Bio& 241 A&P 1 Unit 2 / Lecture 4

Functional classification of joints (based on degree of movement permitted within the joint) Synarthrosis: Immovable joints a) Sutures = joint between bones in the skull b) Synchondrosis = epiphyseal plate (Hyaline cartilage is eventually replaced by bone) c) Synostosis = epiphyseal line of mature bones Amphiarthrosis: Slightly movable joints a) Syndesmosis = dense fibrous connective tissue located on the distal or proximal portion of long bones   (eg. distal tibia and fibula (fibular groove), also distal radius and ulna (ulnar notch) - held by ligaments b) Symphysis = cartilaginous joint (fibrocartilage) (eg. pubic symphysis and intervertebral discs)

Functional classification of joints (based on degree of movement permitted within the joint) Diarthrosis: Freely movable joints c) synovial joints: have a space between the bones called a synovial joint cavity, containing synovial fluid. The joint also has articular cartilage.   All diarthrosic joints are structurally synovial

Synarthrosis: immovable joints Suture

Synarthrosis: immovable joints Synchondrosis

Amphiarthrosis: Slightly movable joints Symphysis

Amphiarthrosis: Slightly movable joints Syndesmosis

Synarthrosis or Amphiarthrosis? Gomphosis Unique junction between your teeth and where tooth fits into cavity, periotial ligaments,

Diarthrosis: freely movable joints

Structural classification of joints (based on the presence or lack of a joint cavity and fibrous connective tissue type) Fibrous Joints NO joint cavity. Fibrous CT hold bones together. Cartilaginous Joints NO joint cavity. Cartilage connects bones together Synovial Joints HAVE a joint cavity, containing synovial fluid, and ligaments which provide extra support. Cartilage is also present. Now what material holds joints together

Fibrous joints Synthartotic and ampharartic

Cartilaginous Joints Synchondroses: Epiphyseal plate First Rib and Manubrium Symphyses: Pubic symphysis Synchondroses – hyaline cartilage

Synchondrosis Important for respiration – muscles pull rib 1 open to breathe

Symphysis

Synovial Joints Joint capsule (synovial capsule) is covered by synovial membrane

70% of knee injuries involve stretching or tearing the ACL

Bursa – pockets of synovial fluid Several bursa on knee to help with friction Kneecap – skin and bursa – prepatellar bursa

Types of joints in body Joints are designed to provide range of motion Some give one or more ranges of motion (1-3) See one arrow, one range of motion = uniaxial joint Planar joints – flat pieces of bone – ex: foot flex, navicular and cuneiforms/pharanx – gliding motion Hinge joint- knee and elbow – flexation and extension – deep recess in one bone/notch and a trochlea/surface surface of other bone – bones define range of motion Two arrows, biaxial joint Ball and socket, three arrows = triaxial joint As joint becomes round ball head fitting in a socket, increases range of motion

Pronate or supinate arm – pivot joint Condyloid joint- curved surface sits in curved depression -

Pronate or supinate arm – pivot joint Condyloid joint- curved surface sits in curved depression -

Saddle joint – deeper depression and more pronounced process than condyoid joint ex: thumb joint – allows for two actions Ball and socket – hip is best designed ex – deep socket (acetabulum) and head of femur Use soft tissue to create socket for fitting -flexation/extention, abd/adduction, and rotation

or Plane

or Condyloid