Brainstem and blood supply Flashcards
What are the 3 components of the brainstem?
Midbrain, pons, medulla
Key structures on the midbrain…
Red nucleus, substansia nigra, tectum, crus cerebri, cerebral aqueduct
Key structures on the pons…
pontine nucleus (fibrous), fourth ventricle
Key structures on the medulla…
Inferior olivary nucleus, fourth ventricle, anterior and posterior median sulcus, decussation of the pyramidal tracts, pyramids, gracile and cuneate nucleus , rhomboid fossa
Lateral ventricles
Anterior Horn: That part in the Frontal Lobe.
Body: That part in the Parietal Lobe.
Inferior Horn: That part in the Temporal Lobe.
Posterior Horn: That part in the Occipital Lobe
Two main arteries that supply the brain
Vertebral and internal carotid arteries.
Why is the blood supply in a circle and what effect does this have?
The circle of Willis is there to have a redundancy effect so that if there is a block there is a back up.
What parts of the brain do the main cerebral arteries supply?
Anterior cerebral = medial areas of the hemispheres
Middle = lateral surfaces (parietal and half of temporal)
Posterior = occipital lobe some temporal
What is an aneurysm and what types are there?
An aneurysm is a swelling of the arteriole wall
Saccular and fusiform aneurysms are two main types, and are the most commonly caused by genetics, smoking, drinking, hypertension.
What parts of the body does the anterior cerebral artery supply the brain for?
Motor and sensory for lower limb
What parts of the body does the middle cerebral artery supply the brain for?
Primary motor and primary sensory for the entire body.
What is the most common artery to have an aneurysm?
Anterior communicating artery, mainly occur at points of weakness
Venous drainage cycle…
Deep cerebral veins that supply the midbrain and diencephalon drain into the great cerebral vein which is continuous with the straight sinus. Superficial veins drain straight into the superior and inferior sagittal and cavernous sinus. All sinuses converge into a confluence of sinuses and these all drain into the transverse –> sigmoid –> jugular vein
What is the contents of the cavernous sinus?
O TOM CAT
Oculomotor, trochlea, ophthalmic, maxillary, carotid artery, abducens all travel through the cavernous sinus either side of the pituitary gland.
