8.1 Muscle Flashcards
What is the sarcolemma?
The outer membrane of a muscle cell
What is the sarcoplasm?
The cytoplasm of a muscle cell
What is the sacroplasmic reticulum?
The sarcoplasmic reticulum is the smooth endoplasmic reticulum of a muscle cell. It plays a role in stocking calcium
What are the 3 types of muscle we find in the body?
Skeletal, cardiac and smooth
Which muscle types are Striated?
Skeletal and cardiac
What muscle type is non-striated?
Smooth
Which muscle type has the longest cells? How do we explain this?
Skeletal because the individual cells span the whole length of the muscle.
Which type is muscle has multiple peripheral nuclei?
Skeletal
Which muscle type has spindle shaped cells?
Smooth
Which muscle type has cells that have branched ends?
Cardiac
At what speed to contractions occur in the various muscle types?
Skeletal: rapid and forceful
Cardiac: variable
Smooth slow, sustained and rythmic
What are the 3 different types of fiber that one finds in skeletal muscle and what differentiates them?
Red fibers - small and many mitochondria, rich vascularization, rich myoglobin, responsable for slower, repetitive weaker contraction! eg. postural back muscles
Intermediate fibres
White fibres - bigger, few mitochondria, poor vascularization, poor myoglobin, responsable for stronger and faster contraction. eg. extraocular and finger muscles.
What is myoglobin?
Myoglobin is a red protein containing haem, which functions as an oxygen storing molecule, providing oxygen to the working muscles.
Present in Skeletal and Cardiac muscle but NOT in smooth muscle!
Haemoglobin gives up oxygen to myoglobin especially when pH is low (i.e. in metabolically active tissues, where CO2 is produced)
A muscle cell is also the muscle…
fibre
Between fibres, cells, there is…
endomysium