The Heart Flashcards
What are the 5 layers of the heart?
Fibrous pericardium, serous pericardium, epicardium, myocardium, endocardium
What is the mediastinum?
The area in the chest between the lungs that contains the heart, the trachea, the esophagus and the ascending aorta
Which direction does the apex of the heart face?
Inferolaterally towards the left
What is the general function of the left and right atriums?
Right receives blood from the rest of the body. Left receives blood from lungs.
What is the general function of the left and right ventricles?
Right discharges blood into the pulmonary trunk sending blood to the lungs (pulmonary circulation)
Left discharges blood into the aorta sending blood to the body (systemic circulation).
Which circulatory system is a low-pressure system?
Pulmonary circulation
Which circulatory system is a high-pressure system?
Systemic circulation
The valves between the atriums and the ventricles are called?
Atrioventricular - Tricuspid and Bicuspid
The valves between the ventricles and the blood vessels are called?
Pulmonary semilunar and aortic semilunar.
What is the vessel that carries blood to the heart from the head and arms?
Superior vena cava
What is the vessel that carries blood to the heart from the torso and legs
Inferior vena cava
What do the pulmonary veins do?
Transport oxygenated blood from the lungs to the left atrium.
What do the pulmonary arteries do?
Carry deoxygenated blood to the lungs from the right ventricle.
What is unique about the aorta?
It is the largest single blood vessel in the body. It exits the left ventricle and transports oxygenated blood to the body.
What are the 2 general phases of a heart beat?
Systemic circulation and pulmonary circulation.
What does systole mean?
Contract
What does diastole mean?
Relax
Which part of the hear do the actions refer to?
Action of the ventricles.
What are the 4 stages of the cardiac cycle?
Diastole: Rapid filling, atrial contraction
Systole: Isometric contraction, ejection.
What do auto-rhythmic cells do?
They signal other cardiac muscles to contract. The signal is called action potential.
What system generally regulates the heart beat?
The intrinsic conduction system.
What are some factors that affect heart rate?
Hormones, Dehydration, Age, Gender, Exercise, Body temperature etc.
What does ECG stand for?
Electrocardiograph
The QRS segment (large peak) indicates which phase of the heart beat?
Ventricular depolarisation (ventricular contraction).
How is cardiac output expressed?
The amount of blood ejected by each ventricle in one minute shows how efficiently the heart can meet the demands of the body (heart rate BPM x stroke volume ml/beat = cardiac output)
True or false: Stroke volume can change drastically based on exercise or stress levels
True
What is coronary heart disease?
The most common heart disease. The coronary arteries become narrowed with a build up of fatty materials.
Explain pulmonary circulation
Blood in right ventricle - through pulmonary trunk - splits into right and left pulmonary arteries - enters lungs - blood receives oxygen and delivers carbon dioxide - blood leaves the lungs - enters left atrium via pulmonary veins.
Explain systemic circulation
(Blood from lungs to body tissue) Blood from left atrium - left ventricle - exits via aorta - diverted into blood vessels - reaches tissue to deliver oxygen - picks up wasted CO2 - blood goes back to the heart via superior and inferior vena cavas.
Blood flows from:
Areas of high pressure to areas of low pressure.
Explain the electrical conduction system
Sinoatrial node (pacemaker) causes contraction of both atriums - the AV node receives signal - 100ms delay before passing on message which allows atria to complete pumping blood into the ventricles - signal travels through the bundle of his - divides into 2 bundle branches - signals purkinje fibres to contract the ventricles.
What nervous system regulates the heart rate?
Autonomic nervous system.
Sympathetic nervous system increases heart rate and parasympathetic nervous system decreases heart rate.
