SEHS Topic 1.2 The Muscular System

Outline the general characteristics common to muscle tissue

• Contractility• Extensibility• Elasticity• Atrophy• Hypertrophy• Control by nerves• Serviced by capillaries

Cont’d• Contactility - the ability of muscle tissue to

contract (when its thick (myosin) and thin (actin) filaments slide past each other)

Cont’d

• Extensibility - Muscle extensibility refers to the ability of a muscle group to lengthen. This involves both contractile muscle and ligaments.

• Elasticity - refers to the ability of your muscle and joints to stretch and contract in different directions while retaining their normal length and tension at rest.

cont’d Atrophy and Hypertrophy Muscular atrophy means that muscle that was there has degenerated. - It can happen because of disuse (like if you have a broken bone that's in a cast for a period of time) or because innervation to that muscle has been interrupted (as with a spinal cord injury), or any other reason that it isn't being used.

Cont’d

• Hypertrophy – A nontumorous enlargement of an organ or a tissue as a result of an increase in the size rather than the number of constituent cells

Cont’d –Nerve connection & capillaries

Distinguish between the different types of muscle

• 1. Smooth; 2. Cardiac; 3. Skeletal

Annotate the structure of skeletal muscle• Limit to epimysium, perimysium, endomysium,

muscle fibers, myofibril, sarcomere, actin and myosin

Labeled

Define the terms origin and insertion of muscles• Origin – the attachment of a muscle tendon to a

stationary bone

• Insertion – the attachment of a muscle tendon to a moveable bone

Identify skeletal muscle from the Anterior part of the body

• Must include:

• Deltoid, pectoralis, illiopsoas, sartorius, quadraceps femoris (rectus femoris, vastus intermedialis, vastus medialis, vastus lateralis), tibialis anterior, abdominus rectus, external obliques and biceps brachii

Identify the location of skeletal muscle form the Posterior region of the body

• Must include:• Trapezius, triceps brachii, latissimus dorsi,

gluteus maximus, hamstrings (biceps femoris, semitendinosus, semimebranosus), gastrocnemius, sloeus, erector spinae