Transcript Chapter 37
Protection, Support, Movement Integument Protection Physical Dehydration Body temperature regulation Cutaneous sensation Metabolic functions Blood reservoir Excretion of wastes Respiration (amphibians) Integument Cuticle Hardened outer covering Exoskeleton Roundworms, most arthropods Protein or chitin Integument Skin Softer, ketatin-containing outer covering Associated tissues (scales, hair, feathers, beaks, horns, nails, etc.) Vertebrates Integument Epidermis Stratified squamous epithelium Keratinocytes Keratin—water-proofing protein Melanocytes Melanin—pigment & sunscreen Integument Dermis Mostly dense irregular connective tissue Cushion body against stretch & stress Blood, lymph, nervous tissue Hypodermis Mostly adipose tissue Integument Sweat glands “True sweat” Eccrine Apocrine Ceruminous (ears) Mammary Sebaceous glands Integument Chromatophores Skin & eye color in ectotherms Melanocytes in birds & mammals Color change Pigment translocation Cephalopods—muscles surround elastic cell, change it’s shape Skeleton Hydrostatic skeleton Cnidarians, platyhelminthes, annelids, nematodes Fluid cavity surrounded by muscles Change shape for support & movment Exoskeleton Mollusks, arthropods Calcium carbonate or chitin Limits growth, but more strength, site for muscles Endoskeleton Echinoderms, vertebrates Supports greater weight Doesn’t limit growth Skeleton Ecdysis Moulting of exoskeleton Continuous growth of arthropods not possible Must periodically shed exoskeleton & allow rapid growth Steps: Cuticle separates from epidermis New cuticle secreted by epidermis Old cuticle shed Animal inflates body w/ air or water to expand new cuticle New cuticle dehydrates & hardens Animal vulnerable during this time Soft shelled crabs Skeleton Bone functions Support Protection Movement Storage Hematopoiesis Blood cell production Skeleton Shape Long Short Flat Irregular Location Axial Appendicular Skeleton Compact bone Spongy bone Hyaline cartilage Periosteum Yellow marrow—fat storage Red marrow—blood cell production Ligaments—bone to bone Tendons—muscle to bone Skeleton Osteocytes Osteoblasts Osteoclasts Haversian (central) canal Bones to know…. Mandible Maxilla Zygomatic Sternum Rib Scapula Clavicle Bones to know… Humerus Ulna Radius Carpals Femur Patella Tibia Fibula Tarsals Bone Disorders Osteomalacia (adults), Rickets (children) Vitamin D deficiency Reduction in calcium in bones Soft bone, easily bent or broken Osteoporosis Osteoclast activity outpaces osteoblasts Hormonal influences Nutritional influences Brittle, weak bones Joints Fibrous Immovible Skull sutures, teeth Cartilaginous Slightly moveable Vertebrae, pelvis Synovial Freely moveable Fluid-filled cavity Knee, elbow, fingers Joint Disorders Sprain/strain Stretch or tear of ligaments & tendons Anterior cruciate ligament Osteoarthritis Wear & tear on joints Usually w/ old age Rheumatoid arthritis Degeneration of joints Autoimmune disease Muscle Skeletal Cardiac Smooth Muscle—Skeletal Muscle Fascicle Muscle fiber (cell) Muscle—Skeletal Sarcolemma Myofibrils Muscle—Skeletal Sarcomere Active unit Thin (actin) filament Thick (myosin) filament Neuromuscular Junction Nerve impulse reaches axon termial Channels open in axon, calcium moves into axon terminal Vesicles move to surface of axon Vesicles open, releasing acetylecholine (ACh) ACh travels across synaptic cleft ACh binds to receptors on muscle Contraction stimulated Muscle Sliding Filament Model Animation Muscle—Cardiac Cardiac muscle stimulated by pacemakers in heart Most muscle not directly innervated Intercalated discs connect cells, continuing muscle impulse Muscle—Smooth Muscle Disorders Myasthenia gravis Shortage of ACh receptors Muscular Dystrophy Fragile, abnormal sarcolemma Too much calcium, damages fibers Loss of regeneration, muscles waste Tetanus Clostridium tetani, no release of ACh