muscles, joints and movement

Raymond G Buick FRCS

9 mins

A muscle is a tissue that has the ability to contract

Types of Muscle tissue: Skeletal Cardiac Smooth muscle

Skeletal and cardiac muscle are striated

However, the term “striated”, usually refers to skeletal muscle

Smooth muscle

Skeletal muscle

Cardiac muscle

Skeletal Muscle – striated muscle

Consists of parallel bundles of long multinucleate fibres

Produces the movements of the skeleton

Parts of the skeletal muscle

Fleshy Part: belly, contractile Fibrous Part: Tendon or Aponerosis

Less elastic Less vascular Resistant to friction

Fleshy Belly

Tendon

Each muscle fibre is an individual muscle cell

It has an outer cell membrane called sarcolemma

The cell cytoplasm is called sarcoplasm

Nuclei are multiple, oval in shape and peripherally placed

Epimysium covers the entire muscle

Perimysium surrounds fascicles

Endomysium surrounds individual fibres

Epimysium covers the entire muscle

Perimysium surrounds fascicles

Endomysium surrounds individual fibres

Epimysium covers the entire muscle

Perimysium surrounds fascicles

Endomysium surrounds individual fibres

Fascicle

Epimysium covers the entire muscle

Perimysium surrounds fascicles

Endomysium surrounds individual fibres

Endomysium

Epimysium covers the entire muscle

Perimysium surrounds fascicles

Endomysium surrounds individual fibres

Sarcolemma is the outer cell membrane

sarcolemma

Individual muscle cell

A tendon (sinew) is a tough band of fibrous connective tissue. Usually connects muscle to bone Consolodation of collagen fibres in the perimysium and epimysium. Maximises efficiency of the muscle in moving a bone Strong Collagen

Aponeurosis

Some muscles (especially flattened muscles) are attached to each other. aponeurosis (pleural: aponeuroses) anterolateral abdominal wall a layer of a flat broad tendon shiny, whitish-silvery colour, histologically similar to tendons few blood vessels and nerves

Aponeurosis

anterolateral abdominal wall Lumbar Palmer and planter scalp

like tendons tightly packed collagen bundles arranged in parallel respond to stress from a single direction attach bones to each other stabalise joints

KNEE JOINT

foetal remnant peritoneal fold

foetal remnant ligamentum arteriosum remnant of ductus arteriosus

peritoneal fold ligamentum teres

layer of connective tissue

superficial

deep

layer of connective tissue

superficial fascia - subcutaneous connective tissue - lies beneath / merges with dermis - fibro fatty layer -fibroblasts - aqueous matrix - elastin - collagen - fat - lymphatic tissue

deep fascia beneath the superficial fascia ensheaths muscles

helps attach them to bones provides attachment for intermuscular septa which partitian muscle

groups – muscle compartments

fibrous – sparce fat and fluid thin and expansile substantial layers, very tough - esp. in neck & limbs non-expansile sleeves investing groups of muscles very thick bands – retinacula

deep fascia The UP side of fascia

movement – minimal friction venous return in legs pus retained within a compartment

The DOWN side of fascia important in disease potential spaces between fascia - track through between

facial layers Compartment syndrome

A lubrication device - flattened, fibrous sacs lined with synovial membranes and containing a film of synovial fluid.

Reduces friction between: - tendons and surrounding structures, or - bone and skin (e.g. prepatellar bursa)

Occasionally bursae may communicate with the cavity of a synovial joint, e.g. the suprapatellar bursae of the knee joint, and the subscapularis bursae of the shoulder joint

Raymond G Buick FRCS