Chapter 7 Flashcards
Nerve Cells depend on…
Nerve cells depend on an uninterrupted supply of oxygenated blood
How much blood on average is pumped to the brain per minute?
An average of 750 mL of blood is pumped to the brain per minute
How long can vascular interruption occur before damage is irreversible?
Vascular interruption for 4-6 minutes results in irreversible brain damage
What two arterial systems provide blood to the brain?
Carotid (Anterior) Vertebral basilar (Posterior)
These two arterial systems join at the circle of Willis at the base of the brain
What arteries are included in the anterior blood supply network?
internal carotid arteries, Anterior cerebral artery (ACA), Middle Cerebral Artery (MCA)
What arteries are included in the posterior blood supply network?
Basilar artery, Vertebral arteries
Vertebral Basilar System
Two vertebral arteries
Merge to form basilar artery
Vertebral arteries gives rise to three major arteries
What three major arteries rise from the vertebral arteries?
Posterior spinal
Anterior spinal
Posterior inferior cerebellar
remaining branches serve the spinal cord.
What does occlusion of the anterior spinal artery result in?
Occlusion of the anterior spinal artery results in alternating hemiplegia which is associated with ipsilateral paralysis of the face and tongue as well as contralateral paralysis of the extremities
Which vertebral artery supplies a large part of the cerebellum?
Posterior cerebellar supplies a large part of the cerebellum
Immediately after its formation the basilar artery gives rise to
Anterior cerebellar
Inferior cerebellar
The basilar artery serves…
Serves anterior and lateral surfaces of the cerebellum
Anterior inferior cerebellar artery branches into
Branches into the labyrinthine (internal auditory) artery
Anterior inferior cerebellar artery delivers…
Delivers blood to the inner ear
Damage to the Anterior inferior cerebellar results in….
Damage results in ipsilateral deafness Vestibular dysfunctions (vertigo) and the tendency to fall on the affected side
What is immediately prior to the circle of willis?
Basilar Artery (joining the posterior (and superior?) cerebral artery)
What does the basilar artery serve?
Serves the cerebellum
Damage to the basilar artery causes what?
Damage causes motor incoordination, impaired balance and dysarthria
What causes alternating hemiplegia? Give examples.
Occlusion of the anterior spinal artery branches
Ipsilateral paralysis of the face and tongue
Contralateral paralysis of the extremities
What connects the two systems?
Circle of Willis
What are the Cortical arteries?
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Anterior cerebral artery location
Connects both anterior cerebral arteries, within and along the floor of the cerebral vault. If you follow the artery it follows along the genu of the corpus collosum.
Anterior cerebral artery function
Anterior communicating artery: Supplies the surfaces of the prefrontal and the frontal lobe, and some of the parietal lobe.
Anterior cerebral artery clinical coorelates
Sensory loss, Paralysis in the legs, feet, and toes, Prefrontal lobe symptoms including disorders of thinking, reasoning, self monitoring, memory and planning, Impaired judgment ,Reduced concentration, Impaired executive functioning, Acquired sociopathic behavior
Middle cerebral artery structure
Direct continuation of the internal carotid
Divides into temporal, frontal, and parietal branches.
Middle cerebral artery function
Supplies blood to the entire lateral surface of the brain, Speech, language, sensory motor, motor cortex, broca’s area, Wernicke’s area.
Also serves some of the basal ganglia and the thalamus.
Middle cerebral artery clinical coorelates
Contralateral hemiplegia Tactile agnosia Discriminative touch Reduced pain an temperature Aphasia Homonymous heminaposia Reading and writing deficits
Posterior cerebral artery
Bifurcation of the basilar artery
Supplies blood to the temporal lobe, occipital lobe, primary visual cortex
Also called the posterior communicating artery
Posterior cerebral artery clinical coorelates
Homonymous hemianopsia
Total blindness
Visual agnosia
Memory impairments
Central arteries
anteromedial, Medial striate Anterior choroidal Posterior choroidal Posteromedial posterolateral
Vascular pathology
Cerebrovascular accidents (CVA, Stroke)
Occlusive vascular
(Thrombosis, Embolism)
Hemorrhagic
(Aneurysm,
Arteriovenous malformations)
What frequently causes neurological deficits and (adult) disabilities?
Vascular pathology of the brain are the most frequent causes of neurological deficits and adult disabilities . Ranked as the third most common cause of death after cancer an heart disease
thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system.
embolism
An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule, a bubble of air or other gas (gas embolism), or foreign material. An embolism can cause partial or total blockage of blood flow in the affected vessel.
TIA
A transient ischemic attack (TIA) is a transient episode of neurologic dysfunction caused by ischemia (loss of blood flow) – either focal brain, spinal cord, or retinal – without acute infarction (tissue death). TIAs have the same underlying cause as strokes: a disruption of cerebral blood flow (CBF), and are often referred to as mini-strokes
CVA
Cerebrovascular accident (CVA), cerebrovascular insult (CVI), brain attack; a stroke
hemorrhage
A brain hemorrhage is a type of stroke. It’s caused by an artery in the brain bursting and causing localized bleeding in the surrounding tissues. This bleeding kills brain cells.
The Greek root for blood is hemo. Hemorrhage literally means “blood bursting forth.” Brain hemorrhages are also called cerebral hemorrhages, intracranial hemorrhages, or intracerebral hemorrhages. They account for about 13% of strokes.
Risk factors for embolism
Risk factors- hypertension!!! Heart disease, diabetes, high cholesterol, smoking, obesity, eating habits, physical inactivity, - can be treated with blood thinners
aneurysm
An aneurysm is a localized, blood-filled balloon-like bulge in the wall of a blood vessel.
Types of aneurysm
Aneurysms can also be classified by their macroscopic shape and size, and are described as either saccular or fusiform.
Saccular aneurysms are spherical in shape and involve only a portion of the vessel wall;
Fusiform aneurysms ("spindle-shaped" aneurysms) are variable in both their diameter and length;arteriovenous malformation
Normally, arteries carry blood containing oxygen from the heart to the brain, and veins carry blood with less oxygen away from the brain and back to the heart. When an arteriovenous malformation (AVM) occurs, a tangle of blood vessels in the brain or on its surface bypasses normal brain tissue and directly diverts blood from the arteries to the veins.
