Myology(Myology(ⅠⅠ))

smooth musclecardiac muscle skeletal muscle

Muscles can be divided into the following according to structure：

Skeletal muscle can make contractions, it is one part of locomotor system. The contraction is under the voluntary control, so it is also called voluntary muscles.

Section 1 IntroductionSection 1 Introduction

More than 600 skeletal muscles make up the muscular system

Collectively, the skeletal muscles account for approximately 40% of the body weight .

Each skeletal muscle possesses a definite shape, structure, location and accessory apparatus, and is supplied by abundant blood vessels, lymphatics and nerves, so it can be regarded as an organ.

Ⅰ. Shape and structure of the muscle

long m.

short m .

flat m.

orbicular m.

1. Classification

According to the shape, the muscles may be divided into:

M.of head M.of neck M.of trunk M. of limbs M. of back M. of thorax M. of abdomen diaphragm

According to the position, the muscles may be divided into:

2. Structure

muscle belly

tendon

aponeurosis

muscle belly

tendon

aponeurosis

Ⅱ. Origin, insertion and action of skeletal muscles

The muscular origin ( starting point or fixed point) refers to the position which approaches to the median plane of body or the four limbs part approaches to the proximate attachment point, while the other extremity is insertion or moving point.

•antagonist

•synergist

•agonist

•fixator

•Balance lever movement•Labor-saving movement•Velocity lever movement

ⅢⅢ. Name of muscles. Name of muscles

Shape ： trapezius ， triceps

Location ： pectoralis ， intercostals

Attachment ： sternocleidomastoid, temporalis

Size ： maximum ， minimus ， longus ， brevis

Orientation of fibers ： rectus ， transverse ， oblique

Relative position ： lateral ， medial ， internal and external

Function ： adductor, flexor, extensor, pronator, and levator

Ⅰ) fascia

A. superficial fascia

is found immediately under the skin and covering almost the entire body. containing fat. provides for increased mobility of skin, and contributes to thermal insulation and store energy.

ⅣⅣ. Accessory structure. Accessory structure

B. deep fascia : form the dense inelastic and arranged to regular fiber membrane. may form a strong separate sheath to muscles or the vessels and nerves.

Ⅱ ） synovial bursa: is found between a tendon and a bone or ligament, or between two tendons. lubricate surface of joint.   

fibrous layer

visceral layer (synovial sheath of tendon)

Ⅲ ） Tendinous sheath :

is thought of as a synovial bursa that entends around the tendon to envelop it. has two layers.

Ⅲ ） sesamoid bones: often developed in the tendon and afford for a great amount of pressure. e.g. patella.