muscle fibres

• skeletal muscle

  • muscles in the body that are attached to skeleton
• muscle fibres are specialised:

  • organised arrangement of contractive proteins in cytoplasm
  • surrounded by cell surface membrane
  • many nuclei
• sarcolemma

  • cell surface membrane
  • has many deep tube like projections folding inwards=transverse system tubules
  • runs close to the sarcoplasmic recticulum
• sarcoplasm

  • many mitochondria to produce ATP for contraction
  • many myofibrils- bundles of myosin and actin filaments
• sarcoplasmic recticulum

  • endoplasmic recticulum
  • membranes contain many protein pumps- transports calcium ions in the the lumen of the SR