Question

i in the 'myocardium' of the heart of vertebrates. The card
ocardial cells' are short, cylindrical, mononucleate or
ds branch and form junctions with other cardiac muscle
1 is joined to adjacent myocardial cells by 'electrical s
'. They permit ‘electrical impulses' to be conducted alc
diac muscle fibre. The dark lines across cardiac musc
iscs (IDs). These discs are characteristic of the cardiac
munication junctions which allow the cells to contra
iscs contain three different types of cell junctions
ch are responsible for rapid conduction of action poten
c muscle of vertebrates does not require any nerve stimul
produce impulses spontaneously from a specialised
‘pace maker' (myogenic heart). As such, the card
z its function. However, the rate of heart beat is re
nervation and hormones such as epinephrine/ad
ne myocardial cell results in the excitation of all ot
o produce a 'whole hearted' contraction', of the ent
us the cardiac muscle is described as a 'functional s
is highly resistant to fatigue, because it has numer
es of myoglobin (oxygen storing pigment) and rich
e 'continuous aerobic respiration'.​

Answer 1

kkaghba anssoown wjjsiiis siisgfslmgbwb hhds