Video

The Skeleton is the name given tothe collection off bones in thebody and the tissues thatconnect them.

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 justbe a blob of blood and tissue on the floor.3-It allows us to move. Because our muscles areattached to our bones, when our musclesmove, 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.

Skeleton Facts• When you were born, your skeleton hadclose to 350 bones.

• By the time you become an adult, youwill only have around 206 bones.

• This is because, as you grow, some of thebones fuse together to form one bonesuch as the skull.

…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 handsand feet.• As your bones grow, you get taller. Girlsusually stop growing around age 16, and 18 for boys.• Our bones are 5 times stronger than steel if they are the same weight.

Organization of the Human Skeleton

• Your skeleton is made up of two parts; the axial skeleton and the appendicularskeleton.

Green = AxialPurple = Appendicular

The Axial Skeleton

• Skull 29• vertebral column 24• ribs (12 pairs) 24• Sternum 1• Sacrum 1• Coccyx 1

• Total 80

Green Area

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

There are Four Main types of bone

Flat: like those found in the skull; provide protection for soft tissues and points for muscle attachmentLong: 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 flexibilityIrregular: 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)

Bones

• Bones get theirstrength andrigidity from harddeposits ofminerals such ascalcium andphosphate.

• Bones are strongbut light becausethey are hollowand filled with asubstance calledBone Marrow.

Bone Marrow

• Bone marrow is found in the hollowinterior of bones and is a spongy, fattytissue that houses stem cells. These cellscan transform themselves into platelets,white or red blood cells that are neededfor immunity and circulation.

• Red marrow is found in some flat bones(hip, skull, vertebrae and rib bones) andyellow marrow is a fat tissue storage sitein the middle of some longer bones.

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)

Types of Joints

Hinge Joint

• A hinge joint allowsextension and flexion ofan appendage.

• Note: your knee is amodified hinge joint.

Types of Joints

Ball & Socket Joint

• A ball and socket joint allows for radial movement in almost any direction. They arefound in the hips and shoulders.

Types of JointsPivot Joint

• Pivot joints allow rotation around an axis. Theneck and forearms have pivot joints. In theneck the occipital bone spins over the top ofthe axis. In the forearms the radius twists as itturns over the ulna.

Types of Joints

Saddle Joint

• A saddle joint allows movement back andforth and up and down, but does not allow forpivoting like a ball and socket joint.

Types of Joints

Gliding Joint

• In a gliding or plane joint bones slide pasteach other. Midcarpal and midtarsal joints aregliding joints

Cranium and Facial 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.

Nasal Bones

The Vertebral Column

The spineMade up of 26 irregularly shaped bonesEach vertebra has one round drum shaped body with 3 wing-like projectionsThe vertebrae are held together by bands of ligaments There is a hole in the middle of each vertebra for the spinal cordThe way our spine is made, it limits how much we can bend forward/backwardSome people are more flexible than others

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 supportthe 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

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 RibsThe 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)

The Upper Limbs

Scapula: is loosely held in place by ligaments and muscles,so the arm has great freedom ofmovement in almost any direction.

Humerus: is a long bone in the arm or forelimb that runs from the shoulderto the elbow,has many attachment sites for muscles.

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.

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)

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 allowan attachment point for the legs

• Secondary function is to protect the lower organsof the urinary system and reproductive system.

The Lower Limbs

Femur: longest and strongest bone; its round, smooth head fitsinto a socket formed in the pelvis

Patella: flat, disc-shaped bone just in front of the joint for protection. Loosely attached to allow movement

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.

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)