Blood Supply, Hemorrhage, and Herniation Flashcards
Blood Supply to the Brain: ? • Cervical part - Bifurcation to ? - Anterior to transverse processes of ?
• Petrous part
- Carotid canal in petrous part of temporal - Upward and medially above ?
• Cavernous part
- In the cavernous sinus - Surrounded by sympathetic plexus, CN ?
• Cerebral part
Internal Carotid
• Cervical part
- Bifurcation to CAROTID CANAL
- Anterior to transverse processes of UPPER 3 VERTEBRAE
• Petrous part
- Carotid canal in petrous part of temporal - Upward and medially above FORAMEN LACERUM
• Cavernous part
- In the cavernous sinus
- Surrounded by sympathetic plexus, CN III, IV, VI,
and V1
• Cerebral part
Blood Supply to the Brain:
?
• Cervical part
- Transverse foramina of ?
• Atlantic part
- Perforates the ? and ? - Pass through ?
• Intracranial part
- In the cranium - Unite at the caudal border of pons to form ?
Vertebral Artery
• Cervical part
- Transverse foramina of FIRST 6 CERVICAL VERTEBRAE
• Atlantic part
- Perforates the DURA and ARACHNOID - Pass through FORAMEN MAGNUM
• Intracranial part
- In the cranium
- Unite at the caudal border of pons to form BASILAR
ARTERY
• A ring of 9 arteries supplying blood to the
cerebral hemispheres (6 large arteries
anastomose via 3 small communicating arteries)
Circle of Willis
• 2-Anterior Cerebral a. (branch of internal
carotid)
• 2-Internal Carotid a.
• 2-Posterior Cerebral a. (branch of Basilar)
• Anterior Communicating a.
• 2-Posterior Communicating a.
CN near ICA and Anterior communicating
a. ?
CN II
CN near posterior cerebral a., superior
cerebellar a., and posterior communicating a. ?
CN III
CN near labyrinthine and AICA?
CN IV
Supplies most of the medial and superior surface of the frontal and parietal lobes
Anterior Cerebral A. (ACA)
Supplies lateral surface of frontal and parietal lobes and the superior part of temporal lobe
Middle Cerebral A. (MCA)
Supplies the occipital lobe and the inferior temporal lobe
Posterior Cerebral A. (PCA)
- Border zones: area between arteries
* Susceptible to damage under conditions of sudden systemic hypotension or hypoperfusion
Cerebral Arteries
Anterior Cerebral A. Segments:
- ICA to anterior communicating a.
A1: (Precommunicating segment)
Anterior Cerebral A. Segments:
- anterior communicating a. to where rostrum and genu of corpus callosum meet
A2: (Infracallosal segment)
Anterior Cerebral A. Segments:
- arches around the genu of corpus callosum, ends when vessels turn caudal
A3: (Precallosal segment)
Anterior Cerebral A. Segments:
- superior to corpus callosum
A4: (Supracallosal)
Anterior Cerebral A. Segments:
- caudal to corpus callosum
A5: (Postcallosal)
Middle Cerebral A. Segments:
- ICA to the bifurcation at insula
M1: (Sphenoidal or horizontal segment)
Middle Cerebral A. Segments:
- bifurcation at insula to circular sulcus of insula (right angle turn)
M2: (Insular segment)
Middle Cerebral A. Segments:
- Circular sulcus of insula to external surface of Lateral Fissure
M3: (Opercular segment)
Middle Cerebral A. Segments:
- On the cortex
M4: (Cortical segment)
Posterior Cerebral A. Segments:
- Basilar bifurcation to posterior communicating a.
P1
Posterior Cerebral A. Segments:
- Posterior communicating a. to around the midbrain
P2
Posterior Cerebral A. Segments:
- segment within the quadrigeminal cistern
P3: (Quadrigeminal segment)
Posterior Cerebral A. Segments:
- (Cortical segment)
P4
- Potential space
* Between cranium and periosteal dura
Epidural (extradural)
- Potential space
* Between dura and arachnoid
Subdural (dura-arachnoid interface)
- Real space
- Between arachnoid and pia
- Contains CSF, arteries (Circle of Willis) and veins
Subarachnoid
Herniation Syndromes:
Causes ?
- Hemorrhage
- Mass/tumor
- Trauma
- Abscess
- Infection
- Metabolic conditions
Herniation Syndromes:
- Divisions:
• Supratentorial compartment – above the ? and divided into right and left by the ?
• Infratentorial compartment – below the ?
• Tentorial notch – continuation of the ? and ?
- Supratentorial compartment – above the TENTORIUM and divided into right and left by the FALX CEREBRI
- Infratentorial compartment – below the TENTORIUM CEREBELLI
- Tentorial notch – continuation of the SUPRA and INFRATENTORIAL COMPARTMENT
Subfalcine Herniation • Also called a ? or ? or ? herniation • ? compartment - Displaces brain tissue under the ? • May compress ? - Frontal lobe - Parietal lobe • May evolve into a ?
• Also called a CINGULATE or FALCINE or FALX
herniation
• SUPRATENTORIAL compartment
- Displaces brain tissue under the FALX CEREBRI
• May compress ACA
- Frontal lobe
- Parietal lobe
• May evolve into a TRANSTENTORIAL HERNIATION
Transtentorial Herniation • Also called ? • Brain displaced downward toward the ? • Compromises the ? brainstem, CN ? and possibly even ? • May compress ? and ? • Decorticate rigidity • Decerebrate rigidity
• Also called CENTRAL HERNIATION
• Brain displaced downward toward the
TENTORIAL NOTCH
• Compromises the UPPER brainstem, CN III and possibly even LOWER STRUCTURES
• May compress BASILAR ARTERY and POSTERIOR CEREBRAL ARTERIES
• Decorticate rigidity
• Decerebrate rigidity
Uncal Herniation
• ? and frequently portions of the ? are extruded over the edge of tentorium cerebelli and through the tentorial notch
• Impinge on ?
• UNCUS and frequently portions of
the PARAHIPPOCAMPAL GYRUS are extruded over the edge of tentorium cerebelli and through the tentorial notch
• Impinge on MIDBRAIN
Tonsillar Herniation
• Cerebellar tonsils through ?
• Compression of the ? and ?
Tonsillar Herniation
• Cerebellar tonsils through FORAMEN MAGNUM
• Compression of the MEDULLA and UPPER CERVICAL SPINAL CORD
Blood Supply to Medulla:
- What supplies the medial medulla?
- get anterior medial syndrome
Anterior Spinal A.
Blood Supply to Medulla:
- What supplies the lower levels of the medulla, does fascicule cuneatus and gracilis, does cuneate nucleus
Posterior Spinal A.
Blood Supply to Medulla:
- What supplies the lateral medulla?
- Get lateral medullary syndrome
Posterior Inferior Cerebellar A.
Blood Supply to Medulla:
- Does cochlear nuclei (dorsal and ventral cochlear)
Anterior Inferior Cerebellar A.
Blood Supply to Pons:
- What supplies the medial aspects of the pons
Paramedian branches of basilar A.
Blood Supply to Pons:
- What supplies the lateral pontine and gives lateral pontine syndrome?
Long Circumferential branches of Basilar A and branches of AICA
Blood Supply to the Midbrain:
- What supplies the medial portions of the midbrain?
- Get Weber’s Syndrome
Anteriomedial (paramedian ) branches of basilar bifurcation and P1 segment
Blood Supply to the Midbrain:
- What supplies the inferior and superior colliculus of the midbrain?
Quadrigeminal and superior cerebellar arteries (level of inferior colliculus), quadrigeminal and posterior medial choroidal arteries (level of superior colliculus)
Blood Supply to the Forebrain:
- Supplies the thalamus; medial and lateral geniculate nuclei/bodies?
Thalamogeniculate branches of posterior cerebral A. (branch of P2)
Blood Supply to the Forebrain:
- Hits the optic tract and Hippocampal formation
- Supplies part of the internal capsule
Anterior Choroidal A.
Blood Supply to the Forebrain:
- Supplies the internal capsule
Lateral striate branches (lenticulostriate arteries) of the middle cerebral artery
Blood Supply to the Spinal Cord:
- Supplies dorsal fasciuclates (gracile and cuneatus)
Posterior Spinal A
Blood Supply to the Spinal Cord:
- Part of the legs of the CST is supplied by?
Dorsal Spinal A.
Blood Supply to the Spinal Cord:
- Supplies most of the ventral and dorsal horns
Anterior Spinal A.
Gives off Sulcal arteries- if occluded they affect one side of the spinal cord or medulla
Blood Supply to the Spinal Cord:
- What do Posterior and Anterior Spinal A. anastomose with?
Arterial Vasocorona (AVC)
Bleeding into potential space between skull and dura?
Epidural Hematoma
lens shaped
Epidural Hematoma
- Common Site:
- Source of the bleeding:
- Clinical:
- Treatment:
- fracture of squamous temporal bone or pterion
- Source: middle meningeal artery (2% of all head injuries but more blood to calvaria than dura)
- Clinical: Momentary unconsciousness followed by lucid
period of hours to 1-2 days then unconsciousness - Treatment - surgical
Bleeding between dura and arachnoid?
Subdural Hematoma
(cresennt shaped and more jagged than lens_
Subdural Hematoma:
- Occurence:
- Source of bleeding:
- Clinical:
- Treatment:
- Occurence:Head strikes fixed object
- Source of bleeding: venous, usually cortical veins openings into superior sagittal sinus
- Clinical: Slower accumulation of blood due to pressure and often self-limiting
- Treatment: Surgical
Subarachnoid Hemorrhage:
• Common finding in severe head injury
- More common is rupture of aneurysm
- Source of the bleeding: ?
- Clinical: ?
• Source of the bleeding:
Arterial bleeding from cerebral a
• Clinical: massive bleeding into CSF compartment due to
arterial source with headaches and deteriorating level of
consciousness
“Worse headache of their lives”
- Bleeding within brain substance (stroke)
* Complication in 2-3% of all head injuries
Intracerebral (Subpial) Hemorrhage
Intracerebral (Subpial) Hemorrhage:
- Source:
- Clinical:
• Source – usually middle cerebral a.
• Clinical – hypertension or degenerative arterial disease
commonly seen at autopsy
Uncal Herniation:
- Can hit CN ? Which would present with?
- 3
- Present with contralateral hemiplegia and ipsilateral CN 3 problems (Kernohan Syndrome)