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Lecture 2 support and protection 2nd sem 2008-2009
The document summarizes the structure and functions of the integumentary and skeletal systems. It describes the key components and layers of skin, such as the epidermis and dermis in vertebrates. It also discusses the various derivatives of the skin, including hair, nails, and glands. For the skeletal system, it outlines the main types of skeletons, including hydrostatic, exoskeletons, and endoskeletons. It provides details on the structure and formation of bones and cartilage.
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Lecture 2 support and protection 2nd sem 2008-2009
- 1. Lecture 2. Supportand Protection
- 2. Integumentary System Functions: 1. protectivewrapping – mechanical protection against abrasion and puncture – effective barrier against bacteria – moisture proofing against fluid loss or gain – protect underlying cells against UV 2. regulatory function – temperature regulation
- 3. Integumentary System Functions: 3. informationgetting – sensory receptors 4. excretory function 5. respiratory function 6. survival 7. behavioral interactions between individuals
- 4. Invertebrate Integument 1. Plasmamembrane – unicellular protozoa – gas exchange and waste removal by simple diffusion – uptake of dissolved nutrients Amoeba Paramecium
- 5. Pellicle – thick protein coat found in other protozoa – offers further environmental protection – semi-rigid structure that transmits the force of cilia or flagella to the entire body as the animal moves
- 6. Invertebrate Integument 2. Epidermis – in most multicellular invertebrates – single layer of columnar epithelial cells – some invertebrates have cuticle over the epidermis – delicate and soft in molluscs and contain mucous glands, some of which secrete calcium carbonate of the shell
- 7. Mantle –pair of folds formed by the dorsal body wall – outer surface secretes shell
- 8. (nonchitinous complex of protein and lipids) (protein and chitin) – arthropods have the most complex of invertebrate integuments – for protection and skeletal support
- 9. The arthropod cuticlemay be hardened by: 1. calcification – deposition of calcium carbonate in the outer layers of procuticle
- 10. The arthropod cuticlemay be hardened by: 2. sclerotization – protein molecules bond together with stabilizing cross-linkages within and between adjacent lamellae of the procuticle – formation of a highly resistant and insoluble protein, sclerotin
- 11. Molting of arthropods – epidermal cells divide by mitosis – epidermis secretes enzyme to digest procuticle – absorption of digested materials – new epicuticle and procuticle formed – new cuticle is thickened and calcified or sclerotized
- 12. Vertebrate Integument Skin andderivatives
- 13. Vertebrate Integument Skin andderivatives
- 14. Epidermis –stratified squamous epithelium – devoid of blood vessels – cells of the basal part undergo frequent mitosis – as outer layer of cells are displaced upward by new generations of cells beneath, keratinization takes place – cornified cells, highly resistant to abrasion and water diffusion, comprise the outermost stratum corneum
- 16. Dermis –dense connective tissue layer – contains blood vessels, collagenous fibers, nerves, pigment cells, fat cells, and fibroblasts – support, cushion, and nourish the epidermis – macrophages and lymphocytes provide the first line of defense
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- 20. Similarity of structureof integumentary derivatives - all are built of similar combinations of epidermal (keratinized) and dermal components
- 22. Hairs – epidermal growths that function in protection – shaft, root, and follicle – sebaceous glands, arrector pili muscle, and hair root plexus (touch)
- 23. Hairs • Types 1. Underhair • Dense and soft • For insulation 2. Guard hair • Coarse and longer • For protection against wear and to provide coloration
- 24. Nails • plates of highly packed, keratinized cells • protection, scratching, and manipulation • formed by cells in nail bed called the matrix (in area of lunula) • 1 mm / week • eponychium - cuticle
- 25. Skin Glands • Sebaceous (oil) glands – usually connected to hair follicles – fats, cholesterol, proteins, salts, and cell debris – moistens hair and waterproofs skin
- 26. • Sweat (sudoriferous) glands – Eccrine sweat glands • water, salt, wastes • hairless regions, scattered over the body • function is to cool the body – Apocrine sweat glands • larger • associated with hair follicles • more viscous – fatty acids and proteins
- 27. • Ceruminous glands – modified sudoriferous glands – secrete cerumen (ear wax) – Cerumen protects the skin of the ear canal, assists in cleaning and lubrication, and provides protection from bacteria, fungi and insects
- 28. Mammary glands • Secrete milk • Thickening of epidermis
- 29. Animal coloration – vivid and dramatic when serving as important recognition marks or warning coloration – subdued or cryptic when used for camouflage
- 30. 1. Structural color – produced by the physical structure of the surface tissue; tissue reflects certain light wavelengths and eliminates others – phase interference effects of the microscopic structure of feathers A. sunlight B. camera flash – different response depending on the direction or directionality of illumination
- 31. 2. color dueto pigments – Biochromes – pigments produced by chromatophores – reflect light rays – chromatophores or pigment cells: • melanophores/melanocytes (melanin) • xanthophores (carotenoid) • iridophores (crystals of purine → silvery or metallic)
- 33. Skeletal System Functions: Types: – support 1. Hydrostatic skeleton 2. Rigid skeleton – protection – movement – mineral depot – blood synthesis
- 34. 34 1. Hydrostatic Skeleton • Functions – supports body form – provides resistance for the contraction of muscles to act against • Source – some organisms use their fluid-filled gastrovascular cavity – others use their fluid-filled coelom (body cavity)
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- 38. Muscular hydrostats – like hydrostatic skeletons, these work because they are composed of incompressible tissues that remain at constant volume – muscles arranged in complex patterns
- 39. 2. Rigid Skeletons • consist of rigid elements • usually jointed • muscle attachment • 2 principal types – exoskeleton – endoskeleton
- 40. • Exoskeleton - external skeleton – Molluscs - composed of calcium carbonate – Arthropods - composed of chitin – protection and locomotion
- 41. • Endoskeleton - internal skeleton – Echinoderms and vertebrates – mineralized bone and cartilage – support, protection, and reservoir of calcium and phosphorous – grows as the animal grows ü does not limit space for internal organs ü supports greater weight
- 42. Notochord −semirigid supportive axial rod of protochordates and all vertebrate larvae and embryos − composed of large vacuolated cells surrounded by elastic and fibrous sheaths − stiffening device − except in jawless vertebrates, surrounded or replaced by the back bone during embryonic development Lancelet, Branchiostoma
- 43. Cartilage −major skeletal element of some vertebrates − soft, pliable tissue that resists compression − jawless vertebrates and elasmobranchs have purely cartilaginous skeletons Lamprey
- 44. Bone − livingtissue having significant deposits of calcium salts in the extracellular matrix − endochondral or replacement bone − any bone that develops in and replaces cartilage − i.e. long bone − intramembranous bone − any bone that develops without any associated cartilage − i.e. parietal and frontal bones of the face − cancellous or spongy bone − bone composed of thin intersecting lamellae, usually found internal to compact bone − compact bone − bone substance that is dense
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- 47. Bone Growth andRenewal • Cartilage structures in early development act as models for future bones – calcium salts deposited in matrix by cartilage cells and later by osteoblasts – endochondral ossification • Osteoclasts – break down bone – remove worn cells – deposit calcium in the blood – work with osteoblasts to heal broken bones • Role of hormones – somatotropin, calcitonin, parathyroid hormone
- 48. Stages of IntramembranousOssification
- 49. Stages of IntramembranousOssification
- 50. Stages of IntramembranousOssification
- 51. Stages of IntramembranousOssification
- 52. Stages of EndochondralOssification Secondary Articular ossification cartilage center Epiphyseal Spongy Deteriorating blood vessel bone Hyaline cartilage matrix cartilage Spongy Epiphyseal bone plate Primary formation cartilage ossification Medullary center cavity Bone Blood collar vessel of periosteal bud 1 Formation of bone 2 Cavitation collar of the 3 Invasion of around hyaline internal cavities 4 Formation of the hyaline cartilage by the medullary cavity as 5 Ossification of the cartilage within the periosteal bud ossification continues; epiphyses; when model. cartilage and spongy appearance of completed, hyaline model. bone formation. secondary ossification cartilage remains centers in the only in the epiphyses in epiphyseal plates preparation for stage 5. and articular cartilages
- 53. Plan of thevertebrate skeleton • 2 main divisions – axial skeleton (skull, vertebral column, sternum, and ribs) – appendicular skeleton (limbs, fins, wings, pectoral and pelvic girdles)
- 54. Human Skeletal System • Functions – supports and protects the body – permits movement – provides resistive foundation for muscles to act against • Bones store calcium and phosphate ions • Certain bones produce red blood cells
- 55. 55 The Human Skeleton
- 56. 56 The Skull
- 57. Vertebral Column • Vertebral column – supports the head and trunk – protects the spinal cord and roots of spinal nerves • Segments (from superior to inferior) – cervical - neck – thoracic - chest – lumbar - small of back – sacral – sacrum/pelvic
- 58. # of Body Abbreviatio Term Vertebrae Area n Cervical 7 Neck C1 – C7 Thoracic 12 Chest T1 – T12 Lumbar 5 or 6 Low Back L1 – L5 Sacrum 5 (fused) Pelvis S1 – S5 Coccyx 3 Tailbone None
- 59. Rib Cage • Protects the heart and lungs, and assists breathing • Support by the thoracic vertebrae – Twelve pairs of ribs • true ribs – connect directly to sternum – seven pairs • “false” ribs – do not connect directly to sternum – five pairs
- 60. 60 The Rib Cage
- 61. The Appendicular Skeleton • Consists of – the bones within the pectoral and pelvic girdles – the attached limbs • Pectoral girdle – bones of the shoulder – anterior – supports the arms and hands • Pelvic girdle - bones of the pelvis – posterior – supports the legs and feet
- 62. Bones of thePectoral Girdle, the Arm, and the Hand
- 63. Bones of thePelvic Girdle, the Leg, and the Foot
- 64. Classification of Joints •Fibrous Joints (synarthroses) – immovable – between cranial bones, tibia & fibula, radius & ulna
- 65. Classification of Joints •Cartilaginous Joints (amphiarthroses) – slightly movable – between vertebrae
- 66. Classification of Joints •Synovial Joints (diarthroses) – freely movable – bones separated by a cavity – ball and socket, hinge joints