1. Skeletal System
Video

2. The Skeleton is the name given to
the collection off bones in the
body and the tissues that
connect them.

3. The skeleton has 5 major functions.
1- It protects our vital organs such as the brain,,
the heart, and the lungs..
2- It gives us structure. Without it we would just
be a blob of blood and tissue on the floor.
3-It allows us to move. Because our muscles are
attached to our bones, when our muscles
move, they move the bones.
4- It stores calcium. Which keeps bones and teeth hard.
5- It makes Red and White blood cells. Mainly red blood cells. White blood cells are also produced in your lymph nodes.

4. Skeleton Facts • When you were born, your skeleton had
close to 350 bones.
• By the time you become an adult, you
will only have around 206 bones.
• This is because, as you grow, some of the
bones fuse together to form one bone
such as the skull.

5. …Skeleton Facts
• The smallest bones in the body are found in the ear. (3mm)
• The longest bone in the body is the femur.
• Over half the body's bones are in the hands
and feet.
• As your bones grow, you get taller. Girls
usually stop growing around age 16, and 18 for boys.
• Our bones are 5 times stronger than steel if they are the same weight.

6. Organization of the Human Skeleton
• Your skeleton is made up
of two parts; the axial skeleton
and the appendicular
skeleton.
Green = Axial
Purple = Appendicular

7. The Axial Skeleton • Skull 29 • vertebral column 24
• ribs (12 pairs) 24
• Sternum 1
• Sacrum 1
• Coccyx 1
• Total 80
Green Area

8. The Appendicular Skeleton
• pectoral girdles (2 x 2) 4
• Arms (3 x 2) 6
• Wrists (x 2) 16
• hands (19 x 2) 38
• pelvis 2
• legs (4 x 2) 8
• ankles (7 x 2) 14
• feet (19 x 2) 38
• total 126
Purple Area

9. There are Four Main types of bone
Flat: like those found in the skull; provide protection
for soft tissues and points for muscle attachment
Long: found in the arms and legs;
provide strength and support
Short: found in the wrists and ankles;
not much longer than they are wide; provide flexibility
Irregular: backbone, middle ear; have shapes related
to a specialized function
(ex: vertebra have small extensions for muscle
attachments and an opening for the spinal cord)

10. Flat
Long
Irregular
Short

11. Bones • Bones get their strength and rigidity from hard deposits of
minerals such as
calcium and
phosphate.
• Bones are strong
but light because
they are hollow
and filled with a
substance called
Bone Marrow.

12. Bone Marrow • Bone marrow is found in the hollow
interior of bones and is a spongy, fatty
tissue that houses stem cells. These cells
can transform themselves into platelets,
white or red blood cells that are needed
for immunity and circulation.
• Red marrow is found in some flat bones
(hip, skull, vertebrae and rib bones) and
yellow marrow is a fat tissue storage site
in the middle of some longer bones.

14. Joints • The place where bones meet.
• Most joints allow our bones to move (the skull bones are an exception.)
• There are several types of body joints including:
• Hinge (elbow)
• Ball-and-socket (Hip and shoulder)
• Pivot (head on spine)
• Saddle (interlocking bones in the thumb)
• Gliding (bones slide past each other)

15. Types of Joints Hinge Joint • A hinge joint allows
extension and flexion of
an appendage.
• Note: your knee is a
modified hinge joint.

16. Types of Joints Ball & Socket Joint
• A ball and socket joint allows for radial movement in almost any direction. They are
found in the hips and shoulders.

17. Types of Joints Pivot Joint
• Pivot joints allow rotation around an axis. The
neck and forearms have pivot joints. In the
neck the occipital bone spins over the top of
the axis. In the forearms the radius twists as it
turns over the ulna.

18. Types of Joints Saddle Joint • A saddle joint allows movement back and
forth and up and down, but does not allow for
pivoting like a ball and socket joint.

19. Types of Joints Gliding Joint
• In a gliding or plane joint bones slide past
each other. Midcarpal and midtarsal joints are
gliding joints

21. Cranium and Facial Bones
Nasal Bones
The cranial bones include the flat bones that make up the vault for your brain. Their main function is to protect the brain from trauma.

22. The Vertebral Column
The spine
Made up of 26 irregularly shaped bones
Each vertebra has one round drum shaped
body with 3 wing-like projections
The vertebrae are held together by bands
of ligaments
There is a hole in the middle of each
vertebra for the spinal cord
The way our spine is made, it limits
how much we can bend forward/backward
Some people are more flexible than others

23. -Supports the head and neck, holding the head erect.
Cervical Region: C1-C7 (7bones)
-Supports the head and neck, holding
the head erect.
Thoracic Region: T1-T12 (12 bones)
-rigid group of bones which support
the 24 ribs
Lumbar Region : L1-L5 (5bones)
-largest bones in the vertebral column,
carrying a large share of the body
mass. Quite mobile bones.
Sacrum
-transfer body weight to pelvis
Coccyx- no significant function

24. The Sternum and Ribs 12 pairs of ribs that are flat, curved bone.
Main function is protection and support.
First 7 pairs are attached by cartilage to the sternum (breast bone).These are True Ribs.
Next 3 pairs lie below the sternum;
each pair is attached by cartilage to the pair of ribs above. These are False Ribs
The last 2 pairs are called Floating Ribs because they do not complete the circle and are not attached in front (these ribs are easily broken)

26. The Upper Limbs Scapula: is loosely held in place
by ligaments and muscles,
so the arm has great freedom of
movement in almost any direction.
Humerus: is a long bone in the arm
or forelimb that runs from the shoulder
to the elbow,has many attachment
sites for muscles.

27. Ulna: is one of the two long bones in the forearm, with the palms facing forward the ulna is placed at the
medial side of the forearm closest to the body
Radius: is the bone of the forearm that extends from the lateral side of the elbow to the thumb side of the wrist. The radius is situated on the
lateral side of the ulna.

28. Wrist: is made up of 8 small bones (carpals) which are joined to the 5 metacarpals that form the hand
The bones that make the fingers and thumb
are called phalanges (there are 3 in each finger and 2 in each thumb)

30. Pelvis
Female
Male

31. Functions of the Pelvis
The pelvic girdle is a basin-shaped ring of bones
connecting the vertebral column to the femurs
(upper leg bones)
Main function is to hold up the upper body and allow
an attachment point for the legs
Secondary function is to protect the lower organs
of the urinary system and reproductive system.

32. The Lower Limbs Femur: longest and strongest bone;
its round, smooth head fits
into a socket formed in the pelvis
Patella: flat, disc-shaped bone just
in front of the joint for protection.
Loosely attached to allow movement

33. Tibia: shinbone, or shankbone is
the larger and stronger of the two
bones in the leg below the knee, and
connects the knee with the ankle bones.
Fibula: is a bone located on the lateral
side of the tibia, it is the smaller of
the two bones.

34. Tarsal bones: 7 of these bones make up
the ankle; these provide a sliding joint
which allows the foot to be extended
and flexed. The calcaneus is the largest
tarsal bone also known as the heel bone.
Metatarsals are the 5 bones in the foot.
Phalanges are the bones in the toes.
Each toe has 3 bones except for the
‘big’ toe.(the most medial digit of the foot)