8.1 muscular system

characteristics of muscles

closely packed cells with little extracellular fluid

all muscle cells possess myofilaments composed of actin and myosin proteins

produces volunary and involuntary movements

cardiac muscle

smooth muscle

skeletal muscle

what makes up the walls of the heart what is this muscle derived from spanchnic mesoderm

cardiac muscle

what is the cardiac muscle made up of

medium branched cells with one nuc

myofilaments arranged as myofibrils

intercalated discs btween cells and other special organelles

what makes up the walls of hollow organs and what is it derived from

smooth muscle , spanchnic and somatic mesoderm

what is smooth muscle made up of

small size spindle cells with one nuc

myofilaments not arranged as myofibrils= no striations

what does the skeletal muscle do and what is it derived from

attatched to skin and bones gives voluntary movements

derived from scleratom mesoderm

what is skeletal muscles made up of

long cylindrical cells known as fibers with many nuclei

myofilaments arranges as myofibril=striations

other special organelles

function of skeletal muscles

produced voluntary movments’

maintain posture and body positions

maintaining body temp

storing nutrients

what is the epimysium

connective tissue wrapping all fascilcles a vein,artery, and nerve to create single skeletal muscle organ

where is the epymisum attatched

the bone directly or indectly as a tendon

synergists

muscles that work together to produce given action

prime mover

muscle that causes desired action

antagonist muscles

muscles whose actiion opposes that if the prime mover or synergists

what is a fascicle

bundle of parallel muscle fibers or cells

perimysium

connective tissue wrapping around all the muscle fibers that create a fascicle

what dooes the muscel fiber do

spans muscle attatchment pts

endomysium

connective tissue that fills space btwn each muscle fiber

sacrolemma( muscle fiber cells)

outer boundary and contains sarcoplasm which holds mitochondria , nuclei, and myofibrils surrounded by sarcoplasmic reticulum