Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cardiovascular System (The Heart (Percardial Membranes (Serous Pericardium…
Cardiovascular System
The Heart
Percardial Membranes
Serous Pericardium Membrane made up of simple squamous epithelium and areolar connective tissue. Two type, parietal and visceral.
-
-
Periocardial Cavity Filled with serous fluid to reduce friction between heart and other structures, i.e. sternum, lungs et.al
Fibrous Pericardium is the sac that encloses the heart. Made of Dense Irregular Connective Tissue, from the diaphragm to roots of large vessels. It keeps the heart in place and from over-filling with blood.
Layers of the Heart Wall There are three layers to the heart wall. The Epicardium, Myocardium, and the Endocardium
Epicardium Visceral Pericardium, i.e. simple squamous epithelium, and areolar connective tissue. External Layer.
Myocardium comprised of cardiac muscle tissue, makes up the majority of the cardiac wall and is responsible for its pumping action. Middle Layer
Endocardium Made up of simple squamous epithelium, and areolar connective tissue. Lines the hear and covers the valves. Inner Layer.
-
Papillary Muscles - Connected to the Chordae Tendinae, holds valves in place to prevent backflow/eversion of blood to atria.
Microscopic Anatomy of the Myocardium Intercalated Discs are located throughout the myocardium. They help with synchronization of contractions. Located along the transverse plane. Fascia Adherens a desmosome like structure which acts as an anchor for actin. Gap Junctions help with electrical signals and movement of ions from one cardiac cell to the next.
Heart Valves There are four valves in the heart. Two Atrioventricular Valves, and two Semilunar Valves
Atrioventricular Valves The Mitral Valve (Bicuspid Valve), and the Tricuspid Valve, which are between the upper chambers (atria) and the lower chambers (ventricles).
Semilunar Valves The Aortic Valve and the Pulmonary Valve, which are in the arteries leaving the heart.
Conduction System of the Heart The Sinoatrial Node (SA Node) also known as the Pacemaker is the intrinsic electrical system. Sets the heart rate, generates signals that spread through the myocardium of the atria. Sends electrical signal to the Atrioventricular Node (AV Node), short delay to allow ventricles to fill. The AV node then spreads into the AV Bundle which goes down the Interventricular Septum which has both right and left branches. Contraction occurs at Apex first and squeezes up.
Blood Vessels Veins, Arteries, Capillaries
Arteries There are three types of arteries- Elastic/Conducting, Muscular/Distributing, and Arterioles
Elastic/Conducting Largest and proximal to the heart i.e aortal and major branches. Moves blood away from the heart.
Muscular/Distributing Distal to the Elastic/Conducting arteries. More muscle relative to size than other organs. Takes the blood to organs/parts of organs.
Arterioles smallest arteries. Made up of 1-2 layers of smooth muscle, can constrict and dilate.
-
Capillaries exchange vessels between the arterioles and venules. The blood leaves the heart though the arteries, and is returned through the venules into the veins. The capillaries are the intermediary between the two.
Fenestrated Capillaries with windows. Pores. High rate of exchange. Small Intestine, kidneys, choroid plexus, endocrine glands.
Sinusoid Large, winding. Large items can be exchanged, i.e. proteins.
Continuous most common. Lungs, skin, C.N.S., smooth and skeletal muscle. Intercellular cletts (gaps), somewhat leaky.
Blood Blood is made up of proteins, cells and plasma.
Plasma Liquid portion of blood, 90% water and more than hundren molecules i.e. ions, minerals et al.
Within blood you'll also find Erythrocytes, which are red blood cells formed in red bone marrow. Contains hemoglobin which binds with oxygen. Leukocytes which are involved in immunity. Platelets also known as thrombocytes, they are involved in clotting.