The Skeletal System

The Human Skeleton -Bones are LIVING tissue Bone tissue is composed of: Inorganic salts (calcium phosphate) Water Organic material (bone cells, blood vessels, nerves, and collagen) Bone cells must continually receive food and oxygen Them Not so Dry Bones

Bones: Adult human skeleton is made up of 206 bones Humans start with more bones at birth, more than 300 Bones fuse as growth takes place Bones continue to grow for the first 18 to 20 years of life Bone cells die and are replaced by new ones

The human skeleton: -Bones make up for about 14% of total body weight What do you think makes up for the most of our body weight? -Largest bone is the femur -Smallest bone is the stirrup bone in the ear -Some bones are made up of several bones Examples? -Male and Female skeletons have slight differences Males have slightly thicker and longer legs and arms Females have a wider pelvis and a larger space with in the pelvis

Role of the Skeleton 1. Provides shape and support 2. Works in conjunction with the muscles to cause movement 3. Stores minerals and fat 4. Produces blood cells and platelets 5. Protects organs Examples?

Structure of the Skeleton Two main parts: -Axial Skeleton 80 bones Vertebral Column (spine) Skull Rib cage Most of the body’s muscles originate (anchor) here “core muscles” Examples? -Appendicular Skeleton 126 bones Movable Limbs & Two Girdles Pectoral & Hip Allows for the most movement Shoulders, arms, pelvis, legs

Bones and attachment: Bones are attached to other bones by ligaments: Bones are joined to muscles by tendons:

5 Types of Bones Long Bones Found in arms and legs Ex: humerus, femur Short Bones Most common in wrists and ankles Ex: carpals, tarsals Flat Bones Flat and thin Ex: cranium, scapula, sternum Irregular Bones Odd looking bones Ex: vertebrae, pelvis Sesamoid (Round) Bones Small, flat bones wrapped with tendons Ex: patella

Long Bones: In the body- Humerus, Femur, Tibia, Fibula, Clavicle, Ulna, Radius, Metacarpals, Metatarsals, Phalanges Cartilage- Allows for smooth movement within joints while protecting the ends of bones. Does not have a blood supply or nerve endings

Long Bone Vocab: Periosteum Outer connective tissue that covers the entire length of the bone Medullary Cavity Found inside the shaft or the bone (diaphysis) and is filled with red and yellow bone marrow Compact Bone Dense part of the bone, responsible for the bone’s structural integrity, supports the body’s weight Cancellous/Spongy Bone Filled with marrow in its small cavity-like spaces

Long Bones: -Provide Support -Serve as levers and linkages that allow movement -How do you strengthen long bones?

Injuries: Fractures- breaks or cracks in the bone Closed Fracture: the bone is not exposed to the air through the skin Open Fracture: the bone is exposed Fractures are also distinguished according to the type of fracture and the severity of the break

Types of Fractures Simple Fracture Compound Fracture No separation of the bone, but a break or crack is detectable. Also referred to as a hairline or greenstick fracture. Compound Fracture The bone is broken into separate pieces. Sometimes referred to as a transverse fracture. Comminuted Fracture Broken ends of the bone are shattered into many pieces.

Severity of Fractures: Depends on: Location of the fracture Damage to the bone and surrounding tissue Open or closed fracture

Stress Fractures: -When muscles become too fatigued to absorb the shock placed on them, the stress is transferred to the bone. -This causes the bone to develop a tiny crack. -One of the most common injuries in sports.

Stress Fractures: How are they caused? How are they cared for? Rapid increase in training Switching to a new surface for training Poor footwear with improper cushioning How are they cared for? Recommended to take 6-8 weeks of rest from activity If activity is resumed too quickly, larger stress fractures can develop that take longer to heal

Healing: -Bones heal from breaks by rebuilding themselves -Problems occur when: There is infection Bones heal by themselves and are misaligned

Healing:

Building Strong Bones: Steps taken during adolescence is the best defense against decreased bone density: Balanced diet rich in calcium and vitamin D Weight bearing exercises Healthy lifestyle Bone density testing

Review: How many bones are in the adult body? What are the 3 bones that make up the arm? What are the 4 bones that make up the leg? What are the 3 functions of the skeletal system? Examples of bones. Organs the skeletal system protects and the body system they are a part of. What are the 2 main parts of the skeleton? What are the 5 types of bones? Example of each. Which type of bone contains marrow? Where in the bone? (2) What is the function of cartilage? Compare/Contrast simple and compound fractures. How do you keep the skeletal system healthy?

The Female Triad Article: Pg. 326 Read the article and respond: Explain the Female Triad, how is it related to the skeletal system? Why do you think women still suffer from the Female Triad even when they know the risks of how their body is negatively effected? Support with textual evidence.