Prostaglandins normally dilate the afferent arterioles of the glomeruli. PGE2 and prostacyclin inhibit platelet aggregation and dilate blood vessels. It causes platelets to aggregate and blood vessels to dilate. The arteries dilate, filling the "corpus spongiosum" and "corpora cavernosa" with blood. The reverse occurs at high ambient temperatures, arterioles dilate to increase heat loss. As ACM progresses, the muscle tissue within the ventricles may dilate and weaken. The end result is vascular smooth muscle relaxation, which allow vessels to dilate. Cyclopentolate drops act rapidly to dilate the pupil. Next, the provider will dilate the cervix. By relaxing the tone of this smooth muscle, calcium channel blockers dilate the blood vessels. However, blood vessels in the skeletal muscle dilate as a result of nicotine. The left ventricle begins to dilate during this phase. Her pupils would dilate and she would blink at stimuli that threatened her eyes. Over time, the buds elongate, moving into surrounding mesodermal tissue, dilate, and divide. The pupils dilate suddenly and eye movement resumes when the animal wakes up.