L3 Joints PDF - Mansoura National University

Anatomy of the Joints Dr. Dina Hany & Dr. Mohamed Galal Edited by: Dr. Nora Helal Department of human Anatomy and Embryology Faculty of Medicine Mansoura National University, Egypt  Intended Learning Outcomes (ILOs) 1. Define Joints 2. Contras...

Anatomy of the Joints Dr. Dina Hany & Dr. Mohamed Galal Edited by: Dr. Nora Helal Department of human Anatomy and Embryology Faculty of Medicine Mansoura National University, Egypt  Intended Learning Outcomes (ILOs) 1. Define Joints 2. Contrast between the different types of joints 3. Conclude the factors affecting joint stability 4. State Hilton’s law regarding nerve supply of joints  Agenda 1. What is the definition of joints? 2. What are the different types of joints? 3. What are the factors affecting joint stability? 4. What is Hilton’s law regarding nerve supply of joints?  Definition & Classification Fibrous Joints Definition: Articulation between two or more bones. Classification: 3 types according to the tissue between the bones: Fibrous Joints Cartilaginous Joints Joints Joints Synovial Joints Cartilaginous Joints Synovial Joints  Fibrous joints Characters The articulating bones are connected together by fibrous tissue. Movement No movement or very limited movement. Types o Suture: ▪ Joints between bones of skull. ▪ It ossifies at old age. o Gomphosis: ▪ Between the roots of the teeth & their sockets. o Syndesmosis: ▪ Bones are connected by strong ligaments as: ▪ Inferior tibiofibular joint. ▪ Interosseous membrane between radius & ulna. ▪ Interosseous membrane between tibia & fibula.  Cartilaginous Joints 1st sternocostal Characters The articulating bones are connected together by joint cartilage. Movement No movement or very limited movement. Epiphyseal plate Types A. Primary B. Secondary cartilaginous cartilaginous joints joints Bones connected by Bones connected by Structure hyaline cartilage fibrocartilage Ossify by age Don’t ossify by age Ossification No movement. Limited movement. Movement ▪ 1st sternocostal ▪ Intervertebral disc. Example joint. ▪ Symphysis pubis. ▪ Epiphyseal plate of Intervertebral disc. long bones. Symphysis pubis  Quiz What type of joint is the inferior tibiofibular joint? A) Fibrous gomphosis B) Fibrous syndesmosis C) Fibrous suture D) Primary cartilaginous E) Secondary cartilaginous  Synovial Joints ▪ They are freely mobile joints (allow wide range of movement). ▪ Articular surfaces of bones are covered by thin layer of hyaline cartilage. ▪ The articulating bones are separated by a joint cavity. ▪ The joint is surrounded by a fibrous tissue capsule. ▪ The capsule is thickened in certain parts to form capsular ligaments. ▪ The capsule is strengthened by accessory ligaments. ▪ The capsule is lined by a synovial membrane, which also covers the non-articular parts of the bones. ▪ The synovial membrane secrets synovial fluid, which fills the joint cavity. ▪ synovial fluid has the following functions: o Lubrication and nutrition of articular cartilage. o Allows free movement of the joint.  Synovial Joints ▪ Structures inside some synovial joint: Labrum o Cartilaginous structures: ✓ Disc: as in the temporomandibular joint. ✓ Meniscus: as in the knee joint. ✓ Labrum: as in the hip & shoulder joints. o Ligaments: as cruciate ligaments in knee (ACL, PCL). o Tendon of muscle: as long head of biceps in shoulder joint. long head of biceps  Types of Synovial Joints Synovial joints can be classified according to: Number of Number of Shape of articulating axes of articulating bones movement bones  Types of Synovial Joints According to number of articulating bones Simple Compound Complex 2 articulating bones more than 2 articulating has intra-articular disc or Example: shoulder joint bones menisci Example: elbow joint Example: knee joint  Types of Synovial Joints According to axes of movement Uni-axial Bi-axial Poly-axial Movement occurs in only Movement occurs in two Movement occurs in one axis axes more than two axes  Uni-axial Movement occurs in only one axis Hinge Pivot Axis Transverse (Bilateral) Vertical Movement Flexion & extension Rotation ▪ Superior radioulnar joint. ▪ Elbow joint Examples ▪ Inferior radioulnar joint. ▪ Interphalangeal joints ▪ Atlantoaxial joint. Atlas Axis Elbow joint Interphalangeal joints Atlantoaxial joint  Bi-axial Movement occurs in two axes Movements Example Flexion & Extension. 1. Ellipsoid: Adduction & Wrist. Abduction Flexion & Extension. 2. Bicondylar: Knee. Rotation. Flexion & Extension. Carpometacarpal 3. Saddle: Adduction & joint of thumb Abduction NB: the saddle joint permits small range of rotation  Poly-axial Movement occurs in more than two axes Movements Examples Flexion & Extension ▪ Hip joint. Ball & Abduction & socket Adduction ▪ Shoulder joint. Rotation  Quiz What type of joint is the wrist joint? A) Ellipsoid synovial B) Hinge synovial C) Pivot synovial D) Ball and socket synovial E) Plane synovial  Quiz What type of joint is the shoulder joint? A) Ellipsoid synovial B) Hinge synovial C) Pivot synovial D) Ball and socket synovial E) Plane synovial  Types of Synovial Joints According to shape of articulating bones: Plane joints Hinge joints Pivot joints Bi-condyloid Ellipsoid joints Saddle (condylar) Ball & socket joints  Types of Synovial Joints 1) Plane synovial joints: ▪ Articular surfaces are flat. ▪ Allow gliding movement in any direction. ▪ e.g. Intercarpal & intertarsal joints. 2) Hinge joints: like a door hinge. 3) Pivot: Have a central axis, rotate in a ring. 4) Ellipsoid: have one convex surface fitting into an ellipsoid concavity. 5) Bi-condyloid (condylar): ▪ have two convex surfaces fitting in two concavities. 6) Saddle: Articulating surfaces are alternately concavo-convex. 7) Ball and socket: A rounded head fitting into a cup-shaped concavity.  Joint stability and Nerve supply Factors affecting joint stability: 1. Articulating bones: ✓ Shape. ✓ Size. ✓ Arrangement. 2. Contraction & tone of surrounding muscle. 3. Ligaments: ✓ Strength ✓ Position Nerve supply of joints (Hilton’s law): The nerve supply to a muscle also innervates the joint on which the muscle acts and the skin overlying the muscle.