Ch. 20 The Heart Flashcards
What system is the heart, blood, and blood vessels part of?
The cardiovascular system
What is the function of the cardiovascular system?
- To distribute oxygen and nutrients to the cells of the body
- To take away carbon dioxide and other wastes
How many beats does the heart do per day?
100,000
How many liters of blood does the heart pump daily?
8,000
Beginning with the right atrium, what is the order of the valves through which blood will pass?
Blood will pass through the tricuspid valve (right AV valve), the pulmonary valve, the mitral valve (left AV valve), and finally the aortic valve.
Which division of the autonomic nervous system would increase heart rate?
The sympathetic nervous system would increase heart rate. The cardioacceleratory center controls sympathetic neurons that increase heart rate.
Oxygen-poor blood is pumped to ______ within the ______ circuit
The lungs
Pulmonary circuit
Oxygen-rich blood is pumped to ______ within the ______ circuit
The body
Systemic circuit
What is the pathway the pulmonary circuit takes?
Oxygen-poor blood from the right ventricle through the pulmonary arteries, to the lungs. Oxygen-rich blood back through the pulmonary veins to the left atrium
What is the pathway the systemic circuit takes?
Oxygen-rich blood from the left ventricle through the systemic arteries. Oxygen-poor blood through systemic veins back to the right atrium
Blood returning to the heart from the systemic circuit must complete the…?
Pulmonary circuit before reentering the systemic circuit
Which circuit does the left side of the heart supply blood to?
The systemic circuit
Which circuit does the right side of the heart supply blood to?
Pulmonary circuit
____ carry blood away from the heart
Arteries
____ return blood to the heart
Veins
What are great vessels?
The largest veins and arteries in the body; connected to the heart
What do capillaries do?
Interconnect the smallest arteries and the smallest veins
Why are capillaries called exchange vessels?
Their thin walls permit the exchange of nutrients, dissolved gases, and wastes between the blood and surrounding tissue
What are the 4 muscular chambers of the heart?
Right atrium
Right ventricle
Left atrium
Left ventricle
What does the right atrium do?
Receives blood from the systemic circuit and passes it to the right ventricle
What does the right ventricle do?
Pumps blood into the pulmonary circuit
What does the left atrium do?
Collects blood from the pulmonary circuit and empties it into the left ventricle
What does the left ventricle do?
Pumps blood into the systemic circuit
When the heart beats, what contracts first?
The atria
Where is the heart located?
In the thoracic cavity near the anterior chest wall, directly posterior to the sternum
Where are the great vessels (veins and arteries) connected?
To the superior end of the heart at its base
What is the name of the pointed tip of the heart?
Apex
What does heart size depend on?
Age, height, weight, sex
What are the walls of the heart, from deep to superficial?
Endocardium
Myocardium
Pericardium
Define endocardium
Inner layer whose simple squamous epithelium is continuous with the endothelial lining of blood vessels
Define myocardium
Spiral bundles of cardiac muscle cells
Define pericardium
Surrounds the heart and consists of an outer fibrous pericardium and an inner serous pericardium
What is the name of the expandable extension of an atrium?
Auricle
What is the coronary sulcus?
A deep groove that marks the border between the atria and the ventricles
What marks the boundary between the left and right ventricles?
The anterior interventricular sulcus and the posterior interventricular sulcus
What lies in the coronary and interventricular sulci?
Fat
What are the heart wall’s distinct layers, from superficial to deep?
Outer epicardium
Middle myocardium
Inner endocardium
What does the outer epicardium cover?
The surface of the heart
What does the middle myocardium contain?
Cardiac muscle cells, connective tissues, blood vessels, and nerves
What does the inner endocardium cover?
The inner surfaces of the heart, including the heart valves
What does the connective tissues of the heart include?
Large numbers of collagen and elastic fibers
Each cardiac muscle cell is wrapped in…?
A strong elastic sheath
What are the atria separated by?
The interatrial septum
What are the two atrioventricular valves?
Tricuspid valve
Mitral valve
What do the atrioventricular valves permit?
Blood to flow only in only one direction: from the atria to the ventricles
What are the two semilunar valves?
Pulmonary valve
Aortic valve
What are the two great veins the right atrium receives blood from the systemic circuit through?
Superior vena cava and the inferior vena cava
Where does the superior vena cava deliver blood to the right atrium from?
From the head, neck, upper limbs, and chest
Where does the inferior vena cava deliver blood to the right atrium from?
The rest of the trunk, viscera, and lower limbs
What does the foramen ovale become?
The fossa ovalis
What are cusps?
Blood travels from the right atrium into the right ventricle through a broad opening bordered by three fibrous flaps, called cusps
What do contractions on the papillary muscles pull on?
The chordae tendineae
What are trabeculae carneae?
Muscular ridges on the internal surface of the right ventricle
Which valve guards the entrance to the left ventricle?
The mitral valve
Where does the mitral valve permit blood to flow from and into?
From the left atrium into the left ventricle
What is the difference between the internal organization of the left and right ventricles?
The left ventricle does not have a moderator band
Blood leaves the left ventricle through the _____ and enters the _____
Aortic valve
Ascending aorta
What is the function of the atria?
To collect blood that is returning to the heart and to convey it to the ventricles
Which ventricle is larger and why?
The left ventricle is much larger than the right ventricle because the left ventricle has thicker walls that enable it to push blood through the body’s systemic circuit. The right ventricle needs to pump blood at lower pressure to and from the lungs
When the ventricles are _____, the tricuspid and mitral valves are _____ and the aortic and pulmonary valves are _____
Relaxed
Open
Closed
When the ventricles are _____, the tricuspid and mitral valves are _____ and the aortic and pulmonary valves are _____
Contracting
Closed
Open
Which valve is the most common to falter?
The mitral valve
When using a stethoscope, what are faulty valves heard as?
Heart murmurs
What prevents the backflow of blood from the ventricles to the atria when the ventricles are contracting?
The atrioventricular (AV) valves
What prevents the backflow of blood from the pulmonary trunk and aorta into the right and left ventricles?
The pulmonary and aortic semilunar valves
