MBChB2: Neurosensory System I Flashcards
1. Describe the arterial supply of the different areas of the cerebrum that are supplied by the anterior, middle and posterior cerebral arteries and their branches. 2. Relate the different parts of the brainstem and the cerebellum to its arterial supply. 3. Describe in detail the areas supplied by the choroidal and lenticulostriate arteries and their importance. 4. Describe the consequences of an occlusion of any of the arteries mentioned above.
How is cerebral circulation divided into?
Posterior CC from Internal carotid arteries.
Anterior CC from vertebral arteries.
Anastomosis formed known as circle of willis.
What may an occlusion of the anterior cerebral artery result in?
Loss of strength and sensation in the lower part of body due to the distribution of the homunculus on the pre-central gyrus of the frontal lobe.
What may an occlusion in the middle cerebral artery affect?
Affects strength and sensation in the upper regions of the body.
Where do the medial striate arteries arteries arise from?
First portion of the anterior cerebral artery/
Where do the lateral striate arteries arise from?
First part of the middle cerebral artery.
Blockage of circulation in vertebral and basilar arteries affects circulation to what specific area of the cerebum?
Basilar artery occlusion:
-Visual loss and dizziness.
Posterior cerebral arteries supply the visual cortex.
Vertebral artery occlusion
-little/ no deficit as there is remaining blood supply from opposite vertebral artery.
State the three main arteries that supply the cerebellum?
- Posterior inferior cerebellar artery (PICA)
- Anterior inferior cerebellar artery (AICA)
- Superior cerebellar artery (SCA)
What does the posterior inferior cerebellar artery supply?
Lateral portion of medulla oblongata.
Occlusion of PICA may lead to?
Lateral Medullary syndrome (Wallenberg syndrome)
What is Wallenberg’s syndrome?
Infarction, stroke in lateral medulla.
Oxygenated blood doesn’t arrive as arteries blocked.
Common symptoms
- dysphagia
Where does the Anterior inferior cerebellar artery arise from?
Basilar artery
Where does the superior cerebellar artery arise from?
Near termination of the basilar artery.
Dysmetria
Overshooting when reaching for a target.
Dysdiadochokinsia
Inability to perform rapid alternating movements (finger tapping)
Intention Tremor
Evident during purposeful movements
Nystagmus
Rapid involuntary movements of eye
Wide-based ataxia
tilting/ falling to same side as the cerebellar lesion and poor coordination of movement, including slurred speech.
What are some symptoms of cerebellar dysfunction?
Wide-based ataxia, dysmetria, dysdiadochokinsia, intention tremor, nystagmus.
How to view blood supply of the brain?
Inject contrast material.
Catheter threaded back up the right brachial artery to right subclavian artery, at the level of the right vertebral artery.
- contrast material released
- enters both right vertebral and internal carotid arteries
