Unit 10-Human Body Chapter 36 Skeletal, Muscular & Integumentary System

Functions of the Skeleton Support Protect Attach muscles Store minerals Produce blood cells

206 Bones: Axial skeleton includes skull, ribs & vertebra Appendicular includes bones of arms, legs and girdles

Joints point where 2 bones meet Immovable Slightly movable Freely movable: –Ball & socket –Hinge –Pivot –Saddle

Muscular System

Muscle types Cardiac = –located only in heart Involuntary movement Striated, uni-nuclear, branched

Muscle types Skeletal = –Attached to bones –Ex: pectoralis major Voluntary movement Striated, multinuclear, extremely long

Muscle types Smooth = –Make up hollow organs –Ex: stomach, iris Involuntary movement Not striated, uninuclear, spindle-shaped

Muscle Vocabulary Ligaments = attach bone to bone Tendons = attach muscle to bone or another muscle Flexion = movement that bends joints (ex: biceps) Extension = movement that straightens joints (ex: triceps)

Muscle fibers (cells) are composed of myofibrils…Myofibrils are made up of small filaments Thick filaments are called myosin and thin filaments are called actin A muscle contracts when the thin filaments slide over the thick filaments

Integumentary system Functions: Protect Receive stimuli Regulate temperature Produce vitamin D

Layers of skin: Epidermis –thin “dead” layer for waterproofing Dermis –thick layer containing vessels, nerves, muscle, glands, and hair follicles Hypodermis (subcutaneous) –contains mostly fat for insulation