Brainscape's Knowledge GenomeTM

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


See full index

Oxygen physiology > Ischemia > Flashcards

Ischemia Flashcards

1
Q

Roots

A

Isch - restriction Hema - blood

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

Definition of Ischemia

A

Definition: a decrease in effective blood flow that is incompatible with continuing organ function

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

Brain ischemia

A

2% of the total body weight in humans; it receives 15-20% of the body’s blood supply The brain uses 20% of available oxygen for normal function, making tight regulation of blood flow and oxygen delivery critical for survival

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

Normal blood flow (BF)

A

Human 55 ml/100g/min (Grey) Rat 150 ml/100g/min

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

Factors affecting BF

A

Systemic BP, autoregulation, mean arterial BP: 45-160 mmHg Intracranial pressure Effective perfusion pressure: difference between arterial and intracranial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Limit

A

Above and below this limit, autoregulation is lost and CBF becomes dependent on MAP in a linear fashion. When CPP falls below the lower limit of autoregulation, cerebral ischemia ensures.

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

Type of brain ischemia

A

Complete vs incomplete Reversible vs irreversible Focal vs global Hemorrhage vs nonhemorrhagic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Examples:

A

Hypotension Stroke Cardiac arrest Decapitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Focal vs global ischemia

A

Global ischemia occurs when cerebral blood flow is reduced throughout most or all of the brain Focal ischemia is represented by a reduction in blood flow to a very distinct, specific brain region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Focal ischemia

A

Stroke 3rd most common cause of death The most common cause of adult disability In US >700,000 strokes occur annually leading to 200,000 deaths 4 million stroke survivors, half of them with some degree of disabilit

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

Ischemic stroke

A

80%, blockage of a brain artery, e.g., middle cerebral artery (MCA) Cerebral thrombosis: a thrombus (clot) that develops at the clogged part of the vessel Cerebral embolism: a blood clot that forms at another location in the circulatory system Virchow (1821-1902): known for elucidating the mechanism of pulmonary thromboembolism, coining the terms embolism and thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hemorrhagic stroke

A

Hemorrhagic stroke 20%, bleeding Intracerebral hemorrhage (ICH) Blood is released into the brain parenchyma Subarachnoid hemorrhage (SAH) Blood is released into the subarachnoid space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Major arterial supply of brain

A

Internal carotid artery - middle cerebral artery Vertebral artery - basilar artery The circle of Willis (aka cerebral arterial circle and Willis Polygon) is a circulatory anastomosis that supplies blood to the brain and surrounding structures. Named after Thomas Willis (1621-1675), an English physician. Components: Anterior cerebral artery Anterior communicating artery Internal carotid artery Posterior cerebral artery Posterior communicating artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Treatment for stroke: Ischemic stroke

A

tPA, the gold standard The only FDA approved treatment is tissue plasminogen activator (tPA). tPA works by dissolving the clot and improving blood flow. If administered within three hours (and up to 4.5 hours) tPA may improve the chances of recovering from a stroke. Endovascular procedures To remove the large blood clot. The procedure should be done within six hours of acute stroke symptoms, and only after a patient receives tPA.

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

Treatment for stroke: Hemorrhagic stroke

A

Endovascular procedures Less invasive, involving the use of a catheter introduced through a major artery in the leg or arm, then guided to the aneurysm; it then deposits a mechanical agent, such as a coil, to prevent rupture Surgical treatment

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

Global ischemia

A

Irreversible Reversible: cardiac arrest/CPR, hypotension, increase in intracranial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cardiac arrest and resuscitation:

A

background and significance 6 month survival rate: <10%

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

Cardiac arrest vs heart attack

A

A cardiac arrest is when the heart stops beating, or goes into a rhythm that cannot circulate blood effectively. Patients usually lose a pulse, become unresponsive, and stop breathing. A heart attack specifically refers to a process where there is an obstruction in one of the coronary arteries (which supplies oxygen to the heart itself), often as a result of atherosclerosis. A heart attack can cause a cardiac arrest- sometime at the same time, or sometimes years later.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does cardiac arrest caused neurologic deficits?

A

Ischemia/reperfusion injury Ischemia Anoxia Increase excitability (excessive calcium and glutamate excretion) Mitochondrial and cellular death Cerebral edema BBB impairment Reperfusion injury Inflammatory response Free radical formation Continued cell damage, worsening the inflammatory response, which exacerbates cerebral edema

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

Therapeutic hypothermia

A

Therapeutic hypothermia (aka targeted temperature management) refers to deliberate reduction of the core body temperature, typically to a range of about 32° to 3°C (89.6° to 93.2°F) in patients who don’t regain consciousness after return of spontaneous circulation following a cardiac arrest. Hypothermia Counteracts neuroexcitation in brain cells by stabilizing calcium and glutamate release, reducing the degree of cell death Stabilizes the BBB and suppresses the inflammatory process, reducing cerebral edema Cerebral metabolism decreases 6 to 10% for every degree C that body temperature drops. As cerebral metabolism declines, the brain needs less oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Focal ischemia stroke models

A

MIddle cerebral artery occlusion (MCAO) First developed in 1980s Craniectomy Intraluminal suture MCAO (rats and mice) Reversible (temporal) Mimic: spontaneous thrombus dissolution (rare), or tissue plasminogen activator (tPA) is used to dissolve clot and restore circulation Permanent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Endpoints

A

Behavioral performance in motor or neurological disorder Infarct volume determination Infarction: a localized area of ischemic necrosis resulting from an interruption of either its arterial supply or venous drainage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Animal models of global ischemia

A

Two-vessel occlusion model of forebrain ischemia Transient bilateral common carotid artery (CCA) occlusion plus hypotension (50 mmHg) Four-vessel occlusion model of forebrain ischemia Transient bilateral common carotid artery (CCA) occlusion plus permanent vertebral artery occlusions Cardiac arrest and resuscitation* Endpoints Selective neuronal death Neurological recovery Survival*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Global ischemia

A

Irreversible Reversible: cardiac arrest/CPR, hypotension, increase in intracranial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Delayed selective neuronal death:

A

hippocampal CA1 region Image: hippocampal CA1 neurons four days after cardiac arrest and resuscitation in rat Non-arrested and ADO-treated similar vs untreated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Brain blood flow following cardiac arrest and resuscitation in rat

A

ADO 1h restored to levels similar to non-arrested vs untreated 1h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Differentiate the following conditions due to impairment of cerebral circulation

A

Gray out and whiteout: Loss of color vision Hypoxia Low blood pressure Positive G force Shock, loss of blood Blackout: Complete loss of vision Redout: Blood is driven to the head and causes reddening of the visual field and headache - retinal damage and hemorrhagic stroke Negative G force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Animal Models

A
29
Q

CA causes damage by

A
30
Q

Arterial Supply to Brain

A
31
Q

Ischemic Stroke

A
32
Q

PCAS

A
33
Q

Animal Models 2

A
34
Q

FCI models

A
35
Q

PCAS 2

A
36
Q

Virchow

A
37
Q

Ischemia

A
38
Q

ischemia models

A
39
Q

Reperfusion Brain Injury

A
40
Q

Hemmorhagic Stroke

A
41
Q

Factors affecting CBF

A
42
Q

Endpoints

A
43
Q

Ischemia Diagram

A
44
Q

Fig 1

A
45
Q

Autoregulation

A
46
Q

Study

A
47
Q

Ischemic Cascade Interference

A
48
Q

Focal vs Global

A
49
Q

CARS events

A
50
Q

Images

A
51
Q

Ischemic Cascade Full

A
52
Q

CA events

A
53
Q

Focal Ischemia

A
54
Q

BP and Temp

A
55
Q

HVR

A
56
Q

Study

A
57
Q

Global Ischemia Animal Models

A
58
Q

Images

A
59
Q

HVR

A
60
Q

Scheme 1

A
61
Q

MCAO Model

A
62
Q

MCAO Graph

A
63
Q

Hypoxia and Survival

A
64
Q

CC after CAR

A
65
Q

Delayed Selective Neuronal Death

A
66
Q

Infarction

A
67
Q

Photoreceptors

A
68
Q

BBF after CAR

A
69
Q

pH

A

Oxygen physiology (6 decks)

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