BIOL 2120K Lecture Notes - Lecture 3: Dense Irregular Connective Tissue, Pericardial Fluid, Heart Valve
Document Summary
Arteries always carry blood away from the heart. Veins always carry blood away from the heart. Arteries do not always carry oxygenated blood; veins do not always carry deoxygenated blood. **** follow path of blood through the heart, know it"s happening at the same time. Heart is covered in fibrous pericardium; dense irregular connective tissue (white, outer membrane) ---there is a space filled with pericardial fluid between these two layers. Visceral serous pericardium (has an epithelial layer) aka; epicardium - outer layer of the heart wall. Striated; capable of contraction (using z-band and calcium rushing in, etc. ) Av node sends signal through av bundle, branches to bundle branches, then to purknje fibers, which are in the walls of the ventricles. Nodal cells; no stable rmp - pacemaker cells. Then ca2+ channels (voltage-gated) open for depolarization (fast) K+ channels open for repolarization; l+ and cells becomes more negative. Slow na+ leak begins again to move to threshold.
