Heart Flashcards
Describe the size, shape, location and orientation of the heart in the thorax.
The heart is a muscular organ, roughly the size of a fist, located in the thoracic cavity between the lungs, tilted slightly to the left.
Name the coverings of the heart.
The heart is covered by the pericardium, which includes the fibrous pericardium and the serous pericardium.
Describe the structure and function of each of the three layers of the heart wall.
The three layers are:
* Epicardium: outer layer providing protection
* Myocardium: middle layer responsible for contraction
* Endocardium: inner layer lining the chambers and valves.
Describe the structure and functions of the four heart chambers.
The four chambers are:
* Right atrium: receives deoxygenated blood from the body
* Right ventricle: pumps deoxygenated blood to the lungs
* Left atrium: receives oxygenated blood from the lungs
* Left ventricle: pumps oxygenated blood to the body.
Name the great vessels associated with each heart chamber.
Associated vessels are:
* Right atrium: superior and inferior vena cava
* Right ventricle: pulmonary arteries
* Left atrium: pulmonary veins
* Left ventricle: aorta.
Trace the pathway of blood through the heart.
Blood flows from the body into the right atrium, then to the right ventricle, to the lungs via pulmonary arteries, back to the left atrium, to the left ventricle, and out to the body through the aorta.
Name the major branches of the coronary arteries.
Major branches include:
* Left coronary artery
* Right coronary artery.
Describe the distribution of the coronary arteries.
The left coronary artery supplies the left side of the heart, while the right coronary artery supplies the right side.
Name the heart valves.
The heart valves include:
* Tricuspid valve
* Pulmonary valve
* Mitral valve
* Aortic valve.
Describe the location and function of the heart valves.
Valves are located between:
* Right atrium and right ventricle (tricuspid)
* Right ventricle and pulmonary artery (pulmonary)
* Left atrium and left ventricle (mitral)
* Left ventricle and aorta (aortic).
Function: prevent backflow of blood.
What is the mechanism of operation of the heart valves?
Valves open and close based on pressure changes in the heart chambers.
Describe the structural and functional properties of cardiac muscle.
Cardiac muscle is striated, involuntary, and has intercalated discs for synchronized contraction.
How does cardiac muscle differ from skeletal muscle?
Cardiac muscle is involuntary and branched, while skeletal muscle is voluntary and multinucleated.
Briefly describe the events of cardiac muscle cell contraction.
Contraction is initiated by an action potential, leading to calcium ion release, which triggers muscle fiber shortening.
Name the components of the conduction system of the heart.
Components include:
* Sinoatrial (SA) node
* Atrioventricular (AV) node
* Bundle of His
* Purkinje fibers.
Trace the conduction pathway of the heart.
The conduction pathway is: SA node → AV node → Bundle of His → Purkinje fibers.
Draw a diagram of a normal electrocardiogram tracing; name the individual waves.
Waves include:
* P wave: atrial depolarization
* QRS complex: ventricular depolarization
* T wave: ventricular repolarization.
What abnormalities can be detected on an ECG tracing?
Abnormalities include arrhythmias, ischemia, and hypertrophy.
Describe the timing and events of the cardiac cycle.
The cardiac cycle includes:
* Atrial systole
* Ventricular systole
* Diastole.
Describe normal heart sounds.
Normal heart sounds include ‘lub’ (closure of AV valves) and ‘dub’ (closure of semilunar valves).
How do heart murmurs differ from normal heart sounds?
Murmurs are abnormal sounds due to turbulent blood flow.
Name factors regulating stroke volume and heart rate.
Factors include:
* Preload
* Afterload
* Contractility
* Autonomic nervous system.
Explain the role of the autonomic nervous system in regulating cardiac output.
The autonomic nervous system adjusts heart rate and contractility through sympathetic and parasympathetic stimulation.
Provide examples of age-related changes in heart function.
Examples include decreased maximum heart rate, increased stiffness of the heart muscle, and changes in electrical conduction.
