1. The Muscular System
The Muscles:
Functions
Types
Structure

2. Muscular (1)

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4. Muscular (2)

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6. -

7. -

8. The Muscles
(Functions)
One of the most amazing things about the human
body is the incredible range of movement and
mobility it has. This day to day activity is
accomplished by our muscles through the
extraordinary and fascinating ability of converting
chemical energy, energy stored in nutrients, into
mechanical energy, energy of movement.
Muscles are often viewed as the "machines" of
the body. They help move food from one organ to
another, and carry out our physical movement.

9. Human Muscles

10. Muscles - Labeling
1. Occipitalis 2. Semispinalis Capitis 3. Splenius Capitis 4.
Sternocleidomastoid 5. Trapezius 6. Deltiod 7. Teres Minor 8. Teres
Major 9. Triceps Brachii 10. Latissimus Dorsi 11. Brachioradialis 12.
Extensor Carpi Radialis Longus 13. Anconeus 14. Extensor Carpi
Radialis Brevis 15. Extensor Digitorum 16. Flexor Carpi Ulnaris 17
Extensor Carpi Ulnaris 18. Erector Spinae 19. Internal & External
Oblique 20. Gluteus Medius & Gluteus Minimus (underneath
Gluteus Medius) 21. Gluteus Maximus 22. Vastus Lateralis 23.
Gracilis 24. Adductor Magnus 25. Biceps Femoris 26.
Semitendinosus 27. Semimembranosus 28. Gastocnemius 29.
Soleus 30. Peroneus Longus 31. Flexor Digitorum Longus 32.
Extensor Digitorum Longus

11. Muscular System Anterior View

12. -

13. Muscles - Labeling (2)
• 1. Galea Aponeurotica 2. Epicranius 3. Orbicularis Oculi 4. Nasalis 5.
Levator Labii Superioris 6. Zygomaticus major & minor 7. Orbicularis
Oris 8. Risorius 9. Depressor Anguli Oris 10. Depressor Labii
Inferioris 11. Mentalis 12. Omohyoid 13. Sternohyoid 14. Sternal
Head of Sternocleidomastoid 15. Scalene 16. Trapezius 17. Deltoid
18. Pectoralis Major 19. Serratus Anterior 20. Rectus Abdominis 21.
External Abdominal Oblique 22. Biceps Brachii 23. Brachialis 24.
Pronator Teres 25. Brachioradialis 26. Flexor Carpi Radialis 27.
Extensor Carpi Radialis 28. Tensor Fasciae Latae 29. Iliopsoas 30.
Pectineus 31. Sartorius 32. Adductor Longus 33. Gracilis 34. Rectus
Femoris 35. Vastus Intermedius 36. Vastus Lateralis 37. Vastus
Medialis 38. Gastrocnemius 39. Peroneus Longus 40. Tibialis
Anterior 41. Soleus 42. Peroneus Brevis 43. Extensor Digitorum
Longus

14. Muscle Types
There are three different kinds of muscles in our body:
cardiac, smooth, skeletal
1. Cardiac
Cardiac muscles are involuntary and found only in the heart. They
are controlled by the lower section of the brain called the medulla
oblongata, which controls involuntary action throughout the body.
The heart cells come in long strips, each containing a single
nucleus, one of the key factors in determining which of the three
classes any particular muscle is. The fibers of cardiac muscle are
branching fibers. Cardiac muscle is striated in appearance but like a
smooth muscle in its action. Its movement cannot be consciously
controlled. Located at the walls of the heart, its main function is to
propel blood into circulation. Contraction of the cardiac tissue is
caused by an impulse sent from the medulla oblongata to the SA
nerve located at the right atrium (link-circulatory).

15. Cardiac Muscle - Illustration

16. -
2. Smooth
Smooth muscles, also called involuntary or visceral
muscles, are those muscle fibers which move our
internal organs such as the digestive tract, blood
vessels, and secretory ducts leading from glands. We
have no conscious control over these muscles. They are
called smooth because they have no dark or light fibrils
in their cytoplasm. Smooth muscle forms sheets of
fibers as it wraps around tubes and vessels. Unlike
cardiovascular muscles, smooth muscles are generally
spherical, as most other human cells are, and each
contains one nucleus.

17. Smooth Muscle - Illustration

18. -
Skeletal
The skeletal muscles are the only voluntary
muscles of the body, and make up what we call
the muscular system. They are all the muscles
that move bones and show external movement.
Unlike either of the other two classes, skeletal
muscles contain multiple nuclei because of their
large size, being in strips up to a couple of feet
long.

19. Striated Muscle fibers

20. Skeletal Muscle - Illustration

21. Illustration 2

22. -
They are also called voluntary or striated
muscles. We have conscious control over the
activity of this type of muscle. Striated muscle
fibers (cells) have a pattern of dark and light
bands, or fibrils, in their cytoplasm. A delicate
membrane called sarcolemma surrounds each
skeletal muscle fiber. Skeletal muscle fibers
are arranged in bundles. Fibrous tissue that
envelopes muscles is called fascia.

23. Muscle-Bone Interactions
Lever System
A lever is a rigid bar on which a given load is
moved with supporting help from a fulcrum. A
fulcrum is a fixed point on which lever can
move in different ways or angles. The whole
muscular system interacts in this kind of way
with the skeletal system-hyperlink. Given a
load the muscles pull the bone up or in any
direction against the load. Our joints-hyperlink
usually seem to be the fulcrum on which we
move the lever or bone.

24. -
Skeletal muscles can be broken down into groups based upon the type
of movement they portray. The movement of the muscle is based
upon the type of joint (hyperlink-Skeletal system) upon which the
muscle works. Skeletal muscles can't expand, or make themselves
longer, but they can contract, or make themselves shorter, so they
generally work in pairs. One contracts, and in doing so stretches the
other, and reverses its effects on the joint. For example, when we
contract our major arm muscle, which is called the biceps, in return
the lower arm muscle, called the triceps, extends. So as we contract
one muscle the other one extends. These effects can be broken
down into groups of their own: flexors, extensors, adductors, and
abductors. Flexors and extensors become plantarflexors and
dorsiflexors, respectively, when located within either the wrist or
ankle joints.

25. Flexors
Flexors bend at the joint, decreasing the
interior angle of the joint. The «bracius»
humorous, or biceps, is a flexor of the elbow
joint, bringing the fist towards the shoulder. If
a flexor appears in either the wrist or ankle
joints, it becomes a plantarflexor.

26. Extensors
Opposites of flexors, extensors unbend at
the joint, increasing the interior angle. The
«tracius» humorous, or triceps, is an extensor
of the elbow joint, taking the fist farther away
from the shoulder. If an extensor is found in
the wrist or ankle joints, it becomes a
dorsiflexor.

27. Abductors
Abductors take away from the body, like
lifting the arm to the side. Abd- means to take
away, like abduct and abdicate. Spreading out
your fingers uses abductors, because you are
taking away your fingers from an imaginary
line running down your arm «graphic».

28. Adductors
• Adductors, the opposites of abductors, move
toward the body. Add- means to increase or
include. By lowing an arm raised to the
side, or moving our fingers together while
keeping them straight, our muscles are
adducting.

29. Actions of Skeletal Muscles
* Flexion - Decreasing the angle between
two bones: bending a limb;
* Extension - Increasing the angle between two
bones: straightening out a limb;
* Abduction - Movement away from the
midline of the body;
* Adduction - Movement toward the midline of
the body

30. Actions of Skeletal Muscles
* Rotation - Circular movement around an axis
* Dorsiflexion - Decreasing the angle of the ankle joint
so that the foot bends backward;
* Plantar flexion - The motion that increases the angle in
the ankle joint as when pointing the toes or extending
the foot toward the ground;
* Supination - Facing upward as applied to the hand, the
palm moves from a posterior to an anterior position;
* Pronation - Facing downward; as applied to the
hand, the palm moves from an anterior to a posterior
position.

31. Tendons and Ligaments
Muscles alone can't do the job. At every joint, tendons and ligaments
also help out. Muscles wouldn't be very useful alone because they
don't directly connect to the bone, so even if they contract, they
wouldn't be moving anything. Instead, muscles are connected to
tendons, when themselves are connected to the bones. When the
muscles contract, they pull on the tendons, which in turn pull on
the muscles, and that causes movement.
But without ligaments, that movement wouldn't be too useful
because it would not be directed movement. Without
ligaments, instead of bones bending or rotating about each other
when muscles contract, they would slide by each other. Ligaments
are what hold the bones together. They connect at the ends of
muscles and keep them from slipping and sliding, and force them to
bend.

32. Illustration

33. Major Skeletal Muscles
The muscular body is divided into ten different areas where
muscles can be found:
1. facial,
2. neck,
3. shoulder,
4. arm,
5. forearm,
6. thorax,
7. abdomen,
8. hip,
9. pelvis/thigh,
10. leg.

34. Facial Muscles
Facial muscles are all the muscles that move the
face. Orbicularis oculi-sound are the two
muscles that move the eyes. Frontalis-sound
and Temporalis-sound are the two muscles
which move the forehead and sides of the
head. Zygomaticus-sound and Masseter-sound
are the two muscles that work in conjunction
to move the jaw and upper lip area.
Orbicularis oris-sound is the muscle which
moves the lips.

35. Facial Muscles - Illustration

36. Neck
• The neck area is almost entirely moved by the
sternohyoid-sound and Sternocleidomastoid-
sound. These muscles allowthe neck to move
your head left and right. They work with the
platysma muscle to control how far you can move
your head left and right. What allows your head
to move up and down is the trapezius-sound. The
trapezius is so large that it extends down to the
shoulder and thorax area. The trapezius is a good
example of how some muscles are named by
their shape. the trapezius looks just like a
trapezoid.

37. Illustration

38. Shoulder
• A group of muscles all work together to move
the whole shoulder area. This group takes into
account the trapezius-sound, deltoid-
sound, infraspinatus-sound, teres major-
sound, and the rhomboid major-sound. The
rhomboid major is called so because its shaped
like the geometric shape of a rhombus. Along
with the help of the ball and socket joint-
hyperlink in the shoulder, these gruops of
muscles allow ther arm to throw a ball, pick
things over our head, and give our arms a good
stretch early in the morning.

39. Illustration

40. Arm
• Most known is the arm area. The famous
biceps brachii-sound is the muscle that allows
us to bring our forearm close to our body. The
triceps brachii-sound and brachialis-sound are
the two other muscles located in the arm
region. These muscles allow a person to do
push-ups!

41. Illustration

42. Forearm
A majority of the muscles in the forearm help
control a part of the arm. Amongst these are the
Berachiodialis major-sound, palmaris longus-
sound, and Flexor carpi radialis-sound. The name
of the flexor carpi radialis is a good example of
how muscles are named by their function and
location. This muscle is named carpi because of
the bones that it helps move, the carpals.
Also, the name of radialis is made by the bone
that its attached to, the radius.

43. Thorax
The muscles of the thorax consist of the intercostals and diaphragm. The
intercostal muscles are arranged as three layers (external layer, internal
layer and an incomplete innermost layer) between the ribs. The
diaphragm closes the thoracic outlet and separates the thoracic cavity
from the abdominal cavity. The three layers of the intercostal muscles are:
• external layer -- external intercostal
• internal layer -- internal intercostal
• innermost layer -- transversus thoracic (anterior), innermost (lateral) and
subcostal (posterior)
• The diaphragm is the most important muscle of the thoracic wall. During
normal respiration, this muscle is the primary component. As you can
see, the innermost layer is split into three differently named muscle
groups. The transversus thoracis, innermost intercostal and subcostal
muscles make up the deepest layer of muscles from anterior to
posterior, respectively.

44. Illustration

45. Abdomen
The abdominal area consists of the muscles that
allow us to bend down and move our waist
from side to side. The internal oblique-sound
and external oblique-sound are the muscles
that move our body from left to right. The
transversus abdominus-sound and rectus
abdominus-sound, along with the trapezius-
sound and latissimus dorsi-sound allow us to
bend down and grab objects.

46. Hip
Only two muscles make up the hip area. These
are the gluteus medius-sound and gluteus
maximus-sound. Probably the laziest muscles
in the whole system the gluteus set of muscles
are used only to sit down on.

47. Illustration

48. Illustration

49. Pelvis/Thigh
An overlapping of muscles is what makes this area so
firm. The pelvis area is usually referred to as the upper
part of the leg. Muscles like the pectineus-sound and
illiopsoas-sound , which help support the upper leg
area are known as pelvic muscles. Thigh muscles are
very rich in capillaries and support the whole body. The
upper thigh muscles are abductor longus-
sound, gracilis-sound, sartorius-sound, and tensor
fasciae latea. The lower thigh muscles are rectus
femoris-sound, vastus lateralis-sound and medialis-
sound. Located in the back of the leg are the
hamstrings-sound. These muscles help us
run, jump, and walk!

50. Leg
Helping the thigh region support the body is the Leg
region. These muscles like the gastrocnemius-
sound, soleus-sound, porenius longus-sound, and
tibialis anterior-sound, which absorb the impact
when one walks and runs. They also give better
coordination for moving. The thigh region thrusts
the body forward while the leg region
coordinates where it should be thrust and where
it should stand.

51. Thanks!