Cardio vascular system Flashcards
3 components of circulatory system
fluid medium
system of channels
pump
2 circuits
pulmonary
systemic
location of heart
thoracic cavity
near anterior chest wall
posterior to sternum
flow through atria
right - receives from systemic passes to right ventricle
left - receives from pulmonary passes to left ventricle
flow through ventricles
right - receives from right atrium passes to pulmonary
left - receives from left atrium passes to systemic
what the heart wall made of
pericardium
pericardium
fibrous tissue (collagen)
stabilises heart position
lubricates (pericardial fluid)
pericardium structure
outer fibrous layer
parietal layer
visceral layer
myocardium
thick muscle layer between epicardium and endocardium
myocardium structure
short and wide
y shaped
large central nucleus
many mitochondria
interconnections with cardiac cells via intercalated discs
involuntary
intercalated discs
junction between cardiac cells
2 components of intercalated discs
gap junctions; allow depolarisation to pass between cells synchronising muscle contraction
desmosomes: bind adjacent myocytes together
endocardium
covers inner surfaces of heart - internal chambers and valves
has epithelial tissue
catecholamines (adrenaline)
epinephrine
released by adrenal medulla when sympathetic activated eg exercise
catecholamines (noradrenalin)
norepinephrine
initial increase of hr by long exposure decreases
