muscle Flashcards
skeletal muscle structure
multinucleated
cardiac muscle structure
single nucleus
intercalating disks
smooth muscle structure
mononucleated
what does skeletal muscle form from in utero
mononucleated myoblasts
can myoblasts self repilcate
no- can’t replace if damaged
hence scar tissue
what attaches muscle to bones
tendons
when injured what can skeletal muscle cells do
replaced by satellite cells
undergo hypertrophy to copensate
1 skeletal muscle fibre is made of lots of
myofibrils
what are myofibrils made from
sarcomeres- the repeating unit
thick filaments are made from ____ and contain
myosin
cross bridges
thin filaments are made from
actin
what causes cross bridge to attach to actin
hydrolysis of ATP- ATP gets converted to ADP
what causes the cross bridge to detach from actin
attachment of ATP
role of troponin, tropomyosin and Ca2+
tropomyosin covers myosin binding site, helped by troponin
Ca2+ stops this by binding to troponin making it pull tropomyosin away
what does the sarcoplasmic reticulum store
Ca2+ ions
what do the transverse tubules act as
conduction system- AcH travels down it to reach the sarcoplasmic reticulum
muscle units consist of
motor neurons and muscle fibres
force exerted by muscle
tension
force exerted on muscle
load
contraction with constant length
isometric- holding still