Cells most sensitive to hypoxia are ?
**Core Concept**
Cells most sensitive to hypoxia are those with high metabolic rates and low myoglobin levels, which are primarily neurons and cardiac myocytes. Hypoxia refers to a condition in which there is insufficient oxygen available to meet the metabolic demands of the cell.
**Why the Correct Answer is Right**
Neurons are highly sensitive to hypoxia due to their high metabolic rates and reliance on aerobic respiration for energy production. Cardiac myocytes, which are responsible for generating the electrical impulses that control heart contractions, are also highly sensitive to hypoxia. This is because they have a high demand for oxygen to meet their energy requirements. In contrast, cells with lower metabolic rates, such as those in the liver or muscle, are less sensitive to hypoxia.
**Why Each Wrong Option is Incorrect**
* **Option A:** Red blood cells are actually quite resistant to hypoxia, as they have a low metabolic rate and can survive for extended periods without oxygen.
* **Option B:** The kidney is a highly vascularized organ, but it is not as sensitive to hypoxia as neurons or cardiac myocytes.
* **Option D:** The liver is a metabolically active organ, but it is not as sensitive to hypoxia as neurons or cardiac myocytes due to its ability to adapt to low oxygen levels.
**Clinical Pearl / High-Yield Fact**
In conditions of severe hypoxia, neurons are often the first cells to be affected, leading to symptoms such as confusion, disorientation, and eventually, coma. This highlights the importance of maintaining adequate oxygenation in critically ill patients.
**Correct Answer: C. Neurons and cardiac myocytes.**