Label the blood vessels and parts of the nephron by selecting the letter for the correct structure from the key below. The items in the key may be used more than once.
a. afferent arteriole
b. arcuate artery
g. distal convoluted tubule
m. nephron loop-ascending limb
n. nephron loop-descending limb
h. efferent arteriole
o. peritubular capillary
i. glomerular capsule
p. proximal convoluted tubule
l. glomerulus
d. collecting duct
k. interlobar artery
The correct answer and explanation is :
The nephron is the functional unit of the kidney, and it is crucial for filtering blood and producing urine. The nephron consists of several structures, each playing a key role in the filtration, reabsorption, and secretion of substances. To label the blood vessels and parts of the nephron, I’ll outline the structure and function of each part and then match it with the appropriate letter from the key provided.
Key Structures and their Functions:
- Afferent arteriole (a): This is the blood vessel that carries blood toward the glomerulus, where filtration begins. It supplies the blood to the nephron.
- Arcuate artery (b): This artery runs along the boundary between the renal cortex and medulla. It is responsible for delivering blood to the interlobar arteries and helps supply blood to the nephrons.
- Distal convoluted tubule (g): This is the segment of the nephron that follows the loop of Henle. It is involved in the further reabsorption of sodium, calcium, and chloride ions and the secretion of potassium and hydrogen ions.
- Nephron loop-ascending limb (m): This part of the loop of Henle is responsible for the active transport of sodium and chloride ions out of the filtrate, contributing to the concentration gradient in the kidney.
- Nephron loop-descending limb (n): This part of the loop allows water to passively leave the filtrate due to the high osmolarity in the medulla, helping concentrate urine.
- Efferent arteriole (h): This is the blood vessel that carries blood away from the glomerulus after filtration. It has a smaller diameter than the afferent arteriole, helping to maintain high pressure in the glomerulus for efficient filtration.
- Peritubular capillary (o): These capillaries surround the renal tubules and are involved in the reabsorption and secretion of substances between the nephron and the blood.
- Glomerular capsule (i): This is the double-walled structure that surrounds the glomerulus. It captures the filtrate produced by the glomerulus.
- Proximal convoluted tubule (p): This is the first segment of the nephron, where the majority of reabsorption of water, glucose, and essential ions takes place.
- Glomerulus (l): This is the network of capillaries within the glomerular capsule, where filtration of blood occurs.
- Collecting duct (d): This duct collects urine from multiple nephrons and carries it toward the renal pelvis for excretion.
- Interlobar artery (k): These arteries run between the renal lobes and help supply blood to the kidneys, eventually branching into smaller arteries that supply individual nephrons.
- Segmental artery (9): This artery supplies the kidneys and branches from the renal artery into the interlobar arteries.
- Cortical radiate artery (e): These arteries supply blood directly to the nephron, branching from the interlobar arteries and entering the renal cortex.
- Cortical radiate vein (f): These veins collect blood from the peritubular capillaries and return it to the interlobar veins.
- Interlobar vein (l): These veins collect deoxygenated blood from the renal cortex and medulla and return it to the renal vein.
Conclusion:
Each part of the nephron and blood vessels plays an essential role in maintaining kidney function, from blood filtration to the regulation of urine composition. The matching of letters to structures will help identify the exact roles each part plays in kidney physiology.