Lect 14 - CNS (Blood)

Question 1

What supplies blood to the brain? Where do they ascend?

Answer 1

Carotid Arteries

Common Carotids ascend the nect

Question 2

Carotid Arteries divide to form

Answer 2

Internal Carotids
External Carotids

Question 3

Carotid Sinus (Where? What does it contain?)

Answer 3

Base of the internal carotid artery

Contains baroreceptors and chemoreceptors

Question 4

Where are he baroreceptors and chemoreceptors (Heart)

Answer 4

In the Carotid Sinus

Question 5

External Carotids (Function)

Answer 5

Supplies blood to the neck and outside of the skull

Question 6

External Carotids (Branches)

Answer 6

Lingual Artery
Facial Artery
Occipital Artery
Superficial Temporal Artery

Question 7

Internal Carotids (Function)

Answer 7

Enters the skull to supply blood to the brain

Question 8

Internal Carotids (Branches)

Answer 8

Ophthalmic Artery (Eye)
Anterior Cerebral Artery (Frontal/Parietal)
Middle Cerebral Artery (Midbrain/Lateral Cerebrum Surface)

Question 9

Vertebral arteries fuse to form what?

Answer 9

Forms Basilar Artery

Question 10

Basilar Artery branches to form

Answer 10

Left and Right Posterior Cerebral Arteries

Question 11

Posterior Cerebral Arteries are connected by? Where are they connected to?

Answer 11

Posterior Communicating Arteries

Connects with internal carotid arteries

Question 12

Starting from the Vertebral Artery describe the branching of blood supply in the brain

Answer 12

Anterior Cerebral Artery x2 –> Anterior Communicating –> Middle Cerebral Arteries –> Posterior Communicating Arteries –> Posterior Cerebral –> Loops Again

Question 13

Function of Anterior and Posterior Communicating Arteries

Answer 13

Completes the circle of Willis by joining Cerebral Anterior/Posterior arteries

Acts as a safety mechanism by bringing blood to the brain from Carotids and Vertebral Arteries

Question 14

Anterior Communicating Arteries

Answer 14

Connects left and right anterior cerebral arteries

Question 15

Cerebral Arterial Circle

Answer 15

Ring like anastomosis between basilar and carotid arteries

Circle of Willis

Question 16

What three main arteries supply the cerebellum?

Where do they branch off from?

Answer 16

Superior Cerebellar
Anterior Inferior Cerebellar
Posterior Inferior Cerebellar

Branches off Basilar Artery to supply Pons, Medulla, Midbrain

Question 17

What forms the Cerebral Arterial Circle (Circle of WIllis)

Answer 17

Anterior Communicating Artery
Anterior Cerebral Artery
Posterior Communicating Artery
Posterior Cerebral Artery

Question 18

Backup Blood Supply for the Brain

Answer 18

Vertebral –> Basilar –> Posterior Cerebral
–> Posterior Communicating Arteries

Internal Carotid Arteries –> Anterior Cerebral / Middle Cerebral

Question 19

Anterior Cerebral Arteries vs Middle Cerebral Arteries

Answer 19

Anterior supplies Frontal/Parietal Lobe
Involved in Cerebral Arterial Circle

Middle supplies Midbrain and lateral surfaces of cerebrum

Question 20

Middle Cerebral Artery (What cortexes are being supplied)

Answer 20

Covers frontal, parietal, and temporal lobes
Mainly focuses on temporal lobe

Posterior Parietal Cortex
Auditory Cortex

Middle Region of the brain

Question 21

Middle Cerebral Artery (The cortices being supplied effect what?)

Answer 21

Supplies blood to the Motor and Somatosensory cortices that handle the Trunk (Body), Face, Upper Extremities (Arms)

Question 22

Anterior Cerebral Artery (What cortexes are being supplied)

Answer 22

Inferior to frontal lobe
The Medial surface of the frontal and parietal lobes (Deep within the brain)

Question 23

Anterior Cerebral Artery (The cortices being supplied effect what?)

Answer 23

Supplies blood to the Motor and Somatosensory cortices that handle the Lower Extremities (Legs)

Question 24

Posterior Cerebral Artery (What cortexes are being supplied)

Answer 24

Inferior and Medial of the Temporal Lobe
Hippocampus
Inferior and medial of the Occipital Lobe
Thalamus

Question 25

What is CPP

Answer 25

Cerebral Perfusion Pressure The pressure of the blood being delivered to the brain at the capillary level

Question 26

What is ICP

Answer 26

Intracranial Pressure Pressure inside the skull, caused by brain tissues and fluids

Question 27

How does ICF change?

Answer 27

Cranial Cavity has a fixed volume ICP is changed by changes in volumes of tissues/fluid

Question 28

How to calculate CPP

Answer 28

CPP = MAP - ICP Mean Arterial Pressure - Intracranial Pressure

Question 29

Small changes of ICP

Answer 29

Can be handled by displacing Cerebral Spinal fLuid into the spinal cord = Decreases ICP by a bit

Question 30

Larges changes of ICP

Answer 30

The skull must lose volume, however, there is a limit to how much it can lose as there is only a fixed volume of blood, brain, and CSF If change is too larged CPP is rendered inadequate and blood can not flow through brain

Question 31

How can a mass or obstruction in the cranium cause death

Answer 31

Causes an increase in intracranial pressure --> Decreased CPP --> Not enough blood flow in brain (Global Brain Ischemia)