Download Musculoskeletal System

Musculoskeletal System
1. Bones
2. Muscles
3. Skin
Bones Bones Bones
The skeletal system
Interesting Information
• A fully grown human
skeleton has 206 bones.
• A baby has 275 – How
does that happen?
• The longest bone in your
body is your femur.
• The smallest bone is the
stirrup inside your ear.
• Your hands contains 26
bones each.
• Your feet contain ¼ of all
of the bones in the
human body!
5 Functions of the Skeletal System
1.
2.
3.
4.
5.
Provides shape and support
Enables you to move
Protects your internal organs
Produces blood cells
Stores minerals until your body needs
them
Shape and Support
• Your skeleton supports and shapes your body like a
steel frame shapes and supports a building.
• The vertebral column (back bone) is the center of the
skeleton.
• You have 26 vertebrae.
• Your backbone is flexible and able to bend – if it could
not, you would not be able to bend or twist.
• Label the skeleton – individual and group
• Each bone should be a different color.
labeled skeleton
Your skeleton allows movement
• Most bones are associated with muscles –
muscles pull on the bones to make the
body move.
• Bones also provide a sort of cage for your
vital organs located in your abdomen.
Produces and Stores….
• The long bones of your body – legs and arms –
are factories that make blood cells.
• Bones store minerals such as calcium and
phosphorus. (these are the minerals that make
bones hard)
• When the body needs these minerals, the bones
release small amounts of them into the blood
Bones are ALIVE
• Bones are strong.
• They can absorb more
force without breaking
that concrete or granite.
• Bones are lightweight.
• Only 20% of the adult’s
body weight.
• Bone Growth
• Bones are made up of
cells and tissue.
• As you grow they form
new bone tissue.
• After you are grown, they
continue to form new
bone tissue to repair
tissue from accidents or
normal wear and tear.
Structure of Bone (draw picture)
• Outer Membrane – where blood vessels enter
and leave the bone
• Compact Bone – hard and dense but not solid –
small canals run through the compact bone that
carry blood vessels and nerves
• Spongy Bone – like a sponge – this structure
spongy bone lightweight but strong
• Marrow – connective tissue contained in the
spaces in the bones center and ends
– Red marrow – makes red blood cells (ends of your
femur, hip bones, sternum)
– Yellow Marrow – stores fat for energy reserve
How bones form
• As an infant – much of your
skeleton was made of
Cartilage ( a connective
tissue much more flexible
than bone)
• By the time you stop growing
cartilage replacement by
bone tissue is mostly
complete….
• Cartilage remains in your
nose ears and knees
Joints of the Skeleton – where 2
bones meet
• Immovable joints – allow little or no movement
(example – bones of the skull or ribs to sternum)
• Movable Joints – allow a wide range of
movement – held together by ligaments
– Ball and socket joints – allows movement in a circle
(arm + shoulder, hip+ femur)
– Pivot Joint – allows movement from side to side
(Neck)
– Hinge Joint – allows forward and backward
movement (knee, elbow)
– Gliding Joint – bend and flex with limited side to side
movement (wrist and ankles)
Bone Health
• Get plenty of exercise –
during exercise your bones
support your weight – helps
your bones grow denser and
stronger
• Eat a well balanced diet
– Meats, whole grains, leafy green
veggies – phosphorus
– Dairy products – calcium
This helps to prevent
OSTEOPOROSIS later in life –
a condition in which the bodies
bones become weak and break
easily
Help with “it all fits together”
• Periosteum
• The periosteum is a fibrous sheath that covers
bones. It contains the blood vessels and nerves
that provide nourishment and sensation to the
bone.
• Tendon
• Tendons are tissues that connect muscles to
bone. When muscles contract, tendons pull on
bones. This causes parts of the body (such as a
finger) to move.
Label the Skeleton
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Humerus
Phalanges x 2
Ischium
Femur
Tibia
Sternum
Metatarsals
Sacrum
Radius
Carpals
Ribs
Ilium
Ulna
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Metacarpals
Cranium
Clavicle
Tarsals
Pubis
Mandible
Patella
Fibula
Scapula
The Muscular System
You have about 600 muscles in
your body!!
• There are 2 types of muscle action:
– Involuntary Muscles – these are not under
your conscious control – responsible for
activities like digesting food, breathing, heart
beating
– Voluntary Muscles – muscles that are under
your control
Three types of muscles
1. Skeletal Muscle – attached to bone by a
tendon (a strong connective tissue that
attaches muscle to bone)
– Skeletal muscles appear banded or striated
– Voluntary muscles
– They will tire quickly
Three Types of Muscles
2. Smooth Muscles – Found
on the inside of many
internal organs (walls of
the stomach and blood
vessels)
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•
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Involuntary muscles – work
automatically to control
movement in your body
(example: digestion)
Under a microscope – these
muscles are not striated but
smooth
The react slowly and tire
slowly compared to skeletal
muscles
Three Types of Muscles
3. Cardiac Muscle – has characteristics of
both skeletal and smooth muscles
•
•
Like smooth muscles – cardiac muscles do
not get tired – it can contract repeatedly =
heartbeats
Like skeletal muscles – it appears striated
How do muscles work?
• Muscle cells contract
when they receive a
message from the
nervous system.
• Muscles cells can only
contract – not extend.
• Because of this –
muscles must work in
pairs. While one muscle
contracts – the other
muscle in the pair
returns to its original
length
Taking Care of your Skeletal
Muscles
• Exercise is important for maintaining
strength and flexibility.
• Muscle cells grow wider ---> muscle
thickens stronger muscle
Skin – Integumentary System
If an adult’s skin is stretched flat, it
would cover about 1.5 meters –
about the size of a twin mattress!
The skin’s 6 major functions…
1. Protects the body by forming a barrier
keeping diseases and micro-organisms
outside the body.
2. Keeps important substances inside the
body.......acts like plastic wrap to keep
water in.
The skin’s 6 major functions…
3. Helps the body maintain a steady
temperature.
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Blood vessels run through the skin
Too warm? Blood vessels enlarge to
increase blood flow – allows heat to move
from the body to the outside
Sweat glands respond to excess heat by
producing perspiration.
As perspiration evaporates from your skin,
heat escapes.
The skin’s 6 major functions…
4. Because perspiration contains some dissolved
waste materials – your skin helps to eliminate
waste.
5. Gathers information about the environment –
nerves in skin provide information about
pressure, pain, temperature
6. Produce Vitamin D in the presence of the sun.
Vitamin D – helps cells process calcium for
healthy bones
Structure of Skin – 2 main layers
• Epidermis – outer layer of skin
– does not contain nerves or blood vessels
– New epidermal cells form deep in the
epidermis  mature and move upward- the
cells die and become the surface layer of skin
– This process provides protection for the skin
– Some epidermal cells make fingernails
– Some epidermal produce melanin – gives the
skin its color
Structure of Skin – 2 main layers
• Dermis – lower layer of skin – located
between the epidermis and a layer of fat
– Contains nerves, blood vessels, sweat
glands, hairs, and oil glands
– Sweat glands produce perspiration – which
reaches the surface through openings called
PORES.
– Strands of hair grow within the dermis in
structures called FOLLICLES
Caring for your skin
•
Four simple habits can help you keep
your skin healthy:
1. Eat Properly - replacing cells requires the
energy you get from a healthy diet
2. Drinking water – replace the water you lost
through perspiration
3. Limit sun exposure – repeated sun exposure
can damage skin cells and cause them to
become cancerous
4. Keeping skin clean and dry – removes dirt
and bacteria … clogged pores – leads to
acne…fungus – athletes foot 
Dry skin – can cause skin
to look prematurely aged
Skin Cancer – Do you
know the 2 careers
where skin cancer is the
most prevalent?
Athlete’s Foot – fungal
infection from walking on
contaminated surfaces –
very contagious and can
grow in your shoes 