Cardiovascular System - Heart Anatomy Ms. Mullings

Objective You will be able to describe the location of the heart and identify the major anatomical areas

Heart Position, Size, Shape Approx. size of your fist Hollow Cone Shaped Weighs less than one pound Located in thoracic cavity, between lungs and deep to sternum Tilts to left, so about 2/3 of heart lies to left of median plane

Heart Parts Base: broad superior portion of heart; the point of attachment for the “great vessels” Apex: inferior end of heart that tapers to a blunt point; sits immediately above the diaphragm

Coverings and Wall Enclosed in a double-walled sac called the pericardium Inner layer- visceral pericardium (epicardium) Outside layer- parietal pericardium/sac Fluid in between the two layers called the pericardial fluid Lubricates the membranes and allows to beat almost without friction; isolates the heart from other thoracic organs

Heart Wall Three layers: Epicardium Myocardium- the thickest layer by far; performs work of heart; made of cardiac muscle Endocardium- lines the interior of the heart chambers; continuous with blood vessels

Heart Wall

Heart Chambers Four hollow chambers: two atria (singular atrium) and two ventricles Atria- thin walled receiving chambers for blood returning to the heart from the great veins Ventricles- pumps that eject blood into the arteries and keep flowing around body Intraventricular Septum- septum that divides the heart longitudinally

Superior Vena Cava Aortic Arch Right Pulmonary A Left Pulmonary A Left Pulmonary V Ascending Aorta Right Atrium Left Atria Pulmonary Trunk Pulmonary Semilunar Valve Aortic Semilunar Valve R AV/Tricupsid Valve L AV/Bicuspid/Mitral Valve Right Venticle Left Ventricle Inferior Vena Cava Epicardium Interventricular Septum Descending Aorta Myocardium

Valve Info To pump blood effectively, the heart needs valves that ensure a predominantly one-way flow A valve is between each atrium and ventricle and at the exit from each ventricle into its great vessel No valve exists between great vessels and atria Each valve consists of 2-3 flaps of tissue called cusps

Atrioventricular Valves AV valves Regulate the openings between the atria and ventricles Right AV valve (aka the tricuspid valve) has 3 cusps Left AV valve (aka the biscupid or mitral valve) has 2 cusps String-like tendons- chordae tendineae- connect the valves to the floor of the ventricle

Semilunar Valves Regulate the blood flow from the ventricles into the great arteries The pulmonary semilunar valve controls the opening from the R ventricle into the pulmonary trunk The aortic semilunar valve controls the opening from the L venticle into the aorta Each has 3 cusps and no chordae tendineae

Practice Question The partition in the superior midline of the heart is the _______________.

Practice Question The pointed tip of the heart is called the ____________.

Practice Question The type of blood that is found in the right ventricle is __________________.

Practice Question The layer of the heart wall that contains cardiac muscle tissue is the: a) visceral pericardium b) parietal pericardium c) endocardium d) epicardium e) myocardium

Practice Question The atria of the heart: a) are located superiorly and are the receiving chambers of the heart b) located inferiorly and are the receiving chambers of the heart c) are located superiorly and are the discharging chambers of the heart d) located inferiorly and are the discharging chambers of the heart

Practice Question Which of the following areas receives blood directly from the four pulmonary veins? a) lungs b) R atrium c) R ventricle d) L atrium e) L ventricle

Practice Question Which of the following blood vessels is NOT part of systemic circulation: a) coronary arteries b) aorta c) inferior vena cava d) carotid arteries e) pulmonary arteries

Practice Question T or F: the heart is enclosed by a double sac of serous membrane known as the peritoneum.

Practice Question T or F: the pulmonary arteries carry deoxygenated blood to the lungs.

Practice Question T or F: the aorta is that largest artery within the pulmonary circulation.

Gap-Fill Exercise The heart is a cone-shaped muscular organ located within the _____________. Its apex rests on the ___________, and its base is at the level of the second rib. The coronary arteries that nourish the myocardium arise from the_______________. The coronary sinus empties into the ______________. Relative to the role of the heart chambers, the ____________ are receiving chambers, whereas the ___________ are discharging chambers. The membrane that lines the heart and also forms the valve flaps is called the ____________. The outermost layer of the heart is called the ____________. The fluid that fills the pericardial sac acts to decrease ___________ during heart activity. The heart muscle, or ____________, is composed of specialized type of muscle called cardiac muscle.