chapter 36
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CHAPTER 36. THE SKELETAL, MUSCULAR & INTEGUMENTARY SYSTEMS. CHAPTER 36.1. THE SKELETAL SYSTEM HW: P. 925 #1-4. THE SKELETON. Functions: Supports the body Protects internal organs Enables movement Stores mineral reserves Site for blood cell formation - PowerPoint PPT PresentationTRANSCRIPT
THE SKELETAL, MUSCULAR & INTEGUMENTARY SYSTEMSCHAPTER 36
CHAPTER 36.1THE SKELETAL SYSTEMHW: P. 925 #1-4
THE SKELETON• Functions: • Supports the body• Protects internal organs• Enables movement• Stores mineral reserves• Site for blood cell formation
• Axial: skull, vertebrae and rib cage
• Appendicular: bones of upper and lower limbs
Structure of Bones (Fig. 36.3)• Bones: solid network of living
cells and protein fibers surrounded by deposits of calcium salts
• Periosteum: tough layer of connective tissue that surrounds the bone
• Compact Bone: dense bone• Haversian Canals: tube
network for vessels and nerves
• Spongy Bone: lattice network of bone; adds support without mass
• Bone Marrow: soft tissue inside bone; yellow = fat; red = blood cell formation
BONE DEVELOPMENT• Ossification:
cartilage replaced by bone• Osteocytes: mature bone cells• Osteoblasts: produce bone (“blast off”)• Osteoclasts: break down bone
• Where can you find cartilage in your body?
TYPES OF JOINTS• Joints: where bones attach;
allow for movement without damage
• Types of joints:• Immovable: no movement
(i.e. skull bones)• Slightly movable: small,
restricted movements (i.e. vertebrae)• Freely movable: movement in
one or more directions• Ball-and-socket: most
movement (i.e. shoulder)• Hinge: back-and-forth motion
(i.e. knee, elbow)• Pivot: bones rotate (i.e. forearm)• Saddle: bones slide (i.e. thumb)
STRUCTURE OF JOINTS• Cartilage between
bones helps reduce friction
• Ligaments fuse with bone membranes and connect bone to bone.
• Synovial fluid allows for smooth bone movement
SKELETAL SYSTEM DISORDERS
• Arthritis: inflammation of joints
• Osteoporosis: severe bone loss (mostly in women)
CHAPTER 36.2THE MUSCULAR SYSTEMHW: P. 931 #1-5
TYPES OF MUSCLE TISSUE (Fig. 36-6)
• Skeletal muscle cells: long, slender, multi-nucleated and striated; voluntary (aka muscle fibers); attached to bones
• Smooth muscle cells: spindle-shaped, one nuclei and non-striated; involuntary; lines organs, vessels and digestive tract
• Cardiac muscle cells: striated with one or two nuclei; involuntary; only found in the heart
SKELETAL MUSCLE STRUCTURE (Fig. 36-7)
• Thin (actin) & Thick (myosin) filaments myofibrils (sarcomere) muscle fiber (cell) bundle of muscle fibers skeletal muscle
MUSCLE CONTRACTION (Fig. 36-8)
• Thick filaments: myosin protein
• Thin filaments: actin protein (“thin” and “tin”)
• Filaments arranged into a sarcomere (from Z to Z line)
• Sliding filament model: A muscle contracts when the thin filaments slide over the thick filaments.
• Energy for contraction supplied by ATP
• Neuromuscular junction: synapse between neuron and muscle cell
• Acetlycholine: neurotransmitter that binds to muscle fibers and causes calcium to release
• Calcium is KEY to muscle contractions (allows myosin to bind to actin)
• More muscle cells stimulated = stronger contraction
MUSCLES AND BONES• Tendons connect
muscles to bone.• Muscles contract and
tendons pull on bones, function like levers around a fixed point (joint)
• Regular exercise is important in maintaining muscular strength and flexibility.
CHAPTER 36.3The Integumentary SystemP. 936 #1-5P. 939 #1-10, 14, 16, 23
THE SKIN• Functions:•Protection—barrier against infection and injury (most important)•Regulates body temp.•Removes waste•Protection against UV rays
THE STRUCTURE OF SKIN (Fig. 36-13)
• Two layers:•Epidermis: outer layer; dead and living cells (inner cells divide constantly)• Keratin: tough, fibrous
protein• Melanocytes: cells that
make melanin (brown skin pigment)
•Dermis: inner layer; contains vessels, nerves, glands, etc…
HAIR AND NAILS• Hair: protection from
UV rays; insulation from cold; traps dirt and other particles; grow from hair follicles (pockets in the dermis)
• Nails: made of keratin; grow from the nail root; protects tips of fingers and toes
SKIN DISEASES
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