BSCI201 Exam 3 Notes April 4 th 2015 Structural Classes of Joints 1 Fibrous Joints bones are connected by dense regular CT They lack a joint cavity there is no space between the bones forming the fibrous joints a Sutures located only in the skull i The sutures in skull of baby child are amphiathoric joint slightly movable to allow for expansion and growth at brain to about 3 3 5 lbs in weight 1 When a baby reaches 3 5 lbs the sutures undergo synosrosis whereby the amphiarthoric become synarthrotic joints in the adult a Synarthoric sutures form the cranial vault to protect the brain 10 12 years old b Syndesmoses ii Sutures in children are amphiarthratic joints hydrocephaly increase in cerebrospinal fluid in the ventricles of the brain does not cause brain damage Chord like dense regular CT called ligaments synthrotic Membranous called interosseous membrane amphiarthrotic joint c Gomphoses also known as pegs in sucker joints The root of the tube s set in the alveolar socket in the lower mandible or in the maxilla connected by short ligaments called periodontal ligaments Synorthrotic joints are IMMOVABLE o When the gomphosis becomes amphiatrotic joints diventhrotic joint tooth loss 2 Cartilaginous Joints bones are connected by cartilage and joint cavity is absent 2 types of cartilaginous joints a Syemondroles synarthrotic joints immovable hyaline cartilage connected bones b Symphysis amphiarthoric joints fibrocartilage connect bones i Ex Pubic symphysis c Exam T F know tissues dense regular FALSE d Most common ligament torn ACL 3 Synovial Joints joint cavity is present and contains synovial fluid which acts as a lubricant Synovial fluid is filtered from the blood vessels in the dense irregular connective tissue of the fibrous capsule Joint cavity is enclosed encapsulated by the articular capsule o Articular Capule Outer fiborous capsule dense irregular CT Inner synovial membrane Three types of ligaments reinforcing synovial joints ALL synovial joints are diathrotic joints freely moving The type of movement allowed at synovial joint is dictated by the shape of the articulating surfaces of the bones forming the synovial joint structure defines function a Plane joints b Hinge c Pivot d Condyloid e Saddle f Ball and Socket 1 Capsular 2 Extra capsular 3 Intra capsular April 6 th 2015 Synovial Joints Articular cartilage Articular capsule Joint Cavity Movement of Synovial Joints Gliding slipping movements Flexion movement that decreases the angle of a joint Extension movement that increases the angle of a joint Abduction movement away from the midline Abbuction movement toward the midline Circumduction movement of the limb that describes a cone in space Rotation movement of a bone around an axis Inversion Eversion Shapes of Synovial Joints 1 Plane joints bones appear flat Intercarpals intertarsals a b Gliding movement 2 Hinge trough like structure a Bone 1 Trough b Bone 2 cylindrical projection c Ex Elbow joint d Allows for extension and flexion a Bone 1 rounded protrusion b Bone 2 ring of sleeve c Ex Rodionular joint d Allows for rotation 3 Pivot articulating surface of rounded protrusion and ring or sleeve e Allows us to motion no Atlanto axial joint 4 Condyloid joint articulating surface of oval protrusion and depression a Bone 1 oval protrusion b Bone 2 Oval depression c Ex Metatarsophalangeal d Allows us to motion Yes atlanto occipital joint e Flexion Extension abduction adduction and circumduction 5 Saddle joint each bone has a convex and concave a Bone 1 concave convex b Bone 2 convex concave c Flexion extension abduction adduction circumduction 6 Ball and Socket a Bone 1 spherical head b Bone 2 cup like socket c All movements allowed d Ex shoulder and hip joint Arthritis Osteoarthritis o Localized to joint o Biomechanical leads to the loss of cartilage matrix o Pain stiffness and limited motion o Osteophytes are present o Rheumatoid factors absent Rheumatoid Muscle System 3 Types of muscle as organs organized using the three types of muscle tissues connective wrappings blood vessels and nerve fibers Skeletal Cardiac Smooth o Striation o Multinucleated o Striations o Uni nucleated o No striation o Uni nucleated Skeletal Muscle the organ Consists of skeletal muscle tissues with connective tissue wrappings and blood vessels Skeletal muscle cells are known as skeletal muscle fibers because the cells are elongated Each skeletal muscle fiber is covered by a delicate CT membrane called endomysium A group of endomysium covered muscle fibers wrapped in coarse CT membrane is called the perimysium A group of fascicles wrapped in tough CT membrane is called epimysium Muscle fibers in a skeletal muscle form bundles called fascicles o The muscle fibers in a single fascicle are parallel but the organization of the fascicles in the skeletal muscle can vary parallel convergent pennate and circular Convergent Circular Parallel Pennate Skeletal muscle attach to the skeletal system Each skeletal muscle the organ has 2 attachment sites on bones How does a skeletal muscle attach to the surface of bones Attachment sites for each skeletal muscle Origin the bone that does not move Insertion the bone that moves when the skeletal muscle contracts How does a skeletal muscle attach to the surface of bones Direct attachment the epimysium of the skeletal muscle attaches DIRECTLY to the periosteum of the bones o No tendons present o Ex Abdominal surface Indirect the epimysium of the skeletal muscle is extended by a tendon and the tendon attaches to the periosteum on the surface of the bone NO DIRECT CONTACT between the skeletal muscle and the bone About 99 of all skeletal muscle in the human body are attached to bones indirectly Advantages to indirect attachment of skeletal muscles 1 For efficient attachment of skeletal muscle to bone surfaces Indirect attachment the tendon occupies a smaller surface area on the bone than the entire muscle 2 Tendons are tougher They are dense regular connective tissue hence can withstand pulling forces to protect the skeletal muscles 3 With indirect attachment several skeletal muscles can attach to the same bone to allow for antagonistic and agonistic actions of skeletal muscles Indirect attachment allows for bones to act as levers to coarse movement when skeletal muscle contracts Muscles attached to the bone contract 4 Microscopic Structure of the Skeletal Muscle Fiber to explain contraction of skeletal muscle the organ Myofibrils rod like structures that run the entire length
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