cardiovascular anatomy Flashcards
branches off the arch of the aorta
- brachiocephalic trunk
- right subclavian
- right common carotid
- left common carotid
- left subclavian
what are the layers of the heart (external-internal)
- epicardium
- myocardium
- endocardium
epicardium
- thin layer
- outermost layer
- formed by visceral and serous pericardium
- composed of connective tissue and fat
- connective tissue secretes small amount of lubricating fluid into the pericardial cavity
- where nerves and blood vessels of the heart are found
- functions as an additional layer under the pericardium to help protect the heart
myocardium
- thick later
- cardiac muscle
- responsible for contraction and relaxation
- provides structure
- conducting electrostimulation
- composed of cardiac muscle
- is an involuntary striated muscle
endocardium
- thin layer
- lines cavities and valves
- lines inner surface
- main function is to provide protection
- comprised of lose connective tissue and simple squamous epithelial tissue
- regulates contractions and aids cardiac embryological development
what is cardiac tamponade
compression of the heart due to a build up of fluid around the heart
- fluid build up in the pericardial cavity compromises the heart volume
where are the main parts of the hearts conducting system found
in the septum
- the interatrial septum and the interventricular septum
flow of blood through the heart
- enters through the superior and inferior vena cava and coronary sinus
- blood enters into the right atrium
- blood passes through the tricuspid valve
- blood enters the right ventricle
- blood is pumped up through the pulmonary artery through the pulmonary valve
- blood enters the lungs where it is oxygenated
- blood re-enters the heart through 1 of 4 pulmonary veins
- entering into the left atrium
- blood is passed through the mitral valve into the left ventricle
- blood is then pumped through the aortic valve into the aorta
what prevents back flow of blood in addition to the valves
- the papillary muscles
- the chordae tendineae
veins of the heart
- superior and inferior vena cava (deoxygenated blood too heart)
- pulmonary veins (oxygenated blood to the heart from the lungs)
arteries of the heart
- pulmonary artery (deoxygenated blood from heart to the lungs)
- aorta (oxygenated blood away from heart to rest of body)
sections of the main part of the aorta
- ascending aorta
- arch of aorta
- descending aorta
what is an aneurysm
a dilation of the artery
pulmonary arteries/ trunk
- pulmonary trunk splits in 2 around T5-T6
- the pulmonary trunk is a think short vessel
- two branches of the left and right pulmonary arteries enter each lung
pulmonary veins
- 4 pulmonary veins
- there is one superior and one inferior vein arriving from each lung
- superior vena cava returns blood from the upper lobes
- the inferior vena cava returns blood from the lower lobes
superior vena cava formation
- formed through the merging of the brachiocephalic veins
- drains into the right atrium at the 3rd rib
inferior vena cava formation
- formed in the pelvis by the joining of the common iliac veins
- collects blood from the hepatic, lumbar, gonadal, renal and phrenic veins
- enters the pericardium at T8
what are the great vessels of the heart
- the 4 main vessels that transport blood to and from the heart
- aorta, pulmonary artery, pulmonary vein, (superior and inferior) vena cava
what separates the two sides of the heart
- the interatrial septum (between the atriums)
- the interventricular septum (between the ventricles)
stages of electrical conduction of the heart
- excitation signal is created by the sinoatrial node
- the wave of excitation spreads across the atria causing them to contract
- the signal then reaches the atrioventricular node where the signal is delayed
- it is then conducted into the bundle of His down the interventricular septum
- the bundle of His and the Purkinje fibres spread the wave of impulses along the ventricles
- this causes the ventricles to contract
what are the effects of the nervous system on the SA node
- sympathetic = increases the firing rate of the SA node, increasing the heart rate
- parasympathetic = decrease firing rate of the SA node, decreasing the heart rate
what are the connecting layers in the heart
- subepicardial layer - between the myocardium and epicardium
- subendocardial layer - between and joins the endocardium and myocardium
what layer of the heart are the purkinje fibres located in
the subendocardial layer
what are the main layers of the pericardium
- fibrous pericardium (external)
- serous pericardium
fibrous pericardium
- made of tough connective tissue
- relatively non-distensible
- rigid structure prevents rapid overfilling of the heart
serous pericardium
- separated into 2 layers: outer parietal layer and the internal visceral layer
what is the purpose of the pericardial cavity
to hold lubricating serous fluid that helps to minimise friction from heart contractions
what is the function of the pericardium
- fixes the heart in the mediastinum, limiting its motion
- prevents overfilling of the heart
- lubrication
- protection from infection
what is the innervation of the pericardium
phrenic nerve is responsible for somatic innervation of the pericardium
what are the names of the valves in the heart
- atrioventricular valves - tricuspid and mitral
- semilunar - pulmonary and aortic
what are the names of the coronary arteries that supply the heart
- right coronary and left coronary arteries - arise from the left and right aortic sinuses within the aorta
what vessels does the left coronary artery give off
- left anterior descending artery
- left marginal artery
- left circumflex artery
what vessels does the right coronary artery give off
- right marginal artery
- posterior interventricular artery
what is the venous drainage of the heart
the coronary sinus
what are the tributaries of the coronary sinus
- great cardiac vein
- small cardiac vein
- middle cardiac vein
- posterior cardiac vein
