Essentials of Anatomy and Physiology

The Vascular System 303 other waste products. The site of exchange between fetus and mother is the placenta, which contains feta ...

and nutrients from the mother’s blood enter fetal circulation. The umbilical veincarries this oxygenated blood from the placenta ...

Fig. 13–8). Because the fetal lungs are deflated and do not provide for gas exchange, blood is shunted away from the lungs and t ...

and pulmonary circulation becomes fully functional within a few days. VELOCITY OF BLOOD FLOW The velocity, or speed, with which ...

begins in a narrow bed and is flowing rapidly. If the river bed widens, the water spreads out to fill it and flows more slowly. ...

vertical, gravity must be overcome to return blood from the lower body to the heart. Three mecha- nisms help promote venous retu ...

If more vasoconstriction occurs, blood pressure will increase (the container has become even smaller). This is what happens in a ...

output is approximately 5000 mL per minute. Exercise cardiac output is three times that, about 15,000 mL per minute. Keep in min ...

venous return increases, cardiac muscle fibers are stretched, and the ventricles pump more forcefully (Starling’s law). Thus, ca ...

The second nervous mechanism involves periph- eral resistance, that is, the degree of constriction of the arteries and arteriole ...

313 Inhibit vasomotor center Vasodilation decreases peripheral resistance Heart rate slows, decreases cardiac output B. P. decre ...

AGING AND THE VASCULAR SYSTEM It is believed that the aging of blood vessels, especially arteries, begins in childhood, although ...

The vascular system consists of the arteries, capillaries, and veins through which blood travels. Arteries (and arterioles) (see ...

right atrium to the left atrium to bypass the fetal lungs. The ductus arteriosus permits blood to flow from the pulmonary arter ...

Regulation of Blood Pressure—intrinsic mechanisms and nervous mechanisms Intrinsic Mechanisms The heart—responds to increased v ...

autonomic nervous system that carries impulses to blood vessels. Which blood vessels? Which tissue in these vessels? Explain why ...

CHAPTER 14 The Lymphatic System and Immunity 319 ...

320 CHAPTER 14 Chapter Outline Lymph Lymph Vessels Lymphatic Tissue Lymph Nodes and Nodules Spleen Thymus Immunity Innate Immuni ...

The Lymphatic System and Immunity 321 New Terminology Acquired immunity (uh-KWHY-erd) Active immunity (AK-tiv) Antibody-mediated ...

Achild falls and scrapes her knee. Is this likely to be a life-threatening injury? Probably not, even though the breaks in the s ...