The primary source of blood supply to brainstem is
the vertebral artery
A blockage in the left MCA means sensory deficits on which side of body
right side (MCA -- contralateral side)
A blockage in the Middle Cerebral Artery would mean more serious deficits in which part of body? -- Upper or Lower?
Upper Body
The MCA supplies the cortical areas above and below which landmark
Lateral fissure
The common carotid artery bifurcates into
External Carotid Artery
Internal Carotid Artery
The Internal Carotid Artery enters the skull where it gives rise to
The Opthalmic Artery
The Anterior Choroidal Artery
Posterior Communicating Artery
then bifurcates into the ACA and MCA
Branches off the ACA are given off distal to the
Anterior Communicating Artery
Occlusion of the MCA results in
1. Contralateral paralysis in the lower part of face and UPPER EXTREMITY
2. Loss of sensation to UPPER EXTREMITY
3. Hemianopsia of the Contralateral Visual Fields of Both Eyes
4. Aphasia (if in dominant hemisphere) --can be expressive or receptive or a COMBO***5. Auditory Cortex is in the area supplied by MCA but probably not a significant loss of hearing due to bilateral projection
The External Carotid Artery gives rise to
Numerous Branches Supplying the Face and Neck
Which is the most direct continuation of the Internal Carotid Artery
the MCA
What lies just above the corpus callosum in the depths of the Longitudinal Fissue
the ACA
What is located deep within the lateral fissure between the frontal/parietal/temoral lobes
the MCA
Which segment of the MCA supplies the cortex of frontal, parietal, and temporal lobes
M4
Which is larger, the ACA or MCA
MCA
Which segment of the MCA supplies the insular cortex?
M2
Which segment of the MCA gives off arteries to basal ganglia
M1
Which artery supplies the INFERIOR LATERAL surfaces of the frontal/parietal/and superior temporal lobe?
MCA
Occlusion of the ACA may cause these deficits
1 - Paralysis in contralateral Lower Extremity
2 - Sensory deficits in contralateral Lower Extremity
3 - Urinary Incontinence
4 - Ipsilateral Anosmia (smell)
5 - Mental Confusion (difficulty with divergent thinking)
Why would ACA occlusion affect the LOWER EXTREMITY?
Because of how Homunculus is situated; The UPPER EXTREMITY is more in the Parietal Region (and the ACA only supplies a small portion of this region)
A blockage in the right ACA would produce more serious deficits in which half of the body? -Upper or Lower
ACA - lower body
The Middle Cerebral Artery (MCA) divides into
Superior and Inferior Branches
Which segment of MCA supplies the inner aspect of the opercula
M3
Which artery supplies the SUPERIOR LATERAL surface of the frontal and parietal lobes
the ACA
Blockage in the right ACA means sensory deficits on which side of the body
left side
Which artery supplies the MEDIAL surface of the frontal and parietal lobes
ACA
Which artery supplies parts of the basal ganglia and the corpus callosum
ACA
Which parts of the brain does the vertebral artery supply
medulla, and parts of the cerebellum, and spinal cord via several branches
Name the branches of the Vertebral Artery
PICA
PSAs (usually a branch of PICA, though)
Anterior Spinal Artery (just one)
From where is the Anterior Spinal Artery formed
It is formed by a contribution from both vertebral arteries
What is the largest branch of the Vertebral Artery
PICA
What does PICA supply
the inferior medial part of the cerebellum
What artery is formed by the joining of the two vertebral arteries
the basilar artery
Where is the basilar artery located?
along the median depression on the anterior basilar pons
Name the branches of the basilar artery
AICA
the Pontine Branches
-Paramedian
-Short and Long Circumferential Branches to the Pons
Superior Cerebellar Artery
PCAs
At which point does the basilar artery bifurcate into the paired PCAs
junction of pons and midbrain
What does the PCA supply (in general)
the posterior region of the brain including the midbrain and thalamus
The Posterior Communicating Arteries connect the PCAs to the __________________
The Anterior Communicating Arteries connect the ACAs to _______________
Internal Carotid Artery
each other
What part of the cerebral cortex does the PCA supply
VENTRAL and MEDIAL surfaces of Temporal Lobe
VENTRAL and MEDIAL and LATERAL surfaces of the Occipital Lobe
Which segment of PCA gives off temporal branches
P3
Which segment of the PCA goes from the posterior communicating artery to temporal area
P2
The P4 segment of the PCA gives off which two branches
parieto-occipital branches
calcarine branches
Why is the Calcarine Branch of P4 so important?
it supplies the PRIMARY VISUAL CORTEX and some of the Association Visual Cortex
How far forward does the PCA extend?
The parieto-occipital sulcus
Occlusion of the PCA results in
-Homonymous Hemianopsia - Blindness in the Contralateral fields of vision in both eyes
-Memory Disturbances as a result of damage to the hippocampal region (usually recovers since the lesion must be bilateral to cause lasting effects on memory)
What is the most common artery involved in strokes
MCA
The circle of Willis passes around the ______ and _______ and crosses the ______________________.
optic chiasm and optic tract
cerebral peduncles of the midbrain
Name the vessels of the circle are:
1 - ACA and the Anterior Communicating Artery
Small part of the internal carotid artery
2 - Posterior Communicating Arteries
3 - PCA
Numerous perforating branches are given off to supply deep structures
The spinal cord receives its blood supply from two different arteries
the ASA
the PSAs (supply the axons that form the post. columns)
The ASA is located in the __________________ and supplies the _________________.
The paired PSA is located in the ____________________ and supplies the _____________________.
ASA: anterior median fissure and supplies anterior 2/3 of spinal cord
PSA: posterolateral sulcus and supplies the posterior 1/3 of spinal cord
The spinal veins in the spinal cord form an internal venous plexus where?
The internal venous plexus communicates with an external venous plexus located where?
Inside the confines of Dura
Extradural Fat (between Dural Sac & Vertebrae)
A source of metastatic disease reaching the vertebrae and brain can be found in
the venous plexus (it has no valves and blood can flow in either direction)
In Venous Drainage of the Brain, where are the external veins located
subarachnoid space on all surfaces of the hemispheres
Which veins drain the core of the cerebrum?
Internal Veins
Blood from external and internal veins empty into
the dural sinuses
Name the 8 Major Dural Sinuses
1 - Superior Sagittal Sinus
2 - Inferior Sagittal Sinus
3 - Straight Sinus
4 - Transverse Sinus
5 - The Confluence of Sinuses
6 - The sigmoid Sinus
7 - The Cavernous Sinues
8 - small occipital sinus in the falx cerebri
What forms the confluence of sinuses
the junction of the straight sinus (SS) and the paired sinus (PS) and the superior sagital sinus (SSS)
Which sinus is located lateral to the pitutitary gland and hypophyseal stalk
cavernous sinus
The Superior Sagittal Sinus and Inferior Sagittal Sinus border the edges of the __________