Cardiovascular Review Supplement
6
Histology Review Supplement
Cardiovascular Tissue Review
From the PhysioEx main menu, select Histology Atlas. Click on the white Sort By drop-down menu and select Histology Review from the list. Refer to the slides in the Cardiovascular Tissue Slides folder as you complete this worksheet.
Which component of the intercalated disc is a junction that provides the intercellular communication required for the myocardium to perform as a functional syncytium? Gap junctions
Heart
The heart is a four-chambered muscular pump. Although its wall can be divided into three distinct histological layers (endocardium, myocardium, and epicardium), the cardiac muscle of the myocardium composes the bulk of the heart wall.
Blood Vessels
Blood vessels form a system of conduits through which lifesustaining blood is conveyed from the heart to all parts of the body and back to the heart again.
Click slide 3.
Generally, the wall of every vessel is described as being composed of three layers, or tunics. The tunica intima, or tunica interna, a simple squamous endothelium and a small amount of subjacent loose connective tissue, is the innermost layer adjacent to the vessel lumen. Smooth muscle and elastin are the predominant constituents of the middle tunica media, and the outermost tunica adventitia, or tunica externa, is a connective tissue layer of variable thickness that provides support and transmits smaller blood and lymphatic vessels and nerves. The thickness of each tunic varies widely with location and function of the vessel. Arteries, subjected to considerable pressure fluctuations, have thicker walls overall, with the tunica media being thicker than the tunica adventitia. Veins, in contrast, are subjected to much lower pressures and have thinner walls overall, with the tunica adventitia often outsizing the tunica media. Because thinwalled veins conduct blood back to the heart against gravity, valves (not present in arteries) also are present at intervals to
Histology Review Supplement
Cardiovascular Tissue Review
From the PhysioEx main menu, select Histology Atlas. Click on the white Sort By drop-down menu and select Histology Review from the list. Refer to the slides in the Cardiovascular Tissue Slides folder as you complete this worksheet.
Which component of the intercalated disc is a junction that provides the intercellular communication required for the myocardium to perform as a functional syncytium? Gap junctions
Heart
The heart is a four-chambered muscular pump. Although its wall can be divided into three distinct histological layers (endocardium, myocardium, and epicardium), the cardiac muscle of the myocardium composes the bulk of the heart wall.
Blood Vessels
Blood vessels form a system of conduits through which lifesustaining blood is conveyed from the heart to all parts of the body and back to the heart again.
Click slide 3.
Generally, the wall of every vessel is described as being composed of three layers, or tunics. The tunica intima, or tunica interna, a simple squamous endothelium and a small amount of subjacent loose connective tissue, is the innermost layer adjacent to the vessel lumen. Smooth muscle and elastin are the predominant constituents of the middle tunica media, and the outermost tunica adventitia, or tunica externa, is a connective tissue layer of variable thickness that provides support and transmits smaller blood and lymphatic vessels and nerves. The thickness of each tunic varies widely with location and function of the vessel. Arteries, subjected to considerable pressure fluctuations, have thicker walls overall, with the tunica media being thicker than the tunica adventitia. Veins, in contrast, are subjected to much lower pressures and have thinner walls overall, with the tunica adventitia often outsizing the tunica media. Because thinwalled veins conduct blood back to the heart against gravity, valves (not present in arteries) also are present at intervals to