neuro objectives 6-8 - Sheet1

Question 1

What percentage of total cardiac output does the brain require despite making up only 2% of body mass?

Answer 1

15-20%

Question 2

Through which arteries does blood reach the brain?

Answer 2

Internal carotid arteries and vertebral arteries

Question 3

What percentage of the body’s oxygen and glucose does the brain use?

Answer 3

20% of oxygen and 25% of glucose

Question 4

What is the primary regulator of blood flow within the CNS?

Answer 4

Carbon dioxide (CO2), a potent vasodilator

Question 5

How does high CO2 (hypercapnia) affect cerebral blood flow?

Answer 5

High CO2 increases blood flow to the brain, raising intracranial pressure and potentially causing mental changes.

Question 6

What happens when O2 levels drop below 60 mmHg in the brain?

Answer 6

Blood vessels vasodilate, increasing intracranial pressure as more oxygen is delivered.

Question 7

How does acidosis (increased hydrogen ion concentration) affect cerebral blood flow?

Answer 7

Acidosis causes vasodilation, increasing cerebral blood flow.

Question 8

Why is the brain extremely sensitive to hypoxia?

Answer 8

Hypoxic damage to the brain becomes irreversible after only a few minutes.

Question 9

Through which veins does blood leave the brain?

Answer 9

Cerebral veins -> venous plexuses and dural sinuses -> internal jugular veins

Question 10

What happens when blood backs up in the brain?

Answer 10

Increased intracranial pressure

Question 11

What is intracranial pressure (ICP)?

Answer 11

Hydrostatic force measured in the cerebrospinal fluid (CSF) compartment in the brain.

Question 12

What is the normal ICP range?

Answer 12

0-15 mmHg

Question 13

What ICP level and duration is considered a medical emergency?

Answer 13

ICP of 20 mmHg for more than 5 minutes.

Question 14

How is ICP measured?

Answer 14

Through a lumbar puncture (LP/spinal tap) or ventriculostomy.

Question 15

What are the three components in the skull that affect ICP?

Answer 15

Brain tissue, blood, and CSF.

Question 16

What factors influence increased ICP?

Answer 16

Cerebral edema, hypercapnia, hypoxemia, increased metabolic demands, increased intra-abdominal and intra-thoracic pressure, venous outflow obstruction, and excessive CSF production.

Question 17

What are classic signs of elevated ICP?

Answer 17

Projectile vomiting, pounding headache, blurred vision, confusion, decline in LOC, pupillary changes, unrelieved crying in babies, bulging fontanels, speech changes.

Question 18

What formula determines Cerebral Perfusion Pressure (CPP)?

Answer 18

CPP = MAP - ICP (where MAP is Mean Arterial Pressure).

Question 19

What is the normal MAP range?

Answer 19

60-100 mmHg

Question 20

At what CPP does cerebral ischemia occur?

Answer 20

CPP < 30 mmHg is incompatible with life.

Question 21

What is cerebral edema?

Answer 21

Net accumulation of water in the brain tissue due to trauma, infection, hemorrhage, tumor, ischemia, infarct, or hypoxia.

Question 22

What harmful effects can cerebral edema cause?

Answer 22

Distortion of blood vessels, displacement of brain tissues, and herniation.

Question 23

What is hydrocephalus?

Answer 23

A condition characterized by excess CSF within the cranial vault or subarachnoid space, leading to increased ICP.

Question 24

What are signs of hydrocephalus in children?

Answer 24

Megamind (enlarged head), bulging fontanelles.

Question 25

What are common symptoms of herniation syndromes?

Answer 25

Poor concentration, drowsiness leading to loss of consciousness, pupillary changes, Cheyne-Stokes respirations, and hemodynamic instability.

Question 26

What is the physiological benefit of the Circle of Willis?

Answer 26

It allows compensatory blood flow to different brain structures if one artery is occluded.

Question 27

What is the mechanism behind cerebral edema?

Answer 27

Increased capillary permeability and/or damage to brain cells, leading to fluid accumulation.

Question 28

What is the risk associated with hypercapnia in herniation syndromes?

Answer 28

Hypercapnia causes vasodilation, which increases ICP.