Chapter 19: The Heart Flashcards
What is the function of arteries in the cardiovascular system?
A) Carry blood toward the heart
B) Carry blood away from the heart
C) Exchange gases and nutrients
D) Store blood for future use
B) Carry blood away from the heart
Explanation: Arteries transport oxygen-rich blood from the heart to the body’s tissues. The only exception is the pulmonary arteries, which carry oxygen-poor blood to the lungs.
Which vessels connect the smallest arteries to the smallest veins?
A) Arteries
B) Veins
C) Capillaries
D) Lymphatic vessels
C) Capillaries
Explanation: Capillaries are microscopic blood vessels that facilitate the exchange of oxygen, carbon dioxide, nutrients, and waste between the blood and tissues.
Which circuit is responsible for carrying oxygen-poor blood to the lungs?
A) Systemic circuit
B) Pulmonary circuit
C) Lymphatic circuit
D) Coronary circuit
B) Pulmonary circuit
Explanation: The pulmonary circuit transports oxygen-poor blood from the right side of the heart to the lungs, where it picks up oxygen and releases carbon dioxide.
Which major artery carries blood from the left side of the heart to the rest of the body?
A) Pulmonary trunk
B) Superior vena cava
C) Inferior vena cava
D) Aorta
D) Aorta
Explanation: The aorta is the largest artery in the body and is responsible for distributing oxygen-rich blood from the heart to the systemic circulation.
The pulmonary circuit delivers oxygen-rich blood to the body’s organs.
A) True
B) False
B) False
Explanation: The pulmonary circuit carries oxygen-poor blood to the lungs for gas exchange. The systemic circuit delivers oxygen-rich blood to the body.
The systemic circuit supplies blood to the lungs.
A) True
B) False
A) True
Explanation: While the pulmonary circuit is responsible for oxygenating blood, the lungs also receive blood supply from the systemic circuit through bronchial arteries.
Veins always carry oxygen-poor blood.
A) True
B) False
B) False
Explanation: Most veins carry oxygen-poor blood, but pulmonary veins are an exception. They transport oxygen-rich blood from the lungs to the left side of the heart.
The _______ is the muscular pump that drives blood through the cardiovascular system.
Heart
Explanation: The heart pumps blood through the pulmonary and systemic circuits, ensuring oxygen and nutrients reach body tissues.
The right half of the heart pumps blood into the _______ circuit, while the left half pumps blood into the _______ circuit.
Pulmonary; systemic
Explanation: The right side of the heart sends oxygen-poor blood to the lungs (pulmonary circuit), while the left side sends oxygen-rich blood to the rest of the body (systemic circuit).
The heart lies within a thick partition called the _______ between the lungs.
Mediastinum
Explanation: The mediastinum is the central compartment of the thoracic cavity that houses the heart, great vessels, esophagus, and trachea.
Which side of the heart supplies blood to the pulmonary circuit?
A) Left side
B) Right side
C) Both sides
D) Neither side
B) Right side
Explanation: The right side of the heart pumps oxygen-poor blood into the pulmonary circuit, which carries it to the lungs for oxygenation.
Which of the following describes the pericardium?
A) A single-layered membrane that encloses the heart
B) A two-layered sac that surrounds and protects the heart
C) The muscular wall of the heart
D) The outermost layer of the heart itself
B) A two-layered sac that surrounds and protects the heart
Explanation: The pericardium consists of an outer fibrous layer and an inner serous layer, which helps protect the heart and reduce friction during heartbeats.
What is the function of pericardial fluid?
A) To help transport oxygen to heart tissues
B) To reduce friction between the pericardial layers during heartbeats
C) To provide structural support to the heart
D) To supply the heart with nutrients
B) To reduce friction between the pericardial layers during heartbeats
Explanation: The pericardial fluid lubricates the heart’s movement, preventing friction that could cause damage to the tissues.
Which part of the heart is responsible for pumping blood into the systemic circuit?
A) Left atrium
B) Left ventricle
C) Right atrium
D) Right ventricle
B) Left ventricle
Explanation: The left ventricle pumps oxygen-rich blood into the systemic circuit through the aorta.
What condition occurs when the pericardium becomes inflamed and causes pain with each heartbeat?
A) Myocardial infarction
B) Pericarditis
C) Endocarditis
D) Cardiac tamponade
B) Pericarditis
Explanation: Pericarditis is inflammation of the pericardium, leading to a painful friction rub as the heart beats.
Most of the heart lies to the right of the median plane.
A) True
B) False
B) False
Explanation: Most of the heart lies to the left of the median plane, with its apex pointing slightly leftward.
The fibrous pericardium is a tough, collagenous sac that is directly attached to the heart.
A) True
B) False
B) False
Explanation: The fibrous pericardium surrounds but is not attached to the heart. It is attached to structures such as the diaphragm and the great vessels.
The pericardial cavity contains 5 to 30 mL of fluid.
A) True
B) False
A) True
Explanation: This small amount of pericardial fluid helps lubricate the heart and minimize friction during contractions.
The superior vena cava drains blood from the lower body into the right atrium.
A) True
B) False
B) False
Explanation: The superior vena cava drains blood from the upper body, while the inferior vena cava drains blood from the lower body.
The heart weighs about _______ grams (or ______ ounces) in an adult.
300 grams (10 ounces)
Explanation: The heart’s weight varies slightly between individuals but is approximately 300 g (10 oz) in an adult.
The space between the parietal and visceral layers of the serous pericardium is called the _______.
Pericardial cavity
Explanation: The pericardial cavity contains pericardial fluid and allows the heart to move without excessive friction.
The _______ pericardium is a simple squamous epithelium that reduces friction, while the _______ pericardium is a tough, collagenous sac that anchors the heart.
Serous; fibrous
Explanation: The serous pericardium secretes pericardial fluid and reduces friction, while the fibrous pericardium provides structural support.
The great vessels entering and leaving the heart include the _______ and _______ vena cavae, the pulmonary trunk, and the aorta.
Superior; inferior
Explanation: The superior and inferior vena cavae return deoxygenated blood to the heart, while the pulmonary trunk and aorta transport blood away from the heart.
Which of the following is the thickest layer of the heart wall?
A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardium
B) Myocardium
Explanation: The myocardium is composed of cardiac muscle tissue and is responsible for the heart’s contractions. It is the thickest layer because it performs the heart’s work.
The epicardium is also known as which of the following?
A) The outer fibrous layer of the pericardium
B) The visceral layer of the serous pericardium
C) The inner lining of the heart chambers
D) The thickest muscular layer of the heart
B) The visceral layer of the serous pericardium
Explanation: The epicardium is the outermost layer of the heart wall and is synonymous with the visceral layer of the serous pericardium.
Which part of the heart is responsible for lining the interior of the heart chambers?
A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardial sac
C) Endocardium
Explanation: The endocardium is a thin layer of simple squamous epithelium that lines the heart chambers and is continuous with the blood vessel endothelium.
The twisting or wringing motion of the heart during contraction is caused by which of the following?
A) The endocardium’s elasticity
B) The pericardium’s friction-reducing properties
C) The vortex of the heart’s myocardial muscle bundles
D) The shape of the heart valves
C) The vortex of the heart’s myocardial muscle bundles
Explanation: The myocardium is arranged in spiral bundles that allow the ventricles to contract with a twisting motion, helping to efficiently eject blood.
The epicardium is primarily made of thick adipose tissue throughout the entire heart.
A) True
B) False
B) False
Explanation: While the epicardium contains adipose tissue in some areas, it is generally thin and translucent, allowing the underlying cardiac muscle to be visible.
The endocardium is continuous with the endothelium of blood vessels.
A) True
B) False
A) True
Explanation: The endocardium lines the heart chambers and extends into the blood vessels, maintaining a smooth surface for blood flow.
The heart is composed mostly of myocardium.
A) True
B) False
A) True
Explanation: The myocardium makes up the bulk of the heart and is responsible for pumping blood through the circulatory system.
The coronary sulcus separates the atria from the ventricles externally.
A) True
B) False
A) True
Explanation: The coronary sulcus is a groove on the surface of the heart that marks the division between the atria and the ventricles.
The heart wall consists of three layers: _______ (outer), _______ (middle), and _______ (inner).
Epicardium, myocardium, endocardium
Explanation: These layers form the structure of the heart, with the myocardium being the thickest and most muscular.
The thickest layer of the heart, responsible for contraction, is the _______.
Myocardium
Explanation: The myocardium is composed of cardiac muscle fibers and is the powerhouse of the heart’s function.
The twisting motion of the ventricles during contraction is a result of the _______ of the heart.
Vortex
Explanation: The myocardium’s muscle fibers are arranged in a spiral pattern, forming a vortex that enhances the efficiency of contraction.
The _______ is a groove on the heart’s surface that contains major coronary arteries and separates the atria from the ventricles.
Coronary sulcus
Explanation: The coronary sulcus houses important blood vessels that supply the heart muscle and marks the external boundary between the atria and ventricles.
What is the function of the fibrous skeleton of the heart?
A) It helps conduct electrical impulses between the atria and ventricles
B) It provides structural support and prevents overstretching of the valves
C) It produces red blood cells
D) It pumps blood through the heart
B) It provides structural support and prevents overstretching of the valves
Explanation: The fibrous skeleton is made of collagenous and elastic fibers that support the valves and great vessels, preventing excessive stretching from blood pressure changes.
Which heart chamber receives blood returning from the systemic circulation?
A) Left ventricle
B) Left atrium
C) Right ventricle
D) Right atrium
D) Right atrium
Explanation: The right atrium receives oxygen-poor blood from the systemic circulation via the superior and inferior vena cavae.
What is the primary function of the pectinate muscles in the atria?
A) They help anchor the heart valves
B) They provide structural support and increase contraction strength
C) They produce electrical impulses for contraction
D) They prevent the heart chambers from over-expanding
B) They provide structural support and increase contraction strength
Explanation: Pectinate muscles are internal ridges in the atria that allow for stronger contraction without adding significant weight to the heart.
Which structure separates the right and left ventricles?
A) Interatrial septum
B) Coronary sulcus
C) Interventricular septum
D) Chordae tendineae
C) Interventricular septum
Explanation: The interventricular septum is a thick, muscular wall that divides the two ventricles and prevents the mixing of oxygen-rich and oxygen-poor blood.
Which valve prevents backflow of blood from the left ventricle into the left atrium?
A) Pulmonary valve
B) Aortic valve
C) Tricuspid valve
D) Mitral (bicuspid) valve
D) Mitral (bicuspid) valve
Explanation: The mitral valve (also called the left AV valve) prevents backflow of blood from the left ventricle into the left atrium during contraction.
The fibrous skeleton of the heart is a conductor of electricity.
A) True
B) False
B) False
Explanation: The fibrous skeleton acts as an electrical insulator, preventing electrical signals from passing directly between the atria and ventricles.
The right ventricle has a thicker wall than the left ventricle.
A) True
B) False
B) False
Explanation: The left ventricle has a much thicker wall because it needs to generate higher pressure to pump blood throughout the entire body.
The coronary sulcus separates the atria from the ventricles externally.
A) True
B) False
A) True
Explanation: The coronary sulcus is a groove that marks the division between the atria and ventricles and contains coronary blood vessels.
The chordae tendineae help prevent AV valve prolapse.
A) True
B) False
A) True
Explanation: Chordae tendineae are tendon-like cords that anchor the AV valves to the papillary muscles, preventing the valves from inverting when the ventricles contract.
The trabeculae carneae are internal ridges in the atria.
A) True
B) False
B) False
Explanation: The trabeculae carneae are internal ridges found in the ventricles, not the atria, and they help prevent the ventricular walls from sticking together during contraction.
The heart has four chambers: two superior _______ and two inferior _______.
Atria; ventricles
Explanation: The atria receive blood, while the ventricles pump blood out of the heart.
The right AV valve is also known as the _______ valve, while the left AV valve is called the _______ valve.
Tricuspid; mitral (bicuspid)
Explanation: The right AV valve has three cusps (tricuspid), while the left AV valve has two cusps (mitral/bicuspid).
The _______ muscle bundles give the ventricles their characteristic wrinkled appearance and help prevent suctioning of the walls during contraction.
Trabeculae carneae
Explanation: These muscular ridges in the ventricles prevent the walls from sticking together.
The fibrous cords that connect the valve cusps to papillary muscles are called _______.
Chordae tendineae
Explanation: The chordae tendineae prevent AV valve prolapse by anchoring them to the papillary muscles.
The _______ sulcus encircles the heart and separates the atria from the ventricles externally.
Coronary
Explanation: The coronary sulcus marks the boundary between the atria and ventricles and contains major coronary blood vessels.
Which of the following is NOT a function of the fibrous skeleton of the heart?
A) Providing structural support for the heart
B) Anchoring cardiomyocytes for contraction
C) Conducting electrical impulses between the atria and ventricles
D) Preventing overstretching of the heart valves
C) Conducting electrical impulses between the atria and ventricles
Explanation: The fibrous skeleton actually serves as an electrical insulator, preventing direct electrical conduction between the atria and ventricles, which ensures proper timing of heart contractions.
What are the receiving chambers of the heart called?
A) Ventricles
B) Atriums
C) Atria
D) Valves
C) Atria
Explanation: The right atrium receives oxygen-poor blood from the systemic circulation, and the left atrium receives oxygen-rich blood from the pulmonary circuit.
Which chamber of the heart has the thickest myocardium?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
D) Left ventricle
Explanation: The left ventricle has the thickest myocardium because it pumps blood to the entire body, requiring greater force than the other chambers.
Which structure separates the right and left atria?
A) Interventricular septum
B) Chordae tendineae
C) Interatrial septum
D) Coronary sulcus
C) Interatrial septum
Explanation: The interatrial septum is a thin wall that separates the two atria and helps prevent the mixing of oxygen-rich and oxygen-poor blood.
What is the function of the chordae tendineae?
A) They contract to close the heart valves
B) They anchor the AV valve cusps to papillary muscles
C) They help the atria pump blood
D) They separate the right and left ventricles
B) They anchor the AV valve cusps to papillary muscles
Explanation: The chordae tendineae prevent the AV valves from inverting (prolapsing) when the ventricles contract, ensuring one-way blood flow.
The fibrous skeleton of the heart provides electrical insulation between the atria and ventricles.
A) True
B) False
A) True
Explanation: The fibrous skeleton prevents direct electrical conduction between the atria and ventricles, ensuring coordinated contractions.
The right atrium receives oxygen-rich blood from the lungs.
A) True
B) False
B) False
Explanation: The right atrium receives oxygen-poor blood from the body via the superior and inferior vena cavae.
The left ventricle pumps blood into the pulmonary circuit.
A) True
B) False
B) False
Explanation: The right ventricle pumps blood into the pulmonary circuit, while the left ventricle pumps blood into the systemic circuit.
The trabeculae carneae help prevent suction and sticking of the ventricular walls during contraction.
A) True
B) False
A) True
Explanation: The trabeculae carneae are muscular ridges inside the ventricles that help keep the walls from sticking together during contraction.
The left AV valve is also called the mitral valve.
A) True
B) False
A) True
Explanation: The left AV valve (also known as the mitral valve or bicuspid valve) regulates blood flow between the left atrium and left ventricle.
The heart has four chambers: two upper _______ and two lower _______.
Atria; ventricles
Explanation: The atria receive blood, while the ventricles pump blood out of the heart.
The _______ septum separates the right and left ventricles.
Interventricular
Explanation: The interventricular septum is a thick muscular wall that divides the two ventricles.
The fibrous skeleton is made of _______ and _______ fibers.
Collagen; elastic
Explanation: The fibrous skeleton provides support and flexibility to the heart, preventing overstretching of the valves.
The _______ sulcus separates the atria from the ventricles externally.
Coronary
Explanation: The coronary sulcus is a groove that contains coronary arteries and separates the atria from the ventricles.
The function of the _______ is to keep the AV valves from flipping inside out or bulging into the atria when the ventricles contract.
Chordae tendineae
Explanation: The chordae tendineae are tendon-like structures that help keep the AV valves properly positioned.
Which structure separates the right and left ventricles?
A) Interatrial septum
B) Chordae tendineae
C) Interventricular septum
D) Coronary sulcus
C) Interventricular septum
Explanation: The interventricular septum is a thick muscular wall that separates the ventricles and prevents the mixing of oxygenated and deoxygenated blood.
Which of the following best describes the function of the atrioventricular (AV) valves?
A) They regulate blood flow between the atria and ventricles
B) They prevent backflow of blood into the atria
C) They ensure one-way blood flow through the heart
D) All of the above
D) All of the above
Explanation: AV valves (tricuspid and mitral) allow blood to flow from the atria to the ventricles while preventing backflow when the ventricles contract.
What prevents AV valve prolapse during ventricular contraction?
A) Trabeculae carneae
B) Chordae tendineae and papillary muscles
C) Coronary sulcus
D) Interventricular septum
B) Chordae tendineae and papillary muscles
Explanation: Chordae tendineae anchor the AV valve cusps to papillary muscles, preventing the valves from inverting under high pressure.
What is the primary function of the semilunar valves (pulmonary and aortic valves)?
A) To allow blood flow between atria and ventricles
B) To prevent blood from flowing back into the ventricles
C) To generate the heart’s electrical impulses
D) To separate the atria from the ventricles
B) To prevent blood from flowing back into the ventricles
Explanation: The semilunar valves ensure that blood flows into the pulmonary trunk and aorta without backflow into the ventricles.
Which chamber of the heart has the thickest myocardium?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
D) Left ventricle
Explanation: The left ventricle has the thickest myocardium because it pumps blood to the entire body, requiring greater force.
The right ventricle pumps oxygenated blood to the systemic circuit.
A) True
B) False
B) False
Explanation: The right ventricle pumps deoxygenated blood to the pulmonary circuit for oxygenation in the lungs.
The coronary sulcus separates the atria from the ventricles externally.
A) True
B) False
A) True
Explanation: The coronary sulcus is a groove that houses major blood vessels and demarcates the external boundary between the atria and ventricles.
The pectinate muscles are found in the atria and resemble the trabeculae carneae in the ventricles.
A) True
B) False
A) True
Explanation: Pectinate muscles provide internal support for the atria and have a ridged appearance similar to the trabeculae carneae in the ventricles.
The mitral valve is also known as the tricuspid valve.
A) True
B) False
B) False
Explanation: The mitral valve (or bicuspid valve) has two cusps, while the tricuspid valve has three cusps and is located on the right side of the heart.
The interventricular septum is primarily composed of cardiac muscle.
A) True
B) False
A) True
Explanation: The interventricular septum is a thick, muscular partition that separates the left and right ventricles and helps with contraction.
The heart has four chambers: two superior _______ and two inferior _______.
Atria; ventricles
Explanation: The atria receive blood, while the ventricles pump blood to the lungs and the rest of the body.
The right AV valve is also known as the _______ valve, while the left AV valve is called the _______ valve.
Tricuspid; mitral (bicuspid)
Explanation: The right AV valve (tricuspid) has three cusps, while the left AV valve (mitral/bicuspid) has two cusps.
The fibrous cords that connect the AV valve cusps to papillary muscles are called _______.
Chordae tendineae
Explanation: The chordae tendineae prevent AV valve prolapse by securing them to the papillary muscles.
The right ventricle pumps blood into the _______ trunk, while the left ventricle pumps blood into the _______.
Pulmonary; aorta
Explanation: The right ventricle sends deoxygenated blood to the lungs, while the left ventricle sends oxygenated blood to the body.
The semilunar valves include the _______ valve and the _______ valve.
Pulmonary; aortic
Explanation: The pulmonary valve prevents backflow from the pulmonary trunk, and the aortic valve prevents backflow from the aorta.
