INTRODUCTION To The SKELETONGeneral Features- bones and articulations (joints)Bone- organ of the skeletal system that is mostly bone tissue and includes connective tissue, cartilage and blood vesselsBone types (5.11)Introduction to SKELETON page2Development and GrowthArticulations- joint (2 or more bones are joined)Movement at articulations (8.3)INTRODUCTION To The SKELETONGeneral Features- bones and articulations (joints) Bone- organ of the skeletal system that is mostly bone tissue and includes connective tissue, cartilage and blood vessels Compact= dense, solid, usually forms the outer walls of the boneSpongy= cancellous, lighter, springier, often found on the inside of the bonesBone types (5.11)long- much longer than they are wide, cavity that contains marrow, arm and leg bones, hand and finger and toe bonesshort- as short or shorter than they are in diameter, blocky, cube shaped, wrist and ankle bones, generally have no marrow cavity flat- thin parallel faces of compact bone, roof bones of the skull, ribs, shoulder bladeirregular- variety of shapes, vertebrae - pneumatized- contain sinuses, face bones, air spaces in bonesesamoid- bones that form in tendons or ligaments, patellaBone markings (5.12) process- any projection or bump on a bone, muscle attachment sites or parts of jointscrest- prominent ridgeline- low ridge, where a muscle attaches (ridges on hip and skull) foramen/a- hole in a bonetubercle- small rounded process on a bonetuberosity- larger process that is irregular and roughened fossa- spoon-shaped depressionhead- large smooth round knob at the end of a bone (part of a joint) Long Bone Terminology (5.3) diaphysis- shaft of a long boneepiphysis- knob like structure at the end epiphyseal plate or disc = metaphysis- border between diaphysis and epiphysis articular cartilage- covers the end of the epiphysis, part of an articulation or jointperiosteum (5.10) - sleeve of dense irregular conn. tiss. on outside of a bonemedullary cavity- hollowed space in diaphysis spongy & compact bone- epiphysis has some compact bone but it is filled with spongy boneIntroduction to SKELETON page2Development and Growthendochondral (cartilaginous)- “in cartilage” 1. Cartilage Model- cartilage structure where a bone will form 2. Primary Ossification (5.7)- spongy bone forming in the diaphysis= forms compact bone on the inside and spongy bone in a hollow cavity in the middle(bone grows big-ger)3. Secondary Ossification-spongy bone forms in the interior of the epiphysis and compact bone forming on the outside 4. Growth- metaphysis stays as cartilage growth in length and in diameter; grow in length= race between cartilage growth + bone replacement5. Maturation- cartilage slows, bone speeds up- bone replaces all cartilage- epiphyseal linemembranous (intramembranous= dermal; skull roof bone and lower jaw) 1. Thick connective tissue membrane 2. Middle of the Thickness- spongy bone forms= growth in thickness3. Upper and lower surfaces of spongy bone form compact bone “maturation”- long bones have all the cartilage replaced by mid teens and pelvic bones grow until mid to late 20s Articulations- joint (2 or more bones are joined) synovial (freely moveable joints) (8.1)- sleeve of membrane called the synovial membrane surrounds it and secretes synovial fluid that lubricates the jointType of Movement:ball-and-socket (8.6)-shoulder and hip joint; spherical knob fits into a spherical socket, provides the most freedom of movement, movement in two planes + rotationcondyloid/condylar = ellipsoid- oval knob in an oval socket, angular movement in two planes but no rotation; base of the finger and wrist bones and radius and jawhinge- only allows bending in one direction, knee joint gliding- flat or nearly flat surfaces that can slide; sternum and the clavicle fibrous(non synovial)- limited movement (skull) amphiarthrosis= slightly moveable; inter vertebrae disks of the backboneSuture= immovable joints- synarthroses Movement at articulations (8.3)⎡flexion- movement in the anterior/posterior plane that reduces the angle between articulating elements ⎡extension- increases the angle between articulating elements Ex. Flexion would be curling your arm up and extension would be putting it back down⎡adduction- movement toward the body ex. moving the upper limb back to the side⎡abduction- movement away from the longitudinal axis of the body in the frontal plane ex. swinging the upper limb away from the side rotation