___,_____ and ____ are three processes involved in urine formation.

Answer

To answer the question regarding the three processes involved in urine formation, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Identify the First Process: Glomerular Filtration**
- The first process in urine formation is **glomerular filtration**. This occurs in the Bowman's capsule, where blood is filtered through the glomerulus. During this process, most components of the blood, except for cells and large proteins, are filtered out.

2. **Identify the Second Process: Tubular Reabsorption**
- The second process is **tubular reabsorption**. This occurs primarily in the proximal convoluted tubule (PCT) and the distal convoluted tubule (DCT) of the nephron. During this stage, approximately 99% of water and essential electrolytes are reabsorbed back into the bloodstream.

3. **Identify the Third Process: Tubular Secretion**
- The third process is **tubular secretion**. In this phase, certain ions and substances, such as potassium (K+) and hydrogen ions (H+), are secreted from the blood into the tubular fluid. This helps in regulating the body's pH and electrolyte balance.

### Final Answer:
The three processes involved in urine formation are **glomerular filtration, tubular reabsorption, and tubular secretion**.

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