arteriole

Examples of arteriole in the following topics:

• Blood Pressure

  • Blood flows to the arterioles (smaller arteries) where the rate of flow is slowed by the narrow openings of the arterioles.
  • Throughout the cardiac cycle, the blood continues to empty into the arterioles at a relatively even rate.
  • Blood pressure is related to the blood velocity in the arteries and arterioles.

• Epinephrine and Norepinephrine

  • For example, high levels of epinephrine cause smooth muscle relaxation in the airways, but cause contraction of the smooth muscle that lines most arterioles.
  • Once the afferent arterioles are constricted, blood flow into the nephrons of the kidneys stops.

• Dead Space: V/Q Mismatch

  • If ventilation is greater than perfusion, the arterioles dilate and the bronchioles constrict, increasing perfusion while reducing ventilation.
  • Likewise, if ventilation is less than perfusion, the arterioles constrict while the bronchioles dilate to correct the imbalance.

• Blood Flow Through the Body

  • From the aorta, blood flows into the arteries and arterioles and, ultimately, to the capillary beds.
  • While the diameter of each individual arteriole and capillary is far narrower than the diameter of the aorta, the rate is actually slower due to the overall diameter of all the combined capillaries being far greater than the diameter of the individual aorta.
  • If all of the sphincters are closed, then the blood will flow directly from the arteriole to the venule through the thoroughfare channel.

• Arteries, Veins, and Capillaries

  • The major arteries diverge into minor arteries, and then into smaller vessels called arterioles, to reach more deeply into the muscles and organs of the body.
  • Arterioles diverge into capillary beds.

• Other Hormonal Controls for Osmoregulation

  • Renin is secreted by a part of the juxtaglomerular complex and produced by the granular cells of the afferent and efferent arterioles.

• Kidney Structure

  • Cortical radiate arteries, as the name suggests, radiate out from the arcuate arteries, branch into numerous afferent arterioles, and then enter the capillaries supplying the nephrons.

• Kidney Function and Physiology

  • The process of glomerular filtration filters out most of the solutes due to the high blood pressure and specialized membranes in the afferent arteriole.