Rea Cardiovascular System Flashcards
what is the lymphatic system
network of tissues, vessels and organs that work together to move a colourless, watery fluid called lymph back into your circulatory system
what is the circulatory system
an organ system transporting oxygen, carbon dioxide and nutrients
what is the cardiovascular system
heart, blood vessels, blood and the lymphatic system
what are blood vessels
arteries, veins and capillaries
what are the two loops of circulation
pulmonary circulation and systemic circulation
what is pulmonary circulation
this is when there is oxygen depleted blood that passes from the heart to the lungs and is returned as oxygenated blood to heart
what is systemic circulation
this is circulation in the rest of the body, where oxygen rich blood passes from the heart to the rest of the body. the deoxygenated blood is returned to the rest of the heart
what are the two divisions of the mediastinum
superior and inferior
what are the layers of the heart
pericardium, myocardium and endocardium
what are the layers of the pericardium
fibrous and serous
describe the fibrous layer of the pericardium
tough outer layer which anchors heart to diaphragm
what is the function of the fibrous pericardium
prevents rapid overfilling of the heart but can also restrict if there is an accumulation of fluid compressing the heart - especially important in the right side as this reduces cardiac output
what is pericardial effusion
accumulation of fluid which compresses the heart
what is the parietal layer
the serous pericardium
what are the layers of the serous pericardium
outer visceral and inner parietal
what is the pericardial space
a cavity with a small amount of lubricating serous fluid which reduces friction of the layers during beating of the heart
what is the function of the superior vena cava
deoxygenated blood from the head and neck and upper limbs
what is the function of the inferior vena cava
deoxygenated blood from below the level of the heart like the abdomen, pelvis and lower limbs
what is the pulmonary trunk
the left and right arteries which take blood on to the lungs
what is the brachiocephalic trunk
the right common carotid artery
what does the carotid artery supply
the head and neck
what are the branches of the aorta above the heart for the head and neck
coronary arteries
brachiocephalic trunk
left common carotid artery
left subclavian artery
what does the subclavian artery supply
upper limb
what is the function of the ductus venosus
allows blood to bypass the liver to the inferior vena cava
what does the ductus venosus become at birth
the ligamentum venosum
which proportion of blood supplied to the ductus venosus is maternal
30%
what is the function of the forammen ovale
allows blood to flow from the right atrium to the left atrium
what does the ductus arteriosus do
links pulmonary trunk to aorta in utero
what do the umbilical arteries carry
deoxygenated blood back to the placenta
what is the fossa ovalis
remnant of patent fossa ovalis that lets blood flow from right atrium to left atrium
what does the superior vena cava drains
head, neck, upper limbs, left and right
what does the inferior vena cava drain
everything below the level of the heart (abdomen, pelvis and lower limbs)
what are aortic sinuses
dilations just above the aortic valve
how many aortic sinuses are there
3
which aortic sinuses arise from the left and right coronary arteries
two out of three
what is the right atrial appendage
an additional part of the right atrium typically used as the site for an external pacemaker to be positioned
what is the crista terminalis
site of origin of the pectinate muscles found at the opening of the right atrial appendage
what is the function of musculi pectinati
allow for stretch and improve the volume of the right atrium
where does the venous blood from the heart enter the coronary sinus
via the orifice of the sinus
how many pulmonary veins are there
2 on the left and 2 on the right
what do the pulmonary veins do
carry oxygenated blood to the left atrium
which atrium of the heart receives blood from the pulmonary vein
the left atrium
where is the crista terminalis located and what is its function
the opening of the right atrial appendage and is the site of origin of the pectinate muscles
what is the site of origin of the pectinate muscles
the crista terminalis
to what degree is the left ventricle wall thicker than the right
three times
why is the left ventricle thicker
as it has to pump blood into the systemic circulation
why is the right ventricle smaller and less powerful than the left
it only has to pump blood to the lungs
what are some septal defects
- interventricular / interatrial septum
- hole in the heart
- atrial septal defect
- ventricular septal defect
- atrioventricular septal defect
describe atrial and ventricular septal defect
these are defects present at birth and are small holes sometimes present at birth and can usually close themselves however if they are larger they can compromise the lungs and heart due to increased blood pressure
describe atrioventricular septal defect
requires surgery as it will compromise the patient leading to problems breathing, racing heart, weak pulse, cyanosed and tiring easily
which valves are posterior
tricuspid and mitral
which valves are anterior
aortic and pulmonary
what does lymphatic fluid surround
the heart and blood vessels
what is the mediastinum
the part of the chest in the middle, including all the structures bar the lungs.
when delivering compressions during cpr, where do the balls of the hands go
the xiphoid process
what does the superior mediastinum extend from
the top of the manubrium to the sternal angle
what does the thymus do
this sets immune function but forming memory for coughs and colds through t cells and c cells.
what is found in the posterior mediastinum
aorta and oesophagus
what is the function of the fibrous pericardium
anchors the heart onto the diaphragm
describe the five layers of the heart wall from the outside in
fibrous pericardium, parietal, visceral, myocardium and endocardium
what can pericarditis affect
movement of the heart
what is found between the parietal and visceral pericardium and what is the function of this
serous fluid, to allow smooth movement of parietal over visceral pericardium
which aspect of the heart wall is in contact with the blood
the endocardium
which ventricle has the deoxygenated blood
right
which ventricle has the oxygenated blood
left
which ventricle forms the bulk of the heart anterior
right ventricle
is the left ventricle located more anterioly
no posterior
describe the route blood follows in the fetus
comes in via the umbilical cord through the placenta to go to the heart despite being oxygenated.
what is the purpose of the ductus venosus for the fetus
allow blood to bypass the liver, although it does not take all of it, only 40-50% of the blood is taken to bypass the liver.
why are there specialisations to prevent entry of blood into the lungs in utero
because the fetus does not breathe in utero
what is the specialisation of the heart to prevent blood going to the lungs and how does it work
the foramen ovale, and it works by allowing blood in the right atrium to jump to the left ventricle to go into the systemic circulation
when does the foramen ovale shut
when the baby first cries
what does the ductus arteriosis do
allows blood to go from the pulmonary trunk to the left atrium into the systemic circulation
which vessels supply the heart
the coronary arteries
where are coronary arteries found
the surface of the heart within a fatty connective tissue
what does the foreman ovale become once the baby cries and it closes
the fossa ovalis
what is the orifice of the coronary sinus
this is where the heart’s blood is drained to go back through the heart for oxygenation
what are the chordate tendinae
heart strings joined on papillary muscle to hold the valves in place when blood pressure in the right ventricle increases in order to prevent backflow of blood
what can heart attacks to the heart valves
cause them to burst
where is the left atrium on the heart
close to the back of the heart
where can holds occur in the hearts of babies
between the atria
between the ventricles
atrioventricular holes
what does a hole in the heart lead to
mixing of oxygenated and deoxygenated blood, menaing blood has been mixed and is not going where it should be
what is hypertrophy
increased cell size
how can larger holes in the heart be healed
endovascular repair (going through the vessels in the groin) or heart surgery
how does size of heart holes affect the mixing of blood
the larger the holes, the more mixing of the blood
why are the semilunar valves named in this way
they are half moon shaped
what makes the pulmonary valves different
they lack chordate tendinae and papillary muscles
what is lub
the loud noise produced due to the closure of the atrioventricular valves at the time of the ventricule systole
what do the chordinate tendinae and papillary muscles do when the pressure builds up in the left ventricle
they contract and pull down to hold the valves in place
what keeps the semilunar valves shut under pressure if they lack the chordinate tendinae and papillary muscles
the backward pressure keeps them shut by gravity
what can happen to the blood when a tooth is extracted
air can enter and cause a blood clot
what is infarction
death of the tissue and irreversible damage
which coronary arteries account for the greatest number of heart attacks
left coronary arteries
what is golden hour
the hour in which a heart attack should be treated
what does systole do to arterial walls
expands them
what are chordae tendinae
heart strings that connect to the papillary muscles and prevent the mitral and tricuspid valves flipped back into the atria during ventricular contraction
what is systole
ventricular contraction
describe the process of atrioventricular valves opening
- blood returning to the heart fills the atria, putting pressure against the atrioventricular valves, forcing them open
- as the ventricles fill, atrioventricular valve flaps hang limply into the ventricles
- atria contract, forcing additional blood into the ventricles
describe the process of the atrioventricular valves closing
- ventricles contract, forcing blood against the atrioventricular valve cusps
- the atrioventricular valves close
- papillary muscles contract and chordae tendinae tighten to prevent the valve flaps from everting into the atria
how do semilunar valves open
as the ventricles contract, and the intraventricular pressure rises, blood is pushed up against the semilunar valves, forcing them open
how do semilunar valves close
as ventricles relax and intraventricular pressure falls, the blood flows back from the arteries, filling the cusps of semilunar valves and forcing them to close
what are the semilunar valves
half moon shaped structures. these are the aortic and pulmonary valves. they do not have chordae tendinae unlike the mitral and tricuspid valves, and they hold the blood here to prevent backflow into the right and left ventricles
what is anastomosis
junction of vessels
what are end arteries
these only supply oxygenated blood to a specific portion of tissue and they exist in the spleen, liver, intestines, end of digits, ears, nose and penis
what does ischaemia result in
collateral circulation
what is ischaemia
inadequate blood supply to the heart
what is collateral circulation
alternate or back up blood vessels that the body can take over when another artery or vein become blocked or damaged - new blood vessel growth to pass around the area of reduced blood supply
what is angina pectoris
this is the chest discomfort experienced when the heart does not receive sufficient blood supply - the chest pain related to CAD
what is CAD
coronary artery disease
what is myocardial infarction
damage to the heart muscle caused by a loss of blood supply due to blocks in the arteries
which branches of the coronary arteries cause infarction
40-50% are the anterior left coronary arteries, 15-20% circumflex coronary arteries and 30-40% right coronary arteries
what is the longest vein of the body
saphenous vein
which veins are used for a coronary artery bypass graft
internal mammary, saphenous, internal thoracic
why may the saphenous vein not be the most preferred vessel to use for a coronary artery bypass graft
it is not an artery
what is the pacemaker of the heart
the sinoatrial node
what does the moderator band do
this allows for more rapid conduction across to the anterior papillary muscle to help with conduction times
what are purkinje fibres
specialised conducting fibres that create a synchronised contraction across the ventricles to maintain regular heart rate
how do purkinje fibres compare to cardiac myocytes
they are bigger
what is atrial septal defect
incomplete closure of the foramen ovale
what causes holes in the heart
when the foramen ovale do not close properly
when is the lub sound produced
ventricular systole
when is the dup sound produced
atrial systole
which sound is harder out of lub and dup
dup
which condition makes the heart relevant to dentistry
subacute bacterial endocarditis
where does SBE occur
rheumatic or congenitally abnormal valves
can SBE affect prosthetic valves
yes
what are some organisms that can lead to SBE
streptococcus viridians and staphylococcus aureus
what can cause SBE as a result of dentistry
dental abscesses
what can SBE lead to
stenosis or regurgitation causing a murmur as a result of valvular vegetations
how does SBE lead to valvular vegetations
the bacteria can make the valves become sticky and they do not close properly. vegetations prevent the heart from working - can cause death.
what must be used to treat SBE
broad spectrum antibiotics and metronidazole
what is atrial fibrillation
rapid, irregular contraction of different parts of the atria
what is ventricular fibrillation
rapid, irregular contraction of the ventricles
this is not compatible with systemic or coronary circulation
leads to cardiac arrest
which type of cardiac arrest may occur on the dental chair
ventricular fibrillatio
what is arrhythmia
when the heart beat is too fast or too slow
what maintains arterial blood pressure during diastole
recoil of the arterial walls
what regulates the flow of blood through the arteries
the varying diameter of capillaries
what are the three histological layers to arteries
tunica intima
tunica media
tunica adventitia
what are the three types of artery
elastic
muscular
arterioles
what are the elastic arteries
- aorta
- common carotid
- subclavian
- pulmonary arteries
what are the muscular arteries
- radial
- femoral
- coronary
- cerebral
what are the arterioles
the terminal branches supplying the capillary bed
