Aim: Locomotion

Animal Movement What are the advantages of being mobile? sessile

Lots of ways to get around…

Lots of ways to get around… mollusk mammal bird reptile

Lots of ways to get around… bird insect mammal bird

Functions of Muscular/Skeletal Support Protection Making blood cells Shape Movement

involuntary, contract on their own Muscles involuntary, contract on their own voluntary All cells have a fine network of actin and myosin fibers that contribute to cellular movement. But only muscle cells have them in such great abundance and far more organized for contraction. SMOOTH MUSCLE Smooth muscle was the first to evolve. Lining of blood vessels, wall of the gut, iris of the eye. Some contract only when stimulated by nerve impulse. Others generate electrical impulses spontaneously and then are regulated by nervous system. CARDIAC MUSCLE Small interconnected cell with only one nucleus. Interconnected through gap junctions. Single functioning unit that contract in unison via this intercellular communication. Mostly generate electrical impulses spontaneously. Regulated rather than initial stimulation by nervous system. SKELETAL MUSCLE Fusion of many cells so multi-nucleated. Attached by tendon to bone. Long thin cells called muscle fibers. involuntary evolved first

Muscles movement Muscles do work by contracting skeletal muscles come in antagonistic pairs flexor vs. extensor contracting = shortening move skeletal parts

Muscles movement 1) Tendons connect bone to muscle 2) Ligaments connect bone to bone

Cartilage turns to bone through ossification Protein fibers of elastin and collagen No blood vessels (relies on diffusion) Flexible, in between joints Cartilage turns to bone through ossification

Fast twitch & slow twitch muscles Slow twitch muscle fibers contract slowly, but keep going for a long time more mitochondria for aerobic respiration long distance runner “dark” meat = more blood vessels

Fast twitch muscle fibers contract quickly, but get tired rapidly sprinter “white” meat

Muscle limits Muscle fatigue Muscle cramps low O2 nerve fatigue lactic acid lowers pH which interferes with protein function nerve fatigue Muscle cramps build up of lactic acid lack of energy (ATP) ion imbalance

Botox Bacteria Clostridium botulinum toxin blocks release of nerve transmitter muscle

Axial & Appendicular Skelton Skeletal System Contains 206 bones 2 main parts: Axial & Appendicular Skelton Axial skull, vertebrae, ribs, & breastbone Appendicular Arms & leg bones Pelvic & Shoulder Girdle

Types of Joints Ball & Socket Shoulder & hips Allow movement in ALL directions ball & socket Hinge Elbow and knee Back-and-forth motion hinge Pivot Base of skull Allow side-to-side as well as up-down motion pivot

Diseases associated with Locomotion ALS Lou Gehrig’s disease motor neurons degenerate Myasthenia gravis auto-immune antibodies to nerve transmitter chemical Stephen Hawking