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Unit 10 Chapter 34 Protection, Support, and Locomotion. Skin: the Body’s Protection. Integumentary System Contains skin and its related parts—hair, nails & glands Functions: Regulates body temperature Receives stimuli from environment Produces vitamin D Protection of underlying tissues.
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Skin: the Body’s Protection • Integumentary System • Contains skin and its related parts—hair, nails & glands • Functions: • Regulates body temperature • Receives stimuli from environment • Produces vitamin D • Protection of underlying tissues
Skin: the Body’s Protection • Epidermis: • Outer layer of skin, composed of dead, flattened cells • Contains Melanin, a pigment that colors the skin & protects cell from damage by radiation
Skin: the Body’s Protection • Dermis • Inner, thicker portion of the skin • Contains blood vessels, nerve endings, hair follicles, sweat & oil glands
Skin: the Body’s Protection • Hypodermis (subcutaneous layer) • Below the dermis • Contains primarily of fat for cushioning & insulation
Bones: the Body’s Support • Skeletal Systemdivisions: • Axial skeleton • Includes the skull, vertebrae, ribs & sternum • Appendicular skeleton • Includes bones of the arms & legs, and shoulder & hip bones
Bones: the Body’s Support • Skeletal system functions: • Protection • Support • Attach muscles • Produce blood cells • Store minerals
Bones: the Body’s Support • Joints • Where two bones meet • Facilitates the movement of bones in relation to one another
Bones: the Body’s Support • Ligaments • Connective tissue that attaches one bone to another • Tendons • Connective tissue that attach muscles to bones
Bones: the Body’s Support • Spongy bone • Soft bone containing many spaces filled with red marrow • Compact bone • Dense bone with an inner cavity containing yellow marrow • Haversian system • Circular area in compact bone containing blood vessels, nerves, and living cells called osteocytes
Muscles for Locomotion • Smooth muscle • Involuntary movement • Found in hollow body organs, i.e. stomach, arteries, iris of eye • Spindle-shaped cells, non-striated, one nucleus per cell
Muscles for Locomotion • Cardiac muscle • Involuntary movement • Found only in the heart • Branching, striated (striped) cells, with one nucleus per cell
Muscles for Locomotion • Skeletal muscle • Voluntary movement • Found attached to bones, i.e. biceps, triceps, hamstrings, etc • Long, striated (striped) cells, with many nuclei
Extensor and flexor muscles Click on image to play video.
Muscles for Locomotion Common Skeletal muscles
Muscles for Locomotion • Muscle contraction: • Muscle fibers (cells) are made up of smaller units called myofibrils • Myofibrils contract (shorten) as filaments, called myosin & actin, slide toward one another