General Myology

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3 categories of muscles:

Smooth muscles (organs, eg. digestive tract)

Cardiac muscles (heart)

Skeletal muscles (responsible for movement)

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Long muscles:

mainly located in the limbs.

The more swollen end is the muscle head and the more tapered end is the muscle tail. Each of them can be continued by a tendon.

According to the arrangement of fleshy bundles to the tendon the muscle is: (1) strap (2) spindle shaped (3) pennate (4) bipennate (5) multipennate, (6) muscle digastric, (7) polygastric

According to their cleavage the muscle is: (8) biceps, triceps, quadriceps.

Flat muscles:

Membranous appearance.

Found under the skin, lining of the body’s cavities.

(9) Flabelliform muscle.

Short muscles:

Small

(10) Orbicular, 8 sphincter

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Origin and Insertion:

2 points where muscle is attached

General rules:

Origin:

in the limb: proximal connection

between trunk & limb: trunk connection

in the trunk: cranial connection

Insertion:

in the limb: distal connection

between trunk & limb: limb connection

in the trunk: caudal connection

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Tendon:

connect a muscle to a bone (periosteum)

Appearance of a strong fibrous rope and pearly white. It transmits the remote action of a fleshy muscle. Not stretchable: a stretching more than 3% of its length results in alteration of its structure.

Fascia:

a fibrous layer consisting of superimposed CT layers. We distinguish (i) aponeurosis of insertion that is a broad flat tendon and (ii) coating fascia that is spread on the surface of muscle fleshy bodies. In limbs it surrounds some muscles group to canalize their contraction

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Vessels and Nerves:

Muscles are vascularised and each controlled by one nerve

Innervation report:

number of muscle fibers receiving an order from the same motor nerve cell.

is even lower than the control is delicate.

It is about 10 for a eye muscle and 2000 for a leg muscle.

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Bursae (synovial vesicular cavities):

allow shifting/sliding of a mobile organ on a surface.

They can be Subcutaneous, subligamenteous, submuscular, subaponeurosis, Subtendinous.

Tendinous sheath:

a tunnel that allows the passage of one or more tendons.

Usually when tendon crosses joint

consists of a bony/ligamentous/fibro-cartilage surface supplemented by a connective tissue wall.

Synovial vagina or synovial sheath:

facilitate the tendons passage through a tendinous sheath.

similar to a synovial membrane.

Prevents tendon from having friction

Filled with liquid

Tendinous recess or tendinous pouch:

Similar to an articular recess (but at the synovial vagina)

Developed where the tendinous sheath is thin or absent.

Not for this semester

Retinaculum:

Transverse reinforcement of some tendinous sheats that are aligned on the same plane (i.e. extensor retinaculum, flexor retinaculum).

Surround two tendinous sheaths to join them