Download Unit 3, Lesson 4: The Muscular System

The Muscular
System
Function of the muscular system
• Provides movement in
conjunction with the skeletal
system
• Important in life support
• Used by humans and other
animals for food
Classifications of Muscles
• Voluntary: Movement of the muscle is
under the control of the animal
• Involuntary: Movement of the muscle is
not controlled by the animal
Types of Muscles
• Smooth
Muscles:
Involuntary
muscles,
found in the
walls of
internal
organs and
the blood
vessels.
Smooth Muscles
• Are not under voluntary control
• Are spindle shaped and are not
striated.
• Interlace to form Sheets of smooth
muscle tissue.
• Are found in many internal organs:
Stomach, Intestines, Blood Vessel
walls
Types of Muscles
• Cardiac
Muscles:
Muscles that
form a network
to make up the
heart. Not under
control of the
brain, but under
their own control
Cardiac Muscles
• Only found in the Heart
• Are Striated
• Are NOT under Voluntary
Control
• Contract Without Direct
stimulation by the Nervous
System
Types of Muscles
• Skeletal Muscles:
Have a striped
appearance, include
voluntary and
involuntary,
attached to and
moves your bones.
This is a majority of
the muscle tissue in
your body.
Skeletal Muscles
• Are made of Elongated Cells
called MUSCLE FIBERS
• Are grouped into dense
bundles called FASCICLES
• Are LARGE and have MORE
than ONE NUCLEUS
• Most are Voluntary
Muscles of the Front Limb
• The largest and
most important
muscle in animals
attaching the front
legs to the body is
the serratus
ventralis. It is fan
shaped and
supports the trunk
of the body
between the legs.
Muscles of the Front Limb and
Shoulder
• The rotator cuff tendons
attach to the deep rotator
cuff muscles. This group of
muscles lies just outside
the shoulder joint. These
muscles help raise the arm
from the side and rotate
the shoulder in the many
directions. They are
involved in many day-today activities.
Muscles of the Front Limb and
Shoulder
• The large deltoid muscle
is the outer layer of
shoulder muscle. The
deltoid is the largest,
strongest muscle of the
shoulder. The deltoid
muscle takes over lifting
the arm once the arm is
away from the side.
Muscles of the Upper Arm
• The bicep brachii muscle is
located in the upper arm.
The primary function of the
bicep muscle is elbow
flexion, or the movement of
the forearm towards the
shoulder. This muscle is also
used for turning the hand
from a palms down position
to palms up position.
Muscles of the Lower (Fore) Arm
• The muscles of the lower arm,
or forearm are used to flex or
move the hand, wrist and
fingers.
• Brachioradialis is only one of
the almost 30 muscles. It
flexes the forearm at the
elbow
Muscles of Back Limbs or Legs
Muscles of the Muscles of the Back
Limb (Hip and Thigh)
• The hip is
surrounded by
thick muscles.
• The gluteals make
up the muscles of
the buttocks on the
back of the hip.
Muscles of the Muscles of the Back
Limb (Hip and Thigh)
The inner thigh is
formed by the
adductor muscles.
The main action of
the adductors is to
pull the leg inward
toward the other leg.
Muscles of the Muscles of the Back
Limb (Hip and Thigh)
The muscles that flex the
hip are in front of the hip
joint. These include the
iliopsoas muscle.
This deep muscle begins in
the low back and pelvis
and connects on the inside
edge of the upper femur
Muscles of the Muscles of the Back
Limb (Hip and Thigh)
• Another large hip
flexor is the rectus
femoris. The rectus
femoris is one of
the quadriceps
muscles, the
largest group of
muscles on the
front of the thigh.
Muscles of the Back Limb
• The primary
movements are
extension and flexion.
• The main extensor
muscle of the hip is the
Hamstring.
• The Hamstrings are the
group of muscles that
are positioned at the
back of our thighs.
Muscles of the Upper Leg
Anterior
• The
Quadriceps
are the
extender
muscles on
the front side
of the thigh.
Their main
function is to
extend the
knee.
The
Hamstrings
are the
muscles on
the back side
of the upper
leg. Their
function is to
bend the leg.
Posterior
Muscles of the Upper Leg
Muscles of the Lower Leg
• The Gastrocnemius is
the calf muscle that is
visible from the
outside of the body.
• It attaches to the heel
with the Achilles
Tendon and
originates behind the
knee on the femur,
crossing two joints.
Muscles of the Lower Leg
• The function of the
Gastrocnemius is to
elevate the heel (known
as plantar flexion).
• The function of the
Soleus is exactly the
same as the
Gastrocnemius: to raise
the heel. The only
difference is that it
works in a different
position: with the knee
bent.
Muscles of the Trunk, Head
and Neck
• Many of the muscles originate from the
vertebrae
Muscles of the Trunk, Head
and Neck
• There is greater flexibility in the neck than
in the spinal column because of the
muscles within
The
Complex
System that
is
responsible
for
movement
and
protection
of internal
organs