by which artery, a clinician can identify the responsible vessel based on the symptoms alone. Middle cerebral artery strokes, for example, may cause weakness and numbness of the hands and face, whereas an anterior cerebral artery stroke may cause weakness and numbness of the legs. A posterior cerebral artery stroke may cause blindness whereas a basilar stroke may cause complete paralysis.
Middle cerebral artery stroke
Cause weakness and numbness of the hands and face
Anterior cerebral artery stroke
Weakness and numbness of the legs
Posterior cerebral artery stroke
Blindness
Basilar stroke
Complete paralysis
How long must a neurological deficit last to be classified as a stroke
24 hours
Berry aneurysms
Aneurysms are deformities in arterial vessel walls causing them to balloon and make them prone to rupture. Berry aneurysms, named after their characteristic appearance, may be found in the cerebral circulation on the sides of cerebral arteries. They are often asymptomatic until they rupture. A ruptured berry aneurysm most often causes a subarachnoid haemorrhage, leaking arterial blood into the subarachnoid space. Symptoms include a severe, sudden-onset headache, vomiting or a reduction in a patient’s conscious level.
Pathway of venous blood drainage in the brain
Internal cerebral veins
Larger external cerebral veins
Dural venous sinuses:
1. Sigmoid sinuses —> internal jugular veins
2. Emissary veins —> bones of the skull
2 routes of venous blood in dural venous sinuses to drain into extra cranial veins
- Sigmoid sinuses —>Internal jugular vein
- Emissary veins - cross the endosteal layer of dura and drain into bones of the skull
Which veins drain venous blood into the bones of the skull
Emissary veins
Cavernous sinus
One of the dural venous sinuses that is found behind the orbit (eye socket) on both sides is called the cavernous sinus. It is clinically relevant because the internal carotid artery and several important nerves pass through it: the oculomotor nerve (CN III), trochlear nerve (CN IV), ophthalmic nerve (CN V1), maxillary nerve (CN V2) and abducens nerve (CN VI). Venous blood draining from the face can potentially drain into the cavernous sinus, thereby providing a connection for superficial infection of the face to reach intracranial structures. Infection in the cavernous sinus can lead to meningitis or thrombosis. A thrombosis here will cause an increase in pressure and compress these nerves leading to problems with eye movements and sensation over the face.
Venous sinus thrombosis
Just like other vessels in the body, blood can clot within the dural venous sinuses. If this occurs, drainage of venous blood will be compromised, meaning there will be an increase in intracranial pressure causing a headache and potentially a significant and devastating compression of intracranial structures.
Which cranial nerves pass through the cavernous sinus
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Ophthalmic nerve (CN V1)
Maxillary nerve (CN V2)
Abducens nerve (CN VI)
Ventricles
Central cavities in the brain filled with cerebrospinal fluid
Joined to each other
Continuous with the subarachnoid space
Choroid plexus
Produce cerebrospinal fluid
Located in lateral ventricles
Third ventricle
A very thin chamber in the midline separating the 2 sides of the Diencephalon
Pathway of cerebrospinal fluid
Lateral ventricles —> interventricular Foramen —> third ventricle —> cerebral aqueduct—> fourth ventricle —> subarachnoid space
What connects the third and fourth ventricle
Cerebral aqueduct
Fourth ventricle
Diamond-shaped
Located posterior to brain stem but anterior to cerebellum
What connects the lateral ventricles and third ventricle
Interventricular foramen
Where is CSF primarily produced
Lateral ventricles by choroid plexus
Lateral ventricles
Located within the cerebral hemispheres
How does the CSF leave the ventricular system
Inferiorly- via the central canal to fill the subarachnoid space around the spinal cord
Posteriorly and laterally- via the median aperture of Magendie and lateral apertures of Luschka to enter to subarachnoid space around the brain
What connects the fourth ventricle and subarachnoid space around the spinal cord
Central canal
What connects the fourth ventricle and subarachnoid space around the brain posteriorly
Median aperture of Magendie
What connects the fourth ventricle and subarachnoid space around the brain laterally
Lateral apertures of Luschka
Subarachnoid cisterns
Larger pockets of CSF in the subarachnoid space
How is CSF recycled back into the bloodstream
Arachnoid granulations - diffuses across the walls
Arachnoid granulations
Outpouchings that push out of the subarachnoid space around the brain into the dural venous sinuses
Hydrocephalus
Hydrocephalus (meaning ‘water in the head’ or ‘water on the brain’) is the term used to describe the accumulation of CSF, often characterised by enlarged lateral ventricles. This is most often caused by a blockage to the flow of CSF through the ventricular system. The compression of the rest of the brain may cause headache, vomiting, drowsiness, reduced conscious level or seizures. It can be relieved by placing a ‘shunt’ which is a device that diverts the CSF around the obstruction. A common type of shunt is known as a ‘VP’ (ventriculo-peritoneal) shunt, that diverts the CSF from the cerebral ventricles to the peritoneal cavity in the abdomen through a tube that is buried under the skin.
- Using your knowledge of the functional areas of the brain and their blood supply, what might be the likely consequence of a blockage of the following arteries?
a. Left middle cerebral artery.
Expressive and/or receptive dysphasia
Weakness in the face and upper limb
Altered or absent sensation in the face and upper limb and/or weakness in swallowing
- Using your knowledge of the functional areas of the brain and their blood supply, what might be the likely consequence of a blockage of the following arteries?
b. Right posterior cerebral artery.
Left visual field deficit and cerebellar dysfunction
- Using your knowledge of the functional areas of the brain and their blood supply, what might be the likely consequence of a blockage of the following arteries?
c. Basilar artery.
Disruption of numerous cranial nerve functions and both ascending and descending tracts- potentially can cause ‘locked-in’ syndrome where patient is unable to feel or move almost all parts of their body but retains consciousness
- Which lobes of the brain are located superior to the lateral sulcus?
Frontal and parietal lobes
- Which lobes of the brain are located, inferior to the lateral sulcus?
Temporal lobe
- Which lobes of the brain are located deep to the lateral sulcus?
Insula
- What is the name of the sheet of fibrous material that divides the two hemispheres of the brain in the longitudinal fissure? What is this tissue part of?
Falx cerebri
2 layers of dura mater
- What are the names of the large vessels that drain venous blood from the brain to the internal jugular veins?
Dural venous sinuses
Final one before internal jugular vein= sigmoid sinuses
- Between which two layers of the meninges would you find CSF?
Arachnoid mater and Pia mater in subarachnoid space
- What are the three routes that CSF can take out of the fourth ventricle?
Central canal
Median aperture
Lateral apertures
- Where is CSF produced and where is it reabsorbed?
Produced in lateral ventricles by choroid plexus
Reabsorbed in arachnoid granulations
- Which arteries supply the following areas of the brain?
a. Wernicke’s area.
Middle cerebral artery
- Which arteries supply the following areas of the brain?
b. Broca’s area.
Middle cerebral artery
- Which arteries supply the following areas of the brain?
c. Primary auditory cortex.
Middle cerebral artery
- Which arteries supply the following areas of the brain?
d. Part of the somatosensory cortex receiving sensory information from the arms and face.
Middle cerebral artery
- Which arteries supply the following areas of the brain?
e. Part of the motor cortex that controls the feet and toes.
Anterior cerebral artery
- What layers of tissue must be penetrated during surgery to reach the surface of the brain from outside the head?
Skin
Fascia
Aponeurosis of scalp muscles
Fascia
Periosteum
Skull
Dura mater
Arachnoid mater
Pia mater
- What type of bleed between the layers of the meninges is likely in the following cases?
a. Young adult patient who suffers a lateral head injury after falling off a bicycle without a helmet. They remain conscious for 12 hours after the injury, before becoming profoundly unconscious.
Extradural haemorrhage
- What type of bleed between the layers of the meninges is likely in the following cases?
b. Elderly patient with a history of heavy alcohol use who stumbles at home and bangs their head. They retain consciousness, but the family notices they are becoming gradually more confused over the next two weeks.
Subdural haematoma
- What type of bleed between the layers of the meninges is likely in the following cases?
c. A middle-aged patient with a known cerebral aneurysm who suffers a very severe, sudden-onset, ‘worst-ever’ headache and becomes photophobic with vomiting and drowsiness.
Subarachnoid haemorrhage
Function of Insula
Disgust, emotion, homeostasis, perception, motor control, self-awareness, cognitive function, and interpersonal experience
Olfactory nerve is cranial nerve…
CN I
Sylvian fissure
formed by the anatomical relationship between the frontoparietal operculum, the temporal operculum, and the insula.
Which part of motor cortex homunculus is next to great longitudinal fissure/corpus callosum
Genitals
Which part of motor cortex homunculus is next to lateral fissure
Pharynx
Homunculus genitals —> pharynx
Genitals
Foot
Leg
Trunk
Shoulder
Elbow
Wrist
Hand
Fingers
Eyes
Nose
Face
Lips
Jaw
Tongue
Pharynx
Striate cortex
First cortical point of visual synapse in occipital lobe
6 layers of neocortex
Superficial projects:
Input of other cortical areas
Projects to other cortical areas
Input from thalamus
Middle projects:
Projects to brain stem and spinal cord
Deep projects:
Projects to thalamus
Simply: input into the brain enters
At the back
Simply:output from the brain, eg movement, exits the brain
At the front
Superficial projects of neocortex
Receive inputs :
From other cortical areas
Projects to other cortical areas
input from thalamus
Middle projects of neocortex
Projects to brain stem and spinal cord
Deep projects in neocortex
Thalamus
How many layer of neocortex are there
6
Structural asymmetry of the brain
Frontal petalia- right frontal lobe projects further forward than the left
Occipital petalia- left occipital lobe projects further back than right
Left lateral fissure is longer
Frontal petalia
Right frontal lobe projects further forward than left
Occipital petalia
Left occipital lobe projects further back than right
Which lateral fissure is longer
Left due to Wernicke’s area
Which arteries are part of anterior circulation
Anterior cerebral and middle cerebral
Originate from internal carotid
Which artery feeds the posterior circulation
Vertebral arteries
Where do the vertebral arteries originate from
Subclavian artery
Which cells line the ventricles
Ependymal cells
Ependymal cells
Line ventricles
Cilia
How is CSF drained
Arachnoid granulations
Peripheral nerves to lymphatics
Nasal mucosa lymphatics deep cervical lymph nodes
Cranial nerves I—->XII
Olfactory tract
Optic tract
Oculomotor
Trochlear
Trigeminal
Abducent
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Hypoglossal
Accessory
Amount of CSF approximately in circulation
120ml
