GENERAL MYOLOGY

BY

DR.EMAN ESHRAH

MYOLOGY : Science Dealing With Muscles and Related (Accessory Structures).

Myo= muscle, Ology= science

وملحقاتها العضالت دراسة علم .هو

Muscle:

• A contractile tissue consisting of bundles of muscle fibers, which moves a particular bone or part of the body: ex. the heart muscle; the muscles of the arm.

• ACTIVE ORGAN OF MOTIONS.

•Muscle cells called fibers not cells why?

TYPES OF MUSCLES

القلب عضالت

هيكلية عضالت

حشوية Visceral musclesعضالت

INVOULANTRY MUSCLES

Voluntary Muscles

How could skeletal muscle fibers form bundles ?

Forms of skeletal muscles:

1 -long muscles : limbs.

2 -Flat muscles : abdomen, chest.

3 -Sphincter muscles or orbicular muscles:

Ring like muscles circumscribe orifices which they close so called sphincters.

Sphincter ani (around anus).

Orbicularis oris (around mouth).

Orbicularis oculi (around eye).

Flat muscle

Long muscles

sphincters

Muscle attachment

Muscle attachment

Origin: Is the attachment which remains fixed when the muscle contracts (FIXED END).

Insertion :Is the movable attachment of the muscle (MOVABLE END).

Tendon : Cord like band of fibrous tissue.

Developed at ends of muscles and

by it muscle attached to bones.

*Sesamoid bones : present between tendons and bones where tendons subjected to great pressures .Ex . 1- Proximal and distal sesamoid .

2- Patella (largest sesamoid ).

Difference between tendon and ligaments?

Aponeuroses :

Thin strong flat tendon

Represent attachment of flat muscles.

Example : oblique muscles of abdomen.

Raphae:

Is an interdigitation of aponeurosis of flat

muscles:

Example: Raphea between short aponeorosis = pharyngeal raphae.

Raphea between wide and long aponeorosis = raphae between abdominal muscles =

Linea alba.

Muscle attachment:

1 -origin.

2 -Insertion.

3 -Tendon.

4 -Aponeurosis.

5 -Raphae

Accessory (related ) structures of muscles:

1 -Bursa.

2 -Tendon sheath (Vagina tendinis).

3 -Fascia (Superficial, Deep).

1- Bursa : simple synovial sac between tendon or muscle and some deeper structure mostly bony prominence.

2- Tendon sheath (vagina tendinis) :

1- Synovial sac around tendon.

2- Formed of two layers :

Inner layer close to tendon.

outer layer attach to groove lodged tendon.

these two layers continues with MESOTENDON.

TENDON SHEATH (VAGINA TENDINIS)

BONE

Periosteum

layers of synovial sheath

Tendon

mesotendon

Peritendon

BURSA SYNOVIAL SHEATH

Superficial Fascia :

1- Formed of loose connective tissue .

2- May contain fat.

3- Subcutaneous fascia.

Deep Fascia:

1- Formed of one or more layers of Dense Fibrous tissue.

2- Spread over muscles.

3- May fuse with Epimysium. Tendons, Bones or Ligaments.

4- Form Fibrous Sheaths Around Muscles.

5- Stretch across grooves which lodged tendons converting these grooves into canals by bands termed = Annular Ligaments.

Classification of Skeletal muscles

1- Shape :

Rhomboideus= الشكل معينة

Trapezius = الشكل منحرفة شبه

2- Action :

Flexor قابضةExtensor باسطة

3- Size :

major كبيرة minor صغيرة

4- Attachments :

Brachio-cephalicus =

brachium =arm.

Cephalicus= Head

5- Position: ex: pectoral, abdominal muscles.

6- Division : biceps, رأسين triceps ذات

7- Direction of muscle fiber:

1- RECTUS : خطوط في العضلية األلياف تنتظم مستقيمة

2- OBLIQUS: مائلة خطوط في العضلية األلياف تنتظم

8- Arrangement of their fibers:

1- Parallel.متوازية

2- Fusiform.مغزلية

3- Circular.

4- Unipennate. Pennate = feather like.

5- Bipennate.

6- Multipennate.

Summary

1- Definition of Myology – Muscle.

2- Types of muscles.

3- How skeletal muscle fibers form bundles.

4- Forms of skeletal muscles.

5- Attachments of skeletal muscles.

6- Accessory structures of skeletal muscles.

7- classification of skeletal muscles.

TYPES OR CLASSIFICATION OF BONES?

Compact bone

Spongy layer Diploae

Structure of long bone

Chemical composition and physical properties of bone:

1- Bone formed of organic and inorganic matter in the ratio of 1:2. (33% organic, 67% inorganic ).

2- Organic matter (ossein): give Elasticity. مرونة

3- Inorganic matter : give Rigidity صالبة, calcium carbonate, calcium phosphate mainly .