Cerebral Blood Flow and TIA Quiz
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Questions and Answers

Which of the following is the minimal cerebral metabolic rate of Oâ‚‚ (CMRO2) required for brain function?

  • 55 ml/kg/min
  • 33 ml/kg/min (correct)
  • 22 ml/kg/min
  • 40-55%

What happens when the energy level falls below 22 ml/kg/min?

  • Functional problems
  • Normal electrical activity
  • Dizziness, concentration & memory problems
  • Structural & cell death (correct)

What percentage of cerebral blood flow (BF) is required to maintain the neurons in the brain?

  • 60%
  • 40% (correct)
  • 22%
  • 33%

What is the approximate blood flow (BF) to the brain?

<p>750 mL (C)</p> Signup and view all the answers

Which type of stroke is typically caused by atherosclerosis or other pathological causes?

<p>Thrombosis (C)</p> Signup and view all the answers

What is the main cause of a transient ischemic attack (TIA)?

<p>Atherosclerosis (A)</p> Signup and view all the answers

What is the current preferred test for patients with a suspected TIA?

<p>MRI (A)</p> Signup and view all the answers

What is the main feature of intracerebral hemorrhage?

<p>Blood is released into the brain matter (D)</p> Signup and view all the answers

Which of the following is true about the demand for blood flow in the brain at different heart rates?

<p>At 120-140 HR, the brain requires above 100 ml/kg/min of blood (A)</p> Signup and view all the answers

What is the main source of energy for the brain?

<p>Glucose (D)</p> Signup and view all the answers

Why can't fatty acids be used by the brain?

<p>Fatty acids cannot cross the blood-brain barrier (C)</p> Signup and view all the answers

Why does the brain need a lot of ATP?

<p>Both neurons and astrocytes require ATP for their respective functions (A)</p> Signup and view all the answers

Which of the following is a characteristic of penetrating arterioles in the brain?

<p>They control blood flow to discrete regions of the cortex (C)</p> Signup and view all the answers

What is the aim of innervation from the PNS to pial arteries?

<p>To decrease vessel tone (A)</p> Signup and view all the answers

What is the relationship between cerebral perfusion pressure (CPP), mean arterial pressure (MAP), and intracranial pressure (ICP)?

<p>CPP = MAP - ICP (D)</p> Signup and view all the answers

Which of the following mechanisms is NOT proposed for autoregulation of cerebral blood flow?

<p>Endothelial (C)</p> Signup and view all the answers

Which neurotransmitter acts on N-methyl-D-aspartate receptors (NMDAR) to increase intracellular calcium levels in neurons?

<p>Glutamate (A)</p> Signup and view all the answers

What is the main role of neuronal NO synthase (nNOS) in the regulation of cortical microvessels?

<p>To dilate vessels by generating cGMP (C)</p> Signup and view all the answers

Which of the following is NOT a vasoactive mediator released from pyramidal cells and GABA interneurons?

<p>Prostacyclin (PGI2) (C)</p> Signup and view all the answers

What happens to cerebral blood flow (CBF) during severe hypocapnia?

<p>CBF decreases due to vasoconstriction (D)</p> Signup and view all the answers

Which enzyme metabolizes heme in phagocytes?

<p>Heme oxygenase (HO-1) (D)</p> Signup and view all the answers

What is the function of iron-binding proteins in phagocytes?

<p>To prevent oxidative cell damage (C)</p> Signup and view all the answers

Which transcription factor is activated by ICH and perpetuates inflammation and oxidative stress?

<p>NF-B (B)</p> Signup and view all the answers

Which transcription factor inhibits NF-B and induces antioxidative defense components?

<p>PPAR (D)</p> Signup and view all the answers

Which transcription factor acts as an effective regulator of oxidative stress and blood detoxification components?

<p>Nrf2 (A)</p> Signup and view all the answers

What is the role of PPAR in hematoma cleanup?

<p>Stimulates phagocytosis mediated hematoma cleanup (A)</p> Signup and view all the answers

Which of the following is true about the autoregulation of cerebral blood flow (CBF)?

<p>In cerebral autoregulatory failure, the curve shifts to the left. (A)</p> Signup and view all the answers

What happens when the intracranial pressure (ICP) increases?

<p>Herniation of the brain stem may occur. (C)</p> Signup and view all the answers

What is the role of feedforward control in regulating cerebral blood flow (CBF)?

<p>It occurs before changes in blood levels of oxygen, carbon dioxide, or other metabolites. (C)</p> Signup and view all the answers

What is the main disadvantage of feedback control of cerebral blood flow (CBF)?

<p>It can lead to blackouts in imminent danger. (D)</p> Signup and view all the answers

Which of the following is the approximate cerebral metabolic rate of Oâ‚‚ (CMRO2) required for brain function?

<p>33 ml/kg/min (D)</p> Signup and view all the answers

What happens when the energy level falls below 22 ml/kg/min?

<p>Stroke (B)</p> Signup and view all the answers

What is the approximate blood flow (BF) to the brain?

<p>750 mL to 1L (B)</p> Signup and view all the answers

What is the approximate content of Oâ‚‚ in blood that is absorbed by the brain?

<p>40-50% (B)</p> Signup and view all the answers

Which of the following vasoactive mediators is released from pyramidal cells and GABA interneurons?

<p>Prostaglandin E2 (PGE2) (D)</p> Signup and view all the answers

What is the effect of severe hypercapnia on the autoregulation range of cerebral resistance vessels?

<p>Decreased autoregulation range (D)</p> Signup and view all the answers

What is the effect of severe hypocapnia on the caliber of maximally constricted cerebral resistance vessels?

<p>Smaller than normocapnia (C)</p> Signup and view all the answers

What is the effect of severe hypocapnia on the autoregulation range of cerebral resistance vessels?

<p>Increased autoregulation range (A)</p> Signup and view all the answers

Which of the following best describes the relationship between heart rate (HR) and the demand for blood flow in the brain?

<p>As HR increases, the demand for blood flow in the brain increases. (A)</p> Signup and view all the answers

What is the main reason why fatty acids cannot be used by the brain as an energy source?

<p>Fatty acids cannot cross the blood-brain barrier. (B)</p> Signup and view all the answers

What is the main role of astrocytes in the regulation of blood flow in the brain?

<p>Astrocytes pump sodium outside the astrocytes. (C)</p> Signup and view all the answers

Which of the following best describes the regulation of blood flow in the brain?

<p>Regulation of blood flow in the brain is primarily feedforward-based. (C)</p> Signup and view all the answers

Which of the following is NOT a proposed mechanism for autoregulation of cerebral blood flow (CBF)?

<p>Endothelial (A)</p> Signup and view all the answers

What is the relationship between cerebral perfusion pressure (CPP), mean arterial pressure (MAP), and intracranial pressure (ICP)?

<p>CPP = MAP - ICP (C)</p> Signup and view all the answers

What is the effect of sympathetic nervous system (SNS) stimulation on cerebral blood flow (CBF)?

<p>SNS stimulation constricts pial arterioles, leading to decreased CBF (C)</p> Signup and view all the answers

What happens to the autoregulation of cerebral blood flow (CBF) in patients with chronic hypertension (CAH)?

<p>The upper and lower limits of autoregulation are shifted to higher levels (A)</p> Signup and view all the answers

Which of the following is NOT a cause of a transient ischemic attack (TIA)?

<p>Arteritis (B)</p> Signup and view all the answers

What is the main difference between thrombotic and embolic strokes?

<p>Thrombotic strokes are caused by a partially occluded vessel while embolic strokes are caused by an artery-to-artery stroke (A)</p> Signup and view all the answers

What is the main feature of intracerebral hemorrhage?

<p>Toxicity to cells caused by heme and iron (D)</p> Signup and view all the answers

What is the role of hemopexin in the body?

<p>To bind to heme and protect the body from toxicity (C)</p> Signup and view all the answers

Which of the following is NOT a vasoactive mediator released from astrocytes in the brain?

<p>NO (C)</p> Signup and view all the answers

Which of the following is a characteristic of the autoregulation of cerebral blood flow (CBF)?

<p>It is regionally heterogeneous (A)</p> Signup and view all the answers

What happens to cerebral blood flow (CBF) during severe hypercapnia?

<p>It increases (A)</p> Signup and view all the answers

What is the relationship between cerebral perfusion pressure (CPP), mean arterial pressure (MAP), and intracranial pressure (ICP)?

<p>CPP = MAP - ICP (C)</p> Signup and view all the answers

Which enzyme is responsible for metabolizing heme in phagocytes?

<p>Heme oxygenase (HO-1) (C)</p> Signup and view all the answers

What is the function of iron-binding proteins in phagocytes?

<p>To sequester iron and prevent oxidative cell damage (B)</p> Signup and view all the answers

Which transcription factor acts as an effective regulator of oxidative stress and blood detoxification components?

<p>Nrf2 (C)</p> Signup and view all the answers

Which transcription factor inhibits NF-B and induces antioxidative defense components?

<p>PPAR (A)</p> Signup and view all the answers

What is the role of PPAR in hematoma cleanup?

<p>Stimulates phagocytosis mediated hematoma cleanup (B)</p> Signup and view all the answers

What happens when intracranial pressure (ICP) increases?

<p>Activates transcription factor NFB, perpetuating inflammation and oxidative stress (D)</p> Signup and view all the answers

Which of the following enzymes is responsible for metabolizing heme in phagocytes?

<p>Heme oxygenase (HO-1) (B)</p> Signup and view all the answers

What is the function of iron-binding proteins in phagocytes?

<p>To prevent oxidative cell damage (A)</p> Signup and view all the answers

Which transcription factor acts as an effective regulator of oxidative stress and blood detoxification components?

<p>Nrf2 (A)</p> Signup and view all the answers

What is the role of PPAR in hematoma cleanup?

<p>Stimulates phagocytosis mediated hematoma cleanup (D)</p> Signup and view all the answers

What is the effect of severe hypercapnia on the autoregulation range of cerebral resistance vessels?

<p>Decreases the autoregulation range (B)</p> Signup and view all the answers

What is the main feature of intracerebral hemorrhage?

<p>Perpetuation of inflammation and oxidative stress (C)</p> Signup and view all the answers

What is the main reason why fatty acids cannot be used by the brain as an energy source?

<p>Fatty acids cannot cross the blood-brain barrier (C)</p> Signup and view all the answers

Which of the following mechanisms is NOT proposed for autoregulation of cerebral blood flow?

<p>Vasodilatory mechanism (B)</p> Signup and view all the answers

What happens when intracranial pressure (ICP) increases?

<p>Cerebral blood flow decreases (A)</p> Signup and view all the answers

Which of the following is NOT a vasoactive mediator released from astrocytes in the brain?

<p>Acetylcholine (B)</p> Signup and view all the answers

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