How many among the given statements are incorrect?
a. All of the nodal tissue in human heart is capable of generating 70-75 action protentials in a minute.
b. Lymph is devoid of all formed elements of blood.
c. Cardiac output is defined as the volume of blood pumped by each ventricle in a cardiac cycle.
d. Wall of left ventricle is thickest among all four chambers of human heart.

Options

A. Four
B. Three
C. Two
D. One

Answer

To determine how many statements among the given ones are incorrect, let's analyze each statement one by one.

**Step 1: Analyze Statement A**
- Statement: "All of the nodal tissue in the human heart is capable of generating 70-75 action potentials in a minute."
- Analysis: This statement is incorrect. The sinoatrial (SA) node is the primary pacemaker of the heart and is responsible for generating 70-75 action potentials per minute. Other nodal tissues, like the atrioventricular (AV) node and Purkinje fibers, generate action potentials at a slower rate. Therefore, this statement is incorrect.

**Step 2: Analyze Statement B**
- Statement: "Lymph is devoid of all formed elements of blood."
- Analysis: This statement is also incorrect. While lymph does not contain red blood cells, it can contain some white blood cells (like lymphocytes) and platelets. Therefore, it is not devoid of all formed elements of blood, making this statement incorrect.

**Step 3: Analyze Statement C**
- Statement: "Cardiac output is defined as the volume of blood pumped by each ventricle in a cardiac cycle."
- Analysis: This statement is incorrect. Cardiac output is defined as the volume of blood pumped by the heart (both ventricles) in one minute, not just by each ventricle in a single cardiac cycle. This definition is more aligned with stroke volume, which refers to the volume pumped by each ventricle in one contraction. Thus, this statement is incorrect.

**Step 4: Analyze Statement D**
- Statement: "Wall of left ventricle is thickest among all four chambers of the human heart."
- Analysis: This statement is correct. The left ventricle has the thickest wall because it needs to generate enough pressure to pump oxygenated blood to the entire body. Therefore, this statement is correct.

**Conclusion: Count the Incorrect Statements**
- From the analysis:
- Statement A: Incorrect
- Statement B: Incorrect
- Statement C: Incorrect
- Statement D: Correct

Thus, there are **3 incorrect statements** among the given options.

**Final Answer: 3**

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