Transcript The Muscular System

The Muscular System
• What do skeletal muscles do?
• How do muscles work?
The Muscular System
•
Muscle is an organ that can
relax and contract, and
provides the force to move
your body parts.
Muscular system
• There are more than 630 muscles in your
body. On average, your body weight is
40% muscle.
• Muscles consists of million of fibers
packed with protein. Not all proteins are
identified yet.
The Amazing Muscle
• The job of a muscle is to move the body.
Without muscles the skeleton couldn’t
move. Muscle help to move the mouth to
form speech, help to blink, digest food,
breathe, pump the heart and allow a
person to smile.
Functions of the Muscular System
• Produce movement
• Maintain posture and body
position
• Support soft tissue
• Guard entrances and exits
• Maintain body temperature
To move or not to move
• 1. Voluntary muscles –
muscles that you are able
to control
• 2. Involuntary muscles –
muscles that you cannot
control (cardiac muscle and
smooth muscle)
Muscle Groups
• We have three types of
muscles:
• Skeletal muscles
• Smooth muscle
• Cardiac muscle
Three types of muscle
Skeletal
Cardiac
Smooth
Skeletal muscle
characteristics
• Large muscles
• Help maintain posture
• Facilitate (help with)
locomotion(movement)
• Move jointed bones
• Joined to bones by tendons
Cardiac muscle
• Main muscle of heart
• Heart muscle cells
behave as one unit
• Found only in the heart
• Involuntary
Smooth muscle
• Found in walls of
internal organs
• Involuntary
movement
• Tendon ~ strong, tough
connective tissue cord,
connect muscle to bone
• Example *Achilles Tendon
(attaches to calf muscle and
heel bone)
• Skeletal muscle action
produces movements at
synovial joints. Usually one
end of the muscle is attached to
a relatively immovable or fixed
on side of a joint, while the
other end of the muscle is
attached to a movable end or
origin.
Types of body movement
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Flexor
Extensor
Abduction
Adduction
Hyperextension
Dorsiflexion
Rotation
circumduction
• Let’s look at each one
Flexion (Flexor) ~ decreasing the
angle between two bones and
body part
•
Extension ( Extensor) ~
increasing the angle
between two bones and
body part
• Abduction-moving of a
body part away from the
central axis of the body .
• Adduction-moving of a
body part toward the
central axis of the body.
• HyperextensionExtension of a bodily joint
beyond its normal range
of motion.
• Dorsiflexion-the act of
bending backward (of the
body or a body part
• Rotation-The act or
process of turning around
a center or an axis.
• Circumduction-The
circular movement of a
limb.
The End
Of muscular system, now let’s
look at the skin.
Advance science only
• Before we begin let’s watch a dancer
perform and see how the different system
work together to make a great perfomance.
• http://www.youtube.com/watch?v=DmUhi
CaTm3k
• http://www.youtube.com/watch?v=tpAEkZ
qOVX0
Integumentary System
• The bodily system
consisting of the skin and its
associated structures, such
as the hair, nails, sweat
glands, and sebaceous
glands.
• The skin is one of the
more versatile in our
body, the skin is vital in
maintaining
homeostasis.
Integumentary system
Functions:
• Protective layer for the body
• Helps us to maintain
homeostasis
• Helps us to react to our
environment
• The skin is composed of layers and is
known as the body’s largest organ: This
lead to the development of skin grafts and
transplants.
• Let’s learn to the components of the skin.
Epidermis
• The outer, protective,
nonvascular layer of the
skin of vertebrates,
covering the dermis.
•
Seen here in a scanning electron micrograph, the epidermis is a tough coating formed from
overlapping layers of dead skin cells, which continually slough off and are replaced with cells from
the living layers beneath. The epidermis is the outermost of three layers that make up the skin.
Dermis
• The dense inner layer of
skin beneath the epidermis,
composed of connective
tissue, blood and lymph
vessels, sweat glands, hair
follicles, and an elaborate
sensory nerve network.
Accessory organs
• They are recognized as
important in the protective
mechanism of the human body.
• Nail, hair follicles, sebaceous
glands, melanin, sudoferous
glands, eccrine glands and
sweat glands. Let’s look at each
one.
Sebaceous gland
• A cutaneous gland that
secretes sebum (usually
into a hair follicle) for
lubricating hair and skin
cutaneous gland
pertaining to, or affecting
the skin.
Sudoriferous Gland
• Producing or secreting
sweat
Subcutaneous tissue
• The fat layer lying just
beneath the dermis
Follicle
• a small cavity, sac, or
gland which holds the
hair.
Melanin
• any of a class of insoluble
pigments, found in all forms
of animal life, that account
for the dark color of skin,
hair, fur, scales, feathers,
etc.
Eccrine glands
• Any of the numerous small
sweat glands distributed
over the body's surface that
produce a clear aqueous
secretion