PE - sac revision

long bone

longer than they are wide, and they have a hollow shaft containing marrow

short bone

roughly cubical, with the same width and length

Sesamoid bones

small bones developed in tendons around some joints

Flat bones

provide flat areas for muscle attachment and usually enclose cavities for protecting organs

Irregular bones

have no regular shape characteristics.

Cartilage

Cartilage is a smooth, slightly elastic tissue found in various forms within the body

ligaments

Cross over joints joining bone to bone. Provide stability at joints preventing dislocation.

tendones

connect muscle to bone

cartilage

shock absorbing gel between joints

tendons

are inelastic, very strong and allow movement

fibrous joints

no movment

cartilaginous joints

allows small movments

synovial joints

offers full range of movement

smooth muscle

found in hollow organs which we have no control over

cardiac muscle

Involuntary muscle fibers that pump blood from the heart into the arteries.

skelital muscles

are voluntary muscles that are attached to bones and help facilitate movement.

voluntary

Muscles that we can control consciously.

invouluntary

Muscles that we cannot control consciously.

three main function of the muscular system

body movement, adequate posture and essential body functions

convergent

Muscle fibers that spread out from the main tendon, balancing strength and mobility.

unipennate muscles

fibres are only found on one side of a central tendon

bipennate muscles

fibres run off either side of a central tendon

multipennate muscles

fibres branch out from several tendons

Fusiform muscle

Muscle fibers run along the length of the muscle and same direction of the tendon, allowing for movement over a large range but producing less force.

epimysium

Surround the skeletal muscle

perimysium

surrounds the fasciculi

endomysium

surrounds the muscle fibre found within one fasciculs

I band

where only actin is found

A band

where both actin and myosin are found. It equates with the length of the myosin filaments.

H zone

where only myosin is found. It is the gap between the ends of the actin.

sarcomere

the smallest unit of muscle contraction

Sliding filament theory

what happens in each sarcomere as a muscle contracts. As its name suggests, the myofilaments (actin and myosin) slide across each other.

what are myofibrils

are long strands which make up muscle fibers

Sarcomeres

the smallest unit of muscle contraction. Each one is designated by a line at either end called a Z line.

Each sarcomere

consists of two protein myofilaments called actin and myosin

myofibrils

consists of many individual units, called sarcomeres, which are responsible for contracting the muscle.