Efferent arteriole

Definition

The efferent arteriole is a small blood vessel that carries blood away from the glomerulus in the kidney. It plays a crucial role in regulating blood flow and pressure within the nephron, affecting the filtration process and the overall function of the renal system.

5 Must Know Facts For Your Next Test

1. The efferent arteriole maintains glomerular pressure by regulating the outflow of blood from the glomerulus, which is essential for effective filtration.
2. It branches into peritubular capillaries, which surround the nephron and are involved in reabsorption of water and solutes back into the bloodstream.
3. The diameter of the efferent arteriole can change to help regulate blood flow and pressure within the glomerulus, impacting kidney function.
4. Hormones like angiotensin II can cause constriction of the efferent arteriole, leading to increased filtration pressure in the glomerulus.
5. Disruptions in the function of the efferent arteriole can lead to conditions such as hypertension or kidney disease due to impaired blood flow and filtration.

Review Questions

• How does the efferent arteriole contribute to regulating blood pressure within the glomerulus?
  • The efferent arteriole helps regulate blood pressure within the glomerulus by controlling how much blood leaves it. By constricting or dilating, it can either increase or decrease the pressure in the glomerulus, ensuring that adequate pressure is maintained for proper filtration. This balance is essential for effective kidney function and overall fluid homeostasis.
• Discuss the relationship between the efferent arteriole and peritubular capillaries in terms of kidney function.
  • The efferent arteriole gives rise to peritubular capillaries that surround nephrons. These capillaries play a key role in reabsorbing nutrients, water, and electrolytes after filtration occurs in the glomerulus. The close relationship between these two structures allows for efficient exchange of substances between filtrate and blood, highlighting their collaborative role in maintaining fluid and electrolyte balance.
• Evaluate how hormonal regulation of the efferent arteriole impacts kidney health and overall fluid balance in the body.
  • Hormonal regulation of the efferent arteriole, particularly through angiotensin II, significantly impacts kidney health and fluid balance. When angiotensin II constricts the efferent arteriole, it increases glomerular filtration rate (GFR), which can be beneficial during states of low blood volume. However, prolonged constriction may lead to increased workload on kidneys, contributing to conditions like hypertension or chronic kidney disease. Thus, understanding this balance is vital for maintaining overall health.

Related terms

afferent arteriole: The afferent arteriole is a small blood vessel that brings blood into the glomerulus, playing a key role in regulating the pressure needed for filtration.

glomerulus: The glomerulus is a network of tiny blood vessels in the kidney where filtration occurs, separating waste products from blood.

nephron: The nephron is the functional unit of the kidney, responsible for filtering blood and forming urine through processes like filtration, reabsorption, and secretion.