The correct option is Nephron.
Explanation
The kidneys are the primary organs of the human excretory system, responsible for osmoregulation and the removal of metabolic waste from the blood. The efficiency of the kidney depends on millions of microscopic functional units that perform the processes of filtration, reabsorption, and secretion.
Option Analysis
- Nephron: Nephron (Correct)
The nephron is the fundamental structural and functional unit of the kidney. Each human kidney contains approximately one million nephrons. A single nephron consists of two main parts: the renal corpuscle (which includes the glomerulus and Bowman's capsule) and the renal tubule (comprising the Proximal Convoluted Tubule, Loop of Henle, and Distal Convoluted Tubule). It is within the nephron that blood is filtered and urine is formed. - Neuron: Neuron (Incorrect)
The neuron is the basic structural and functional unit of the nervous system, responsible for transmitting electrical and chemical signals throughout the body. It is unrelated to kidney function. - Nephrite: Nephrite (Incorrect)
Nephrite is a mineral species of the amphibole group and is one of the two distinct minerals commonly known as jade. It is a geological term and has no biological significance in human anatomy. - Glomeruli: Glomeruli (Incorrect)
The glomerulus (plural: glomeruli) is a specific component within the nephron. It is a tuft of capillaries located at the beginning of a nephron where the filtration of blood takes place. While essential, it is only a part of the functional unit, not the unit itself.
Key Takeaway: The nephron is the comprehensive microscopic unit of the kidney responsible for urine formation, whereas the glomerulus is merely the filtration component contained within it.