a.
Contractilitate
Excitabilitate
Conductibilitate
Automatism
b.
( Prima liniuta )
Fc= 75 contractii/min
Debit Sistolic= 75 ml = Volum-bataie = VB
Dc=Fc*VB
Dc= 75*75 = 5625 ml / min = 5,625 L / min
( A doua liniuta )
x ml O2 / 100 ml sange neoxigenat ( vena cava )
20 ml O2 / 100 ml sange oxigenat
250 ml O2 / min ( consum )
Pe minut ajung la tesut 5625 ml de sange.
Iar 100 ml sange oxigenat contine 20 ml O2.
=> Pe min ajung la tesut
20 ( ml O2 ) * 5625 : 100 = 1125 ml O2 / min
Consumul este de 250ml O2 / min
=> Sangele neoxigenat contine
1125-250=875 ml O2 / min ( Oxigen neconsumat )
La inima ajung tot 5625 ml sange / min.
=> x ( ml O2 ) * 5625 : 100 = 875
x= 875 * 100 : 5625
x= 15,55 ml
=> 100 ml de sange neoxigenat ( sangele venei cave ) contine 15,55 ml O2
c.
Cerinta:
Daca Fc se reduce de la 75 contractii/min la 65 contractii/min, calculati Dc.
Rezolvare:
Dc=Fc*VB
Dc= 65*75=4875ml/min
