Introduction To CVS Anatomy Flashcards
Arteriosus venous structure
Smooth muscle and elastic fibres in arteries are much bigger than veins
Vein has a valve, artery does not
DeOx blood in veins and Ox blood in arteries (apart from pulmonary veins and arteries (its vice versa))
Venous system -
Veins drain from all organs of the skin which will all drain into the superior and inferior vena cava
Veins have valves to restrict back flow and are located near/ inbetween muscles so that when muscles contract, they help move the blood along the venous tubes
The heart - chambers and vasculature
Superior and inferior Vena cava enter into the Right atrirum, blood then flow in to the right ventricle, when the tricuspid valve opens, and from here it leaves via the pulmonary artery when the pulmonic valve opens which divides and goes towards each individual lung
Blood in this part of the heart is deoxygenated and under low pressure
The pulmonary veins bring oxygenated blood back to the heart where it enters the left atrium, when the bicuspid/mitral valves open the blood enters the left ventricle.
From here it leaves via the aorta when the aortic valves open
The blood in this part of the heart is oxygenated and under high pressure, hence why this side of the heart has a larger ventricle wall - to help cope with extra pressure but also this side requires more force as blood is being pumped around the body
Arterial structure - 3 layers
Tunica intima - which is the endothelial cells, and the internal elastic lamina
Tunica media - which contains the smooth muscle cells and the external elastic lamina
Tunica adventitia - which contains the connective tissue surrounding the artery
In larger arteries they are quite elastic to contest the high pressure e.g. aorta and its branches. Medium sized arteries are usually distributing arteries - muscular.
Small arteries are arterioles which are resistance vessels and are used to control blood pressure by dilating or constricting
Blood pressure and the aorta
Aorta expands when you increase the pressure - therefore accommodating the increase in volume experienced when you open the valve from the right ventricle - this helps transfer pulsation flow to continual flow
Blood flow - Under resting Conditions (70Kg man), Cardiac Output (CO) ~ 5L/min (4-6L/min)
(CO= heart rate (HR) x stroke volume (SV)) HR= 60-90 beat per minute SV= 55-83ml/beat
Exercise: CO 20-35L/min HR 150-200bpm SV up to 200ml/beat
Heart wall
Heart wall:
Pericardial sac surrounding heart
3 layers of tissue -
Epicardium - a serous membrane, smooth outer surface of the heart
Myocardium - middle layer composed of cardiac muscle cell and responsibility for heart contracting
Endocardium - smooth single celled inner surface of the heart chambers
Pectinate muscles - muscular ridges in auricles and right atrial wall
Trabeculae carnage - muscular ridges and columns on inside of the walls of the ventricles
Heart valves
Tricuspid valve - 3 parts to the valve - in the right side of the heart from the RA to the RL
Mitral (Bicuspid) valve - 2 parts to the valve - in the left side of the heart from the LA to the LV
Aortic valve - from LV to the aorta
Pulmonary - from RV to the pulmonary artery
Diastole - Tricuspid and Mitral valve open and Aortic valve and pulmonary valve closed
Systole - vice versa
Oesophagus and a trans oesophageal echocardiography scan
Oesophagus is very close to the anterior of the heart - in order to see if the aortic and pulmonary valves are working - we can do a tranoesophogeal echocardiography scan
Coronary arteries
On the right - starts with right coronary - breaks into right mitral artery and the posterior interventricular artery
On the left - starts with left coronary, then breaks into circumflex artery and anterior interventricular
All coronary veins drain into the coronary sinus that drains into the RA
