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A&P Ex. 44
Exercise 44: Heart Structure
Question | Answer |
---|---|
What is the heart? | A muscular pump |
Where is the heart? | Located within the mediastinum and resting upon the diaphragm. It is enclosed by the lungs, thoracic vertebrae, and sternum, and attached. |
The hear and the proximal ends of the attached blood vessels are enclosed by what? | A double-layered pericardium. Innermost layer: visceral layer of serous pericardium covering surface of the heart. Outer layer: parietal layer of serous pericardium with fibrous pericardium (tough, protective sac) surrounding the heart. |
What is the pericardial cavity? | Space between the parietal and visceral layers of pericardium that contains a small volume of serous (pericardial) fluid. |
What are the 4 chambers of the heart: | 2 superior atria and 2 inferior ventricles |
What does the interatrial septum and interventricular septum do? | They prevent oxygenated blood in the left side of the chambers from mixing with deoxygenated blood in the right chambers |
Atrioventricular (AV) valves (___(1.)___) are located (2.). | 1. Mitral and tricuspid ; 2. between each atrium and ventricle |
Semilumar valves (__(1.)__) are at (2). | 1. aortic and pulmonary ; 2. The exits of the ventricles into the 2 large arteries. |
What do the heart valves do? | Only allow blood flow in one direction |
Fibrous pericardium | outer layer of pericardium (pericardial sac) |
Pericardial cavity | Between parietal and visceral layers of serous pericardial membranes |
Myocardium | Composed of cardiac muscle tissues |
Endocardium | lines heart chambers |
Right Atrium | Receives blood from systemic veins |
Left Atrium | Receives blood from pulmonary veins |
Auricles | earlike extensions of atria allowing greater expansion for blood volumes |
Right ventricle | pumps blood into pulmonary circuit |
Left ventricle | Pumps blood into systemic circuit; has thicker myocardium than right ventricle |
Atrioventricular orifices | openings between atria and ventricles and guarded by AV valves |
tricuspid valve | The right atrioventricular valve; has 3 cusps |
Mitral valve | Left atrioventricular valve; bicuspid valve; has 2 cusps |
Semilunar valves | Regulate glow into 2 large arteries that exit from ventricles |
Pulmonary valve | Has 3 pocketlike cusps at entrance of pulmonary trunk |
Aortic valve | Has 3 pocketlike cusps at entrance of aorta |
Chordea tendineae (tendinous cords) | connect AV valve cusps to papillary muscles |
Papillary muscles | Projections from inferior ventricles; anchor AV valve cusps during ventricular contraction |
Coronary sulcus | Atrioventricular sulcus or groove ; encircles heart between atria and ventricles |
Interventricular sulci | Grooves with blood vessels along septum between ventricles |
Arteries | Carry blood AWAY from the heart |
Veins | Return the blood TO the heart |
What do the arteries of the SYSTEMIC circuit contain? | Oxygen-rich blood |
What do the arteries of the PULMONARY circuit contain? | Oxygen-poor blood |
Superior Vena Cava | returns blood to right atrium from superior part of systemic circuit |
Inferior vena cava | Returns blood to right atrium from the inferior part of system circuit |
Pulmonary arteries | Main artery of pulmonary circuit |
Pulmonary arteries | Main arteries to lungs |
Pulmonary veins | Return blood from pulmonary circuit into left atrium |
Aorta | Main artery of systemic circuit |
Left and right coronary artery originate from where? | Originates from base of aorta |
Cardiac veins | Drain the myocardium into coronary sinus |
Coronary sinus | for return of blood from cardiac veins into right atrium |