Muscles:
STRUCTURE FUNCTION
MUSCLE Contract in antagonistic pairs
(biceps = flexor & triceps =
extensor).
TENDON Connect muscle to bone and pull
on it when muscle contracts.
LIGAMENT Holds bones together to prevent
dislocation.
CARTILAGE Reduces friction/wear.
SYNOVIAL MEMBRANE Secretes synovial fluid.
SYNOVIAL FLUID Acts as a lubricant/ allows
smooth movement.
Skeletal muscles are made up of thousands of muscle fibres.
Muscle fibres are multinucleate because cells have fused
together to be longer to reduce the number of points of
weakness along a fibre.
Each fibre is surrounded by a plasma membrane called a
sarcolemma, which has many deep folds called T-tubules.
The cytoplasm is called sarcoplasm & it contains many
mitochondria (provide ATP) & specialised endoplasmic
reticulum called sarcoplasmic reticulum (which contains
calcium ions).
They also contain myofibrils which
themselves are made up of two
types of myofilament – thin actin &
thick myosin.
Myofibrils are the contractile units.
To the left is a sarcomere – it
shortens in length as a muscle
contracts.
STRUCTURE FUNCTION
MUSCLE Contract in antagonistic pairs
(biceps = flexor & triceps =
extensor).
TENDON Connect muscle to bone and pull
on it when muscle contracts.
LIGAMENT Holds bones together to prevent
dislocation.
CARTILAGE Reduces friction/wear.
SYNOVIAL MEMBRANE Secretes synovial fluid.
SYNOVIAL FLUID Acts as a lubricant/ allows
smooth movement.
Skeletal muscles are made up of thousands of muscle fibres.
Muscle fibres are multinucleate because cells have fused
together to be longer to reduce the number of points of
weakness along a fibre.
Each fibre is surrounded by a plasma membrane called a
sarcolemma, which has many deep folds called T-tubules.
The cytoplasm is called sarcoplasm & it contains many
mitochondria (provide ATP) & specialised endoplasmic
reticulum called sarcoplasmic reticulum (which contains
calcium ions).
They also contain myofibrils which
themselves are made up of two
types of myofilament – thin actin &
thick myosin.
Myofibrils are the contractile units.
To the left is a sarcomere – it
shortens in length as a muscle
contracts.
