TYPE SHAPE FUNCTIONS EXAMPLE
FLAT BONE SHIELD PROTECTS
INTERNAL
ORGANS
SKULL
LONG BONE STICK FACILITATE
MOVEMENT
FEMUR
SHORT BONE CUBE STABILITY &
MOVEMENT
CARPALS
IRREGULAR COMPLEX PROTECT
INTERNAL
ORGANS
VERTEBRAE
SESAMOID ROUND REINFORCE
TENDONS
PROTECTS
FROM STRESS
& WEAR
SESAMOID BONES
•Latin word sesum(seed like)
•Sesame Seeds
•Small rounded masses of bones
•Tendons at point subjected to great
pressure.
•Bony nodules embedded in the
tendons or joint capsules.
Sesamoid Bones of Upper Limb
•Pisiform –lying within the tendon of
flexor carpi ulnaris
•2 SB –palmar surface of the head of
First MC bone (FPL)
•1 SB –capsule of IPJ of the thumb
•1 SB –ulnar side of the capsule of MCPJ
Of little finger
Sesamoid Bones of Lower
Extremity
•Patella –quadriceps tendon
•Fabella –lateral head of
Gastrocnemius
•2 SB -first metatarsal bone connects to
the big toe.
•Riders bone –Adductor Longus
PECULIARITY
•No Periosteum
•Haversion Canal System not
Present
•Ossifies after birth
•Absence delay puberty
•Serve to protect the tendon as it flexes,
and also help to keep the toe aligned.
FUNCTIONS
•They resist the pressure
•They alter the direction of the pull of the
muscle
•Reduce the friction
•Maintain local circulation