Cardiovascular System (Textbook) Flashcards
What does the heart rest on?
The diaphragm
What is the pointed apex formed by?
The left ventricle
In what directions is the heart directed?
Anteriorly, inferiorly and to the left
What is the base of the heart opposite to?
The apex
What is the base of the heart formed by?
The atria of the heart (mostly the left atrium)
What are the two parts of the pericardium?
1) Fibrous pericardium
2) Serous pericardium
What is the superficial fibrous pericardium composed of?
Tough, inelastic, dense irregular connective tissue.
What are the functions of the fibrous pericardium?
Prevents over-stretching of the heart, provides protection, and anchors the heart in the mediastinum.
What is the serous pericardium?
A thinner, more delicate membrane that forms a double layer around the heart
Which layer of the serous pericardium is fused to the fibrous pericardium?
Parietal layer
What are the three layers of the heart wall?
Epicardium
Myocardium
Endocardium
What are the two tissue layers of the epicardium?
The outermost is the visceral layer of pericardium and is a thin, transparent, outer layer of the heart wall composed of mesothelium. Beneath this is a variable layer of delicate firboelastic tissue and adipose tissue.
Where does the adipose tissue of the epicardium become thickest?
Over the ventricular surfaces, where it houses major coronary and cardiac vessels of the heart.
What does the epicardium contain to supply the myocardium?
Blood vessels, lymphatics and vessels.
What is the myocardium responsible for?
The pumping action of the heart.
What is the myocardium composed of?
Cardiac muscle tissue
How much of the heart wall does the myocardium make up?
95%
What is the endocardium?
A thin layer of endothelium overlying a thin layer of connective tissue.
What are the functions of the endocardium?
Provides a smooth lining for the chambers of the heart and covers the valves of the heart.
What is the function of the auricle?
Slightly increases the capacity of an atrium so that it can hold a greater volume of blood.
What are the sulci of the heart?
A series of grooves on the surface of the heart that contain coronary blood vessels and a variable amount of fat.
What does each sulcus mark?
The external boundary between two chambers of the heart.
Where is the deep coronary sulcus situated?
Encircles most of the heart and marks the external boundary between the superior atria and inferior ventricles.
What is the anterior interventricular sulcus?
What does it continue on around to the posterior surface of the heart to become?
A shallow groove on the anterior surface that marks the external boundary between the right and left ventricles on the anterior aspect of the heart.
Posterior interventricular sulcus, which marks the external boundary between the ventricles on the posterior aspect of the heart.
What forms the right surface of the heart?
What are the three veins from which it receives blood from?
The right atrium
Superior vena cava, inferior vena cava, and coronary sinus
What is average thickness of the right atrium?
2-3 mm
What is the difference between the anterior and posterior walls of the right atrium?
The inside of the posterior wall is smooth and the inside of the anterior wall is rough due tot he presence of muscular ridges called pectinate muscles, which also extend into the auricle.
What is found between the right and left atrium?
A thin partition called the interatrial septum.
Describe the prominent feature of the interatrial septum.
An oval depression called the fossa ovalis, the remnant of the foramen ovale, an opening in the interatrial septum of the fetal heart that normally closes soon after birth.
What is another name for the tricuspid valve?
Right atrioventricular valve.
What are the valves of the heart composed of?
Dense connective tissue covered by endocardium
What is the average thickness of the right ventricle?
4-5 mm
What forms most of the anterior surface of the heart?
Right ventricle
Describe the inside of the ventricles
Contains a series of ridges formed by raised bundles of cardiac muscle fibers called trabeculae carneae.
What is the function of trabeculae carneae?
Convey part of the conduction system of the heart.
How are the cusps of the tricuspid/bicuspid valve attached to the wall of the heart?
The cusps of the valve are connected to tendonlike cords, the chordae tendineae, which in turn are connected to cone-shaped trabeculae carneae called papillary muscles.
How is the LV and RV separated internally?
Interventricular septum
What is the wall thickness of the left atrium the same as?
The wall thickness of the right atrium
What forms most of the base of the heart?
Left atrium
What does the left atrium receive blood from?
The lungs through four pulmonary veins.
What is different about the internal wall of the left atrium? Why is this?
It has smooth posterior and anterior walls. Pectinate muscles are confined to the auricle of the left auricle.