cardiovascular system overview Flashcards
where does deoxygenated blood enter the heart?
right atrium
what does deoxygenated blood enter the heart through?
the superior vena cava (head, neck and upper limbs)
the inferior vena cava (below heart and lower limbs)
what is the valve inbetween the right atrium and ventricle?
the tricuspid (right atrioventricular) valve
what is the valve between the right ventricle and pulmonary artery?
pulmonary valve
where does the pulmonary artery carry blood?
away from heart to the lungs
where does oxygenated blood enter the heart?
the left atrium
what does oxygenated blood enter the heart through?
the pulmonary veins
what is the valve between the left atrium and ventricle?
the mitral (bicuspid) valve
what is the valve between the left ventricle and aorta?
the aortic valve
where does the aorta carry blood?
to the body
what are fossa ovalis?
embryological remnant (groove/depression) of the patent fossa ovalis in foetal life. That used to allow blood to flow between the right atrium and the left atrium
what are aortic sinuses?
- dilatations just above the aortic valve
- there are 3 of these and from 2 arise the left and right coronary arteries
what is the function of the aortic sinuses?
provide space behind the open aortic leaflets so that the leaflets do not occlude the coronary artery orifices
what is the circulatrory system?
Organ system transporting oxygen, carbon dioxide, nutrients etc.
what are the two loops in the circulatory system?
- pulmonary circulation
- systemic circulation
describe the pulmonary circulation loop
- Lungs
- Oxygen depleted blood
- Passes from heart to lungs
- Returns oxygenated blood to heart
describe the systemic circulation loop
- Body
- Oxygen rich blood
- Passes from heart to rest of body
- Returns deoxygenated blood to heart
what is the mediastinum?
the compartment that runs the length of the thoracic cavity between the pleural sacs of the lungs
what are the parts of the mesiastinum?
- superior
- inferior (anterior, middle and posterior)
what are the boundaries for the superior mediastinum?
upper- T1
lower- sternal angle
what does the superior mediastinum contain?
- aortic arch
what does the anterior mediastinum contain?
- fat
- thymus
what does the middle mediastinum contain?
- heart
what does the posterior mediastinum contain?
- aorta
- oesophagus
what is pericardium?
the two layered, protective, fluid-filled sac around the heart
what are the two layers of the pericardium?
- fibrous layer
- serous layer
what is the function of the fibrous layer of the pericardium?
- outer layer
- anchors heart to diaphragm
- prevents rapid overfilling of the heart
- restricts if there is an accumulation of fluid- pericardial effusion
what is the function of the serous layer of the pericardium?
- has an outer parietal layer and inner viscous layer
- produces pericardial fluid (pericardial space) that lubricates your heart as it beats, reducing friction
- fatty inside layer has coronary arteries
what happens of the coronary arteries are blocked?
- myocardial infarction (heart attack)
what is the function of the coronary arteries?
they supply the heart muscle with blood
where do the R and L pulmonary arteries branch from?
the pulmonary trunk
where do the coronary arteries branch from?
the aorta
what arteries branch off of the aorta?
- coronary arteries- to heart
- brachiocephalic trunk- to head and neck
- left common carotid artery- to head and neck
- left subclavian artery- to upper limbs
what allows blood to bypass the liver to the inferior vena cava in fetal circulation?
the ductus venosus
what does the ductus venosus become at birth?
the ligamentum venosus
what allows blood flow from the right to left atrium in fetal circulation?
foramen ovale
what creates a shortcut to avoid the fetus’s non-working lungs?
the ductus arteriosus (links pulmonary trunck with the aorta
what carries deoxygenated blood back to the placenta in fetal circulation?
umbilical arteries
what is the right atrial appendage?
- additional part of the right atrium
- typically used as the site for an external pacemaker to be positioned
what is crista terminalis?
- at the opening of the right atrial appendage
- the site of origin of the pectinate muscles
what is the musculi pectinati?
allow for stretch and improve the volume of the right atrium
what is the orifice of the coronary sinus?
- opening of coronary sinus
- where venous blood from the heart enters
how much thicker is the left ventricle then the right?
3 times thicker (also thicker capillary muscles and trabeculae carnae)
why is the left ventricle thicker than the right?
it has to pump blood into the systemic circulation (rest of body)
what is a intraventricular/interatrial septum?
hole in the heart
ASD/VSD – present at birth. Small holes sometimes close themselves, and larger ones will compromise the lungs and heart due to increased blood pressure.
AVSD – require surgery as it will compromise the patient leading to problems breathing, racing heart, weak pulse and cyanosed (blue) and tiring easily.
how many leaflets does the tricuspid valve have?
3
how many leaflets for the mitral valve have?
2
describe the positioning of the heart valves
Tricuspid (3 leaflets) and mitral (2 leafelts) are posterior and the aortic and pulmonary vales are more anterior.
what is the lub sound of the heart?
closure of atrioventricular valves, at same time of ventricular systole
what is the bud sound of the heart?
the closure of semilunar valves, at same time as atrial systole
what are the semilunar valves?
aortic and pulmonary
what are chordae tendinae?
are the heart strings that connect to the papillary muscles and prevent the mitral and tricuspid vales flipping back into the atria during ventricular contraction (systole)
which valves require chordae tendinae?
mitral and tricuspid
which valves do not have chordae tendinae and why?
the semilunar valves as gravity closes them
describe infective endocarditis
Most common is subacute bacterial endocarditis
Occurs on rheumatic or congenitally abnormal valves
Can affect prosthetic valves
Due to many organisms (streptococcus viridans/staphylococcus aureus)
Can be a result of dental abscess
Variety of presentations
A murmer (stenosis or regurgitation) can be present due to valvular vegetations
what are end arteries?
only supply oxygenated blood to a specific portion of tissue. These vessels exist in the spleen (splenic artery), liver, intestines, ends of digits, ears, nose and penis
what type of artery are coronary arteries?
end arteries
what is ischaemia?
- coronary artery disease
- when your coronary arteries become narrowed by a build-up of fatty material within their walls
- causing collateral circulation to develop
- this is new blood vessel growth to pass around the area of reduced blood supply
what is angina pectoris?
chest pain related to coronary artery disease
what is infarction?
heart attack due to lack of oxygen
- Anterior IV branch of LCA (40-50%)
- RCA (30-40%)
- Circumflex branch of LCA (15-20%)
what is the longest vein of the body?
saphenous vein
what is a coronary artery bypass graft?
- surgical procedure used to treat coronary heart disease
- diverts blood around narrowed or clogged parts of the major arteries to improve blood flow and oxygen supply to the heart
- saphenous vein, internal mammary artery or internal thoracic artery used
what is the pacemaker of the heart?
sinoatrial node- generates electrical signals
what is the function of the moderator band?
allows for more rapid conduction across to the anterior papillary muscle and helps with conduction times
what are purkinje fibres?
are specialized conducting fibres, bigger than cardiac myocytes and create a synchronised contraction across the ventricles, thus maintaining our regular heart rate
