1 / 52

Skeletal Systems

Skeletal Systems. How do animals move? Passive Active: Locomotion swimming Terrestrial Flying Efficiency of each. Functions of Skeletal System Three types of skeletal systems Hydrostatic Exoskeleton Endoskeleton Invertebrates (echinoderms) Vertebrates (vertebrates).

rollin
Download Presentation

Skeletal Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Skeletal Systems

  2. How do animals move? • Passive • Active: • Locomotion • swimming • Terrestrial • Flying • Efficiency of each

  3. Functions of Skeletal System • Three types of skeletal systems • Hydrostatic • Exoskeleton • Endoskeleton • Invertebrates (echinoderms) • Vertebrates (vertebrates)

  4. Functions of Skeletal System • Protection • Support • Reservoir of minerals – esp. Ca and P • Framework against which muscles operate

  5. Exoskeletons • Calcium carbonate • mollusks • Chitin • Polysaccharride of modified glucose molecules • Leathery  stiff with Calcium carbonate • Water impermeable • Varies in thickness • Secretion of epith. Cells • Requires molting – ecdysis – during growth • arthropods

  6. Endoskeletons • Spicules bound by protein filaments • Echidoderms • Bone and/or cartilage

  7. Two Types of Osseous Tissue • 1. Compact bone • Osteon – Basic unit • 2. Spongy Bone • Trabeculae provide bracing effect • Red Marrow produces blood cells

  8. Osteon – Compact Bone Canaliculi Concentric lamellae Central canals Osteon Lacunae Light micrograph of an osteons

  9. The Skeletal System • Axial Skeleton • 80 bones • skull, hyoid, vertebrae, ribs, sternum, ear ossicles • Appendicular Skeleton • 126 bones • upper & lower limbs and pelvic & pectoral girdles

  10. Types of Bones – Shape General Characteristics, Examples • Long Bone • Flat Bone • Sutural Bones • Irregular Bone • Short Bone • Sesamoid Bone

  11. Anatomy of a long bone: Diaphysis Epiphysis Metaphysis epiphyseal plate/line Periosteum Medullary cavity endosteum

  12. Joint capsule Cellular layer of periosteum Cellular layer of periosteum Fibrous layer of periosteum Fibrous layer of periosteum Compact bone Endosteum • Periosteum: - 2 layers: • Outer (fibrous) • inner (cellular) • Collagen fibers continuous with: • Bone • adjacent joint capsules • tendons and ligaments

  13. Trabeculae of Spongy Bone • oriented along lines of stress - Latticework • Harbor and protect red marrow ( blood cells develop) • Ends of long bones + inside flat bones No true Osteons.

  14. Cells of Osseous Tissue • Develop/repair from cartilage, respond to stress, hormonal changes • Cells: • Osteocytes = mature bone cells – in lacunae • Osteoblasts: build – create osteoid during osteogenesis • Osteoprogenitor cells  osteoblasts • Osteoclast – breakdown bone – osteolysis • Hormonal regulation

  15. Rickets and Osteomalacia • Disorders resulting in abnormal/poor ossification • Rickets: (Children) • Vitamin D deficiency • Bowed limbs • Pain • Limbs easily broken • Osteomalacia • Failure of adult bone to ossify • hip fractures are common • most common in elderly SE Asian

  16. Bone Development – Two Ways: 1) Intramembrannous – bone formed between sheets of connective tissue as skull bones 2) Endochondral – formed from hayaline cartilage model – long bones

  17. Intramembranous Bone FormationFlat Bone

  18. Long Bone Growth • Epiphyseal growth – increases in length • Appositional Growth – increase in diameter

  19. Bone Growth in Width • Only by appositional growth at the bone’s surface • Periosteal cells differentiate into osteoblasts and form bony ridges and then a tunnel around periosteal blood vessel. • Concentric lamellae fill in the tunnel to form an osteon.

  20. Bone Growth in Length • Epiphyseal plate or cartilage growth plate • cartilage cells are produced by mitosis on epiphyseal side of plate • cartilage cells are destroyed and replaced by bone on diaphyseal side of plate • Between ages 18 to 25, epiphyseal plates close. • cartilage cells stop dividing and bone replaces the cartilage (epiphyseal line) • Growth Hormone controls activity of cells involved • Growth in length stops at age 25

  21. Factors Affecting Bone Growth • Nutrition • adequate levels of minerals and vitamins • calcium and phosphorus for bone growth • vitamin C for collagen formation • vitamins K and B12 for protein synthesis • Sufficient levels of specific hormones • during childhood need insulinlike growth factor • promotes cell division at epiphyseal plate • need hGH (growth), thyroid (T3 &T4) and insulin • sex steroids at puberty • growth spurt and closure of the epiphyseal growth plate • estrogens promote female changes -- wider pelvis

  22. Bone Repair – Similar to Development

  23. Dynamic Tissue • Remodeling –a continuous process of breakdown and rebuilding • Osteoclasts: break bone down • Osteoblasts: replacement of bone • continues through adult life • distal femur is fully remodeled every 4 months

  24. Sagittal suture Parietal bone Anterior fontanel LE 6-18c Coronal suture Frontal suture Frontal bone Frontal suture Anterior/superior view

  25. Spinal Curves Present at Birth Thoracic sacral Develop after birth cervical Lumbar Abnormal Curves Scoliosis Lordosis Kyphosis

  26. 3________ 2________ 1________ 6-33

  27. Intervetebral Discs: • Absorb vertical shock • Limited movement - • Fibrocartilagenous ring / pulpy center • Vertebral Canal • Interconnected vertebral foramina • Intervetebral Foramina • Passage for spinal nerves

  28. Pectoral Girdle • Articulates with humerus • Where is the only direct articulation between pectoral girdle and axial skeleton? • Characteristics: • High mobility – low stability: elevation, depression, Also – retraction, protraction • Secured to axial skeleton via ligaments, muscles

  29. Pelvic Girdle • Paired ossa coxae (singular: os coxae) • Composite bone: ilium, ishium and pubis • Join at pubic symphisis • Male versus female – easily observed –

  30. Pelvic brim: bony edge of true pelvis • Pelvic inlet: an opening enclosed by pelvic brim • Pelvic outlet: circumference bounded by coccyx, ischial tuberosities, inferior pubic symphysis • Perenium: region of pelvic outlet in life – reinforced by muscles in life

  31. Joints: • Arthrology – Study of Joints • Kinesiology = study of motion

  32. Arthrology- Classification of Joints In Two Ways 1. Structural classification based upon: • presence of space between bones • type of connective tissue holding bones together • Fibrous: fibrous connective tissue • Cartilaginous: fibrous or hyaline cartilage • Both are Synarthrosis or amphiarthrosis –offer no or little movement • Synovial • Diarthrosis = free movement 2. Functional classification based upon movement: • immovable = synarthrosis • slightly movable = amphiarthrosis • freely movable = diarthrosis

  33. Synovial Joints • Synovial cavity separates articulating bones • Freely moveable (diarthroses)

  34. Features of Synovial Joints • Articular cartilage at ends of bone • Articular capsule encloses joint • Thickenings  ligaments • Synovial membrane lines capsule • Synovial Fluid lubrication, nourishment, shock absorption • Accessory ligaments within and outside joint capsule • Articular discs or menisci at edges of capsule improve fit and stabilize joint • Bursae = saclike structures reduce friction – ‘ball bearings’

  35. Articular Cartilage • Jelly-like, water squeezes out under pressure • Provides lubrication in joint – but how? • Microscopic dimples may help • dynamics of cartilage coupled with construction of joint play a part • Attacked/broken down  arthritis

  36. Arthritis • Inflammation of a joint - + 100 kinds • Osteoarthritis – degeneration of joint surfaces due to wear • Rheumatoid arthritis – inflammation of synovial membrane due to autoimmune disease • Drugs (Ibuprofen, Celebrex, Vioxx) – inhibit prostaglandins which trigger inflammation

  37. Types and Complexity of Motion

  38. Types and Complexity of Motion • Linear motion – gliding • Monaxial • Biaxial • Angular motion • Angle between shaft and surface changes • Monaxial – hinge joint • Biaxial – saddle joint • Triaxial - ball and socket joint • Rotation • Spinning of shaft on longitudinal axis – atlas and axis,

  39. Flexion, Extension & Hyperextension Tortora & Grabowski 9/e 2000 JWS

  40. Abduction and Adduction Condyloid joints Ball and Socket joints Tortora & Grabowski 9/e 2000 JWS

  41. Circumduction • Movement of a distal end of a body part in a circle • Combination of flexion, extension, adduction and abduction • Occurs at ball and socket, saddle and condyloid joints Tortora & Grabowski 9/e 2000 JWS

  42. Rotation • Bone revolves around its own longitudinal axis • medial rotation is turning of anterior surface in towards the midline • lateral rotation is turning of anterior surface away from the midline • At ball & socket and pivot type joints

More Related