Download MYOLOGY PREMED5

MYOLOGY
STUDY OF MUSCLE IS CALLED “MYOLOGY”
•MUSCLE : It is an ordinary arrangement of
Connective tissue and contractile cells.
•FUNCTIONS :
1. Movement -> alternative contraction and
relaxation
2. Protection of vessels and nerves
3. Pumping of blood.
5. Shapes to the organs & body
6. Transportation (food, blood, waste products)
MYOLOGY
• TYPES OF MUSCLES :
- Based on their shape and innervation
muscles are divided in to 3 Types
1. SKELETAL MUSCLE (Striated Voluntary)
2. CARDIAC MUSCLE (Striated Involuntary)
3. SMOOTH MUSCLE (Plain Involuntary)
MYOLOGY
1. SKELETAL MUSCLE :-
Attached to bone and produce movement.
Also called striated voluntary.
(Presence of striations and under will control)
PARTS (MACROSTRUCTURE) :1. PROXIMAL ATTACHEMENT
(ORIGIN OR HEAD)
2. BELLY (BODY)
3. DISTAL ATTACHEMENT
(INSERTION OR TENDON)
MYOLOGY
1. PROXIMAL ATTACHEMENT :Attachment that least moves
2. DISTAL ATTACHEMENT :Attachment that moves most
- Ends of muscles form in to cards of fiber tissue
called “TENDONS”
3. Belly :- Middle flabby part of muscle is called “BELLY”
APONEUROSIS:- Thin & strong fibrous sheet of flat muscles
RAPHAE:- Inter digitations of tendenious ends of muscle fibers
MYOLOGY
• STRUCTURE OF SKELETAL MUSCLE (MICRO):-
• PARTS :-
1. FASCICLE
2. MUSCLE CELL
(Muscle fiber)
3. MYOFIBRIEL
4. MYOFILEMENTS
MYO FILAMENTS
MYOLOGY
1.FASCICLE :- Group of muscle cell bind together
and form “Fascicle”
2. Muscle cell :- Elongated cells
3. MYOFIBRIEL:- Cylindrical, threadlike bundles of
myofilaments
4. MYOFILAMENT:- Contractile protein elements of muscle
MYOLOGY
• MUSCLE CELL OR FIBER :(INTRACELLULAR ORGANIZATION)
1. NUCLEUS : Cellular structure contains D.N.A.
(genetic) material
2. SARCOLEMMA : Specific name of the
plasma membrane.
3. SARCOPLASMIC RETICULUM (S.R.) :
Name of Endoplasmic reticulum.
It interconnects tubules surrounding each
myofibril like a slaves of a swatter
4.TERMINAL CISTERNAE :
Sac like regions of Sarcoplasmic Reticulm (S.R.).
It carries Ca+ ions.
MUSCLE CELL OR FIBER
5. T – TUBULES:
MYOLOGY
Invaginations of sarcolemma projecting deep
in to muscle fibers called “T-tubules”
opens out on to the surface of the Sarcolemma.
6. TRIAD :
- -> Terminal cisternae
It is a group of 3 units -- - -> T-tubule
- -> Terminal cisternae
7. CYTOSOL :
Intra cellular fluid.
Organelles of cell are suspended init.
8. MITOCHONDRIA :
A.T.P. Synthesizers, powerhouses of cell,
suspended in cytosol.
MYOLOGY
• MYOFIBRIL :
- Thread like Cylindrical
bundles of
contractile filaments
• MYOFILAMENTS :
-
Contractile proteins of
muscle cell.
2 TYPES :
1. THIN FILAMENT
(Protein – ACTIN)
2. THICK FILAMENT
(Protein – MYOSIN )
MYOFIBRIL
MYOLOGY
COVERS OF MUSCLE TISSUE
Muscle tissue is covered by
3 layers of connective tissue
sheathes. They are,
1.
Epimysium : Outermost sheath
covers each muscle bulk.
2.
Perimysium : Middle sheath
that covers each fascicle.
3.
Endomysium : Innermost
sheath that covers each muscle
fiber.
1. SKELETAL MUSCLE
• HISTOLOGY :
- Elongated cells
- Visible striations
-
Multiple, peripheral nuclei.
- Voluntary
Eg: Biceps brachi
CARDIAC MUSCLE :
- Branched cells
- single central nuclei
- visible strations
- Involuntary
PROPERTY –> SPONTANIOUS & RHYTHMICAL CONTRACTION
Eg: Myocardium of heart.
SMOOTH MUSCLE
• - Spindle shaped cells
- Single central nucleus
- No visible striations
- Involuntary
Eg: Stomach, Urinary bladder, Uterus.
MYOLOGY
• TWO JOINT MUSCLE :
Muscle which crosses two or more joints and performs
two opposite actions at the two different joints are called “TWO
JOINT MUSCLE”
Eg.: Gastrocnemius
contraction -> Flexion of knee & Ext. of foot (D.F.)
APPLIED ANATOMY :
Spasticity (Hypertonecity): Increased tone of the muscle
Flacidity (Hypotonecity) : Decreased tone of the muscle
Atrophy or wasting
: Decreased size of muscle
Hypertrophy
: Increased size of muscle bulk
Fatigue
: Short lasting weakness of muscle