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

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

Locomotion 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

Human Locomotion 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 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.

Cartilage

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

Tendons Tendons: tough inelastic fibrous cords which attach muscles to bones

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

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

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

Types of Muscle: Skeletal 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

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

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

Muscle Contractions 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

Disruptions in Homeostasis Arthritis: joint inflammation

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

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

Body Cavity Cranial Cavity Holds the Brain and is bounded by the skull

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

Body Cavity 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