Chapter 18 A&P

Blood enters the left and right coronary arteries directly from which vessel or chamber? circumflex artery pulmonary trunk left ventricle aorta

aorta; Blood flows to the right and left coronary arteries directly from the aorta.

A patent ductus arteriosus permits...

blood to flow from the aorta into the pulmonary trunk; A patent ductus arteriosus would connect the pulmonary trunk to the aorta.

Which blood vessel carries blood from the anterior to the posterior of the heart? left coronary artery posterior interventricular artery marginal artery circumflex artery

circumflex artery; The circumflex artery is a branch of the left coronary artery that carries blood towards the back of the heart.

Which of the following is the innermost layer of the heart? endocardium epicardium parietal layer visceral layer

endocardium; The endocardium lines the inside of the heart. Its surface is composed of simple squamous epithelium.

The role of the chordae tendineae is to open the AV valves at the appropriate time. True or False?

false; The role of the chordae tendineae is to anchor the AV valves against the large pressure changes that occur as the ventricles contract.

Which heart chamber receives oxygenated blood from the lungs? left atrium right atrium left ventricle right ventricle

left atrium; Oxygenated blood from the lungs returns to the left atrium of the heart.

Failure in a particular chamber of the heart tends to cause a backup of blood in the lungs, known as pulmonary congestive heart failure. Failure of which chamber of the heart would lead to such a backup? left ventricle right ventricle left atrium right atrium

left ventricle; Failure in the left ventricle can cause increased blood hydrostatic pressure in the lungs, causing fluid buildup in the alveoli.

Which chamber of the heart has the highest probability of being the site of a myocardial infarction? left atrium right atrium left ventricle right ventricle

left ventricle; The left ventricle has to pump blood around the entire body and overcome the largest pressures (120/80 mm Hg). This is the largest chamber in the heart and has the most muscle around it compared to the other chambers.

Which chamber of the heart sends oxygenated blood to the systemic circuit via the aorta? left ventricle left atrium right atrium right ventricle

left ventricle; The left ventricle sends blood to the systemic circuit via the aorta and its branches.

Which layer of the heart wall contracts and is composed primarily of cardiac muscle tissue? endocardium epicardium myocardium visceral layer of the serous pericardium

myocardium; The myocardium is composed of cardiac muscle and a dense network of connective tissue.

Which of these muscles is particularly associated with anchoring the right and left atrioventricular valves? pectinate muscles trabeculae carneae myocardium papillary muscles

papillary muscles; Papillary muscles contract to tense the right and left atrioventricular valves via the chordae tendineae just before ventricular systole.

What separates the parietal and visceral pericardium? fibrous pericardium pericardial cavity myocardium epicardium

pericardial cavity; The pericardial cavity separates the parietal and visceral pericardium. This cavity contains serous fluid that lubricates the visceral and parietal membranes.

Which of the following descriptions does NOT describe atrioventricular (AV) valves? anchored inferiorly by specialized connective tissue open based on pressure changes in the atria versus the ventricles pocket-like flap-like

pocket-like; Pocket-like is a description that fits semilunar valves better.

Which of the following is a branch of the right coronary artery? anterior interventricular artery coronary sinus circumflex artery posterior interventricular artery

posterior interventricular artery; The posterior interventricular artery is a branch of the right coronary artery, although an anastomosis with the circumflex artery meets with it near its origin.

The right side of the heart is considered the systemic circuit pump. True or False?

False; The right side of the heart pumps oxygen-poor blood to the lungs to be re-oxygenated. For this reason, the right side of the heart is considered the pulmonary circuit pump. The left side of the heart pumps blood to the body, and is therefore considered the systemic circuit pump.

Which statement regarding cardiac muscle structure is accurate?

Myofibrils of cardiac muscle tissue vary in diameter and branch extensively; The myofibrils of cardiac muscle have various diameters; they also branch in order to maintain connections, via intercalated discs, with other muscle cells.

Which description is INCORRECT for the layers of the heart and its serous membranes?

The epicardium is also considered the parietal pericardium; The epicardium is also considered the visceral pericardium.

Which statement is correct regarding the ventricles? The right ventricle empties into the pulmonary trunk. The right ventricle forms a complete circle in cross section. The left ventricle empties into the pulmonary circuit. The left ventricle has a thinner wall than the right ventricle.

The right ventricle empties into the pulmonary trunk; The right ventricle empties into the pulmonary trunk and the pulmonary circuit.

Cardiac tamponade results in ineffective pumping of blood by the heart because the excessive amount of fluid in the pericardial cavity will______. prevent the visceral layer of the serous pericardium from properly surrounding the heart prevent the heart from filling properly with blood prevent proper oxygenation of the blood interfere with the ability of this fluid to lubricate the serous membranes

prevent the heart from filling properly with blood; The heart is wrapped by a double-walled sac called the pericardium. The pericardial cavity lies between the parietal and visceral layers of the serous pericardium. It is filled with a very small amount of serous fluid. If additional fluid fills the pericardial space, it adds pressure on the outside of the heart, preventing it from filling normally.

Which of the following does NOT deliver deoxygenated blood to the heart? inferior vena cava superior vena cava pulmonary veins coronary sinus

pulmonary veins; The pulmonary veins deliver oxygenated blood to the left atrium.

Which of these vessels returns blood to the left atrium of the heart? coronary sinus superior vena cava pulmonary trunk pulmonary veins

pulmonary veins; The pulmonary veins transport oxygen-enriched blood from the lungs to the left atrium.

The presence of an incompetent tricuspid valve would have the direct effect of causing ______.

reduced efficiency in the delivery of blood to the lungs; The tricuspid valve separates the right atrium and the right ventricle. It must remain tightly closed during ventricular contraction so blood can be pumped out of the ventricle and into the pulmonary arteries.

In an ischemic heart, the affected cardiac muscle cells are likely to have an altered ______. number of Z discs number of desmosomes number of slow Ca+2 channels resting membrane potential

resting membrane potential; Ischemia is cell and tissue damage that result from a lack of proper blood and oxygen delivery. The damaged tissue is normally replaced by scar tissue that lacks the normal cell structure of the original tissue. So "scarred" cardiac muscle would lack the pumps and channels that are necessary to establish resting membrane potential.

Into which chamber of the heart do the superior vena cava, inferior vena cava, and coronary sinus return deoxygenated blood? left ventricle right atrium right ventricle left atrium

right atrium; All of these vessels deliver blood to the right atrium.

The right atrioventricular valve prevents backflow of blood from the right ventricle into the __________. left atrium right atrium pulmonary trunk left ventricle

right atrium; Flow from the right ventricle to the right atrium is prevented by the right atrioventricular valve.

A blockage in which of these vessels could cause a myocardial infarction in the lateral right side of the heart? circumflex artery right marginal artery posterior interventricular artery anterior interventricular artery

right marginal artery; The right marginal artery branches from the right coronary artery to nourish the lateral areas of the right ventricle. A blockage in this vessel could damage this area.

Consider the following characteristics of the cells found in muscle tissue. Which feature is shared by both cardiac muscle and skeletal muscle? branched cells intercalated discs striations triads

striations; Since both cardiac and skeletal muscles possess arrangements of motor proteins in regularly arrayed sarcomeres, they both display the banding known as striations.

Which valve is located between the right atrium and ventricle? tricuspid valve bicuspid valve mitral valve pulmonary semilunar valve

tricuspid valve; The tricuspid valve separates the right atrium and ventricle.

The __________ valve is located between the right atrium and the right ventricle. mitral pulmonary semilunar aortic semilunar tricuspid

tricuspid; The tricuspid valve is located between the right atrium and right ventricle.