1.
The _______ is a four-chambered, hollow, muscular organ that has a cone-shape.
Explanation
The heart is a four-chambered, hollow, muscular organ that has a cone-shape. It is responsible for pumping blood throughout the body, supplying oxygen and nutrients to the cells. The heart is composed of four chambers: two atria and two ventricles. The atria receive blood from the body and lungs, while the ventricles pump blood out to the rest of the body. The muscular walls of the heart contract and relax rhythmically to maintain a steady flow of blood. Its cone-shaped structure allows for efficient pumping and circulation of blood.
2.
The size of the heart is about _____ cm long and ___ cm wide.
Correct Answer
C. 14; 9
Explanation
The size of the heart is approximately 14 cm long and 9 cm wide.
3.
The heart is located within the ______ and rests on the ______ and is slightly _____ of the midline.
Correct Answer
mediastinum, diaphragm, left
Explanation
The heart is located within the mediastinum, which is the central compartment of the thoracic cavity. It rests on the diaphragm, which is a muscular partition separating the thoracic and abdominal cavities. The heart is slightly to the left of the midline, a position known as left-sided cardiac apex.
4.
The heart is bordered laterally by the _______, posteriorly by the ___________ and anteriorly by the ________.
Correct Answer
lungs, spinal column, sternum
Explanation
The heart is located in the chest cavity and is surrounded by various structures. Laterally, it is bordered by the lungs, which are the primary organs responsible for respiration. Posteriorly, the heart is bordered by the spinal column, which provides support and protection to the spinal cord. Anteriorly, the heart is bordered by the sternum, also known as the breastbone, which forms the front part of the ribcage. These structures create a protective enclosure around the heart, ensuring its proper functioning and minimizing the risk of injury.
5.
The ______ of the heart is the broader portion and is directed __________.
Correct Answer
base, posterosuperiorly
Explanation
The base of the heart refers to the broader portion of the organ. It is directed posterosuperiorly, meaning it is positioned towards the back and top of the body. This positioning is important for the proper functioning of the heart, as it allows for efficient blood flow and coordination with other structures within the chest cavity.
6.
Which of the great vessels emerge from the base of the heart?
Correct Answer
E. Both B & C
Explanation
Both the aorta and the pulmonary trunk emerge from the base of the heart. The aorta is the largest artery in the body and carries oxygenated blood from the heart to the rest of the body. The pulmonary trunk, on the other hand, carries deoxygenated blood from the heart to the lungs for oxygenation. Therefore, the correct answer is both B (aorta) and C (pulmonary trunk).
7.
The ______ of the heart is the distal portion and is made up largely of the tip of the ________ at the level of the _____________.
Correct Answer
apex, left ventricle, 5th intercostal space
Explanation
The apex of the heart refers to the distal portion, which is the tip of the left ventricle. This is located at the level of the 5th intercostal space.
8.
The exact position of the ___________ varies somewhat from person to person. It is located at the ________ and to the _______ of the sternum. It is possible to either palpate or hear it at this location.
Correct Answer
apical heartbeat, 5th intercostal space, left
Explanation
The apical heartbeat refers to the exact position of the heartbeat that can vary slightly from person to person. It is located at the 5th intercostal space, which is the space between the ribs, on the left side of the sternum. It is possible to either feel or hear the heartbeat at this location.
9.
The heart and the origins of the great blood vessels are enclosed in a loose fitting sac termed the ____________ which consists of two layers.
Correct Answer
B. Pericardium
Explanation
The correct answer is pericardium. The pericardium is a loose fitting sac that encloses the heart and the origins of the great blood vessels. It consists of two layers, the outer fibrous layer and the inner serous layer. The pericardium provides protection and support to the heart and also allows it to move and beat within the chest cavity.
10.
What is the outer layer of the pericardium that is a loose fitting sac that is composed of thick, white fibrous CT called?
Correct Answer
E. Fibrous pericardium
Explanation
The fibrous pericardium is the correct answer because it is the outer layer of the pericardium that is composed of thick, white fibrous connective tissue. It forms a loose-fitting sac that surrounds and protects the heart. The fibrous pericardium provides structural support and helps to prevent overstretching of the heart.
11.
The __________ anchors the heart in the mediastinum.
Correct Answer
fibrous pericardium
Explanation
The fibrous pericardium is a tough, dense, and fibrous outer layer of the pericardium that anchors the heart in the mediastinum. It forms a protective sac around the heart and prevents it from overexpanding or shifting within the chest cavity. The fibrous pericardium also helps to maintain the position of the heart and provides stability during movements such as contraction and relaxation.
12.
What is the name of the delicate inner layer of the sac that covers the heart?
Correct Answer
C. Visceral pericardium
Explanation
The correct answer is visceral pericardium. The visceral pericardium is the delicate inner layer of the sac that covers the heart. It is also known as the epicardium and is composed of a thin layer of connective tissue and a layer of epithelial cells. The visceral pericardium helps protect the heart and also produces a lubricating fluid that allows the heart to beat smoothly within the pericardial cavity.
13.
Another name for the visceral pericardium is the __________.
Correct Answer
D. Epicardium
Explanation
The epicardium is another name for the visceral pericardium. The visceral pericardium is the innermost layer of the pericardium, which is the protective sac surrounding the heart. It is composed of a thin layer of connective tissue and is in direct contact with the surface of the heart. The epicardium helps to protect and lubricate the heart, allowing it to beat smoothly within the pericardial cavity.
14.
The visceral pericardium folds back upon itself and becomes the _______________.
Correct Answer
E. Parietal pericardium
Explanation
The visceral pericardium refers to the inner layer of the pericardium that surrounds the heart. It folds back upon itself and becomes the parietal pericardium, which is the outer layer of the pericardium. The parietal pericardium is a tough, fibrous sac that protects and supports the heart.
15.
The parietal pericardium forms the inner lining of the _________.
Correct Answer
A. Fibrous pericardium
Explanation
The parietal pericardium forms the inner lining of the fibrous pericardium. The fibrous pericardium is the tough, outer layer of the pericardium that surrounds and protects the heart. The parietal pericardium is a thin, serous membrane that lines the fibrous pericardium and helps to lubricate and reduce friction between the heart and the surrounding structures.
16.
The space between the visceral and parietal layers is called the ___________. It contains about __________ ml of pericardial fluid.
Correct Answer
pericardial cavity, 25-35
Explanation
The space between the visceral and parietal layers of the pericardium is called the pericardial cavity. This cavity contains approximately 25-35 ml of pericardial fluid. The pericardial fluid acts as a lubricant, reducing friction between the layers of the pericardium during heart contractions and movements.
17.
The _________, the _________ and the ___________ are the three layers that compose the wall of the heart.
Correct Answer
epicardium, myocardium, endocardium
Explanation
The epicardium, myocardium, and endocardium are the three layers that make up the wall of the heart. The epicardium is the outermost layer, also known as the visceral pericardium, which covers the surface of the heart. The myocardium is the middle layer and consists of cardiac muscle tissue responsible for the contraction of the heart. The endocardium is the innermost layer, lining the chambers of the heart and providing a smooth surface for blood flow. Together, these three layers work together to support the structure and function of the heart.
18.
The _________ serves as the protective outer covering of the heart. It is a _______ that consists of ____ covered by __________.
Correct Answer
epicardium, serous membrane, CT, epithelium
Explanation
The epicardium serves as the protective outer covering of the heart. It is a serous membrane that consists of connective tissue covered by epithelium.
19.
The ______ constitutes the greatest mass of the heart wall.
Correct Answer
D. Myocardium
Explanation
The myocardium is the middle layer of the heart wall and is responsible for the contraction of the heart. It is composed of cardiac muscle tissue, which gives the heart its ability to pump blood. The myocardium is the thickest layer of the heart wall and makes up the majority of its mass. It is surrounded by the epicardium on the outer surface and the endocardium on the inner surface. The pericardium is the protective sac that surrounds the heart, and the pericardial cavity is the space between the layers of the pericardium.
20.
The _____ is the protective inner lining of the heart.
Correct Answer
E. Endocardium
Explanation
The endocardium is the correct answer because it is the protective inner lining of the heart. It is made up of a thin layer of endothelial cells that lines the chambers of the heart and covers the heart valves. The endocardium helps to prevent blood clots and provides a smooth surface for blood to flow through the heart.
21.
The endocardium lines the ________, ______ and is continuous with the ________ that enter and leave the heart.
Correct Answer
heart chambers, valves, great blood vessels
Explanation
The endocardium is the innermost layer of the heart, lining the heart chambers, valves, and great blood vessels. It provides a smooth surface for blood flow and helps prevent clotting. The endocardium is continuous with the blood vessels that enter and leave the heart, ensuring a seamless connection between the heart and the rest of the circulatory system.
22.
_______ are specialized cardiac muscle fibers that are involved with the conduction system of the heart and are found in the endocardium.
Correct Answer
E. Purkinje fibers
Explanation
Purkinje fibers are specialized cardiac muscle fibers that are involved in the conduction system of the heart. They are located in the endocardium, which is the innermost layer of the heart. These fibers help to transmit electrical impulses through the heart, coordinating the contraction and relaxation of the cardiac muscle.
23.
_______ are blood vessels that carry blood to the heart, and ________ are blood vessels that carry blood away from the heart.
Correct Answer
Veins, arteries
Explanation
Veins are blood vessels that carry blood back to the heart, while arteries are blood vessels that carry blood away from the heart. Veins have thinner walls and contain valves to prevent the backflow of blood, as they transport deoxygenated blood from the body tissues back to the heart. Arteries have thicker walls and higher pressure, as they carry oxygenated blood from the heart to the rest of the body.
24.
The ________ contains blood and lymph capillaries and nerve fibers.
Correct Answer
B. Epicardium
Explanation
The epicardium is the outermost layer of the heart wall and is composed of connective tissue. It contains blood and lymph capillaries and nerve fibers, which help to supply oxygen and nutrients to the heart muscle and transmit nerve signals for proper heart function.
25.
_______ may be noted in the deeper portion of the epicardium along paths
of large blood vessels.
Correct Answer
B. Fat
Explanation
Fat may be noted in the deeper portion of the epicardium along paths of large blood vessels.
26.
The myocardium consists largely of _________ whose cells are interwoven
to form a complex network
Correct Answer
C. Cardiac muscle
Explanation
The myocardium consists largely of cardiac muscle, which is responsible for the contraction and pumping action of the heart. The cells of cardiac muscle are interwoven to form a complex network, allowing for coordinated and efficient contraction of the heart. This network of cardiac muscle cells enables the heart to pump blood effectively throughout the body.
27.
The ________consists of epithelium and CT.
Correct Answer
C. Endocardium
Explanation
The endocardium is the correct answer because it is the innermost layer of the heart and is composed of epithelium and connective tissue (CT). The endocardium lines the chambers of the heart and covers the heart valves, providing a smooth surface for blood flow and preventing clot formation.
28.
The function of the ________ is to contract and pump blood out of the heart.
Correct Answer
E. Myocardium
Explanation
The correct answer is myocardium. The myocardium is the middle layer of the heart wall and is responsible for contracting and pumping blood out of the heart. It is composed of specialized cardiac muscle cells that work together to create the force needed to propel blood throughout the body.
29.
The ____________ functions to moisten the opposing surfaces and facilitates movement of the heart within the pericardial sac as the heart contracts and relaxes.
Correct Answer
D. Pericardial cavity
Explanation
The pericardial cavity is the correct answer because it is the space between the parietal and visceral pericardium where fluid is present. This fluid helps to lubricate the opposing surfaces of the heart and the pericardial sac, allowing for smooth movement of the heart as it contracts and relaxes. The pericardial cavity acts as a cushion, reducing friction and preventing damage to the heart during its rhythmic movements.