week 5: cardiovasular physiology: structure of lungs and heart: organisation of heart, lungs and vessels Flashcards
thoracic cavity is divided laterally into
two pulmonary cavities
pulmonary cavities occupied by
lungs
in medial compartment of thorax between pulmonary cavities
mediastinum
mediastinum divided into superior and inferior at level
vertebra T4/5
what can you feel as a bump on front of chest
sternal angle
newbrium and body of sternum meet
inferior mediastinium can be divided
anterior: area in front of heart
middle mediastinum: heart
posterior: area behind heart and pericardium
important structures found in mediastinum
heart
trachea
major blood vessels and nerves
oesophagus
pleura
enclosed sack lung grows into during development
what makes up the pleural sack
2 membranous layers that surround each lung: parietal and visceral pleura
pleural cavity
small space between the parietal and visceral pleura
thin film of serous pleural fluid function
reduces friction
creates surface tension between parietal and visceral layers to aid inspiration
(allows lungs to inflate smoothly when chest expands)
size of lung comparison
left lung slightly smaller as heart expands into left side
lobes of left lung
upper and lower lobe separated by oblique fissure
lobes of right lung
upper, middle and lower
oblique fissure
horizontal fissure divides upper and middle
heart position in relation of rib cage
sits slightly to left of sternum
runs from rib 2/3 to rib 4/5
apex of heart runs down through mid clavicular line
heart is on axis
key anterior surface features of heart
right ventricle takes up maortiy area of viewpoint
right atrium in view
pulmonary trunk that runs to lungs
arch of aorta to right of pulmonary trunk
superior and little bit of inferior vena cava
key posterior surface features of heart
majority of view taken up by left ventricle
left atrium in view
4 chambers of heart
2 atria
2 ventricles
4 valves of heart
aortic
pulmonary
tricuspid
mitral
2 main coronary arteries of heart
left and right
numerous branches
1 main coronary vein of heart
coronary sinus
numerous tributaries
apex of heart vs lungs
heart: bottom
lungs: top
pericardium
membranous layer surrounding heart
pericardial sac layers
fibrous pericardium
serous pericardium
fibrous pericardium surrounds serous pericardium and serves as a protective layer
serous pericardium
2 layers: parietal and visceral
fluid filled pericardial cavity between the two layers
what is the parietal layer in contact with
fibrous pericardium
fibrous pericardium and partietal layer fuse together
helps to create protective outer membrane for heart
three layers of heart wall
endocardium
myocardium
epicardium
endocardium
endothelial tissue
areolar tissue
paracrine
myocardium
cardiac muscle cells
connective tissue
contractive
epicardium
viseral layer of serous pericardium
protective layer
cardiac muscles
thin sheets of muscle that wrap around each other in spiral
twisting and contraction
helps blood move in right direction
cardiac muscle sheets: atrial
atrial musculature forms bands that wrap around atria in a figure-8 pattern
caridac muscle sheets: ventricular
ventricular musculature forms bands that spiral around the ventricles
intraventricular spetum
seperates right and left venricle
papillary muscles
attach via chordae tendonae
to AV valves
valve between right atria and ventircle
three cusps
tricuspid valve
valve between left atria and ventricle
two cups
biscuspid
pulmonary valve and aortal valve
semi lunar valves
each have three cusps
blood enters right atrium through
superior vena cava
inferior vena cava
blood flow from right atrium to right ventricle
through tricuspid valve
blood from right ventircle
flows to pulmonary trunk through pulmonary valve
to lungs
oxygenated blood from lungs enter left atrium through
pulmonary veins
4 pulmonary veins
blood flow from left atrium to left ventricle
through mitral valve
blood flows from left ventricle to
aorta through aortic valve
then to systemic circulation and supply blood to body
three main circulation
pulmonary
coronary
systemic
pulmonary circulation
blood to and from lungs
coronary circulation
blood to and from heart
systemic circulation
blood to and from body
