Anatomy and Histology of the Cardiovascular System

Vocabulary practice flashcards covering anatomical features, blood supply, nerve supply, and histological structures of the cardiovascular system based on lecture notes.

Pericardium

A fibroserous sac that encloses the heart and the roots of the great vessels, functioning to restrict excessive movements of the heart and serve as a lubricated container for contraction.

Fibrous pericardium

The strong, conical outer portion of the pericardium whose base is firmly attached to the central tendon of the diaphragm and apex is directed upwards.

Serous pericardium

A closed serous sac invaginated by the heart that lines the fibrous pericardium and coats the heart, composed of visceral and parietal layers.

Epicardium

The visceral layer of the serous pericardium that lies in direct contact with the heart; histologically, it is the outer protective layer composed of mesothelium and subepicardial connective tissue.

Pericardial cavity

The space between the parietal and visceral layers of the serous pericardium that contains a small amount of pericardial fluid.

Oblique sinus

A recess formed by the reflection of the serous pericardium around the large veins on the posterior surface of the heart, limited laterally by the pulmonary veins and venae cavae.

Transverse sinus

A short passage lying between the reflection of serous pericardium around the aorta and pulmonary trunk anteriorly, and the superior vena cava and left auricle posteriorly.

Musculi pectinati

Horizontal muscular ridges found along the anterior wall of the right atrium that arise from the crista terminalis, also present in small numbers within the left auricle.

Crista terminalis

A longitudinal muscle ridge on the anterior wall of the right atrium from which the musculi pectinati originate.

Fossa ovalis

An oval depression situated on the smooth inter-atrial septum along the posterior wall of the right atrium.

Trabeculae carneae

Irregular muscular ridges located within the rough inflow portions of the right and left ventricles.

Moderator band

A muscular band (septomarginal trabecula) extending between the inter-ventricular septum and the anterior wall of the right ventricle.

Chordae tendineae

Fine fibrous cords extending from the apices of papillary muscles to the cusps of the atrioventricular valves.

Infundibulum

The smooth, funnel-shaped outflow part of the right ventricle that leads directly into the pulmonary orifice.

Aortic vestibule

The smooth non-muscular outflow portion of the left ventricle that leads into the aortic orifice.

Interventricular septum

A septum lying obliquely between the two ventricles consisting of a lower muscular portion and an upper membranous portion.

Right coronary artery

An artery arising from the anterior aortic sinus that descends in the coronary sulcus to supply the right heart and ends by anastomosing with the circumflex artery.

Left coronary artery

An artery arising from the left posterior aortic sinus that passes between the pulmonary trunk and left auricle, branching into the anterior interventricular and circumflex arteries.

Coronary sinus

A wide venous channel located in the posterior part of the coronary sulcus that drains cardiac veins into the right atrium.

Endocardium

The inner layer of the heart wall comprising endothelium, subendothelium, and a subendocardium rich in veins, nerves, and impulse conducting fibers.

Myocardium

The middle and thickest muscular layer of the heart wall, consisting of cardiac muscle fibers inserted into the fibrous cardiac skeleton.

Sarcomere

The structural and contractile unit of myofibrils, defined as the region between two successive Z lines containing thin actin filaments and thick myosin filaments.

Intercalated disks

Junctional complexes crossing cardiac muscle fibers at the Z line level that connect adjacent cardiac muscle cells.

Fascia adherens

The principal component of the transverse portion of intercalated disks that mechanically holds cardiac muscle cells together.

Gap junctions

Cell junctions predominant in the longitudinal portion of intercalated disks that allow passage of ionic contractile signals between cells.

Dyad

A cardiac muscle triad-analog formed by a single wide T-tubule at the Z line level in junctional contact with a small flattened saccule of sarcoplasmic reticulum.

Sino-Atrial (S.A.) node

A saddle-shaped area located anterolateral to the superior vena cava opening that acts as the heart's pacemaker, consisting of modified small cardiac muscle cells.

Purkinje fibers

Specialized, large-diameter cardiac muscle cells located in the subendocardial layer that rapidly conduct action potentials and possess pale, vacuolated cytoplasm due to abundant glycogen.

Atrial natriuretic factor (ANF)

A polypeptide diuretic hormone stored within electron-dense membranous granules near the nuclear poles of specialized endocrine atrial muscle fibers.

Tunica intima

The innermost tunic of a blood vessel wall, composed of endothelium resting on a basal lamina, subendothelium, and an internal elastic lamina.