Understanding Skeletal and Muscular Systems

To be used with Skeletal and Muscular Systems Guided Notes To be used with Skeletal and Muscular Systems Guided Notes Adapted from: M Adapted from: M. . Baroody Baroody

Movement is a Life Function for all living things Locomotion: organism Locomotion: change in position of an Tropism Walking/Sliding

Why do we need to move? Survival Value of Locomotion 1. Get food and shelter 2. Escape from predators 3. Move to regions better suited to survival 4. Find mates 5. Move away from toxic wastes

What allows us to move? Skeleton and Muscles

Functions of the skeleton: 1. Supporting framework for internal organs and tissues. 2. Anchorage sites for muscle action. 3. Protects the internal organs. 4. Provides leverage for body movement. 5. Blood cells are produced in the bone marrow. The bones also store minerals.

Cartilage: tough, fibrous, elastic connective tissue Cartilage Functions 1. Pliable (stretchable) support 2. Flexibility of joints 3. Cushioning of joints Cartilage makes up most of the embryo's skeleton. Most of this cartilage changes to bone by adulthood.

Ligaments connect bones to bones (joints) tough and elastic Ligaments:

Provided by Nucleus Communications, Inc. Tendons tough inelastic fibrous cords which attach muscles to bones Tendons:

A is a tendon (it connects the bone at D to the muscle at B) C is a ligament (connects bones)

Muscles only body tissue able to contract create movement by flexing and extending joints body energy converters (many muscle cells contain many mitochondria) Muscles

Smooth Muscle: Smooth in appearance Involuntary in action Slowly contracting but contractions are long in duration Lines blood vessels, alimentary canal, and body openings

Skeletal Muscle Voluntary in action Contain many striped long fibers called striations Found in association with skeletal bones the nervous system interacts with skeletal muscles to produce motion

Cardiac Muscle: Resembles skeletal muscle with lined appearance Involuntary in action Composes the hardest working muscle-- the heart

Myosin, Actin, Cross-bridges Muscles can only pull, cannot push Voluntary Can control Such as: Involuntary Cannot control Such as: Force increases with the number of fibers that are stimulated

Violent muscle contractions require a lot of oxygen. If oxygen is not available muscle fatigue will set in. Muscle fatigue: results from oxygen debt lactic acid accumulates in skeletal muscles rest restores the oxygen balance

Arthritis Arthritis: joint inflammation

Tendonitis junctures a common condition in athletes Tendonitis: tendon inflammation at bone

Types of bone breaks (fractures): Range from a simple fracture to a compound fracture

Cranial Cavity Holds the Brain and is bounded by the skull

Thoracic Cavity Holds the lungs and heart and is bounded by the ribs, sternum, diaphragm, and spine

Abdominal Cavity Holds the stomach, pancreas, liver, small intestine, large intestine, kidneys, spleen, bladder, and reproductive organs. Bounded by the diaphragm, ribs, abdominal muscle, and pelvis