Muscle tissue

function

allows the body to move

allows movement of individual structures within the body

e.g. causes heart to beat

allows lungs to relax and expand

moves food through the digestive system

muscle

a specialised tissue containing cells capable of contraction

myogenesis

process of developing muscle tissue

occurs during embryonic development

muscle fibres form from the fusion of myoblasts into multi-nucleated fibres called myotubes

embryonic —> myoblasts —> myotubes —> myofibres

myofibrils

cylindrical strands of contractile proteins that make up muscle fibres

what can myofibrils be broken down into?

sarcomeres

sarcomeres

segments of myofibrils that contain bundles of parallel actin and myosin filaments

what is enabled when the actin and myosin filaments slide in between each other?

muscle contraction

shortening of the sarcomere

structure of muscle fibre diagram

types of muscle

skeletal, cardiac, smooth

is skeletal muscle voluntary or involuntary?

voluntary

is cardiac muscle voluntary or involuntary?

involuntary

is smooth muscle voluntary or involuntary?

involuntary

why is cardiac muscle involuntary?

it is myogenic - it can contract without nervous input

voluntary muscle

used consciously

involuntary muscle

controlled by the autonomic nervous system

where is skeletal muscle located?

attached to, support and move the skeleton

where is cardiac muscle located?

specialised muscles found in the heart

where is smooth muscle located?

digestive system, reproductive tracts, the vascular system, bladder and bowels

appearance of skeletal muscle

cylindrical shape with multiple nuclei arranged around the outside

striated appearance due to the arrangement of the fibres

appearance of cardiac muscle

elongated, branching cells

one or two nuclei per cell

striations characterised by dark and light bands

found with excitatory and conductive muscle fibres, which conduct electrical impulses and control the heartbeat

appearance of smooth muscle

spindle-shaped cells with one nucleus

function of skeletal muscle

movement of the skeleton at joints

work in antagonistic pairs

function of cardiac muscle

contraction of the heart tissue

function of smooth muscle

allows hollow organs to contract

skeletal muscle diagram

cardiac muscle diagram

smooth muscle diagram