Introduction To Brain, Cranial Meninges And Blood Supply Flashcards

1
Q

4 main parts of the brain

A

Cerebrum
Cerebellum
Diencephalon
Brainstem

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2
Q

Where is the cerebrum

A

Largest part covering the superior and lateral aspects of the brain, covered in folds of tissue

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3
Q

Division of cerebrum

A

Made up of 2 hemispheres each divided into 4 lobes

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4
Q

Where is the cerebellum

A

Smaller, bolbous structure underneath the posterior part of the cerebrum

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5
Q

What is the location of the Diencephalon

A

Area is deep within the brain, beneath the cerebrum but above the brain stem

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6
Q

Where is the brain stem

A

Connects the cerebrum and Diencephalon to the spinal cord

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7
Q

Function of the frontal lobe

A

Contains the primary motor cortex involved in planning and executing conscious movement
Contains the prefrontal cortex involved in behaviour, personality and decision making

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8
Q

Function of the primary motor cortex

A

Planning and executing conscious movement

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9
Q

Function of the prefrontal cortex

A

Behaviour, personality and decision making

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10
Q

Function of the temporal lobe

A

Contains the primary auditory cortex responsible for processing auditory information
Contains the hippocampus involved in formation of memories

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11
Q

Function of the hippocampus

A

Formation of memories

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12
Q

Function of the parietal lobes

A

Contain the primary somatosensory cortex involved in processing sensory information

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13
Q

Function of the primary somatosensory cortex

A

Processing sensory information

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14
Q

Function of the primary auditory cortex

A

Processing auditory information

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15
Q

Function of the occipital lobe

A

Contains the primary visual cortex responsible for processing visual information

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16
Q

Function of the primary visual cortex

A

Processing visual information

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17
Q

Function of the cerebellum

A

Helps maintain posture, balance and corrects fine movements

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18
Q

Function of the brain stem

A

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

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19
Q

Gyri

A

Folds/ridges of the exterior aspect of the brain

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20
Q

SuIci

A

Furrows/grooves in between the gyri

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21
Q

Central sulcus

A

Large sulcus in the coronal plane separating the frontal and parietal lobes
One on both hemispheres

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22
Q

Lateral sulcus (Sylvian fissure)

A

Large sulcus in the transverse plane separating the temporal lobe from the frontal and parietal lobes
One on both hemispheres

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23
Q

Insula

A

Part of the cerebral cortex that can only be seen by opening the lateral sulcus

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24
Q

Opercula

A

The parts of the frontal, parietal and temporal lobes that cover the insula

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25
Q

Longitudinal fissure

A

Large groove separating the two hemispheres

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26
Q

Corpus callosum

A

A large bundle of white matter that connects the two hemispheres

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27
Q

Olfactory tracts

A

Nerve fibres carrying information about smell from the nasal cavity
Run along the inferior surface of the frontal lobes on each side of the

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28
Q

Optic nerve

A

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)

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29
Q

Optic chiasm

A

Point where 2 optic nerves partly cross over each other

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30
Q

Mammillary bodies

A

Rounded structures found behind the optic chiasm and pituitary gland
Part of Diencephalon

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31
Q

Hypothalamus

A

Part of Diencephalon
Only just visible behind the optic chiasm
Mammillary bodies located on its inferior surface

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32
Q

What is the hypothalamus part of

A

Diencephalon

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33
Q

Crus cerebri

A

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)

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34
Q

Interpeduncal fossa

A

Fossa between the cerebral peduncles
May have a layer of arachnoid matter overlying it

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35
Q

Parts of the brain stem

A

Midbrain
Pons
Medulla oblongata

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36
Q

Location of the midbrain

A

Most superior part of brain stem where the crus cerebri are located

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37
Q

Location of the pons

A

Large, bulbous, central part of brain stem

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38
Q

Location of the medulla oblongata

A

Most inferior part of the brain stem that tapers down to become the spinal cord inferiorly

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39
Q

Cerebellum

A

Lined with many small fissures and is made up of 2 hemispheres connected by a central vermis
Connects to the brainstem

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40
Q

What connects the 2 hemispheres of the cerebellum

A

A central vermis

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41
Q

Functional areas of the frontal lobe

A

Primary motor cortex
Pre motor cortex
Prefrontal cortex
Broca’s area

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42
Q

Functional areas of the parietal lobe

A

Primary somatosensory cortex

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43
Q

Functional areas of the temporal lobe

A

Primary auditory cortex
Hippocampus
Amygdala
Wernicke’s area

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44
Q

Functional areas of the occipital lobe

A

Primary visual cortex

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45
Q

Location of the primary motor cortex

A

Most posteriorly in the frontal lobe
Immediately anterior to the central sulcus

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46
Q

Location of Broca’s area

A

Inferior frontal lobe of the dominant hemisphere (usually left0

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47
Q

Which hemisphere is usually dominant

A

Left

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48
Q

Anterior to posterior frontal lobe functional areas

A

Prefrontal cortex
Premotor cortex
Primary motor cortex

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49
Q

Function of the primary motor cortex

A

Execution of motor function

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50
Q

Function of the premotor cortex

A

Planning and preparation of movements

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51
Q

Function of the prefrontal cortex

A

Personality, behaviour, problem solving, impulse control and inhibition, social and sexual behaviour

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52
Q

Function of Broca’s area

A

Spoken language production

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53
Q

Location of the parietal lobe

A

Central sulcus to the parietooccipital fissure

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54
Q

Location of the primary somatosensory cortex

A

Immediately posterior to the central sulcus

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55
Q

Role of the dominant parietal lobe (left)

A

Perception and mathematical and language operations

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56
Q

Role of the non-dominant parietal lobe (right)

A

Visuospatial function

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57
Q

Location of the primary auditory cortex

A

Immediately below the lateral sulcus

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58
Q

Location of the hippocampus

A

Inferior and medially in the temporal lobe

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59
Q

Location of the amygdala

A

Deep within the temporal lobe

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60
Q

Role of amygdala

A

Perception of fear

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61
Q

Location of wernicke’s area

A

Most superior and posterior part of dominant temporal lobe

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62
Q

Function of wernicke’s area

A

Understanding and coordination spoken language

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63
Q

Location of the occipital lobe

A

Most posterior part of cerebrum

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64
Q

Limbic system contains

A

Group of structures found in the medial margins of the hemispheres, including the hippocampus, amygdala and parts of the cortex
Also contains the Diencephalon

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65
Q

Function of limbic system

A

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

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66
Q

Homunculus

A

Mapping of specific parts of the body to parts of the cortex (the gyri)
There is a motor and sensory cortices

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67
Q

Where are the face and mouth represented in the homunculus

A

On the lateral aspects of the primary motor and somatosensory cortices

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68
Q

Where are the upper limb and torso represented in the homunculus

A

Most superior part of the cortex

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69
Q

Where are the feet represented in the homunculus

A

Most medial part of the cortices

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70
Q

Cranial meninges

A

3 layers of tissue that envelop the brain and spinal cord

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71
Q

3 layers of cranial meninges

A

Dura mater
Arachnoid mater
Pia mater

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72
Q

Dura mater

A

Most external, lying against the skull
It is fibrous, thick and does not stretch

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73
Q

Arachnoid mater

A

Intermediate layer
It is much thinner and more flexible
Resembles a spider’s web

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74
Q

Pia mater

A

Most internal- lies on surface of the brain
It is very thin (cannot be seen with the naked eye)

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75
Q

Layers of matter from skin to cerebral cortex

A

Skin
Aponeurosis
Periosteum
Skull
Dura mater (endosteal layer and meningeal layer)
Arachnoid mater
Subarachnoid space
Pia mater
Cerebral cortex

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76
Q

2 layers of dura mater

A

Outer Endosteal layer
Inner Meningeal layer

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77
Q

Outer endosteal layer

A

Layer of dura
Adherent to interior of the skull

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78
Q

Inner meningeal layer

A

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

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79
Q

Falx cerebri

A

A double layer of folded dura lying in the longitudinal fissure that separates the 2 hemispheres

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80
Q

Tentorium cerebelli

A

A double layer of folded dura that separates the occipital lobe and cerebellum

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81
Q

Falx cerebelli

A

Separates the 2 lobes of the cerebellum

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82
Q

Dural venous sinuses

A

Channels between the outer endosteal layer and inner meningeal layer filled with venous blood

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83
Q

What separates the cerebellum and occipital lobe

A

Tentorium cerebelli

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84
Q

Superior sagittal sinus

A

Formed in the space between the 2 layers of dura
Located superiorly and runs along the top of the brain in the sagittal plane

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85
Q

Inferior sagittal sinus

A

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

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86
Q

Which dural venous sinus lies on top of the corpus callosum

A

Inferior sagittal sinus

87
Q

Straight sinus

A

Found where the Falx cerebri connects to the Tentorium cerebelli posteriorly
Allows venous blood to drain backwards from the inferior sagittal sinus

88
Q

Which dural venous sinus is found where the Falx cerebri and Tentorium cerebelli connect

A

Straight sinus

89
Q

Transverse sinuses

A

Found on both lateral aspects extending from the Tentorium cerebelli around the side of the skull

90
Q

Sigmoid sinuses

A

S-shaped sinuses that connect the transverse sinuses to the internal jugular veins outside the skull to drain venous blood from the brain

91
Q

Which sinus connects the transverse sinus and internal jugular vein

A

Sigmoid sinus

92
Q

Confluence of sinuses

A

Where the straight sinus meets the transverse sinuses and superior sagittal sinus
Found at most posterior aspect of skull

93
Q

Cavernous sinuses

A

Found anteriorly either side of the sella turcica of the sphenoid bone
Internal carotid passes through it

94
Q

Arachnoid mater

A

Single layer that loosely follows the contours of the meningeal layer of the dura

95
Q

Subarachnoid space

A

A thin space between the arachnoid and pia
Contains cerebrospinal fluid

96
Q

Cisterns

A

A sealed space between gyri filled with CSF formed by arachnoid covering over the sulcus

97
Q

Pia mater

A

Tightly adhered to the brain and spinal cord
Forms blood-brain barrier

98
Q

Where are the arteries that supply the brain located

A

Subarachnoid space

99
Q

What forms the blood-brain barrier

A

Pia fuses with the endothelial cells of the capillaries

100
Q

Function of blood-brain barrier

A

Limits passage of certain molecules into the brain and spinal cord protecting them from harmful substances

101
Q

4 features of the blood-brain barrier

A

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

102
Q

Astrocytes

A

have specialised projections (end feet) that wrap around capillaries to restrict flow of certain molecules in blood-brain barrier

103
Q

Meningitis

A

Inflammation of the meningeal layers
Often caused by viral or bacterial infection

104
Q

Symptoms of meningitis

A

Headache, stiffness of the neck, photophobia (bright lights causing discomfort)

105
Q

Diagnosing meningitis

A

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)

106
Q

Which is more serious viral or bacterial meningitis

A

Bacterial= requires intravenous antibiotics
(Viral usually resolves on its own)

107
Q

3 main types of intrameningeal bleeding

A

Extradural haemorrhage
Subdural haematoma
Subarachnoid haemorrhage

108
Q

Extradural haemorrhage

A

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’.

109
Q

Subdural haematoma

A

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.

110
Q

Subarachnoid haemorrhage

A

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.

111
Q

Difference between a haemorrhage and haematoma

A

Haemorrhage- active bleed
Haematoma - collection of blood without an active bleed

112
Q

Coning

A

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

113
Q

Tonsillar herniation

A

Tonsils (part of cerebellum) may be forced out of the Foramen magnum

114
Q

Uncal herniation

A

Uncus (part of temporal lobe) may be forced under the Tentorium cerebelli

115
Q

Which 2 pairs of arteries supply the brain

A

Internal carotid arteries
Vertebral arteries

116
Q

What percentage of blood do the vertebral arteries supply the brain with

A

20%

117
Q

What percentage of blood do the internal carotid arteries supply the brain with

A

80%

118
Q

Which area of the brain do the vertebral arteries supply

A

Mainly the posterior parts such as the occipital lobe, cerebellum and brainstem

119
Q

Which areas of the brain do the internal carotid arteries supply

A

Cerebrum (not occipital lobe) and Diencephalon

120
Q

Arteries of the Circle of Willis

A

Internal carotid arteries
Vertebral arteries
Basilar artery
Posterior cerebral arteries
Middle cerebral arteries
Anterior cerebral arteries
Posterior communicating arteries
Anterior communicating arteries
Cerebellar arteries

121
Q

Basilar artery

A

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

122
Q

Pontine arteries

A

Branches of the basilar artery
Supply the brain stem

123
Q

Posterior cerebral arteries

A

Formed by the bifurcation of the basilar artery
Pass posteriorly

124
Q

Middle cerebral arteries

A

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

125
Q

Anterior cerebral arteries

A

Branches of the internal carotid arteries as they enter the skull
Pass anteriorly then wrap backwards over the corpus callosum

126
Q

Which arteries pass over the corpus callosum

A

Anterior cerebral arteries

127
Q

Which arteries are formed from the internal carotid arteries

A

Middle and anterior cerebral arteries

128
Q

Posterior communicating arteries

A

Join the posterior cerebral to the middle cerebral arteries

129
Q

Anterior communicating arteries

A

Joins the left and right anterior cerebral arteries

130
Q

3 pairs of cerebellar arteries

A

Anterior inferior cerebellar arteries
Posterior inferior cerebellar arteries
Superior cerebellar arteries

131
Q

What does the anterior cerebral artery supply

A

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

132
Q

What does the middle cerebral artery supply

A

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

133
Q

Internal capsule

A

Transmits all fibres to and form the cortices

134
Q

What does the posterior cerebral artery supply

A

Mainly the occipital lobe
Small portion of inferior temporal lobe

135
Q

What does the basilar artery supply

A

Carries blood from vertebral arteries to circle of Willis
Supplies the pons

136
Q

What do the cerebellar arteries supply

A

Cerebellum
Parts of the brain stem

137
Q

Anterior circulation

A

Includes anterior and middle cerebral arteries

138
Q

Posterior circulation

A

Includes posterior cerebral, basilar and cerebellar arteries

139
Q

Stroke

A

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.

140
Q

Middle cerebral artery stroke

A

Cause weakness and numbness of the hands and face

141
Q

Anterior cerebral artery stroke

A

Weakness and numbness of the legs

142
Q

Posterior cerebral artery stroke

A

Blindness

143
Q

Basilar stroke

A

Complete paralysis

144
Q

How long must a neurological deficit last to be classified as a stroke

A

24 hours

145
Q

Berry aneurysms

A

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.

146
Q

Pathway of venous blood drainage in the brain

A

Internal cerebral veins
Larger external cerebral veins
Dural venous sinuses:
1. Sigmoid sinuses —> internal jugular veins
2. Emissary veins —> bones of the skull

147
Q

2 routes of venous blood in dural venous sinuses to drain into extra cranial veins

A
  1. Sigmoid sinuses —>Internal jugular vein
  2. Emissary veins - cross the endosteal layer of dura and drain into bones of the skull
148
Q

Which veins drain venous blood into the bones of the skull

A

Emissary veins

149
Q

Cavernous sinus

A

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.

150
Q

Venous sinus thrombosis

A

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.

151
Q

Which cranial nerves pass through the cavernous sinus

A

Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Ophthalmic nerve (CN V1)
Maxillary nerve (CN V2)
Abducens nerve (CN VI)

152
Q

Ventricles

A

Central cavities in the brain filled with cerebrospinal fluid
Joined to each other
Continuous with the subarachnoid space

153
Q

Choroid plexus

A

Produce cerebrospinal fluid
Located in lateral ventricles

154
Q

Third ventricle

A

A very thin chamber in the midline separating the 2 sides of the Diencephalon

155
Q

Pathway of cerebrospinal fluid

A

Lateral ventricles —> interventricular Foramen —> third ventricle —> cerebral aqueduct—> fourth ventricle —> subarachnoid space

156
Q

What connects the third and fourth ventricle

A

Cerebral aqueduct

157
Q

Fourth ventricle

A

Diamond-shaped
Located posterior to brain stem but anterior to cerebellum

158
Q

What connects the lateral ventricles and third ventricle

A

Interventricular foramen

159
Q

Where is CSF primarily produced

A

Lateral ventricles by choroid plexus

160
Q

Lateral ventricles

A

Located within the cerebral hemispheres

161
Q

How does the CSF leave the ventricular system

A

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

162
Q

What connects the fourth ventricle and subarachnoid space around the spinal cord

A

Central canal

163
Q

What connects the fourth ventricle and subarachnoid space around the brain posteriorly

A

Median aperture of Magendie

164
Q

What connects the fourth ventricle and subarachnoid space around the brain laterally

A

Lateral apertures of Luschka

165
Q

Subarachnoid cisterns

A

Larger pockets of CSF in the subarachnoid space

166
Q

How is CSF recycled back into the bloodstream

A

Arachnoid granulations - diffuses across the walls

167
Q

Arachnoid granulations

A

Outpouchings that push out of the subarachnoid space around the brain into the dural venous sinuses

168
Q

Hydrocephalus

A

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.

169
Q
  1. 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.
A

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

170
Q
  1. 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.
A

Left visual field deficit and cerebellar dysfunction

171
Q
  1. 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.
A

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

172
Q
  1. Which lobes of the brain are located superior to the lateral sulcus?
A

Frontal and parietal lobes

173
Q
  1. Which lobes of the brain are located, inferior to the lateral sulcus?
A

Temporal lobe

174
Q
  1. Which lobes of the brain are located deep to the lateral sulcus?
A

Insula

175
Q
  1. 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?
A

Falx cerebri
2 layers of dura mater

176
Q
  1. What are the names of the large vessels that drain venous blood from the brain to the internal jugular veins?
A

Dural venous sinuses
Final one before internal jugular vein= sigmoid sinuses

177
Q
  1. Between which two layers of the meninges would you find CSF?
A

Arachnoid mater and Pia mater in subarachnoid space

178
Q
  1. What are the three routes that CSF can take out of the fourth ventricle?
A

Central canal
Median aperture
Lateral apertures

179
Q
  1. Where is CSF produced and where is it reabsorbed?
A

Produced in lateral ventricles by choroid plexus
Reabsorbed in arachnoid granulations

180
Q
  1. Which arteries supply the following areas of the brain?
    a. Wernicke’s area.
A

Middle cerebral artery

181
Q
  1. Which arteries supply the following areas of the brain?
    b. Broca’s area.
A

Middle cerebral artery

182
Q
  1. Which arteries supply the following areas of the brain?
    c. Primary auditory cortex.
A

Middle cerebral artery

183
Q
  1. Which arteries supply the following areas of the brain?
    d. Part of the somatosensory cortex receiving sensory information from the arms and face.
A

Middle cerebral artery

184
Q
  1. Which arteries supply the following areas of the brain?
    e. Part of the motor cortex that controls the feet and toes.
A

Anterior cerebral artery

185
Q
  1. What layers of tissue must be penetrated during surgery to reach the surface of the brain from outside the head?
A

Skin
Fascia
Aponeurosis of scalp muscles
Fascia
Periosteum
Skull
Dura mater
Arachnoid mater
Pia mater

186
Q
  1. 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.
A

Extradural haemorrhage

187
Q
  1. 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.
A

Subdural haematoma

188
Q
  1. 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.

A

Subarachnoid haemorrhage

189
Q

Function of Insula

A

Disgust, emotion, homeostasis, perception, motor control, self-awareness, cognitive function, and interpersonal experience

190
Q

Olfactory nerve is cranial nerve…

A

CN I

191
Q

Sylvian fissure

A

formed by the anatomical relationship between the frontoparietal operculum, the temporal operculum, and the insula.

192
Q

Which part of motor cortex homunculus is next to great longitudinal fissure/corpus callosum

A

Genitals

193
Q

Which part of motor cortex homunculus is next to lateral fissure

A

Pharynx

194
Q

Homunculus genitals —> pharynx

A

Genitals
Foot
Leg
Trunk
Shoulder
Elbow
Wrist
Hand
Fingers
Eyes
Nose
Face
Lips
Jaw
Tongue
Pharynx

195
Q

Striate cortex

A

First cortical point of visual synapse in occipital lobe

196
Q

6 layers of neocortex

A

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

197
Q

Simply: input into the brain enters

A

At the back

198
Q

Simply:output from the brain, eg movement, exits the brain

A

At the front

199
Q

Superficial projects of neocortex

A

Receive inputs :
From other cortical areas
Projects to other cortical areas
input from thalamus

200
Q

Middle projects of neocortex

A

Projects to brain stem and spinal cord

201
Q

Deep projects in neocortex

A

Thalamus

202
Q

How many layer of neocortex are there

A

6

203
Q

Structural asymmetry of the brain

A

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

204
Q

Frontal petalia

A

Right frontal lobe projects further forward than left

205
Q

Occipital petalia

A

Left occipital lobe projects further back than right

206
Q

Which lateral fissure is longer

A

Left due to Wernicke’s area

207
Q

Which arteries are part of anterior circulation

A

Anterior cerebral and middle cerebral
Originate from internal carotid

208
Q

Which artery feeds the posterior circulation

A

Vertebral arteries

209
Q

Where do the vertebral arteries originate from

A

Subclavian artery

210
Q

Which cells line the ventricles

A

Ependymal cells

211
Q

Ependymal cells

A

Line ventricles
Cilia

212
Q

How is CSF drained

A

Arachnoid granulations
Peripheral nerves to lymphatics
Nasal mucosa lymphatics deep cervical lymph nodes

213
Q

Cranial nerves I—->XII

A

Olfactory tract
Optic tract
Oculomotor
Trochlear
Trigeminal
Abducent
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Hypoglossal
Accessory

214
Q

Amount of CSF approximately in circulation

A

120ml