Ch.7: Comprehensive Joints and Synovial Fluid: Anatomy, Types, and Movements

What is a joint?

A joint, or articulation, is a point of contact between two bones, cartilage and bone, or teeth and bones.

What is the study of joints called?

Arthrology.

What is the study of motion in the human body called?

Kinesiology.

What are the main symptoms of arthritis?

Joint pain and stiffness.

What are the two most common types of arthritis?

Osteoarthritis and rheumatoid arthritis.

What factors determine movement at joints?

The shape of the articulating bones, the flexibility of ligaments, and the tension of associated muscles and tendons.

How does the hormone relaxin affect joints during pregnancy?

It increases the flexibility of the fibrocartilage and loosens ligaments, aiding in childbirth.

What are the three functional classifications of joints?

Synarthrosis (immovable), amphiarthrosis (slightly movable), and diarthrosis (freely movable).

What is a synovial joint?

A joint with a synovial cavity that allows for free movement.

What is the role of articular cartilage in synovial joints?

It reduces friction between bones and absorbs shock.

What is the structure of the articular capsule in synovial joints?

It consists of an outer fibrous membrane and an inner synovial membrane.

What is the function of synovial fluid?

To lubricate the joint, supply nutrients, and remove metabolic wastes from articular cartilage.

What happens to synovial fluid viscosity with joint movement?

It becomes less viscous as movement increases.

What is the purpose of warming up before exercise in relation to joints?

It stimulates the production and secretion of synovial fluid, reducing stress on the joint.

What are bursae in relation to synovial joints?

Sacs that help reduce friction in some synovial joints.

What is the significance of joint structure in terms of strength and flexibility?

Stronger joints are typically immovable, while flexible joints allow greater movement but are less strong.

What is the relationship between joint fit and movement?

Tightly fitted joints are stronger but allow less movement; loosely fitted joints allow more movement but are prone to dislocation.

What type of connective tissue is the synovial membrane made of?

Areolar connective tissue with elastic fibers.

What are articular fat pads?

Accumulations of adipose tissue in the synovial membrane.

What is the role of ligaments in synovial joints?

To hold bones close together and provide stability.

What is the plural of synarthrosis?

Synarthroses.

What is the plural of amphiarthrosis?

Amphiarthroses.

What is the plural of diarthrosis?

Diarthroses.

What type of cartilage covers the bones in a synovial joint?

Hyaline cartilage.

What is the significance of the synovial cavity?

It allows for free movement of the joint.

What can cause the cracking sounds in joints?

The formation of bubbles in synovial fluid due to changes in pressure.

What is the function of the suction in the synovial membrane?

It draws carbon dioxide and oxygen out of blood vessels, forming bubbles in the fluid.

What sound is produced when bubbles in synovial fluid burst?

A cracking or popping sound.

What are accessory ligaments?

Ligaments that lie outside and inside the articular capsule of synovial joints.

Name two examples of accessory ligaments outside the articular capsule.

Fibular (lateral) and tibial (medial) collateral ligaments of the knee joint.

What are articular discs or menisci?

Pads of fibrocartilage inside some synovial joints that help stabilize the joint and direct synovial fluid.

What is the purpose of bursae in synovial joints?

To reduce friction between moving parts.

What is bursitis?

An inflammation of a bursa, often caused by trauma, infection, or excessive joint exertion.

What are the symptoms of bursitis?

Pain, swelling, tenderness, and limited movement.

What does the term 'range of motion' (ROM) refer to?

The range through which the bones of a joint can be moved, measured in degrees.

List the four main categories of movements at synovial joints.

Gliding, angular movements, rotation, and special movements.

How many subtypes are there for synovial joints?

Six subtypes: plane, hinge, pivot, condyloid, saddle, and ball-and-socket joints.

What is a plane joint?

A common type of synovial joint between flat or nearly flat articulating surfaces.

What type of movements do plane joints allow?

Side-to-side gliding movements.

Give an example of a plane joint.

Intercarpal (wrist) or intertarsal (ankle) joints.

What characterizes a hinge joint?

The convex surface of one bone fits into the concave surface of another bone.

What movements are primarily associated with hinge joints?

Flexion, extension, and hyperextension.

Name an example of a hinge joint.

Knee, elbow, or ankle.

What is the role of the anterior cruciate ligament (ACL)?

It limits hyperextension of the knee and prevents anterior sliding of the tibia on the femur.

What is the significance of the posterior cruciate ligament (PCL)?

It prevents the posterior sliding of the tibia on the femur.

What is arthralgia?

Pain in a joint.

What is a bursectomy?

The surgical removal of a bursa.

What does chondritis refer to?

Inflammation of cartilage.

What is dislocation?

The displacement of a bone from a joint with tearing of ligaments, tendons, and articular capsules.

What is a subluxation?

A partial or incomplete dislocation.

What is synovitis?

Inflammation of a synovial membrane in a joint.

What are the menisci in the knee joint?

Fibrocartilage discs that help compensate for the irregular shapes of the articulating bones and circulate synovial fluid.

What are the two types of menisci in the knee joint?

Medial meniscus (semicircular) and lateral meniscus (nearly circular).

What is the function of the transverse ligament of the knee?

It connects the medial and lateral menisci.

What is hyperextension?

Abnormal or excessive extension of a joint beyond its normal range of motion, often resulting in injury.

What is hyperflexion?

Excessive flexion at a joint.

What is inversion in terms of foot movement?

Movement of the soles of the feet medially.

What is eversion in terms of foot movement?

Movement of the soles of the feet laterally.

What is dorsiflexion?

Lifting the toes towards the shin.

What is plantar flexion?

Pointing the toes downward.

What condition causes pain along the bottom of the foot and particularly the heel?

Plantar fasciitis.

What are common predisposing factors for plantar fasciitis?

Flat feet, high arches, wearing high heels, and prolonged standing or weight bearing.

What is a pivot joint?

A freely movable joint that allows only rotary movement around a single/long axis.

What is an example of a pivot joint?

The atlas-axis joint, which allows the head to turn side to side.

What is a condyloid joint?

A modified ball-and-socket joint where an oval-shaped projection fits into an oval depression.

What movements are allowed by a condyloid joint?

Flexion, extension, abduction, adduction, and circumduction.

What is a saddle joint?

A joint where one bone is saddle-shaped and the second bone 'sits' in the saddle, allowing 360° motion.

What is opposition in relation to thumb movement?

The movement of the thumb across the palm to touch the tips of the fingers on the same hand.

What is a ball and socket joint?

A joint where a ball-shaped bone fits into a cuplike depression, allowing motion around multiple axes.

What are the main movements allowed by ball and socket joints?

Flexion, extension, abduction, adduction, circumduction, and rotation.

What is elevation in terms of body movement?

Lifting a body part superiorly, such as shrugging the shoulders.

What is depression in terms of body movement?

Moving a body part inferiorly, such as opening the jaw.

What is protraction?

Non-angular anterior movement in a transverse plane, such as jutting the jaw out.

What is retraction?

Non-angular posterior movement in a transverse plane, such as bringing the jaw back.

What is Temporomandibular Joint Syndrome (TMJ)?

A condition that connects the lower jaw to the skull, causing headaches and jaw pain.

What are common symptoms of TMJ?

Headaches, pain in the jaw, ears, eyes, neck, and shoulder.

What are some causes of TMJ?

Injury to the teeth or jaw, misalignment, teeth grinding, stress, and arthritis.

What is chondroitin sulfate?

An important structural component of cartilage that provides resistance to compression.

What is glucosamine?

A natural compound found in cartilage that cushions joints, often used as a dietary supplement.

What condition is characterized by severe pain and swelling in joints due to uric acid crystallization?

Gout.

What is a common first-line treatment for chronic gout?

Allopurinol, which lowers uric acid production.