Slow capillary velocity allows more time for exchange of nutrients, gases, and waste products with tissues. Reduction in cross-sectional area as small venules join to form veins. Decreased blood pressure during inspiration whenever chest expands. Right ventricle pumps deoxygenated, high carbon dioxide blood to pulmonary arteries. Right and left pulmonary arteries branch into lungs.
Pulmonary capillaries are site where oxygen is picked up and carbon dioxide is given off.
Pulmonary veins leave lungs with oxygenated, low carbon dioxide blood and enter left atrium of heart. Systemic circuit circulates blood through rest of body. Pathway to and from body organs begins with the left ventricle. Blood Blood helps maintain homeostasis. Blood transports molecules to and from capillaries.