How many structures among the following are lined by squamous epithelium?
a) lnner visceral layer of Bowman's capsule,
b) Outer parietal layer of Bowman's capsule
c) proximal convoluted tubule ,
d) Thin segment of descending limb of Henle's loop,
e) Thick segment of ascending lemb of Henle's loop,
f) Distal convoluted tubule, and
g) Collecting duct.

Options

A. 2
B. 3
C. 4
D. 5

Answer

To determine how many structures among the given options are lined by squamous epithelium, we will analyze each option one by one.

1. **Inner visceral layer of Bowman's capsule**: This layer surrounds the glomerulus and is composed of specialized cells called podocytes, which are not classified as squamous epithelium. Therefore, this option is **not lined by squamous epithelium**.

2. **Outer parietal layer of Bowman's capsule**: This layer is composed of simple squamous epithelium. Thus, this option is **lined by squamous epithelium**.

3. **Proximal convoluted tubule**: The proximal convoluted tubule is lined with cuboidal epithelium, not squamous epithelium. Therefore, this option is **not lined by squamous epithelium**.

4. **Thin segment of descending limb of Henle's loop**: This segment is lined with simple squamous epithelium. Thus, this option is **lined by squamous epithelium**.

5. **Thick segment of ascending limb of Henle's loop**: This segment is lined with cuboidal epithelium, not squamous epithelium. Therefore, this option is **not lined by squamous epithelium**.

6. **Distal convoluted tubule**: The distal convoluted tubule is lined with cuboidal epithelium, not squamous epithelium. Therefore, this option is **not lined by squamous epithelium**.

7. **Collecting duct**: The collecting duct is lined with cuboidal epithelium, not squamous epithelium. Therefore, this option is **not lined by squamous epithelium**.

Now, let's summarize the findings:
- **Lined by squamous epithelium**:
- Outer parietal layer of Bowman's capsule
- Thin segment of descending limb of Henle's loop

Thus, there are **2 structures** that are lined by squamous epithelium.

### Final Answer: 2 structures