cardiovascular system Flashcards
what is the pericardium?
- outer casing of the heart
- protective fluid-filled sac surrounding the heart
- outermost layer = fibrous pericardium
where is the heart located?
- between lungs to the left
- twisted to the back
- harder to access the left side of the heart
how many borders does the heart have?
4
what are the borders of the heart?
- superior border = great vessels enter and leave
- interior border = lies on the diaphragm / in line with it
- right border = faces right lung
- left border = faces left lung
the apex
where the ventricles join up
what is the mediastinum?
- central compartment of the thoracic cavity
- area between the lungs
what does the mediastinum contain?
- heart
- great vessels
- thymus
- oesophagus
- trachea
what are anterior (front) landmarks of the heart?
- coronary sulcus
- anterior interventicular sulcus
- auricles
the (anterior) coronary sulcus
- marks division between the atria and the ventricles (right atrium & right ventricle?)
- continues posteriorly
- right coronary artery (RCA) in sulcus anteriorly
- grove for veins & arteries
- RCA sits in within a “line of fat”
the anterior interventricular sulcus
- marks division between ventricles (left & right ventricle)
- continues posteriorly as posterior interventriculary sulcus
- Left anterior descending (LAD) from left coronary artery (LCA) in sulcus anteriorly
- LAD sits within this sulcus
auricles
- atrical appendages
- increase capacity -> extra “spaces” for atria to expand
- used when the heart is working really hard
what are the posterior (back) landmarks of the heart?
- coronary sulcus
- posterior interventricular sulcus
the (posterior) coronary sulcus
- division between atria and ventricles
- continous anteriorly
- coronary sinus in sulcus
the posterior interventricular sulcus
- marks division between ventricles
- continues anteriorly as anterior interventricular sulcus
- posterior descending artery (PDA) from LCA or RCA in sulcus
how can you identify the left atrium?
- 4 pulmonary vein vessels
- found in the back of the heart
layers of the heart wall
- epicardium (outer) = the visceral layer of the serous pericardium
- myocardium (middle) = cardiac muscle
- endocardium (inner) = continuous with endothelium of large vessels of the heart
what are the 2 types of the pericardium?
- fibrous
- serous
fibrous pericardium
- tough & inelastic
- rests on / attached to diaphragm
- open end fused with great vessels
- physically attached to diaphragm
serous pericardium
- parietal layer (fused to fibrous pericardium)
- visceral layer (continuous / part of epicardium)
- pericardial cavity (space between parietal and visceral layers contains pericardial fluid)
what is the role of pericardial fluid? and where is it found?
- in the pericardial cavity
- to reduce friction bc layers rub against each other
- helps the heart expand and contract easier
why is the fibrous pericardium physically attached to the diaphragm?
- to allow synchronised movement when breathing in and out
- prevents heart and diaphragm from hitting each other
what are the chambers of the heart?
- right atrium (RA)
- right ventricle (RV)
- left atrium (RA)
- left ventricle (RV)
right atrium
gets deoxygenated blood from the vena cavae (biggest vein in body) & coronary sinus (at the back of the heart)
right ventricle
pumps deoxygenated blood to the lungs (pulmonary circulation)
left atrium
gets oxygenated blood from lungs via pulmonary veins
left ventricle
pumps oxygenated blood in aorta (systematic circulation)
blood to rest of the body
pulmonary circulation
- the system of transportation
- de-oxygenated blood from the heart to the lungs to be re-saturated with oxygen before being dispersed into the systemic circulation
systematic cirulation
provides the functional blood supply to all body tissue.
what are the types of valves of the heart?
- atrioventricular (AV) valves (tricuspid valve, bicuspid valve)
- semilunar (SL) valves (pulmonary valve, aortic valve)
is the right AV tricuspid or bicuspid?
tricuspid = 3 leaflets / cusps
is the left AV tricuspid or bicuspid?
bicuspid (mitral) =2 cups
what muscles and tendons are involved in the valve cusps
- chordae tendinae
- papillary muscle (projection of myocardium, pushed down / pull on chordae tendinae & valve closes)
pectinate muscles
- on RA
- myocardium projections
- make surface not smooth = facilitate expansion without tension
trabeculae carneae
- contract and pull on the chordae tendinae
- prevent inversion of the bicuspid and tricuspid valves towards the atrial chambers
the great vessels of the heart
- superior vena cava (back from above the heart)
- pulmonary arteries (split in the lungs)
- pulmonary trunk (splits into the pulmonary arteries)
- inferior vena cava (from the bottom of the heart)
- aortic arch (blood to body)
- pulmonary veins (blood from lungs)
- ascending aorta
- left common carotid (goes up the neck)
- brachiocephalic
- left subclavian (upper limbs)
functions of blood
- transportation (nutrients & waste)
- protection (immune system)
- regulation (hormones, proteins)
haematopoiesis
blood production
haemorrhaging
blood loss
blood components
- red blood cells (erythrocytes)
- white blood cells (leukocytes)
- platelets (thrombocytes)
- plasma (the ECM of the blood)
red blood cells
- produced in bone marrow
- erythropoietin - kidney
- no nucleus
- haemoglobin protein
- haematocrit (40-45%)
- anaemia (low number of erythrocytes, low iron)
- polycythaemia (high number of erythrocytes, viscosity)
white blood cells
- protection
- phagocytosis
- 2 classes:
-> granulocytes (neutrophils…)
-> agranulocytes (lymphocytes…) - leukopenia (low WBC count, infection)
- leukocytosis (high WBC countm inflammation)
platelets
- cell fragments
- control blood loss
- fibrin clot -> help body form clots to stop bleeding
- normal count = 150,000 - 450,000 platelets per microliter)
- thrombocytosis (>450,000)
- thrombocytopenia (<150,000)
plasma
- straw-coloured liquid
- blood cells are suspended in it
- ECM of blood
- half of blood is made of plasma
- composed of:
-> water (92%)
-> proteins -> major proteins = albumin
-> glucose
-> electrolytes
what is included in central control of the cardiac cycle?
anything from the heart
what is included in the peripheral control of the cardiac cycle?
blood vessels from the rest of the body
diastole
filling & relaxation
systole
pumping & contraction
(ventricles contracting & pump blood out)
central venous pressure (CVP)
- pressure in the thoracic vena cava near the right atrium
- how much blood is going back to the heart
mean arterial pressure (MAP)
MAP=1/3 (SysP) + 2/3 (DiaP)
- average arteriol pressure throughout one cardiac cycle (systole + diastole)
does diastole or systole take longer?
diastole lasts longer
in systole only for 1/3 of cardiac cycle
aortic pressure
the difference between diastolic & systolic pressure
what does the aortic pulse pressure show?
- how effective the left ventricle is in pulsing blood into the aorta
- the pulse pressure caused by this
the end diastolic volume
- 120ml
- when ventricles are at their maximum capacity