Muscle system Flashcards
What is the sarcomere
the space between the z-discs
what are the three types of muscle cells
cardiac muscles
smooth muscles
skeletal muscles
what are the characteristics of cardiac muscles
only found in the heart
tubular & arranged in a branched like network
striated with one nucleus per cell
contraction is involuntary
what are the characteristics of smooth muscles
long tapered sheets, which are non striated
one nucleus per cell
involuntary contraction
makes up the walls of many internal structures such as the digestive tract and blood vessels
what are the characteristics of skeletal muscles
tubular, long, striated cells
many nuclei per cell
voluntary
what are antagonistic skeletal muscles
muscles that work in pairs. When one contracts the other relaxes and vice versa.
State the hierarchy of muscles from biggest to smallest
muscle
muscle-fibre bundle
muscle fibre
myofibrils
myofilaments
what are the 4 parts of muscle fibres
myofibrils
mitochondria
membrane - called sarcolemma
cytoplasm - called sacroplasm
what is the muscle fibre made out of
Actin and Myosin
what does actin look like
A thin filament attached to the z-line
what does myosin look like
a thick, long filament with little myosin heads extending from it
what is myoglobin
hemoglobin for skeletal muscles
what is the process of muscle contraction and relaxation
Ca2+ is released -> tropomyosin is moved out of the way -> myosin heads bond to actin -> muscle contracts -> nervous stimulation stops -> Ca2+ is pumped away -> ATP unbinds myosin heads from actin -> myosin filaments slide back to relaxed
what is rigor mortis
when something dies the muscles stay contracted bc ATP can’t be created to unbind the myosin heads from the actin
what happens to the z-disks when muscles contract and relax
relaxes: z-disks move apart
contracts: z-disks move together
