Which of the following organs filters excess solutes from the blood?
A.
Stomach
B.
Spleen
C.
Kidney
D.
Gallbladder
The correct answer and Explanation is :
The correct answer is C. Kidney.
Explanation:
The kidneys are essential organs in the body that play a critical role in filtering excess solutes, as well as waste products, from the blood. Located in the lower back, these bean-shaped organs perform a variety of functions to maintain homeostasis, which includes regulating the volume and composition of blood.
1. Filtration Process:
The primary function of the kidneys is to filter blood through a complex structure known as the nephron, which is the functional unit of the kidney. Each kidney contains approximately one million nephrons. Blood enters the nephron through a network of capillaries called the glomerulus. Here, the process of filtration occurs, where water, electrolytes, and small molecules are filtered out of the blood, forming a fluid known as filtrate.
2. Reabsorption and Secretion:
After filtration, the filtrate passes through a series of tubules in the nephron. During this stage, essential substances such as glucose, amino acids, and certain ions are reabsorbed back into the bloodstream. Conversely, waste products and excess ions that are not needed by the body are secreted into the tubules. This selective reabsorption and secretion ensure that the final urine composition is precisely regulated.
3. Urine Formation:
The final product, urine, is collected in the renal pelvis and transported to the bladder through the ureters. This process helps maintain the body’s fluid and electrolyte balance and removes harmful metabolic byproducts from the blood.
4. Homeostasis:
Beyond filtration, the kidneys also regulate blood pressure, erythrocyte production, and acid-base balance. This comprehensive control is crucial for the body’s overall health and stability.
In contrast:
- The stomach is primarily involved in digestion and the breakdown of food.
- The spleen plays a role in filtering blood and managing red blood cells but is not primarily responsible for filtering excess solutes.
- The gallbladder stores and concentrates bile from the liver, which helps in the digestion of fats, but does not filter blood.
Thus, the kidneys are specifically designed for filtering excess solutes and waste products from the bloodstream, making them the correct answer.