{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CARDIOVASCULAR AND LYMPHATIC SYSTEMS Roger J. Bick Reading: Gartner and Hiatt Chapter 8, p147; Klein and McKenzie p155-179 Objectives :-After this lecture and lab you should be able to distinguish and know the layers and cell types of the heart and vasculature The differences between large arteries and large veins The differences between arterioles and small veins Know the different types of capillaries Know the origination, termination and architecture of lymphatics Key Words: Tunica Intima, media, adventitia; elastic artery, muscular artery, arteriole, capillary, metarteriole, venule, muscular vein; valve; smooth muscle, lymphatics Cardiovascular system is comprised of 3 layers throughout. The heart has 3 layers - endocardium (inside - a thin layer of endothelium), myocardium (middle - a thick layer of striated muscle), and epicardium (outer - a thin layer of flat, squamous endothelium), attached to each other by connective tissue. The vessels (veins, arteries and capillaries) have 3 layers :- a tunica intima (inner, akin to the endocardium: tunica [L] means coat), a tunic media (middle, akin to the myocardium) and tunica adventitia (outer, akin to the epicardium). The heart: A pump for blood; Bulk of the tissue is striated, involuntary cardiac muscle, which pumps rhythmically (hopefully); can undergo hypertrophy (thickening), atrophy (thinning), necrosis (damage-induced cell death) and apoptosis (programmed cell death). In the lab you will have a section of heart that will look something like this:- There are 4 valves in the heart, tricuspid (right AV), mitral (left AV), and semilunar (pulmonary artery and aorta) - folds of endocardium covered by endothelium; Tricuspid and mitral valves thicker than semilunar; all contain smooth muscle, lymphatics, blood vessels and a central connective tissue core.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Pericardium is probably not present in your lab specimen. Pericardium (Outer, fluid filled sac covering the heart):- a) Parietal pericardium (outer-nearest the skin) – thin mesothelium that adheres to fat and connective tissue of pericardial cavity. b) Pericardial Fluid – Plasma ultrafiltrate from visceral pericardium; Proteinaceous in nature; lubricant for the contraction/relaxation of the heart; 15-50cc. c) Visceral pericardium – thin mesothelium, sometimes cuboidal, that adheres to epicardium. Epicardium – Thin layer of flat to cuboidal cells, covering fibrous and adipose connective tissue; Contains nerves and vasa vasorum (vessels) of both heart and of coronary vessels found in this connective tissue mass (equivalent to tunica adventitia of the vessels). Myocardium – thickest layer of the heart (usually); Composed of bundles of cardiac muscle of varying thickness (easily distinguished by striations, intercalated discs, branched fibers and centrally located nuclei); strands of connective tissue and some vascular tissue course through it (equivalent to the tunica media of the vessels).
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}