1.5 The Blood Supply to the Nervous System Flashcards
What is the Circle of Willis?
This is a Circle of anastomosing Arteries which supplies blood to the Brain
What are the 3 Arteries which Supply blood to the Circle of Willis?
- The Left Internal Carotid Artery
- The Right Internal Carotid Artery
- The Basilar Artery
Where do the Internal Carotid Arteries arise from?
The Common Carotid Arteries
Where does the Basilar Artery arise from?
The anastomosing of the 2 (Left and Right) Vertebral Arteries
Where do the Vertebral Arteries anastomose to form the Basilar Artery?
At the Pontomedullary Junction (Over the Brainstem) and these then run the length of the Pons
Where do the Vertebral Arteries arise from?
The Subclavian Arteries
Which Arteries completes the posterior Circle of Willis by linking the Internal Carotid Arteries and the Basilar Artery?
The Posterior Communicating Arteries
Which Arteries completes the anterior Circle of Willis by linking the Anterior Cerebral Arteries?
The Anterior Communicating Artery
What Artery, supplying part of the Head, leaves the Internal Carotid Artery before it reaches the Circle of Willis?
The Ophthalmic Artery
What Artery, supplying the Spine, leaves the Vertebral Arteries before they anastomose to form the Basilar Artery
The Posterior Spinal Artery
What Artery, supplying part of the Brain, leaves the Vertebral Arteries before they anastomose to form the Basilar Artery
The Posterior Inferior Cerebellar Artery
Which 3 Arteries, supplying part of the the Brain, leaves the Basilar Artery before it reaches the Circle of Willis?
(Distal to Proximal in relation to the Circle of Willis)
- The Anterior Inferior Cerebellar Artery
- The Layrinthine Artery
- The Superior Cerebellar Artery
What are the 3 pairs of Cerebral Arteries which arise from the Circle of Willis?
- The Anterior Cerebral Artery
- The Middle Cerebral Artery
- The Posterior Cerebral Artery
What area does the Anterior Cerebral Artery supply?
The Median Surface of the Cerebrum, and the superior part of the Superficial Surface of the Cerebrum
What area does the Middle Cerebral Artery supply?
The Anterior Superficial Surface of the Cerebrum, except for the superior part
What area does the Posterior Cerebral Artery supply?
The Posterior Superficial Surface of the Cerebrum (The Occipital Lobe, Midbrain, Hypothalamus, and the Pituitary
What arteries supplies the Primary Motor Cortex?
- Mainly the Middle Cerebral Artery
2. The Anterior Cerebral Artery, for the parts which are at the superior part of the Brain
What artery supplies the Primary Sensory Cortex?
- Mainly the Middle Cerebral Artery
2. The Anterior Cerebral Artery, for the parts which are at the superior part of the Brain
What artery supplies the Primary Visual Cortex?
The Posterior Cerebral Artery
What artery supplies the Primary Auditory Cortex?
The Middle Cerebral Artery
What artery supplies the Area for Olfaction?
The Anterior Cerebral Artery
What do the Vertebro-Basilar System supply?
- The Cerebellum
- The Brainstem
- The Inner Ear
What Cerebral Artery run immediately superior to the Superior Cerebellar Artery
The Posterior Cerebral Artery
What Cranial Nerve emerges from just above the Superior Cerebellar Artery?
The Occulomotor Nerve (Cranial Nerve III)
What is the Clinical Significance of the Proximity of the Occulomotor Nerve (Cranial Nerve III) to the Superior Cerebellar Artery?
Aneurysms are common and can cause Occulomotor Nerve (Cranial Nerve III) Palsy
What are the 3 things which help control blood supply to the Brain?
- The Carotid Sinus
- The Carotid Body
- The Sympathetic Motor Nerves
What is the Carotid Sinus? And where can it be found?
It is a dilatation of the Terminal Part of the Common Carotid Artery
What is the Carotid Body? And where can it be found?
It is an area on the Posterior Wall of the Terminal Part of the Common Carotid Artery
What are the Sympathetic Motor Nerves? And where can they be found?
These arise from the Superior Cervical Ganglion to form a Plexus around the Internal Carotid Artery both within and outwith the Cranium.
What is the function of the Carotid Sinus?
It is a Pressure Receptor which monitors blood flow to the head
What do the Sensory Nerves from the Carotid Sinus run in?
- The Glossopharyngeal Nerve (Cranial Nerve IX)
2. The Vagus Nerve (Cranial Nerve X)
What is the function of the Carotid Body?
It contains Chemoreceptors which are sensitive to Anoxia (Low Oxygen Levels)
What do the Sensory Nerves from the Carotid Body run in?
The Glossopharyngeal Nerve (Cranial Nerve IX)
What will be stimulated on the detection of Anoxia (Low Oxygen Levels)?
- Increased Heart Rate
- Increased Respiratory Rate
- Increased Blood Pressure
Branches of which Arteries fuse to form the Anterior Spinal Artery?
Vertebral Arteries
Which Arteries are the Posterior Spinal Arteries branches of?
The Vertebral Arteries, fusing adjacent to the Medulla and then running down the Posterior Spine
