the cardiovascular system Flashcards
What does the cardiovascular system do?
- Oxygenates blood in the lungs
- distributes it to the tissues
- removes CO2 from the tissues
- transports it to the lungs to exhale
What are some other functions of the CVS?
- Transport of nutrients and hormones
- Removal of metabolic wastes
- infection protection
- thermoregulation
- maintaining fluid balance
How many chambers does the heart have?
four
What does the arterial system do?
Carries blood away from the heart
What does the capillary system do?
exchanges molecules at the cellular level
What does the venous system do?
Carries blood to the heart
What system do veins have in place to prevent backflow?
A valve mechanism, absent in most head and neck veins
Where is the heart located?
In the mediastinum
- behind the sternum
- in front of the thoracic vertabrae
- 2/3 of mass lies to left
What is the outer covering of the heart called and what is its function?
The pericardium
- holds heart and great vessels in place, helps to lubricate and protect heart
What are the two layers of the pericardium?
- Fibrous pericardium
- Serous pericardium (Parietal and visceral)
What are the three layers of the wall of the heart?
- epicardium
- myocardium
- endocardium
What is the epicardium?
The outer covering of the heart
What is the myocardium?
- The thick, contractile middle layer of the heart
- Includes the cardiac muscles, branched and striated, fatigue free
What is the endocardium?
- The endothelial lining (innermost layer)
- Inward folding forms the cusps of major valves
What does the right pump do?
Receives deoxygenated blood from the body and sends it to the lungs
What does the left pump do?
Receives oxygenated blood from the lungs and sends it to the body
How many atria are there?
2
How many ventricles are there?
2
What separates the two atria?
the interatrial septum
What separates the two ventricles?
The interventricular septum
What separates the atria from the ventricles?
The atrioventricular septa
What are the atria?
The recieving chambers
Where does the right atrium recieve blood from?
- superior vena cava
- inferior vena cava
- cardiac veins
Where does the left atrium receive blood from
- pulmonary veins
How many ventricles are there?
2
What are the ventricles?
The pumping chambers, have thicker walls than atriums
Where does the right ventricle pump blood to?
The pulmonary arteries (lungs, pulmnonary circulation)
Where does the left ventricle pump blood to?
- Aorta
- Coronary arteries (body, systemic circulation)
What are the four heart valves?
- Tricuspid
- bicuspid (mitral)
- pulmonary
- aortic
What arteries supply the heart muscles?
The coronary arteries
What is coronary artery disease?
Occlusion of a major coronary artery
- complete: myocardial infarction (heart attack
- incomplete: angina (chest pain when exerting)
What drains blood from the cardiac walls?
Cardiac veins
- then return to coronary sinus, opens into right atrium
What node receives contractile stimuli?
The AV node
How does the AV node work?
Receives contractile stimuli
depolarizes
current passes down conducting fibres through interventricular septum to the base of the heart
then upwards in the ventricles
How does stimulation of the parasympathetic system affect the heart?
- Decreases heart rate
- Reduces force of contraction
How does stimulation of the sympathetic system affect the heart?
- Increases heart rate
- Increases the force of contraction
How does the blood circulatory system go?
aorta, arteries, arterioles, capillaries, venules, veins, vena cava
What are the three divisions of the arterial system?
- Elastic arteries
- Muscular arteries
- Arterioles
What is the capillary system responsible for?
- providing nutrients and oxygen to tissue
- absorbing nutrients, waste products, CO2
- Excretion of waste from body
What is atherosclerosis?
the narrowing of arteries due to plaque
What is thrombus?
A clot on the inner vessel wall
- travels as embolus if dislodged
- can occlude blood vessel causing stroke, heart attack, tissue destruction, spread of infection
What cardiac conditions require antibiotic prophylaxis?
- prosthetic heart valves
- Rheumatic valvular heart disease
- Previous endocarditis
- Unrepaired cyanotic congenital heart disease
- Surgical or catheter repair of congenital heart disease (within 6 months)
