Cardiovascular System Flashcards
What does the cardiovascular system include?
Blood vessels, heart and blood
Functions of the cardiovascular system
Transport → circulation of blood through a network of vessels.Delivery → heart pumps nutrients from gastrointestinal tract,hormones from endocrine glands, oxygen from lungs through the blood. Removal → blood flow facilitates removal of waste products ie sodium and carbon dioxide
Blood vessels
Forma continuous network whereby arteries take oxygenated blood to body tissues and join through a network of capillaries to veins which takethe deoxygenated blood back to the lungs via the heart
Arteries structure
Thick wall → containing smooth muscle and fewer classic fibres
Smooth muscle contracts to constrict lumen (vasoconstriction) and relaxes (vasodilation)
Distribute blood without fall in bp
Blood at higher pressure than in veins
Veins structure
Larger diameter lumens
Thin walls
Minimal smooth muscle
Distensible and collapsible
Veins in extremines contain more values to aid return of blood to heart against gravity
Hold 60 - 70% of blood volume
Systemic circulation
Around the whole body system
Pulmonary circulation
To and from the lungs
Pulmonary vessels → pulmonary arteries
Left and right pulmonary arteries → transport
deoxygenated blood (returned to heart via superior and inferior vena cava) from the right atrium and ventricle, back to the lungs
Pulmonary vessels → pulmonary veins
Left and right pulmonary veins → oxygenated blood from lungs to left atrium to be circulated
around the body via the aorta
Great vessels →superior vena cava
Brings deoxygenated blood to right atrium of the heart from the head, neck and upper limbs
Great vessels →ascending aorta
Takes oxygenated blood from left ventricle of the heart to circulate around the systemic circulation
Great vessels → inferior vena cava
Brings deoxygenated blood to the right atrium of the heart from the thorax, abdomen, pelvis and lower limbs
Great vessels → aortic arch
Is a continuation of the ascending aorta which arches posteriarly to the heart to continue into the descending aorta ( thoracic and abdominal)
Branches from arch of aorta
Right common carotid artery
Right subclavian artery
Brachiocephalic artery
Left common carotid artery
Left subclavian artery
Arch of hard a
Pulmonary trunk
Pulmonary artery
Ascending aorta
What is Serosal pericardium?
Visceral layer → directly surrounds heart
Parietal layer → directly on the deep surface of
Fibrous pericardium
Pericardial fluid →serous fluid filling pericardial cavity
function is to reduce friction
What is fibrous pericardium?
Dense irregular connective tissue forming superficial layer of pericardium
Attached inferiorly to diaphragm and superiorly to great vessels of heart
Function is to limit heart motion and prevent heart over expansion
Endocardium
Smooth, thin inner membrane
Composed of endothelial cells.
Also covers heart valves.
Helps to prevent resistance as blood flows
Myocardium
Heart muscle, composed of cardiac muscle fibres
Thin in atria, thick in ventricles
Epicardium
Thin outer serous membrane (visceral pericardium)
Composed mainly of connective tissue mesothelial cells giving smooth texture to outer heart.
4 chambers of the heart
Right atrium→ received deoxygenated venous blood from the superior and inferior vena cava
Right ventricle → receives blood from the rt atrium through tricuspid valve. Blood exits via pulmonary trunk
Left atrium→ received oxygenated blood from right and left pulmonary veins
Left ventricle→ received blood from the left atrium via bicuspid valve. Blood exits the left ventricle via the aorta. Left ventricle has thick walls
4 heart values
Tricuspid/Rt atrioventricular – between the Rt atrium and Rt ventricle
Mitral/bicuspid/ Lt atrioventricular – between the Lt atrium and Lt ventricle
Pulmonary (semilunar) – between the Rt ventricle and Pulmonary trunk
Aortic (semilunar) – between the Lt ventricle and ascending aorta
Coronary circulation: arteries
Left coronary artery
arises from the aorta→left coronary artery circumflex artery → Left coronary artery:
Anterior interventricular artery Also known as Left Anterior Descending artery (LAD) → Left coronary artery:
Left marginal artery
