They are seized by an uncontrollable urge to move their legs. Their legs actually twitch or jerk, while they experience the sensation of something squirming or wiggling under their skin. Consequently, restless legs syndrome can lead to problems associated with sleep deprivation, such as anxiety and depression.
Gas exchange in the lungs takes place between the blood in the capillary network surrounding the alveoli, and the air in the alveoli itself. All of the blood from the right ventricle flows through the pulmonary artery to the capillary network which surrounds the alveoli.as exchange between the air within the alveoli and the pulmonary capillaries occurs by diffusion. The oxygen must first dissolve before passing through the respiratory epithelium.
Capillaries are where fluids, gasses, nutrients, and wastes are exchanged between the blood and body tissues by diffusion. Capillary walls contain small pores that allow certain substances to pass into and out of the blood vessel.he flow of blood in the capillaries is controlled by structures called precapillary sphincters. These structures are located between arterioles and capillaries and contain muscle fibers that allow them to contract. When the sphincters are open, blood flows freely to the capillary beds of body tissue.