MAP Unit 5: Bones Part 5 - Joints

Fibrous Joints

Joints that lack a synovial cavity and have bones held closely together by fibrous connective tissue.

Fibrous Joint Movement

Permit little or no movement.

Examples of Fibrous Joints

Distal ends of the tibia and fibula, sutures between cranial bones, and teeth in their alveolar sockets.

Synovial Joints

Joints that contain a synovial cavity between the articulating bones.

Articular Cartilage

Hyaline cartilage that covers the ends of articulating bones in synovial joints.

Synovial Capsule

A sleeve-like layer of connective tissue that surrounds a synovial joint.

Fibrous Capsule

The outer layer of the synovial capsule.

Function of the Fibrous Capsule

Attaches to the periosteum of the bone and helps support the joint.

Synovial Membrane

The inner layer of the synovial capsule.

Function of the Synovial Membrane

Secretes synovial fluid to lubricate the joint.

Synovial Fluid

A lubricating fluid that reduces friction inside synovial joints.

Menisci

Pads of fibrocartilage found between the articular surfaces of certain joints.

Function of Menisci

Help bones fit together, maintain joint stability, absorb shock, and direct synovial fluid to areas of greatest friction.

Menisci and Joint Stability

Help maintain the stability of a joint.

Menisci and Shock Absorption

Help absorb shock between articulating bones.

Menisci and Bone Shape

Modify the shape of articulating bone surfaces so different-shaped bones fit together tightly.

Menisci and Synovial Fluid

Direct synovial fluid to areas in the joint where friction is greatest.

Bursae

Sac-like structures that resemble joint capsules and are located within body tissues.

Function of Bursae

Reduce friction between soft tissues and bones and between skin and bones.

Examples of Synovial Joints

Knees, shoulders, wrists, ankles, elbows, and hips.

Cartilaginous Joints

Joints that lack a synovial cavity and have articulating bones held tightly together by cartilage.

Examples of Cartilaginous Joints

The joint between the first rib and sternum and the pubic symphysis in the pelvis.

Fibrous Joints vs. Synovial Joints

Fibrous joints lack a synovial cavity and permit little or no movement; synovial joints have a synovial cavity and allow movement.

Synovial Joints vs. Cartilaginous Joints

Synovial joints have a synovial cavity; cartilaginous joints lack one and are held together by cartilage.

Ligaments

Bands or cords of dense fibrous connective tissue that extend from one bone to another bone.

Function of Ligaments

Connect bone to bone and provide structural stability to joints.

Tendons

Bands or cords of dense fibrous connective tissue that extend from a bone to a muscle for attachment.

Function of Tendons

Attach muscles to bones.

Ligaments vs. Tendons

Ligaments connect bone to bone; tendons connect muscle to bone.

What Connects Bone to Bone?

Ligaments.

What Connects Muscle to Bone?

Tendons.

What Provides Structural Stability to Joints?

Ligaments.

What Reduces Friction Between Soft Tissue and Bone?

Bursae.

What Lubricates Synovial Joints?

Synovial fluid.