Skeletal System 3/11/15

Skeletal System has five functions. Function #1: Provides shape and support. Function #2: Anchor for all of the body’s movement. Function #3: Protects soft organs inside the body. Function #4: Makes red blood cells. Function #5: Stores minerals such as calcium and phosphorus.

Organs of the Skeletal System 206 bones (organs) in an adult skeleton

Bones are classified by shape: Long Bones are found in the arms, legs, fingers and toes.

Bones are classified by shape. Short bones are found in wrists, ankles, and knee caps.

Bones are classified by shape: Irregular bones are found in the spine (vertebrae), sacrum, and jaw.

Bones are classified by shape: Flat bones are found in the ribs and skull.

The Skeleton is the body’s framework Axial Skeleton: Main functions: Provides support and protection Irregular and flat bones - Skull, ribs, vertebrae, pelvis Appendicular Skeleton: Main Functions: to allow movement Long and short bones: Found in Arms, shoulders, legs– scapula, humerus, radius, ulna, femur, tibia, and fibula

There are two types of bone tissue. Compact bone: Covers outside of most bones Very hard and tough surrounds spongy inner layer. Basic supportive layer Spongy bone: Inside of bone Strong but lightweight Makes up most of the short and irregular bones Makes up the ends of long bones

Marrow and Blood Cells Marrow fills spaces within spongy bone. Marrow produces red and white blood cells. New blood cells travel from the marrow into blood vessels that run throughout the bone.

Joints Places where two parts (bones) of the skeletal system meet

Immovable or Fixed Joints Lock bones together like puzzle pieces. Found in skull and pelvis

Slightly Movable Joints Able to flex slightly Found where ribs connect to sternum (breast bone)

Freely Movable Joints Allow your body to bend and move Found in arms and legs, hands and feet, spine

Ligaments Tissues that hold bones together at movable joints Other structures (cartilage and fat) cushion bones and keep them from rubbing together.

Muscular System 3/11/15

3 Functions of the Muscular System: Movement Movement: Works with the skeletal system Skeletal Muscles work in pairs. A muscle on one side of the body pulls in one direction while the other muscle relaxes. TENDONS attach muscles to bones (stretchy connective tissue)

3 Functions of the Muscular System Maintaining body temperature – related to homeostasis When muscles contract, they produce heat Example: quick muscle contractions when you shiver release heat and raise your body temperature

3 Functions of the Muscular System Maintaining posture Most muscles in your body are always a little bit contracted – muscle tone Muscles that maintain posture only relax when you are unconscious.

Your body has different types of muscles. Each type contracts and relaxes All have different functions All are found in different locations

Skeletal Muscle Attached to your skeleton Performs voluntary movement – movement you choose to make Made of long fibers made up of smaller bundles

Skeletal muscles and tendons allow bones to move Tendons – strong connective tissues that attach skeletal muscles to bones Tendons are found on each end of a muscle.

Skeletal muscles and tendons allow bones to move Muscle fibers contract, pull on the tendon, which then pulls on the bone to make it move

Smooth Muscle Found inside some organs – example: intestines and stomach Performs involuntary movement – move without you knowing it Fibers are not as long as skeletal muscles Contracts slowly

Cardiac Muscle Only found in your heart Involuntary muscle like smooth muscle – moves without conscious thought Contracts slowly like smooth muscle

Muscles grow and heal. Skeletal muscles have to develop and strengthen Example: A baby can’t lift its head because neck muscles are not strong enough

Muscles grow and heal. Muscles get bigger when you exercise regularly

Muscles grow and heal. Muscle soreness you feel a day or two after exercise is caused by damage to muscle fibers.