1 / 26

PRINICIPLES OF MYOLOGY

PRINICIPLES OF MYOLOGY. Def: science deals with muscles. Skeletal muscles are the active part of locomotor system Smooth muscles move the viscera Cardiac muscle produces heart contraction. Dr: Ahmed Saber Vet. Anat. 1. 2008. The main characters of muscles are:

bob
Download Presentation

PRINICIPLES OF MYOLOGY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PRINICIPLES OF MYOLOGY Def: science deals with muscles • Skeletal muscles are the active part of locomotor system • Smooth muscles move the viscera • Cardiac muscle produces heart contraction Dr: Ahmed Saber Vet. Anat. 1. 2008

  2. The main characters of muscles are: Irritability or Excitability - responsive to chemical, electrical, or mechanical stimuli Contractility - ability of muscle to contract (shorten) Extensibility - ability to be passively stretched Elasticity - ability to return to its original length Dr: Ahmed Saber Vet. Anat. 1. 2008

  3. Types of muscles 1- smooth muscles: • Structures: long spindle shaped, uni-nucleate, and non-striated (smooth) • Locations: wall of visceral organ • The control:involuntary autonomic control or endocrine control (myo-epithelial cells) • function: Involuntary contractions that move materials through the organs Dr: Ahmed Saber Vet. Anat. 1. 2008

  4. 2- Cardiac muscles • Structures: • cylindrical, mostly uninucleate striated, and Branching and joins forming myocardium network (syncytium). • The fibers are connected end-to-end at sites called intercalated disks. Dr: Ahmed Saber Vet. Anat. 1. 2008

  5. Locations: wall of heart • The control:involuntary • function: Involuntary autonomic control and special local conducting system cause contractions of heart Dr: Ahmed Saber Vet. Anat. 1. 2008

  6. 3- Skeletal muscles They forming about 40-45 % of body weight The muscle cell = muscle fiber = myofiber • structures: • Elongated, multinucleated, with long and transverse striation. • Each muscle is divided into bundles or fascicles • Each fascicles is composed of numerous muscle fiber (cells) • Locations: in all body & forming active part of locomotor system Dr: Ahmed Saber Vet. Anat. 1. 2008

  7. Skeletal muscles (cont.) • The control:voluntary control function: • voluntary somatic movement of the body • Maintain body position • Stabilizing the joint • Heat production • Guarded body entrances and orifices Dr: Ahmed Saber Vet. Anat. 1. 2008

  8. Fiber Fascicle Epimysium Muscle Tendon bone Architecture of skeletal muscle • Each single muscle is consists of numerous bundles (fascicles) • Each fascicles is consists of numerous muscle fibers • The muscle fiber is the structural unite of muscle Dr: Ahmed Saber Vet. Anat. 1. 2008

  9. Architecture of skeletal muscle Muscle fascicle Blood vessels Epimysium Muscle fiber &endomysium Perimysium Epimysium: CT layer ensheated the entire muscle Perimysium: CT layer ensheated each muscle bundle (fascicle) Endomysium: CT layer ensheated each muscle fiber Epimysium, perimysium and endomysium extend at the muscle end forming tendon or aponeurosis They protect the cells and provide passage for vessels and nerves Dr: Ahmed Saber Vet. Anat. 1. 2008

  10. Architecture of skeletal muscle Muscle fiber Perimysium Fascicle Endomysium Epimysium Dr: Ahmed Saber Vet. Anat. 1. 2008

  11. Microscopic structures Myofibril Myofiber Myofilaments Actin Myosin Dr: Ahmed Saber Vet. Anat. 1. 2008

  12. Gross anatomy of skeletal muscle 1- anatomical parts: A- origin: • usually the proximal attachment of muscle • Less movable part • Somtime more that one head (biceps) B- insertion: • Usually distal attachment • More movable C- belly: • The main balk of muscle between origin and insertion Dr: Ahmed Saber Vet. Anat. 1. 2008

  13. Gross anatomy of skeletal muscle 2- skeletal muscle attachment • Bone • Cartilage • Deep fascia (indirectly to bone) • Skin and superficial fascia • Intermediate tendon • No attachment (no origin & no insertion, as orbicularis oris) Also muscle attachment may be Direct attachment: the epimysium is fused to periosteum or perichondrium directly Indirect attachment: epimysium extends as sheet like aponeurosis before attaching to bone, cartilage, fascia or other muscle Dr: Ahmed Saber Vet. Anat. 1. 2008

  14. Gross anatomy of skeletal muscle 3- arrangements of skeletal muscle fibers Based on the angle between fiber and the line of pull • A- Parallel fibers: • Strap (sartorius) • Quadrates (quadratus femoris) • Fusiform (biceps brachi Strap Fusiform Dr: Ahmed Saber Vet. Anat. 1. 2008

  15. Unipennate B- oblique fibers (pennation) The fibers attached to tendon at oblique angle (feather like) 1- unipennate: on one side of tendonex extensor digitorun longus M 2- bipennate : on opposite sides of tendon, ex rectus femoris M 3- multipennate: muscle fibers attached to several fibrous bands within the muscle, the bands join forming one tendon, ex deltoid M 4- Centripennate: one central tendon Bipennate Multipennate Dr: Ahmed Saber Vet. Anat. 1. 2008

  16. C- circular fibers 1- circular: no attachment, around orifices, ex orbicularis oris (around mouth) 2- convergent: broad origin and pointed insertion, ex pectoralis major Circular Convergent

  17. Functional types of muscles • Prime mover (Agonist muscles) • muscles most involved • cause joint motion through a specified plane of motion when contracting • Antagonist muscles • located on opposite side of joint • have the opposite action to agonist Dr: Ahmed Saber Vet. Anat. 1. 2008

  18. 3. Synergist • assist in action of agonists • not necessarily prime movers for the action 4. Fixators (stabilozers) • Fix the joint Dr: Ahmed Saber Vet. Anat. 1. 2008

  19. Blood and nerve supply • Vessels and nerves pass through the connective tissue sheaths • Bell is more vascular • One neuron supply variable number of muscle fibers • Motor unites = neuron+ muscle fiber innervated by this nerun Dr: Ahmed Saber Vet. Anat. 1. 2008

  20. Dr: Ahmed Saber Vet. Anat. 1. 2008

  21. Accessory structures of skeletal muscle 1. Sesamoid bone • In course of some tendon • as superficial and deep flexor tendons • Protect the tendon • Decrease friction • Redirect the pull angle of the tendon Dr: Ahmed Saber Vet. Anat. 1. 2008

  22. Body wall Internal fascia Bodycavity Deep fascia skin Superficial fascia 2. Fascia • is sheath of CT found all over the body • Divided into • Internal fascia (endothoracic, abdominaland pelvic) • External fascia ( superficial and deep fascia) Dr: Ahmed Saber Vet. Anat. 1. 2008

  23. Synovial sac Tendon Bone 3. Synovial sac Is sac filled with synovia Located between two structures to decrease the friction between these structures • Subtendinous • Subcutaneous • subligamentous Dr: Ahmed Saber Vet. Anat. 1. 2008

  24. 4. Tendon synovial sheath • elongated sac under the tendon • The edges of the sac become reflected around the tendon • Consists of • Outer fibrous layer • Double inner synovial • Parietal and visceral layer in between small cavity filled with synovia • At edges meeting, the mesotendon present Dr: Ahmed Saber Vet. Anat. 1. 2008

  25. Mesotendon Outer fibrous Parietal synoviallayer tendon Visceral synoviallayer Synovial fluid 4. Tendon synovial sheath Dr: Ahmed Saber Vet. Anat. 1. 2008

  26. 5. Retinaculum • Transverse band of deep fascia around carpal and tarsal joints • It fix the tendon and ligaments in its position • As, flexor and extensor retinaculum of carpus Dr: Ahmed Saber Vet. Anat. 1. 2008

More Related