L8; Blood Supply Of Cerebrum Flashcards
Branches of the internal carotid artery
- Hypophyseal artery
- Ophthalmic artery
- Posterior communicating artery
- Anterior Choroid/ satellite artery of the optic tract
TERMINAL BRANCHES: - Anterior Cerebral Artery
- Middle Cerebral Artery
Parts of the vertebral artery and its origin
Origin; branch of subclavian
- In scalenovertebral triangle till the transverse foramen of C6.
- In transverse foramen of upper 6 C vertebrae
- In sub occipital triangle; enters skull thru foramen magnum, ascend medulla oblongata along rootlets of HYPOGLOSSAL nerve between pyramid and olive.
Branches of vertebral artery
-2 ANTERIOR spinal arteries;
join together to form a single artery that descends in ANTERIOR MEDIAN FISSURE.
-2 POSTERIOR SPINAL ARTERIES;
remain separate and descend thru posterolatersl sulcus.
- Meningeal branches
- Branches to medulla
- PICA; passes thru vermis of cerebellum to supply med ob and cerebellum.
Basilar artery formed by union of
2 vertebral arteries @ j(x) of medulla and pons and ascend in basilar sulcus.
Branches of basilar artery
- AICA: supplies cerebellum and posterolateral pons
- Pontine branches: supply basilar part of pons
- Superior cerebellar artery
- 2 POSTERIOR CEREBRAL ARTERIES
Clinical significance of 1. Posterior cerebral and 2. Superior cerebellar arteries
Close to midbrain can therefore compress occulomotor, trochlear in case of aneurysm.
Connection of posterior cerebral to internal carotid
Posterior communicating artery
Rupture of cerebral arteries results in
Subarachnoid bleed eg. Beery aneurysm (weakest at junctions)
Rupture of meningeal arteries
Extradural bleeding; eg middle meningeal artery and compress motor cortex
Rupture of bridging veins
SUBDURAL bleed
Clinical significance of superior sagittal sinus
Grey matter shrinks as you age there4 more space that stretches the sinus there4 more likely to rupture
Middle cerebral artery supplies
Superolateral surface
Orbital part inferiority
Temporal lobe
‘Motor speech area’
Frontal eye fieldv(MFG)
Anterior cerebral artery supplies
Medial surface
Small strip in superolateral surface—>’motor sensory of lower limbs’
Medial of inferior part
Posterior cerebral artery supplies
Occipital lobe
Termporal gyrus
Termporal and occipital inferiorly
Venous drainage of brain
- Superior cerebral veins
- Superficial middle cerebral vein
- Inferior cerebral vein
- Internal cerebral vein (union of thalamostriate and choroid veins)
- Basal veins (union of anterior cerebral vein, deep middle cerebral vein & striate veins)
- Great cerebral vein of Galen (union of 2 internal cerebral veins)
MEDIAL MEDULLARY SYNDROME/ Hypoglossal Alternating Hemiplegia
Cause
Clinical effects
Caused by: thrombosis of ANTERIOR SPINAL ARTERY
Clinical Effects:
A-Ipsilateral paralysis of tongue muscles
ie. deviate to affected side of lesion due to involvement of HYPOGLOSSAL NUCLEUS
B- Contralateral hemiplegia (UMN) due to involvement of pyramidal tracts
C- Contralateral loss of conscious proprioception, discriminative touch and vibratory sense due to involvement of MEDIAL LEMNISCUS.
LATERAL MEDULLARY SYNDROME/ WALLENBERG
Cause
Manifestations
Caused by: thrombosis of PICA
Manifestations:
A-Vertigo, nausea, nystagmus due to involvement of VESTIBULAR NUCLEUS
B-Ipsilateral ataxia due to involvement of ICP
C-Ipsilateral loss of pain + temp sensations from face due to involvement of NUCLEUS AND SPINAL TRACT OF CN5
D-Dysphagia, dysphonia, deviation of uvula due to involvement of AMBIGUUS NUCLUES
E-Contralateral loss of pain sensation due to involvement of LATERAL SPINOTHALAMIC TRACT
F-Ipsilateral horners syndrome due to involvement of DESCENDING SYMPATHETIC FIBERS IN RET. FOR
MILLARD GUBLER SYNDROME/ MEDIAL PONTINE SYNDROME
Cause
Manifestations
Cause: Vascular lesion of PONTINE BRANCHES OF BASILAR ARTERY there4 affect basilar region of lower pons.
MANIFESTATIONS:
A-Contralateral paralysis (UMN lesion) due to involvement of PYRAMIDAL TRACTS
B-Internal squint ie. diplopia when looking laterally due to involvement of ABDUCENT NERVE FIBERS TRANSVERSING BASILAR PART—> ‘lateral rectus’ paralysis
C-Facial Palsy due to involvement of FACIAL NERVE FIBERS
B,C can result from corticonuclear fiber involvement
LATERAL INFERIOR PONTINE SYNDROME/ ALTERNATING TRIGEMINAL HEMIPLEGIA
CAUSE
MANIFESTATIONS
Cause: Vascular lesion of AICA there4 affecting lateral inferior pons.
Manifestations:
A-Ipsilateral facial palsy due to LMN paralysis cuz of FACIAL NUCLEUS INVOLVEMENT.
B-Ipsilateral loss of pain & temp from face due to involvement of SPINAL NUCLEUS AND TRACT PF CN5
C- Hearing? (Cochlear N)
D-Vertigo, nausea & nystagmus due to involvement of VESTIBULAR NUCLEUS
E-Contralateral loss of pain, temp due to involvement of LATERAL SPINOTHALAMIC
F- Horner syndrome due to involvement of DESCENDING SYMPATHETIC FIBERS IN RET. FORM
WEBER’S SYNDROME/ Superior alternating hemiplegia
Cause:
Manifestations:
Cause: Vascular lesion of POSTERIOR CEREBRAL ARTERY
Manifestations:
A-Contralateral hemiplegia (UMN paralysis) due to lesion of Crus Cerebri involving CORTICOSPINAL TRACT
B-External Strabismus, fixed + dialated pupils and ptosis due to involvement of OCCULOMOTOR NERVE
BENEDICTS SYNDROME
CAUSE
MANIFESTATION
Cause: lesion of tegmentum of midbrain (basilar and posterior cerebral artery)
Manifestation:
A-Ptosis due to involvement of CN3
B-Fixed + dialated pupil due to PARASYMPATHETIC FIBERS OF CN3—> loss of accommodation reflex
C-Contralateral loss of properioception, desc touch and vib sense due to involvement of MEDIAL LEMNISCUS
D-Tremors, chores and athetosis due to involvement of RED NUCLEUS AND DECUSSATION AT SCP
