Anatomy Study Guide 19 PDF

1. Define mediastinum The space where the heart is located between the right and left pleural sacs within the thoracic cavity. 2. What are the tissue layers of the heart? What is the histology of each layer? What is the function of each layer? Pericardium ○ Histology: Dense irregula...

1. Define mediastinum The space where the heart is located between the right and left pleural sacs within the thoracic cavity. 2. What are the tissue layers of the heart? What is the histology of each layer? What is the function of each layer? Pericardium ○ Histology: Dense irregular connective tissue ○ Function: Produces serous fluid to reduce friction Myocardium ○ Histology: Cardiac muscle tissue ○ Function: To pump blood Endocardium ○ Histology: Simple squamous epithelium ○ Function: Decreases friction of blood cells against heart walls 3. What is the function of the atria? Receiving chambers for incoming venous blood. 4. What is the foramen ovale? What is its function? Foramen ovale ○ Prenatal connection between the atria Function: ○ Allows blood to bypass the lungs 5. What is the function of the ventricles? Pumping chambers for outgoing arterial blood. 6. What are the valves of the heart? Where is each valve located? What is the specific function of each valve? Atrioventricular valves (AV) ○ Location: Right atrioventricular valve is between the right atrium and right ventricle Left atrioventricular valve is between the left atrium and the left ventricle Function ○ Right: Prevents backflow into the right atrium ○ Left: Prevents backflow into the left atrium Semilunar valves (SL) ○ Location Right: Between the right ventricle and the pulmonary artery  Left: Between the left ventricle and aorta Function: ○ Right: Prevents backflow into the right ventricle ○ Left: Prevents backflow into the left ventricle 7. For cardiac systole and diastole, explain what is happening to the: atria, ventricles, atrioventricular valves, and semilunar valves. Atria ○ Systole: Atria are relaxed and blood enters both atria ○ Diastole: Atria contract and blood leaves both atria Ventricles ○ Systole: Ventricles contract and blood leaves the ventricles ○ Diastole: Ventricles are relaxed and blood fills the ventricles Atrioventricular valves ○ Systole: AV valves are closed ○ Diastole: AV valves are open Semilunar valves ○ Systole: SL valves are open ○ Diastole: SL valves are closed 8. What vessels carry blood into the right atrium? Where are they bringing blood from? Inferior Vena Cava ○ Receives blood from the lower extremities and abdomen Superior Vena Cava ○ Receives blood from the head and upper extremities Coronary Sinus ○ Collects blood from the coronary veins 9. What is the ductus arteriosus? Prenatal connection between the aorta and the pulmonary trunk. 10. What is the function of the pulmonary arteries? Pulmonary veins? What are they an exception to the typical oxygenated rules for arteries and veins? Pulmonary arteries ○ Function: Carries deoxygenated blood from the right ventricle towards the lungs. ○ Exception: Arteries usually carry oxygenated blood from the heart Pulmonary veins ○ Function: Carry oxygenated blood from the lungs to the left atrium. ○ Exception: Veins usually carry deoxygenated blood towards the heart 10. Using a flow chart, diagram blood flow through the heart. Right side ○ Deoxygenated blood enters the right atrium via the superior vena cava, inferior vena cava, and coronary sinus. ○ Tricuspid valve ○ Right ventricle ○ Pulmonary semilunar valve ○ Pulmonary trunk ○ Right and left pulmonary arteries ○ Lungs (becomes oxygenated) Left side ○ Lungs (become oxygenated) ○ Pulmonary vein ○ Left atrium ○ Bicuspid valve ○ Left ventricle ○ Aortic semilunar valve ○ Aorta ○ Body