The document discusses the three types of muscles in the human body: skeletal, cardiac, and smooth muscles, detailing their structures, functions, and properties. Skeletal muscles are voluntary and control body movements, cardiac muscles are involuntary and pump blood, while smooth muscles manage the functions of internal organs. Each muscle type has unique characteristics and roles in movement, stability, and physiological processes.

1. TOPIC:TYPES OF MUSCLES IN BODY
PRESENTER:HASHIM ZAFAR
MODERATOR:GAURAV SIR

2. MUSCLES
• Muscles is a contractile tissue which brings about
movement.
• Muscle cell responsible for our movement both visible and
invisible, example walking, talking, bowel movement
,urination, breathing, heartbeats, the dilation and
constriction of the pupils of our eyes and many other.
• When we are still sitting or standing muscle cells keep us
erect.

3. CONT...
• Muscles can be regarded as motors of the body.
• Muscles comprises about 40% to 50% (approximate) of
body weight.
• There are approximate 650 muscles in body.
• Alternating contraction and relaxation of cells

4. FUNCTION OF MUSCLES
• The core function of muscle is convert chemical energy
(ATP) into mechanical force
• Producing movement:-muscles move the bone of
skeletal by their connective tissue attachment. Enable all
kinds of voluntary movement.
• Maintaining posture and body position:- when not
moving the various part of supportive skeletal are held in
position by isomeric muscles contraction.
• Stabilizing joint:-
• Maintains body temperature:-muscle contraction
generates heat that is involve in maintaining body
temperature.

5. PROPERTIES OF MUSCLES
1. Excitability –it is the ability to response to a stimulus,
which may be delivered from a motor or a hormone .
2. Contractibility- it is the ability of muscle cells to
forcefully shorten.
3. Extensibility- is the ability to be stretched. Lack of
extensibility is called spasticity.

6. CONT…
4.Elasticity –it is the ability to recoil or bounce back to the
muscle’s original length after being stretched.
• Muscles have been classified using different criteria ,
namely location , appearance and nature of regulation of
their activities. Base on location , three types of muscles
are identified.

7. Types of muscles in body
1. Skeletal muscles
2. Cardiac muscles
3. Smooth muscle

8. SKELETAL MUSCLE
• Skeletal muscles are also called striped muscles or voluntary.
• Muscles, they are attached to bone and move the skeletal.
• They control the movement of the body in relation to the
Environment, e.g. hands, arms, legs,neck, trunk, eyes.
• skeletal muscle are multinucleate.
• Skeletal muscle is voluntary because its contraction is always
stimulated and controlled by the nervous system.
• The Central Nervous System sends a signal to the muscles via nerves
which then convert chemical energy into movement and the
muscles.

9. Cont…
• attaches to bone, skin or fascia. voluntary control of
contraction & relaxation.

11. IMPORTANT TERM
• Myofibril:-complex organelle compose of bundle of
myofilaments
• Myofilament:-macromolecular structure of contractile
protein
• Sarcomere:-the smallest, single contracting unit of a
segment
• Deep fascia:-binds large groups of muscles into functional
groups
• Muscle:-hundred of fascicles bound together epimysium
• Fascicle:- thousands of muscle fibers bound into discrete
unit by perimysium
• Muscle fiber:-single muscle cell surrounded by
endomysium. Muscle cell are called muscle fibers.

12. Cont…
• Sarcolemma:-plasma or cell membrane of a muscle cell
• Sarcoplasm:- cytoplasm of muscle cell with large
amounts of glycogen and myoglobin
• Myoglobin:-red pigmented oxygen –binding protein
• Connective tissue layer:-Epimysium, Perimysium,
Endomysium.
• Contraction depends on two kind of
myofilament :-
1. Actin
2. Myosin

13. SKELETAL MUSCLE
• Tendons attach muscle to bone

14. INTERACTIONS OF MUSCLES
• Agonist:-(prime mover) it provides major force for
producing movement or doing work.
• For example curing a bar the agonist= biceps brachii
muscle.

15. • Antagonist:-muscles that oppose or reverse,a particular
movement
• Synergist:-a synergist hold the body in position so that
an agonist muscle can operate, any unwanted movement
that might occur as the prime mover contracts.
• Fixator:- when it immobilises the bone of the prime
mover’s origin thus providing a stable base for the action
of the prime mover.

16. Microanatomy of Skeletal Muscle
• Skeletal muscle cells develop when hundreds of individual
embryonic cells called myoblasts fuse. The resulting cells'
cell membrane is called the sarcolemma and the cytoplasm
is called sarcoplasm
• Skeletal muscles are very large. Their diameter is about
100 microns (about 13 times the diameter of a red blood
cell) and they can be as long as 30 to 40 cm (10 to 16 in.
• Skeletal muscles are multinucleate. The nuclei of the
myoblasts that fuse to form the cell remain within the cell.
Some myoblasts do not fuse but remain associated with
the fiber as satellite cells that can divide and differentiate
to repair damaged cells

17. The Proteins of Muscle
Myofibrils are built of 3 kinds of protein
contractile proteins:-
myosin and actin
regulatory proteins which turn contraction on & off:-
troponin and tropomyosin
structural proteins which provide proper alignment,
elasticity and extensibility:-
titin, myomesin, nebulin and dystrophin

18. transverse tubules or T tubules:-
There are internal tubular extensions of the sarcolemma into
the sarcoplasm called transverse tubules or T tubules

19. Myofibrils:-
• each skeletal muscle cell or fiber there are cylindrical structures
called myofibrils.
• Contraction of the myofibrils result in contraction of the entire cell.
sarcoplasmic reticulum:-
• In between the loops of transverse tubule, there is a network of
tubules of smooth endoplasmic reticulum called the sarcoplasmic
reticulum.
terminal cisternae:-
• The sarcoplasmic reticulum surrounds the myofibril like a sleeve. The
sarcoplasmic reticulum on either side of the loops of transverse
tubules fuse to form expanded chambers called terminal cisternae.

20. Triad:-
• The combination of a transverse tubule flanked by two terminal
cisternae is called a triad.
Mitochondria:-
• The energy for muscle contraction is supplied by the numerous
mitochondria that surround the myofibrils.
Glycogen granules:-
• Glycogen granules that also surround the myofibrils as a ready
source of fuel.
Sarcomeres:-
• The myofilaments are organized in repeating units along the length
of the myofibril called sarcomeres.

21. Myofilaments:-
The myofibrils are made-up of myofilaments.

22. Sarcomere Organization
Actin and myosin:-The primary microfilaments in myofibrils are actin (thin) and
myosin (thick) filaments. Within each sarcomere there is a precise arrangement of
these filaments. The sarcomeres of neighboring myofibrils are in alignment and
they create the banding pattern visible with the light microscope.

23. • The difference in the size and density of the thick and thin filaments is responsible
for the banding pattern. The center of the sarcomere has a narrow band called the
H band where there are only thick filaments. The H band is in the center of the A
band that includes a zone of overlap between the thick and thin filaments. In the
zone of overlap, each thick filament is surrounded by six thin filaments and each
thin filament is surrounded by three thick filaments. The I band is where the thin
filaments do not overlap with the thick filaments at either end of the sarcomere,
and straddling the Z line.

24. • The thick filaments are linked in the center of the sarcomere by
proteins that form the M line. At either end of the sarcomere, the
actin filaments are attached to one another by proteins that form the
Z line. The Z lines mark the boundaries of each sarcomere.

25. Thin Filaments
• The thin filament is composed of 300-400 G-actin protein molecules
that form a linear molecule called F-actin. The F-actin molecules are
held together by another protein called nebulin.
• Each G-actin molecule has an active site that binds to a site on the
myosin molecule. This binding is prevented by another protein called
tropomyosin that covers the active site on the actin.
• Tropomyosin is held in position by a protein called troponin. When
calcium ions bind to troponin, the position of tropomyosin changes
to uncover the binding site and permits the binding of actin to
myosin.
• At either end of the sarcomere the actin filaments are attached to
the Z line or disc by a protein called actinin.

26. Thick Filaments
• Thick filaments are composed of a bundle of about 500 myosin
molecules. Each myosin molecule consists of two strands, of which
each has a tail that twists around the other, and a head. The head
projects outward toward the thin filaments and are called cross-
bridges because they attach to the thin filaments during contraction.

27. • The thick filaments are associated with a protein called titin. Titin
contributes to the normal alignment of the thick and thin filaments
and has elastic properties that restores the sarcomere to its original
resting position after being stretched.

28. NERVES AND BLOOD SUPPLY
• Skeletal muscle has a rich blood supply. This is understandable
because contracting muscle fibers use huge amounts of energy and
require almost continuous delivery of oxygen and nutrients via the
arteries. Muscle cells also give off large amounts of metabolic wastes
that must be removed through veins if contraction is to remain
efficient. Muscle capillaries, the smallest of the body’s blood vessels,
are long and winding and have numerous cross-links, features that
accommodate changes in muscle length. They straighten when the
muscle stretches and contort when the muscle contracts.

29. Functions of Skeletal Muscles
• Skeletal muscles support the body. Skeletal muscle
contraction opposes the force of gravity and allows us to
remain upright. Some skeletal muscles are serving this
purpose even when you think you are relaxed.
• Skeletal muscles make bones and other body parts move.
Muscle contraction accounts not only for the movement of
limbs but also for eye movements, facial expressions, and
breathing.
• Skeletal muscles help maintain a constant body
temperature.

30. Cont..
• Skeletal muscle contraction causes ATP to break down,
releasing heat that is distributed about the body.
• Skeletal muscle contraction assists movement in
cardiovascular and lymphatic vessels. The pressure of
skeletal muscle contraction keeps blood moving in
cardiovascular veins and lymph moving in lymphatic
vessels.
• Skeletal muscles help protect internal organs and stabilize
joints.
• Muscles pad the bones that protect organs, and they have
tendons that help hold bones together at joints.

31. Cont…
• support the skeleton and create movement.
• maintain joint stability and posture.
• control range of movement.
• protect the skeleton and internal organs from trauma.
every skeletal muscle fiber is supplied with a nerve ending
that controls its activity.

32. Naming Skeletal Muscles
1. Location of the muscle (ex. Costal)
2. Shape of the muscle (ex. Trapezius)
3. Relative size of the muscle (ex. Minimus)
4. Direction of muscle fibers (ex. Oblique)
5. Number of origins (ex. Biceps, Triceps)
6. Location of the muscle’s origins and/or insertions (ex.
Sterno, Brachialis)
7. Action of the muscle (ex. Flexor, Adductor)

33. CARDIAC MUSCLE
• Cardiac muscles the present in heart. it constitutes bulk
of the heart walls. Many cardiac muscle cells assemble in
a branching pattern to form a cardiac muscle.
• Base on appearance cardiac muscle are striated.
• They are involuntary in nature as the nervous system
does not control their activities directly.
• Most of us have no conscious control how fast our heart
beats.
• Cardiac muscle fibers each have one to two nuclei and
are physically and electrically connected to each other

34. Cont…
• Highly coordinated contractions of cardiac muscle pump
blood into the vessels of the circulatory system.
• same banding organization as skeletal muscle.
• cardiac muscle fibers are shorter than skeletal muscle
fibers and usually contain only one nucleus
• which is located in the central region of the cell. Cardiac
muscle fibers also possess many mitochondria and
myoglobin, as ATP is produced primarily through aerobic
metabolism.

35. Cont…
• An intercalated disc allows the cardiac muscle cells to
contract in a wave-like pattern so that the heart can work
as a pump.
• autorhythmic because of built in pacemaker.

36. STRUCTURE OF CARDIAC MUSCLE
• Cardiac myocytes are short branched muscle cells.
• Connected with gap junction
• Gap junctions transmit
electrical activity between cells
• So cardiac myocytes act as
a single functional unit
(syncitium)

37. PROPERTIES OF CARDIAC MUSCLE
1. Rhythmicity:-rhythmicity mean the ability of heart
to beat regularly without external stimulation.it is
myogenic in origin not neurogenic.
2. Conductivity:-The ability to conduct impulse from one
cell to another---facilitated by the presence of gap
junctions that transmit electrical currents.
3. Excitability:-The heart muscle responds to stimuli which
may be mechanical, electrical or chemical.

38. REFRACTORY PERIOD
• The refractory period of the myocardial fibers is of
much longer duration than that of skeletal muscle
fibers and lasts approximately as long as the cardiac
contraction--------- so no continous contraction
without relaxation (tetanus) can occur in heart.

39. Cardiac Muscle Contraction
• Thick and thin myofilaments are arranged the same as they
are in skeletal muscle with the same bands, zones, and
lines.
• Cardiac muscle contracts and relaxes rapidly, continuously,
and rhythmically.
• The branching cardiac muscle fibers form a network and
the networks are located in the walls of the chambers of
the heart.
• Cardiac muscle is stimulated by specialized conducting
tissues within the heart.

41. • SR and T tubules are well developed‚ so a large amount of calcium
can be released rapidly through the T tubules.
• contains more mitochondria in each muscle cell than skeletal and
smooth muscles‚ providing more ATP energy for continuous
contraction.
• muscle cells are joined by intercalated disks‚ and allow
• muscle groups to form branching networks - both features are
necessary for cardiac muscle to function as a unit sancytium.
• unique arrangement of actin and myosin filaments produces the
cross- striations (an optical illusion the microscope)‚ and rapid
contraction with powerful forces involved.

42. SMOOTH MUSCLES
• Smooth muscle is also present in the eyes, where it
functions to change the size of the iris and alter the shape
of the lens
• Smooth muscle is present in the walls of hollow organs like
the urinary bladder, uterus, stomach, intestines, and in the
walls of passageways, such as the arteries and veins of the
circulatory system,and the tracts of the respiratory,
urinary, and reproductive systems.
• in the skin where it causes hair to stand erect in response
to cold temperature or fear.

43. Cont…
• Smooth muscle non- striated and involuntary. (function are
automatically)
• It surrounds and is found in all internal tissues and organs.
Smooth muscle responds to stimuli from the autonomic
nervous system.
• It is responsible for pushing food through the digestive
system and the physical control of the bladder and bowel.
• It is also found in the vascular and reproductive systems.

44. Cont…
• Smooth muscles contain filaments of actin and myosin .
• Lack transverse tubules and S.R. is not well developed .
• Hormones and stretching affect smooth muscle
contractions .Can contract for a long period of time .
• Cells much smaller than skeletal muscle.

45. Smooth Muscle Contraction
• Smooth muscle contraction resembles skeletal muscle
contraction in that they both involve reactions of actin and
myosin, they are triggered by nerve impulses along the
sarcolemma and the release of calcium ions, and they use
energy from ATP molecules.
• Smooth muscle is slower to contract and slower to relax
than skeletal muscle.
• Some smooth muscles respond to neural and chemical
stimuli. Chemical factors cause muscle contraction
and relaxation
• without an action potential and inhibit or stimulate the
release of calcium ions into the sarcoplasm.

46. Cont…
• The chemical factors include hormones, lack of oxyqen, low
pH, and excess carbon dioxide.
• The direct response of smooth muscle to chemical stimuli
allows activity according to local tissue needs.

47. Myofilament Organization
• Contains both actin & myosin. More actin and less myosin
than skeletal Muscle. Lower contractile force.myofilaments
loosely oriented in long axis of cell.
• Force transferred to cell membrane by intermediate
filaments.
• Meshwork linked
together at dense bodies.

48. Shortening in Smooth Muscle
• Actin & myosin overlap
• Slide along each other during contraction
• Meshwork becomes more compact
• Cell shortens and fattens
• Increase in intracellular free Ca++ is necessary for
contraction
Mechanisms to trigger Ca increase
• Spontaneous Membrane depolarization
• Chemical messengers
Local & blood-borne; Hormones , metabolites

51. Nerve and Blood Supply
In general, one nerve, one artery, and one or more veins
serve each muscle. These structures all enter or exit near
the central part of the muscle and branch profusely
through its connective tissue sheaths (described below).
Unlike cells of cardiac and smooth muscle tissues, which
can contract without nerve stimulation,

52. Difference between skeletal, cardiac and smooth
muscles

53. Structure