Question 1

Why is the heart so sensitive to potassium and calcium concentrations in the blood? Why do these change the ECG?

Accepted Answer

The heart is polarized like other cells by the internal concentrations of potassium. Changes in potassium can lead to arrhythmias via hypokalemia or hyperkalemia. Hyperkalemia is more serious as it can lead to cardiac arrest. The heart is an interesting muscle in that its sarcoplasmic reticulum's release of calcium is dependent on external calcium. That is why the heart contractility and heart rate are both related to calcium.

Question 2

What effect does cadmium have on the vasculature?

Accepted Answer

Cadmium causes angiostatic chemotaxis inhibition and tube formation in vascular endothelium. This coupled to its hypertensive action through the kidney is problematic for the blood vessels.

Question 3

How is methemoglobin not only a toxicity but a method for detecting other toxicants?

Accepted Answer

The formation of the Fe³⁺ methemoglobin is...

Question 4

Why does cardiomyopathy develop readily from exposure of the heart to cancer chemotherapy anthracyclines, ethanol, or the antiviral AZT?

Accepted Answer

The heat is highly sensitive to oxidative agents. Its proximity to the lung and high content of mitochondria make this red organ dependent on oxygen (hypoxia generates ischemic injury).

Exam 18: The Cardiovascular System As Conduit for a Dose Becoming a Dosage: Exposure and Toxicities

Why is the heart so sensitive to potassium and calcium concentrations in the blood? Why do these change the ECG?

What effect does cadmium have on the vasculature?

Correct Answer
verified
Cadmium causes angiostatic chemotaxis inhibition and tube formation in vascular endothelium. This coupled to its hypertensive action through the kidney is problematic for the blood vessels.

How is methemoglobin not only a toxicity but a method for detecting other toxicants?

Correct Answer
verified
The formation of the Fe³⁺ methemoglobin is...
View Answer

Why does cardiomyopathy develop readily from exposure of the heart to cancer chemotherapy anthracyclines, ethanol, or the antiviral AZT?

Correct Answer
verified
The heat is highly sensitive to oxidative agents. Its proximity to the lung and high content of mitochondria make this red organ dependent on oxygen (hypoxia generates ischemic injury).

Exam 18: The Cardiovascular System As Conduit for a Dose Becoming a Dosage: Exposure and Toxicities

Why is the heart so sensitive to potassium and calcium concentrations in the blood? Why do these change the ECG?

What effect does cadmium have on the vasculature?

Correct AnswerverifiedCadmium causes angiostatic chemotaxis inhibition and tube formation in vascular endothelium. This coupled to its hypertensive action through the kidney is problematic for the blood vessels.

How is methemoglobin not only a toxicity but a method for detecting other toxicants?

Correct AnswerverifiedThe formation of the Fe3+ methemoglobin is...View AnswerShow Answer

Why does cardiomyopathy develop readily from exposure of the heart to cancer chemotherapy anthracyclines, ethanol, or the antiviral AZT?

Correct AnswerverifiedThe heat is highly sensitive to oxidative agents. Its proximity to the lung and high content of mitochondria make this red organ dependent on oxygen (hypoxia generates ischemic injury).

Correct Answer
verified
Cadmium causes angiostatic chemotaxis inhibition and tube formation in vascular endothelium. This coupled to its hypertensive action through the kidney is problematic for the blood vessels.

Correct Answer
verified
The formation of the Fe³⁺ methemoglobin is...
View Answer

Correct Answer
verified
The heat is highly sensitive to oxidative agents. Its proximity to the lung and high content of mitochondria make this red organ dependent on oxygen (hypoxia generates ischemic injury).