Chapter 21

All vertebrates have _________. a. an open circulatory system b. a closed circulatory system c. a four-chamber heart d. both b and c

Signals initiated by the __________ cause the heart to contract. a. AV node b. SA node c. pericardium d. brain

Blood pressure is highest in the _________ and lowest in the __________ . a. arteries; veins b. arterioles; venules c. veins; arteries d. capillaries; arterioles

Contraction of __________ is the main force driving the flow of blood away from the heart. a. the atria b. arterioles c. the ventricles d. skeletal muscle

At rest, the largest volume of blood is in the ___________. a. arteries b. capillaries c. veins d. arterioles

In the blood, most oxygen is transported _____________. a. in red blood cells b. in white blood cells c. bound to hemoglobin d. both a and c

The _____________ circuit carries blood from the heart to the lungs, then back to the heart. a. pulmonary b. systemic

The heart chamber with the thickest wall pumps blood into the _________. a. aorta b. pulmonary artery c. pulmonary vein d. superior vena cava

In human lungs, gas exchange occurs at the _________. a. bronchi b. pericardium c. alveoli d. epiglottis

When you breathe quietly, inhalation is _________ and exhalation is ____________. a. passive; passive b. active; active c. passive; active d. active; passive

During inhalation, ___________. a. the thoracic cavity expands b. the glottis closes c. the diaphragm relaxes d. all of the above

The diaphragm is _________ muscle. a. smooth b. skeletal c. cardiac

Match each disorder with its description. __________anemia __________atherosclerosis __________hypertension __________emphysema __________hemophilia __________cardiac arrest __________asthma __________bronchitis a. heart stops beating b. alveoli walls break down c. airways constrict d. impaired blood clotting e. chronic high blood pressure f. inflammation of bronchi g. too few red blood cells h. narrows arteries

Match the words with their descriptions. __________ plasma __________ alveolus __________ hemoglobin __________ veins __________ SA node __________ trachea __________ glottis __________ ventricle __________ atrium a. receives blood from veins b. fluid component of blood c. cardiac pacemaker d. gap between vocal cords e. site of gas exchange f. drives blood flow from heart g. windpipe h.blood volume reservoir i. reversibly binds oxygen

Arrange these structures in the order in which inhaled air flows through them. ________ larynx ________ pharynx ________ trachea ________ bronchus ________ bronchiole