Motor Systems: Support and Movement

1. Motor Systems: Support and Movement Integumentary, Skeletal, and Muscular Systems Chapters 31 and 39

2. Integumentary System • abody’s covering • skin, skin glands, hair, nails, and associated structures • invertebrate skin • secretion, protection, and/or gas exchange • vertebrate skin • complex tissue with several layers • epidermis, dermis, hypodermis • cutaneous vs. subcutaneous • generally no gas exchange function • protection, support, heat regulation, sense of touch • features • sweat and oil (sebaceous) glands • hair follicles and hair • sensory receptors and nerves • pigment cells (melanocytes) • small blood vessels (capillaries)

3. Fig. 31.7 Human skin anatomy

4. Vertebrate Tissues • nerve tissue – discuss later • muscle tissue – discuss later • epithelial tissue (epithelium) • linings and coverings • skin (epidermis and dermis) • glandular epithelium • classification types • simple vs. stratified vs. pseudostratified • squamous vs. cuboidal vs. columnar • any form can be ciliated

5. Fig. 31.1 Types of epithelial tissue in vertebrates

6. Fig. 31.1 Types of epithelial tissue in vertebrates

7. connective tissue • holds body together • bone, cartilage, ligaments, blood, tendons, fascia, fat (adipose) • connective tissue matrix • collagen, fibroblasts, elastin Fig. 31.2 Diagram of fibrous connective tissue

8. Fig. 31.3 Types of connective tissue in vertebrates

9. Fig. 31.3 Types of connective tissue in vertebrates

10. Invertebrate Support and Movement • hydrostatic skeleton (“soft skeleton”) • pressure generated by body fluids • fluids press against inside of body wall • base for muscle action • exoskeleton (“cuticle”) • hard skeleton lying outside soft body parts • chitin • does not grow with org.; must be shed • four functions: • base for muscle action • movement of joints • prevents water loss • protects soft body parts • muscle organization • origin vs. insertion • occur in pairs (antagonists) Fig. 39.13 Antagonistic muscles

11. endoskeleton • hard skeleton that lies within body  grows with organism • muscles also occur as antagonists • echinoderms and vertebrates • Vertebrate Endoskeletons • cartilage skeletons • clear, relatively soft substance • chondrocytes embedded in protein matrix • cartilage is the forerunner to bone • bone skeletons • five functions: • supports body • attachment site for muscles • protection of internal organs • some produce blood cells (red, white, and platelets) • natural reservoir of Ca

12. bone is a living tissue composed of several parts • periosteum • spongy bone • red marrow  produces the various blood cells • compact bone • yellow marrow within the medullary cavity • Haversian systems (osteons) • osteocytes • ends of bones are capped with cartilage  allows joints to function

13. Fig. 39.4 Anatomy of a long bone

14. organized into axial and appendicular divisions • skull, vertebrae, pelvic girdle, pectoral girdle, limbs • joints can be immovable or movable • several different types of movable; some are synovial Fig. 39.5 The human skeleton

15. Vertebrate Muscle • smooth • involuntary • cells are long and tapered; occur in sheets • single nucleus • examples • cardiac • involuntary; only in heart • rhythmic and tireless • single nucleus • cells are cylindrical, branching, and web-like • skeletal • voluntary; moves limbs, other muscles, or just itself • multinucleated and striated; unbranched • contractions tire over time • examples

16. Fig. 31.5 Muscular tissue

17. Fig. 39.12 Human musculature

18. Structure of Skeletal Muscle • not all muscles move bones • tendons and fascia • whole muscle  bundles of muscle fibers (fascicles) • muscles fibers are long and surrounded by sarcolemma • neuromuscular junctions • muscle fibers  myofibrils actin and myosin myofilaments • myofilaments arranged into individual contractile units called sarcomeres

19. Fig. 39.14 Skeletal muscle fiber structure

20. Muscle Contraction • sliding filament model • involves interaction between the myofilaments of each sarcomere • nerve impulses reach a neuromuscular junction • Ca+ ions are released and cause myosin to bind to actin • actin filaments slide past myosin filaments sarcomeres contract  entire muscle contracts  movement occurs • ATP is needed to supply energy for contraction

21. Fig. 39.14 Skeletal muscle fiber function