HUMAN ANATOMY

Chapter 1 Lecture

ArticulationsThe Skeletal System: Articulations

Articulations

Introduction

• Joints, or articulations, are connections between bones that may or may not permit movement.– Cartilage, fluid, or dense

connective tissues is usually involved in holding joints together.

• Joints maybe classified structurally or functionally

Classification of Articulations - StructuralStructural Classification1) Fibrous – No joint cavity – fibrous tissue

a) Suture – very thin fibrous tissueif fused – synostoses

b) Syndesmosis – broader fibrous tissuefontanel

c) Gomphosis – peg in coneexample: tooth in jaw

2) Cartilaginous – No joint cavity – Cartilagea) Synchondrosis – hyaline cartilage

epiphyseal plateb) Symphysis – fibrocartilage

symphysis pubis and intervertebral disks

3) Synovial – Joint (Synovial) cavitya) Gliding – intertarsalb) Hinge – knee and anklec) Pivot – atlantoaxiald) Condyloid or Ellipsoidal – wriste) Saddle – thumbf) Ball and Socket – should and hip

Classification of Articulations FunctionalFunctional Classification of Joint

1) Synarthroses – Immovable Jointsa) Sutureb) Gompohsisc) Synchondrosis

2) Amphiarthrosis – Slightly movable jointsa) Symphysis – pubic symphysisb) Syndesmosis - tibia and fibula

3) Diarthrosis – Freely movablea) Gliding – glidingb) Hinge – flex and extend (1 plane)c) Pivot – rotation – 1 planed) Condyloid or Ellipsoidal – 2 planes

flex, extend, abduct and adducte) Saddle – – 2 planes

flex, extend, abduct and adductf) Ball and Socket – (3 planes)

flex, extend; abduct adduct; and medial and lateral rotation

Synarthroses (Immovable Joints)

• Sutures are joints found only in the skull.– Bony edges interlock and short dense connective

tissue fiber hold the bones together.

• A gomphosis is the joint between a tooth and the alveolar fossa of the maxillae or mandible.– Periodontal ligaments (PDL) hold the tooth to the

bone in the gomphosis.

• A synchondrosis is a joint in which hyaline cartilage separates the ends of the bones involved in the joint.

• A synostosis occurs if bones fuse together to form one bone.

Amphiarthroses (Slightly Movable Joints)

• A syndesmosis occurs when to bones are connected by relatively long connective tissue ligaments.

• Connecting bones using a fibrocartilage pad forms a symphysis. 

Diarthroses (Freely Movable Joints)

• Synovial joints are typically found at the ends of long bones in the upper and lower limbs.

• All synovial joints have six basic characteristics:– A joint capsule– Articular cartilages– A joint cavity filled with

synovial fluid– A synovial membrane lining

the joint capsule

Figure 8.1 Structure of a Synovial Joint

Synovial Joints

Synovial Fluid

• Synovial fluid has three functions:– Lubricates the surfaces of the articular

cartilages on the ends of the bones.– Nourishes the chondrocytes by entering and

exiting the articular cartilages due to the forces acting on the joint.

– Acts as a shock absorber.

PLAY

Movements

Types of Movements

• Angular movements• Rotation

Special Movements

• Movements at the ankle include:– Eversion/inversion– Dorsiflexion/plantar flexion

• Movement of the vertebral column includes:– Lateral flexion

• Movement of the pollex (thumb):– Opposition/reposition

Special Movements

• Movements that occur at many joints include:– Protraction: anterior movement in the

horizontal plane – Retraction: posterior movement in the

horizontal plane– Elevation: cranial movement in the vertical

axis– Depression: caudal movement in the vertical

axis

PLAY Joint Structure

Structural Classification of Synovial Joints

• Plane joints:  – Nonaxial or multiaxial

• Hinge joints: – flexion and extension

• Pivot joints: – rotational movements

Structural Classification of Synovial Joints

• Condylar joints:– flexion/extension and abduction/adduction

• Saddle joints:– biaxial joints that also allow circumduction

• Ball and socket joints: – triaxial joints

Figure 8.7a,b The Temporomandibular Joint (TMJ)

The Temporomandibular Joint

Figure 8.8a Anterior Vertebral Column Figure 8.8b Lateral Vertebral Column

Intervertebral Articulations

Vertebral Movements

• There are four possible movements of the vertebral column:– Anterior flexion, or bending forward– Extension, or bending backward– Lateral flexion, or bending to the side– Rotation–twisting

Figure 8.10 The Sternoclavicular Joint

The Sternoclavicular Joint

Figure 8.11a The Anterior Shoulder Figure 8.11b The Lateral Shoulder

The Shoulder Joint

Figure 8.11c Sectional Shoulder Figure 8.11d Superior Shoulder

The Shoulder Joint

Figure 8.12a Medial Elbow Figure 8.12d Longitudinal Elbow

The Elbow Joint

Figure 8.13b Wrist Joints Figure 8.13c Wrist Ligaments

The Wrist

Figure 8.13d Joints of the Hand

The Joints of the Hand

Figure 8.14a Lateral Hip Figure 8.14c Posterior Hip

The Hip Joint

Figure 8.14b Anterior Hip Figure 8.15a Sectional Hip

The Hip Joint

Figure 8.16a Anterior Knee Figure 8.16b Parasagittal Knee

The Knee

Figure 8.17a Posterior Superficial Figure 8.17b Posterior Deep

The Knee

Figure 8.17c Anterior Knee

The Knee

Figure 8.18a Ankle and Foot Figure 8.18b Ankle and Foot MRI

The Ankle and Foot