Muscular Flashcards
Muscles constitute what percentage of body mass?
40-50%
Anatomical into of muscles
Myofibrils
Functional unit of muscles
Sarcomere
Are muscle cells excitable?
Some, yes. Eg: heart cells (AV nodes, SN nodes, Purkinje)
Define HYPERPLASIA
Increase in cell number
Define HYPERTROPHY
Increase in cell size
Define ATROPHY
Malnourished
Give substance to the following terms with respect to muscular tissue:
Hyperplasia
Hypertrophy
Atrophy
Hyperplasia is not seen in muscles
Hypertrophy is seen in muscles (gym- body building)
Atrophy (PEM eg Kwashiorkar, Marasmus)
Why are certain muscles striated?
All muscles contain contractile actin and myosin proteins . In some muscles these proteins are arranged in an orderly manner (eg skeletal, cardiac) while in others (eg smooth) they ARE PRESENT, just not arranged in an orderly manner.
Do smooth muscles have troponin?
No, they have CALMODULIN
Cardiac muscles are multinucleate. Comment.
FALSE. Uninucleate.
Skeletal muscles are branched/Unbranched.
UNBRANCHED Skeletal muscles.
Which tissue out of the three classifications, is FUNCTIONALLY SYNCITIAL
Cardiac
Smooth muscles show fast/slow contractions.
Sloooooow
Smooth muscles are thickly wrapped with sarcolemma
FALSE
With respect to the outer connective sheath (epi-, Peri-, endo-) which ones are present in Cardiac
Endomysium
Out of the three connective sheaths which wrap muscles, which is absent in smooth muscles
Epimysium.
Smooth muscles have ENDOMYSIUM AND PERIMYSIUM