Chapter 8 The Joints Part B

Movements allowed by Synovila Joints: Three general types of movement: 1- Gliding Movements A flat bone surface glides (slips) over another surface Examples: Intercarpal joints Intertarsal joints Between the flat articular processes of vertebrae

1- Gliding Movement Figure 8.5a

2- Angular Movement Flexion: Extension: Dorsiflexion: Plantar flexion: Bending movement, joint angle is decreased Extension: Reverse of flexion; joint angle is increased Dorsiflexion: Up movement of the foot Plantar flexion: Down movement of the foot

2- Angular Movement (cont’d): Abduction: Movement away from the midline Adduction: Movement toward the midline Circumduction: A cone-shaped movement in space

Angular Movement Figure 8.5b

Angular Movement Dorsiflexion Plantar flexion Figure 8.5c, d

Angular Movement Figure 8.5e, f

The turning of a bone around its own long axis Examples 3- Rotation The turning of a bone around its own long axis Examples Between the first two vertebrae (atlas & axis) Hip joint Shoulder joint Figure 8.5g

Rotation Figure 8.5e, f

Special Movements Supination: Pronation: Inversion: Eversion: Radius and ulna are parallel Pronation: Radius rotates over ulna Inversion: Sole of the foot turns medially Eversion: Sole of the foot turns faces laterally

Special Movements Figure 8.6a

Special Movements Figure 8.6b

Special Movements (cont’d) Protraction: Jaw (mandible) moved out Retraction: Jaw moved back to original position Elevation: Lifting a body part superiorly Depression: Moving elevated body part inferiorly Opposition: Thumb touches tips of other fingers of same hand

Special Movements Figure 8.6c

Special Movements Figure 8.6d

Special Movements Figure 8.6e

Break Slide Biol2401.5039 Mon, Oct 08/’12

Types & Movement of Synovial Joints Classified according to: The shape of the articular surface Accordingly, there are six types of synovial joints: Plane Hinge Pivot Condyloid Saddle Ball-and-socket Figure 8.7a

Synovial Joints: Plane Joint Plane joints Articular surfaces are essentially flat Allow only slipping or gliding movements Motion is nonaxial Only examples: Intercarpal & Intertarsal Between articular processes of vertebrae (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7a

Synovial Joints: Hinge Joints Cylindrical projection of one bone fits into a trough-shaped surface on another Motion is along a single plane (uniaxial) Uniaxial joints permit flexion and extension only Examples: Elbow joint Interphalangeal joint

Hinge Joints (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7b

Pivot Joints Rounded end of one bone protrudes into a “sleeve,” or ring of another The sleeve or ring is composed of: Bone possibly ligament Only uniaxial rotation movement is allowed (around own long axis) Examples: Joint between the atlas and the axis dens (bony ring) The proximal radioulnar joint (ligament ring)

Pivot Joints (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7c

Condyloid or Ellipsoidal Joints Oval articular surface of one bone fits into an oval complementary depression in another Both articular surfaces are oval Biaxial condoyloid joints permit all angular motions Examples: Radiocarpal (wrist) joints Metacarpophalangeal (knuckle) joints

Condyloid or Ellipsoidal Joints (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7d

Similar to, but allow greater movement than, condyloid joints Saddle Joints Similar to, but allow greater movement than, condyloid joints Each articular surface has: Both concave and convex areas Example: Carpometacarpal joint of the thumb

Saddle Joints (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7e

Ball-and-Socket Joints A spherical or hemispherical head of one bone articulates with a cuplike socket of another Multiaxial joints Permit the most freely movement of synovial joints Examples: Shoulder joint Hip joint

Ball-and-Socket Joints (a) Plane (b) Hinge (c) Pivot (d) Condyloid (e) Saddle (f) Ball-and-(g) socket Figure 8.7f

Largest and most complex joint of the body Synovial Joints: Knee Largest and most complex joint of the body Allows flexion, extension, and some rotation Consists of: Three joints in one, with A single joint cavity These three joints include: Lateral tibiofemoral joint & Medial tibiofemoral joint: Each is between respective femoral condyle above and tibial semilunar cartilage “meniscus” below. Femoropatellar joint (intermediate): Between lower femur end & patella

Synovial Joints: Knee Ligaments & Tendons Knee joint is only partially enclosed by a capsule Capsule is absent anteriorly Instead, there are three patellar ligaments (quadriceps tendon continuations): Patellar ligament Lateral patellar retinaculum Medial patellar retinaculum Fibular and tibial collateral ligaments (femoral epicondyles to tibia condyles, & fuse to menisci) Anterior View Figure 8.8c

(a) Sagittal section through the right knee joint Tendon of quadriceps femoris Femur Suprapatellar bursa Articular capsule Patella Posterior cruciate ligament Subcutaneous prepatellar bursa Synovial cavity Lateral meniscus Lateral meniscus Infrapatellar fat pad Anterior cruciate ligament Deep infrapatellar bursa Tibia Patellar ligament (a) Sagittal section through the right knee joint Figure 8.8a

Synovial Joints: Knee – Other Supporting Structures Cruciate ligaments: Cross each other in the notch between femoral condyles Prevent anterior & posterior displacement of articular surface Run to femur Named after their tibial intercondylar site of attachment as: Anterior cruciate ligament Posterior cruciate ligament Main supporting tendons are those of the: Quadriceps (anteriorly) Semimembranosus (posteriorly)

Synovial Joints: Knee – Other Supporting Structures Figure 8.8b

(b) Superior view of the right tibia in the knee joint, showing Anterior Anterior cruciate ligament Articular cartilage on lateral tibial condyle Articular cartilage on medial tibial condyle Lateral meniscus Medial meniscus Posterior cruciate ligament (b) Superior view of the right tibia in the knee joint, showing the menisci and cruciate ligaments Figure 8.8b

Synovial Joints: Knee – Posterior Superficial View Posterior reinforcement of knee joint: Articular capsule Oblique popliteal ligament: Part of the semi-membranosus tendon fuses with capsule Arcuate popliteal ligament: Arcs from fibula head over popliteus muscle Figure 8.8e