Adrenalin direct affect on : -

Options

A. S.A. Node
B. `beta`-cells of Langerhans
C. Dorsal root of spinal cord
D. Epithelial cells of stomach

Answer

**Step-by-Step Solution:**

1. **Understanding Adrenaline**: Adrenaline, also known as epinephrine, is a hormone secreted by the adrenal medulla. It is often referred to as an emergency hormone because it is released during stressful situations, commonly known as the "fight or flight" response.

2. **Location of Adrenal Glands**: The adrenal glands are located on top of the kidneys and consist of two parts: the adrenal cortex and the adrenal medulla. The adrenal medulla is responsible for the secretion of adrenaline.

3. **Effects of Adrenaline**: The primary effects of adrenaline include:
- Increasing heart rate and blood pressure.
- Enhancing cardiac output and the strength of ventricular contractions.
- Stimulating glycogenolysis, which is the breakdown of glycogen into glucose, leading to increased glucose levels in the blood.
- Causing piloerection (raising of body hair) and pupillary dilation.

4. **Target of Adrenaline**: The major target of adrenaline is the heart, specifically the sinoatrial (SA) node, which acts as the pacemaker of the heart. This means that adrenaline directly affects the heart's function by increasing its activity.

5. **Identifying the Correct Answer**: Based on the effects of adrenaline, the correct answer to the question "Adrenalin direct affect on:" is the heart, particularly the SA node.

6. **Excluding Other Options**: Other options such as beta cells of Langerhans, dorsal root of the spinal cord, or epithelial cells of the stomach do not have a direct effect from adrenaline.

**Final Answer**: The correct answer is the heart (specifically the SA node).

---