Muscle

1. STRUCTURE AND FUNCTION
OF MUSCLE
Dr Tabassum Saher
Assistant Professor
SOP
, DPSRU
New Delhi

2. SKELETAL SMOOTH CARDIAC
METHOD OF CONTROL VOLUNTARY INVOLUNTARY INVOLUNTARY
BANDING PATTERN STRIATED NON-STRIATED STRIATED
NUCLEI/CELL MULTI SINGLE SINGLE
MUSCLE TYPES

3. Dr ManishKumar

4. MUSCLE FUNCTIONS
1. Production of Movement
a. Movementofbodyparts andofthe environment
b. Movementofbloodthroughthe heart and
the circulatory vessels.
c. Movementoflymphthroughthe lymphatic
vessels
a. Movementoffood(and, subsequently,food
waste) throughthe GI tract
b. Movement of bile out of the gallbladder and into
the digestivetract
c. Movementofurine throughthe urinary tract

5. 2. Maintenance ofposture
– Musclecontraction isconstantly allowingusto remain
upright.
– Themusclesofour neckare keepingour headup.
–Aswestand, our legmuscles keepuson two feet.
3.Thermogenesis
– Generation ofheat. Occurs viashivering– aninvoluntary
contraction ofskeletal muscle.

6. CHARACTERISTICS OF MUSCLE TISSUE
1. Excitability
– Theability to receive andrespond to astimulus
• Inskeletalmuscle, the stimulusisaneurotransmitter (chemical signal)
release byaneuron (nerve cell).
• Insmooth muscle, the stimuluscould be aneurotransmitter,
ahormone, stretch, DpH, DPco2, or DPo2. (thesymbolDmeans
“achangein”)
• Incardiacmuscle, the stimulus could be aneurotransmitter,
ahormone, or stretch.
– Theresponseisthe generation ofanelectrical impulse that travels
alongthe plasmamembrane ofthe muscle cell.

7. 2. Contractility
– Theability to shorten forcibly whenadequately
stimulated.
– Thisisthe definingproperty ofmuscletissue.
3. Extensibility
– Theability to bestretched
4. Elasticity
– Theability to recoil andresume original length after being
stretched.

8. SKELETAL MUSCLEATTACHMENTS
re
he
ble
in,
he
its
Most span joints and a
attached to bones.
– The attachment of t
muscle to the immovea
bonein ajoint isits orig
whilethe attachment to t
moveable bone is
insertion.

9. MUSCLE ATTACHMENTS
attachments
Indirect
Indirect
typical. The muscle
extends andforms either a
structure (a
or a sheetlike
cordlike
tendon)
structure (aponeurosis)
which attaches to the
or
periosteum
perichondrium.
Direct
are Direct attachments are less
CT common.Theepimysiumis
fusedto aperiosteum or a
perichondrium.

10. Indirect attachment
Tendon Aponeurosis

11. SLIDING FILAMENTTHEORY OFMUSCLE CONTRACTION
TheSarcomere, containingthe contractile proteins actin &
myosin, isthe the basicfunctionalunit of muscle.
Contraction of a whole muscle is actually the sum of singular
contraction events occurring within the individual
sarcomeres.

14. TYPES OF MUSCLE CONTRACTION
Musclecontraction (Under tension)
Isometric Isotonic
Eccentric
Concentric

15. Isotonic contractions are either concentric or eccentric on
basisofwhether shortening or lengthening occurs

16. MOVEMENT MAYOCCUR AT ANY
GIVEN JOINT WITHOUT ANY MUSCLE
CONTRACTION WHATSOEVER:
referred to aspassive
solelydue to external forcessuchasthose appliedbyanother
person, object, or resistanceor the force ofgravityin the
presenceofmuscle relaxation

17. CONCENTRIC
CONTRACTIONS
INVOLVE MUSCLE
DEVELOPING
TENSION AS IT
SHORTENS

18. contractions
Eccentric
involve the muscle
lengtheningunder tension

19. CONCENTRICCONTRACTION
muscle developstension asit shortens
occurs when muscle develops enough force to
overcome
• applied resistance
causesmovementagainstgravityor resistance
described asbeingapositive contraction

20. ECCENTRICCONTRACTION(MUSCLE ACTION)
muscle lengthens under tension
occurs when muscle graduallylessens in tension to control the
• descent of resistance
weightor resistance overcomes muscle contraction but not to
the point that musclecannot control descending movement
controls movement with gravityor resistance
described asanegative contraction
force developed bythe muscle islessthan that of the resistance

21. results in the joint angle changing in the direction of the
resistanceor external force
causes body part to move with gravity or external forces
(resistance)
usedto decelerate bodysegment movement

22. ECCENTRICCONTRACTION(MUSCLEACTION)
Somerefer to this asamuscleactioninsteadofacontraction
sincethe muscleislengtheningasopposed to shortening
Variousexercisesmayuseanyone or all ofthese contraction
types for muscle development

23. ISOKINETICS - A TYPE OF
DYNAMICEXERCISE
USING CONCENTRIC
AND/OR ECCENTRIC MUSCLE
CONTRACTIONS
Dr ManishKumar
speed(or velocity)ofmovementis constant
muscular contraction (ideally maximum contraction) occurs
throughout movement
not another type ofcontraction, assomehave described
Ex. Biodex,Cybex,Lido

24. FASCICULAR
ARRANGEMENT

25. SLOW TWITCH (TYPE 1 FIBRE)
Redin colour
Contract slowlyovera
longer period of time
Bestsuited to aerobic
andendurancetype
activities
Exert lessforce andcan
contract repeatedly

26. FAST OXIDATIVE TWITCH (TYPE2A)
Verysimilar
characteristics to Slow
Twitch fibres
Havethe ability to
contract veryforcefully
overalonger period of
time

27. FAST TWITCH (TYPE2B)
White in colour
Contract rapidlyovera
shorter period oftime
Bestsuited to
anaerobicandhigh
intensity activities
Exert great force in
bursts ofpowerand speed