- Information
- AI Chat
The Heart (CHP 17) - important key notes for exams
Basic Anatomy & Physiology II (BIO-118-51 )
Camden County College
Related Studylists
anatomy and physiologyPreview text
The Heart (CHP 17)
Location & General Features
● Size of a fist ● Weight = 250-300 grams ● Location: in mediastinum; two-thirds lies left of the midsternal line ○ Base of heart = directed toward the right shoulder ○ Apex of heart = points toward the left hip ● Enclosed in the pericardium ● Pericardium structure: ○ Parietal pericardium --> lines the inside of the pericardium ○ Epicardium --> covers the surface of the heart
Layers of the Heart Wall
● Myocardium: mainly cardiac muscle; forms the bulk of the heart ● Endocardium: lines the chambers of the heart
Blood Flow Through the Heart
● Right of side of heart pumps blood into pulmonary circuit ● Left side of heart pumps blood into systematic circuit ● Heart receives no nourishment from the blood passing through the chamber ● Coronary circulation --> blood supply for the heart cells ● Myocardial infarction --> prolonged coronary blockage that leads to cell death
Major Blood Vessels in the Heart
● Aorta ● Superior vena cava ● Inferior vena cava ● Pulmonary artery (which takes oxygen-poor blood from the heart to the lungs where it is oxygenated) ● Pulmonary veins (which bring oxygen-rich blood from the lungs to the heart)
● Coronary sinus
Chambers
● Right & left atria = receiving chambers ● Right ventricle = pumps blood into the pulmonary trunk ● Left ventricle = pumps blood into the aorta
Valves
● Triscupid & biscupid = prevent backflow into the ATRIA when the ventricles contract ● Aortic & pulmonary semilunar valves = found in major arteries leaving the heart; prevent backflow of blood ibntothe ventricles ● Relaxed Heart = AV valves are OPEN; Semilunar valves are CLOSED ● Contracted Heart = AV valves CLOSED; Semilunar valves OPEN
Electrical Events Associated with ECG
The heart relies exclusively on aerobic respiration for its energy demands
● Intrinsic conduction system = made up of specialized cardiac cells that ensure that the heart depolarizes in an orderly fashion ● Autorhythmic cells have an unstable resting potential (pacemaker potentials) --> continuously depolarize ● Impulses pass through the autorhythmic cells in the following order: 1. Sinoatrial node 2. Atrioventricular node 3. Atrioventricular bundle 4. Right & left bundle branches 5. Purkinje fibers ● Autonomic NS MODIFIES the heartbeat ● Sympathetic center INCREASES rate & depth of heartbeat ● Parasympathetic center SLOWS heartbeat ● Electrocardiograph MONITORS/AMPLIFIES electrical signals of the heart; records it as an ECG
The Heart (CHP 17) - important key notes for exams
Course: Basic Anatomy & Physiology II (BIO-118-51 )
University: Camden County College
