Support Systems: Cerebrospinal Fluid System Vascular Supply Flashcards
Support Systems: CFS System and Vascular Supply
Three layers of meninges cover the brain and spinal cord include?
- Dura mater = Surrounds the brain and consists of an outer layer firmly bound to the inside of the skull and an inner layer, layers are fused together except at the dural sinuses, which are spaces for collection of venous blood and CSF.
- Arachnoid = Is a delicate membrane loosely attached to the dura. Projections of arachnoid form arachnoid villi, pierce the dura and protrude into the venous sinuses, clusters of arachnoid villi form arachnoid granulations, they allow CSF to flow into the sinuses.
- Pia mater = Innermost layer, is tightly apposed to the surfaces of the brain and spinal cord. Subarachnoid space (between arachnoid and dura), is filled with CSF
Three spaces: subdural (between dura and arachnoid), epidural (between skull and dura) and subarachnoid (between arachnoid and pia).
Support Systems: CFS System and Vascular Supply
The CSF-filled spaces inside the brain form a system of four ventricles = ?
- Pair of lateral ventricles = (C shaped) located in the cerebral hemispheres.
- Pair of lateral ventricles = “”
- Third ventricle = narrow slit in the midline of diencephalon.
- Fourth ventricle = located posterior to the pons and medulla and anterior to the cerebellum.
Support Systems: CFS System and Vascular Supply
What ventricle?
Pair of Lateral ventricles = (C shaped) located in the cerebral hemispheres.
* Consist of a body; an atrium; and the anterior, posterior, and inferior horns.
* Lateral ventricles are connected to the third ventricle by the interventricular foramina (or foramina of Monro).
- (Purple) = Posterior horn of lateral ventricle
- (Green) = Anterior horn of lateral ventricle
- (Red) = Inferior horn of lateral ventricle
- (Pink) = Lateral ventricle
Support Systems: CFS System and Vascular Supply
What ventricle?
Third Ventricle = is a narrow slit in the midline of diencephalon.
- Third and fourth ventricles are connected by the cerebral aqueduct.
Support Systems: CFS System and Vascular Supply
What ventricle?
Fouth Ventricle = Is located posterior to the pons and medulla and anterior to the cerebellum.
- 4th ventricle continues through the spinal cord as the central canal
- 4th ventricle drains into subarachnoid space via 3 small openings:
- 2 lateral openings (foramina of Luschka) and a
- midline opening (foramina of Magendie)
Support Systems: CFS System and Vascular Supply
What structure?
Cerebral Aqueduct = Third and fourth ventricles are connected by the cerebral aqueduct.
Support Systems: CFS System and Vascular Supply
Describe CFS formation and circulation.
- Most CSF is secreted by choroid plexuses (a network of capillaries) while some is formed by extracellular fluid leaking into the ventricles.
- CSF is formed from blood by filtration, active transport, and facilitated transport of certain substances, results in formation of fluid similar to plasma.
CSF flows from:
- Lateral ventricles into third ventricle via interventricular foramina.
- Third ventricle into the fourth ventricle via the cerebral aqueduct.
- CSF exits the fourth ventricle, and enters the subarachnoid space via lateral & medial foramina
- Flows around the brain and spinal cord within subarachnoid space.
- CSF is absorbed into the venous sinuses via arachnoid ville (or granulations, which project through the dura into the venous sinuses).
Support Systems: CFS System and Vascular Supply
Indentify
green
Choroid Plexus = a network of capillaries.
- Most CSF is secreted by choroid plexuses (a network of capillaries) while some CSF formed by extracellular fluid leaking into the ventricles.
Support Systems: CFS System and Vascular Supply
Indentify x 3
- Green = ?
- Blue = ?
- Orange = ?
- Green = Lateral Ventricle = CFS flows from lateral ventricles into third ventricle via interventricular foramina
- Blue = Third Ventricle = From the third ventricle into the fourth ventricle via the cerebral aqueduct.
- Orange = Fourth Ventricle = CSF exits the fourth ventricle, and enters the subarachnoid space via lateral & medial foramina.
Support Systems: CFS System and Vascular Supply
CSF is primarily formed in the = ? , and circulates through the ventricles and into the = ?
CSF is primarily formed in the ventricles; circulates through the ventricles and into the subarachnoid space (between arachnoid & pia maters) before being absorbed into the venous circulation.
Support Systems: CFS System and Vascular Supply
CSF protects the _ ? _ and regulates _ ? _ .
- Protects CNS by absorbing some physical/mechanical impact (cushion).
- Regulates the content of extracellular fluid; CFS supplies water, certain amino acids, vitamins, proteins and specific ions to extracellular fluid and removes metabolites from the brain.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Blood supply to the brain
Internal carotid artery = Anterior Circulation
Support Systems: CFS System and Vascular Supply
What artery?
blue
Blood supply to the brain
Vertebral Artery = Posterior Circulation
Support Systems: CFS System and Vascular Supply
Identify
pink
Internal carotid artery
Support Systems: CFS System and Vascular Supply
Identify
pink
external carotid artery
Support Systems: CFS System and Vascular Supply
Identify
pink
right common carotid
Support Systems: CFS System and Vascular Supply
Identify
vertebral artery (posterior circulation)
Support Systems: CFS System and Vascular Supply
Identify
pink
right subclavian
Support Systems: CFS System and Vascular Supply
Identify
pink
brachiocephalic artery
Support Systems: CFS System and Vascular Supply
Identify
pink
aorta
Support Systems: CFS System and Vascular Supply
Identify
pink
left common carotid artery
Support Systems: CFS System and Vascular Supply
Identify
left subclavian artery
Support Systems: CFS System and Vascular Supply
Circle of Willis = ?
Circle of Willis = is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Arteries that make up circle of Willis = ?
- Anterior cerebral artery (paired; branch of internal carotid)
- Posterior cerebral artery (paired; branch of basilar artery)
- Anterior communicating artery (unpaired)
- Posterior communicating artery (paired)
- Internal carotid artery (paired)
- Middle cerebral arteries (paired)
Support Systems: CFS System and Vascular Supply
The entire blood supply of the CNS depends on two pairs of arteries = ?
Two internal carotid arteries branches into two large branches:
- Anterior Cerebral Arteries & Middle Cerebral Arteries
- Conceptualized as anterior circulation
Vertebral arteries join together to form a single basilar artery
- Divides at the junction of pons and midbrain into posterior cerebral arteries
- Conceptualized as posterior circulation
The two major sources of blood supply join together via the circle of Willis
Support Systems: CFS System and Vascular Supply
Arterial supply to cerebral hemisphere = ?
- Anterior cerebral artery = Medial frontal and parietal lobes, anterior caudate, putamen, anterior limb of internal capsule.
- Middle cerebral artery = Parts of basal ganglia (Globus pallidus, putamen, body of caudate), most of lateral hemisphere, genu of internal capsule.
- Posterior cerebral artery = Midbrain, occipital lobe, inferomedial temporal lobe , most of thalamus.
Support Systems: CFS System and Vascular Supply
What artery is in green?
Occlusion here results in?
Occlusion of Anterior Cerebral Artery:
- Personality changes with contralateral hemiplegia and hemisensory loss
- Hemiplegia and hemisensory loss is more severe in lower limb
Support Systems: CFS System and Vascular Supply
What artery is in blue?
Occlusion here results in?
Occlusion of Middle Cerebral Artery:
- Homonymous hemianopia combined with contralateral hemiplegia and hemisensory loss involving the upper limb and face
- Language affected if left hemisphere, non verbal communication if right hemisphere involved
Support Systems: CFS System and Vascular Supply
What artery is in yellow?
Occlusion here results in?
Occlusion of Posterior Cerebral Artery:
- Thalamic syndrome, eye movement paresis or paralysis affecting muscles controlling eye movements, cortical blindness, visual agnosia
Support Systems: CFS System and Vascular Supply
Damage to anterior cerebral artery results in?
green
Anterior Cerebral Artery
- Somatosensory = Loss of sensation in lower limb.
- Motor = Apraxia; hemiplegia (lower limb more affected than upper limb and face); impaired gait.
- Special Senses / Autonomic Function = No changes.
- Emotions and Behavior = Flat affect; impulsiveness; perseveration; confusion; motor inactivity.
- Cognition, Language, Memory = Difficulty with divergent thinking.
- Other = Urinary incontinence
Support Systems: CFS System and Vascular Supply
Damage to middle cerebral artery results in?
blue
Middle Cerebral Artery
- Somatosensory = Hemianesthesia affecting face and upper limb more than lower limb
- Motor = Face and upper limb more impaired than lower limb; if striate arteries involved, lower limb paresis or paralysis in addition to face and upper limb impairment.
- Special Senses / Autonomic Function = Homonymous hemianopia
- Emotions and Behavior = IF RIGHT hemisphere (left hemiplegia): easily distracted, poor judgement, impulsiveness; IF LEFT hemisphere (right hemiplegia): apraxia, compulsiveness, overly cautious.
- Cognition, Language, Memory = Left MCA: aphasia, Right MCA: difficulty undertanding spacial relationships, neglect, inpairment of nonverbal communication, dressing apraxia, constructional apraxia.
- Other = none
Support Systems: CFS System and Vascular Supply
Damage to posterior cerebral artery results in?
yellow
Posterior Cerebral Artery
- Somatosensory = Hemianesthesia; slow nociception is perserved
- Motor = If lesion near origin of artery; vertical gaze palsy, oculomotor nerve palsy, loss of medial deviation of the eyes with preserved convergence, vertical skew deviation of the eyes; rarely hemiparesis
- Special Senses / Autonomic Function = Homonymous hemianopia; cortical blindness; hallucinations; lack of depth perception; impaired eye movements, except lateral and inferomedial ete movements; visual agnosia; limbs may show vasomotor and/or trophic abnormalities.
- Emotions and Behavior = Memory loss
- Cognition, Language, Memory = Difficulty reading
- Other = None
Support Systems: CFS System and Vascular Supply
Damage to basilar artery results in?
Basilar Artery
- Somatosensory = Bilateral sensory loss
- Motor = Tetraplegia; abducens nerve palsy (palsy or lateral gaze); locked-in syndrome; oculomotor nerve palsy; decorticate or decerebrate or rigidity; paresis or paralysis of muscles of the tongue, lips, palate, pharynx, and larynx
- Special Senses / Autonomic Function = Vertigo, diplophia, vomiting, nausea, nystagmus, hearing loss, pupil constriction (involvement of descending sympathetic fibers in the pons; however, pupils may be reactive to light).
- Emotions and Behavior = None
- Cognition, Language, Memory = Reduced consciousness
- Other = Coma
Support Systems: CFS System and Vascular Supply
What artery?
blue
Anterior cerebral artery (paired; branch of internal carotid)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Posterior communicating artery (paired)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Anterior communicating artery (unpaired)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Posterior cerebral artery (paired; branch of basilar artery)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Internal carotid artery (paired)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
Support Systems: CFS System and Vascular Supply
What artery?
blue
Middle cerebral arteries (paired)
- Circle of Willis is an anastomotic ring of nine arteries, which supply all of the blood to the cerebral hemispheres.
This is not bold in the powerpoint
