Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bioscience II > Neurological System IV > Flashcards

Neurological System IV Flashcards

1
Q

What percentage of total blood volume circulates to the brain?

A
  • 18%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What percentage of total body oxygen consumption is the brain responsible for?

A
  • 20%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What can happen if the constant flow of oxygen to the brain is interrupted?

A
  • Loss of consciousness

- Irreparable damage (within 5 minutes of anoxia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What pathology occurs secondary to vascular compromise or hemorrhage in the CNS?

A
  • Cerebrovascular disease

- 3rd-leading cause of death in the United States

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cerebral blood flow accounts for what percentage of cardiac output?

A
  • 15-20%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the extracerebral vessels?

A
  • Right carotid artery- Right subclavian

- Left carotid artery- aortic arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the intracranial cerebral vessels?

A
  • Internal carotid artery- anterior cerebral AND middle cerebral arteries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

***What pair of arteries and its’ branches supply the occipital lobe and brain stem?

A
  • Vertebral arteries- basilar artery- posterior cerebral artery
  • Ultimately gives rise to circle of Willis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  • In neuroanatomy, what is the confluence of vessels that give rise to all major cerebral arteries? A major component is that it provides collateral flow to the brain.
A
  • Circle of Willis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

*** The Circle of Willis is fed by what arteries?

A
  • Internal carotid arteries

- Basilar artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What arrangement of arteries completes the Circle of Willis?

A
  • Posterior communicating artery on each side of the circle
  • An anterior communicating artery
  • Each major artery supplies a certain territory
  • This means that sudden occlusion affects its’ respective territory immediately, sometimes irreversibly
    • This may happen with a lesion or with direct occlusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the venous drainage of the brain and coverings include?

A
  • Veins of the brain itself
  • Dural venous sinuses
  • Dura’s meningeal veins
  • Dipoloic veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the eventual cerebral venous drainage of the brain?

A
  • The internal jugular vein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T/F- Cerebral veins contain valves.

A
  • False

- The cerebral veins contain no valves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

***What is the formula that derives Cerebral Perfusion Pressure (CPP)?

A
  • CPP= MAP-ICP

- Normal CPP= 80-100 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

***What is CPP primarily dependent on and what is a consequence of this?

A
  • CPP is primarily dependent on MAP (pressure dependent)
  • A consequence of this is that moderate to severe increases in ICP can significantly compromise CPP and CBF, even if MAP is normal
  • ## ICP is normally below 10
17
Q

What is a diagnostic change that is evident with decreased CPP?

A
  • Changing EEG patterns
18
Q

***Irreversible damage to the brain can occur is there is a sustained CPP below what value?

A
  • 25 mmHg

- CPP less than 50 mmHg will show EEG changes

19
Q

***At what CPP range is cerebral blood flow (CBF) nearly constant?

A
  • 60-160 mmHg

- Beyond these limits, cerebral blood flow becomes pressure dependent

20
Q

How does cerebral vasculature react to a decrease in CPP?

A
  • Cerebral vasodilation
21
Q

How does cerebral vasculature react to an increase in CPP?

A
  • Cerebral vasoconstriction
22
Q

***What effect does chronic arterial hypertension have on the cerebral autoregulation curve?

A
  • Right shift
  • Cerebral autoregulation curve is an “S-curve” that flattens and shows unchanged cerebral blood flow between CPP ranges of 60-160
  • Long-term antihypertensive therapy is of utmost importance.
23
Q

Above what CPP value si the Blood-Brain Barrier compromised and what pathologies can this cause?

A
  • 150-160
  • Cerebral edema
  • Hemorrhage
24
Q

***What are some extrinsic factors that autoregulation?

A
  • Respiratory gas tensions
    - CBF directly proportionate to PaCO2
    - If C02 increases, cerebral blood flow increases (cerebral vasodilation)
    - If C02 decreases, cerebral blood decreases (cerebral vasoconstriction)
  • Temperature
    • CBF changes 5-7% per 1 degree C change in temperature
  • Blood viscosity
    • HCT-30-34 ideal for optimal CBF
  • Autonomic influences
25
Q

***The blood-brain barrier is composed of what 3 barriers?

A
  • Blood and CSF barrier
  • Epithelial barrier
  • Arachnoid barrier
26
Q

In relation to the Blood-Brain Barrier, how are cerebral blood vessels unique?

A
  • The junctions between vascular endothelial cells are nearly fused.
    • The paucity of pores is responsible for the blood-brain barrier
27
Q

What is the role of the Blood-Brain Barrier?

A
  • Effectively isolates the brain and spinal cord extracellular compartment from the intravascular compartment
  • Allows passage of lipid-soluble substances but restricts the movement of those that are ionized or have large molecular weights
28
Q

What midline brain structures receive neurosecretory products from the blood and therefore lack a blood-brain barrier?

A
  • Hypothalamus

- Pituitary gland

29
Q

What are the factors that influence the movement of substances across the Blood-Brain Barrier?

A
  • Size (Less than 200-400 Daltons)
  • Charge (Whether + or -)
  • Lipid solubility
  • Protein binding
30
Q

What important gas mixture freely enters the brain?

A
  • CO2
31
Q

Movement of a given substance across the Blood-Brain Barrier is governed simultaneously by:

A
  • C02
  • 02
  • Lipid-solubility
    • Lipid-soluble substances freely enter the brain
  • Most ions, proteins, and substances penetrate poorly
  • CNS endothelial cells lack transport mechanisms
    • i.e. sodium-potassium pump, receptor channels, etc.
32
Q

What do rapid changes in plasma- electrolyte concentration produce in the brain?

A
  • The transient osmotic gradient between the plasma and the brain
  • Acute hypertonicity draws fluid out of the brain
33
Q

How does acute hypertonicity of plasma affect the movement of water in the brain?

A
  • The net movement of water out of the brain

- Water will follow the concentration gradient

34
Q

How does acute hypotonicity of plasma affect the movement of water in the brain?

A
  • The net movement of water into the brain

- Water will follow the concentration gradient

35
Q

How should marked serum sodium or glucose concentration be treated?

A
  • Corrected slowly
36
Q

What are some factors that may be disrupt the Blood-brain barrier?

A
  • Severe HTN (Normal CPP for CBF autoregulation: 60-160)
  • Tumors
  • Trauma
  • Strokes
  • Infections
  • Marked hypercapnia, (Increase C02, Increased CBF/vasodilation) (Decreased CO2, decreased CBF/vasoconstriction)
  • Hypoxia
  • Sustained seizure activity
37
Q

*** How does hypothermia affect the Blood-Brain Barrier?

A
  • Hypothermia stabilizes the Blood-Brain Barrier.

Bioscience II (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions