The bed of capillaries in a vertebrate kidney where water, urea, and salts are filtered out of the blood is the __________.

• A. Bowman's capsule
• B. collecting duct
• C. loop of Henle
• D. proximal convoluted tubule
• E. glomerulus

Answer: (E)

Verified step by step guidance

1. Understand the function of the glomerulus: It is a network of capillaries located at the beginning of a nephron in the kidney. Its primary role is to filter blood, removing water, urea, and salts.
2. Recognize the structure of the nephron: The nephron is the functional unit of the kidney, consisting of the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.
3. Identify the filtration process: Blood enters the glomerulus, and due to high pressure, water, urea, and salts are filtered out of the blood into Bowman's capsule, forming the initial filtrate.
4. Differentiate between the components: Bowman's capsule surrounds the glomerulus and collects the filtrate. The proximal convoluted tubule, loop of Henle, and collecting duct are involved in further processing and reabsorption of substances from the filtrate.
5. Conclude the role of the glomerulus: It is the initial site of filtration in the kidney, crucial for removing waste products and excess substances from the blood, which are then processed through the nephron.