1.5 The Blood Supply to the Nervous System

Question 1

What is the Circle of Willis?

Answer 1

This is a Circle of anastomosing Arteries which supplies blood to the Brain

Question 2

What are the 3 Arteries which Supply blood to the Circle of Willis?

Answer 2

1. The Left Internal Carotid Artery
2. The Right Internal Carotid Artery
3. The Basilar Artery

Question 3

Where do the Internal Carotid Arteries arise from?

Answer 3

The Common Carotid Arteries

Question 4

Where does the Basilar Artery arise from?

Answer 4

The anastomosing of the 2 (Left and Right) Vertebral Arteries

Question 5

Where do the Vertebral Arteries anastomose to form the Basilar Artery?

Answer 5

At the Pontomedullary Junction (Over the Brainstem) and these then run the length of the Pons

Question 6

Where do the Vertebral Arteries arise from?

Answer 6

The Subclavian Arteries

Question 7

Which Arteries completes the posterior Circle of Willis by linking the Internal Carotid Arteries and the Basilar Artery?

Answer 7

The Posterior Communicating Arteries

Question 8

Which Arteries completes the anterior Circle of Willis by linking the Anterior Cerebral Arteries?

Answer 8

The Anterior Communicating Artery

Question 9

What Artery, supplying part of the Head, leaves the Internal Carotid Artery before it reaches the Circle of Willis?

Answer 9

The Ophthalmic Artery

Question 10

What Artery, supplying the Spine, leaves the Vertebral Arteries before they anastomose to form the Basilar Artery

Answer 10

The Posterior Spinal Artery

Question 11

What Artery, supplying part of the Brain, leaves the Vertebral Arteries before they anastomose to form the Basilar Artery

Answer 11

The Posterior Inferior Cerebellar Artery

Question 12

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)

Answer 12

1. The Anterior Inferior Cerebellar Artery
2. The Labyrinthine Artery
3. The Superior Cerebellar Artery

Question 13

What are the 3 pairs of Cerebral Arteries which arise from the Circle of Willis?

Answer 13

1. The Anterior Cerebral Artery
2. The Middle Cerebral Artery
3. The Posterior Cerebral Artery

Question 14

What area does the Anterior Cerebral Artery supply?

Answer 14

The Median Surface of the Cerebrum, and the superior part of the Superficial Surface of the Cerebrum

Question 15

What area does the Middle Cerebral Artery supply?

Answer 15

The Anterior Superficial Surface of the Cerebrum, except for the superior part

Question 16

What area does the Posterior Cerebral Artery supply?

Answer 16

The Posterior Superficial Surface of the Cerebrum (The Occipital Lobe, Midbrain, Hypothalamus, and the Pituitary

Question 17

What arteries supplies the Primary Motor Cortex?

Answer 17

1. Mainly the Middle Cerebral Artery

2. The Anterior Cerebral Artery, for the parts which are at the superior part of the Brain

Question 18

What artery supplies the Primary Sensory Cortex?

Answer 18

1. Mainly the Middle Cerebral Artery

2. The Anterior Cerebral Artery, for the parts which are at the superior part of the Brain

Question 19

What artery supplies the Primary Visual Cortex?

Answer 19

The Posterior Cerebral Artery

Question 20

What artery supplies the Primary Auditory Cortex?

Answer 20

The Middle Cerebral Artery

Question 21

What artery supplies the Area for Olfaction?

Answer 21

The Anterior Cerebral Artery

Question 22

What do the Vertebro-Basilar System supply?

Answer 22

1. The Cerebellum
2. The Brainstem
3. The Inner Ear

Question 23

What Cerebral Artery run immediately superior to the Superior Cerebellar Artery

Answer 23

The Posterior Cerebral Artery

Question 24

What Cranial Nerve emerges from just above the Superior Cerebellar Artery?

Answer 24

The Occulomotor Nerve (Cranial Nerve III)

Question 25

What is the Clinical Significance of the Proximity of the Occulomotor Nerve (Cranial Nerve III) to the Superior Cerebellar Artery?

Answer 25

Aneurysms are common and can cause Occulomotor Nerve (Cranial Nerve III) Palsy

Question 26

What are the 3 things which help control blood supply to the Brain?

Answer 26

1. The Carotid Sinus
2. The Carotid Body
3. The Sympathetic Motor Nerves

Question 27

What is the Carotid Sinus? And where can it be found?

Answer 27

It is a dilatation of the Terminal Part of the Common Carotid Artery

Question 28

What is the Carotid Body? And where can it be found?

Answer 28

It is an area on the Posterior Wall of the Terminal Part of the Common Carotid Artery

Question 29

What are the Sympathetic Motor Nerves? And where can they be found?

Answer 29

These arise from the Superior Cervical Ganglion to form a Plexus around the Internal Carotid Artery both within and outwith the Cranium.

Question 30

What is the function of the Carotid Sinus?

Answer 30

It is a Pressure Receptor which monitors blood flow to the head

Question 31

What Cranial Nerves do the Sensory Nerves from the Carotid Sinus run through?

Answer 31

1. The Glossopharyngeal Nerve (Cranial Nerve IX)

2. The Vagus Nerve (Cranial Nerve X)

Question 32

What is the function of the Carotid Body?

Answer 32

It contains Chemoreceptors which are sensitive to Anoxia (Low Oxygen Levels)

Question 33

What do the Sensory Nerves from the Carotid Body run in?

Answer 33

The Glossopharyngeal Nerve (Cranial Nerve IX)

Question 34

What will be stimulated on the detection of Anoxia (Low Oxygen Levels)?

Answer 34

1. Increased Heart Rate
2. Increased Respiratory Rate
3. Increased Blood Pressure

Question 35

Branches of which Arteries fuse to form the Anterior Spinal Artery?

Answer 35

Vertebral Arteries

Question 36

Which Arteries are the Posterior Spinal Arteries branches of?

Answer 36

The Vertebral Arteries, fusing adjacent to the Medulla and then running down the Posterior Spine