Chapter 9: Joints Flashcards
Define articulation (arthorsisi)
A joint - point of contact between two bones, between bone and cartilage, or between bone and teeth
Classify joints based on structure and function
Structural (3): presence of a space (synovial cavity)
1. Fibrous: no synovial cavity bound by dense connective tissue rich in collagen
- Cartilangous: no synovial cavity bound by cartilage
- Synovial: has a synovial cavity
Functional (3): relates to degree of movement
- Synarthorsis: immoveable
- Amphiarthoris: slightly moveable
- Diarthrosis: freely moveable
Describe the structure and function of the 3 types of fibrous joints
Suture
Syndesmoses
Interosserous membrane
Suture : occurs only between bones in the skull
Syndesmoses: greater distance between articulating surfaces and more connective tissue than a suture (limited movement)
Interosserous membrane: substantial sheet of connective tissue that binds neighbouring bone bones (ex. between diaphysis of fibula and tibia)
Define synostosis and frontal/metopic structure
A suture of a bony joint tin which there is a complete fusion of 2 separate bones into one
If fusion of bones persists past 6yrs it is known as a frontal/metopic structure
A gomphosis (denotalveolar joint) in which a cone-shaped peg fits into a socked is an example of a _________
syndesmosis joint
Describe the structure and functions of the 2 types of cartilaginous joints
Synchondrosis
Symphysis
Synchondrosis: connecting material is hyaline cartilage (Ex. growth plate)
Symphysis: ends of articulating bones are covered with hyaline cartilage but a broad, flat disc of fibrocartilage connects the bones
(occurs in all bones in midline of the body)
Describe synovial joints and the following components:
Articular capsule Synovial fluid Extracapsular and intracapsular ligaments Articular disc Labrum
Synovial joints are diarthrothsis that are covered in articular cartilage that makes the surfaces slippery but does not bind them
Articular capsule: surrounds synovial joint/cavity and unites the articulating bones. Comprised of 2 layers:
1. Fibrous membrane (outer): consist of irregular connective tissue and sometimes arranged in bundles called ligaments to provide flexibility/strength
- Synovial membrane (inner): areolar connective tissue that accumulates adipose tissue called articular fat pads
Synovial fluid: clear/pale-yelow fluid consists inf hyalurionic acid and ISF that lubcricates the joints and absorbs shocks, and supplies nutrients
Extracapsular (outside capsule) and intracapsular ligaments (within capsule)
Articular disc (not all joints): bind strongly to inside of fibrous membrane and subdivide the cavity, allowing for seperate movements
Labrum: prominent in ball-and-socket joints, helps deepen the socket and increases area of contact
How are synovial joints supplied with blood and nerves?
Although many components are avascular surrounding arteries send out branches that penetrate the ligaments and articular capsule
Bursae vs. Tendon sheaths
Bursae: sac-like structures that alleviate friction as they are filled with fluid that cushions movement
Tendon sheath: tube-like bursae that wrap around tends that experience friction to protect them as they slide back and forth
What are gliding movements?
Nearly flat bone surfaces move back and forth and side to side
What are angular movements?
There is an increase or decrease in angle
Flexion (decrease angle) Extension (restore angle) Hypertension (increase angle) Abuduction (away from midline) Adduction (towards midline) Circumduction (circular): continuous sequence of flexion, abductions, extension, adduction, and rotation of the joint
What are rotation movements?
Bone revolves around its own longitudinal axis
Medial: rotation is turned inwards
Lateral: rotation is turned outwards
Describe the following movements:
Elevation
Depression
Elevation: superior movement of a body part (closing mouth)
Depression: inferior movement of a body part (opening mouth)
Describe the following movements:
Protraction
Retraction
Protraction: anterior movement of body in transverse plane (thrusting jaw forward)
Retraction : posterior movement of body in transverse plane (returning jaw)
Describe the following movements:
Inversion
Eversion
Inversion: Medial movement of sole
Eversion: Lateral movement of sole
(think of rolling your ankle in heels)
Describe the following movements:
Dorsiflexion
Plantar flexion
Dorsiflexion: flexing foot
Plantar flexion: pointing foot
Describe the following movements:
Supination
Pronation
Supination : palms up
Pronation: palms down
Describe the following movements:
Opposition
Movement of thumb across palm to touch fingers
Describe the 6 types of synovial joints:
Plane Hinge Pivot Condyloid Saddle Ball-and-socket
Plane: back and forth or side to side on flat surfaces (blocks moving back and forth) - biaxial or triaxial
Hinge: opening/closing motion (doors) - unaxial
Pivot: think of a turning pole - uniaxial
Condyloid: convex oval shape bone fits into a depression (biaxial)
Saddle: biaxial
Ball-and-socket: triaxial
Define the knee joint
aka tibofermoral joint is the larger and complex joint of the body: it is a modified hinge joint that conceits of 3 joints within 1 synovial cavity:
- Laterally is a tibofemoral joint between lateral condyle of femur, lateral meniscus, and lateral condyle of tibia
- Medially is another tibofemoral joint between medial condyle of femur, medial meniscus, and medial condyle of tibia
- Intermediate patellofermoral joint between the patella and patellar surface of femur
Describe the anatomical components of the knee joint:
Articular capsule Patellar ligament Tibial collateral ligament Fibular collateral ligament ACL PCL Medial & lateral miniscus
Articular capsule
Patellar ligament: continuation of common tendon that extends from patella to tibial tuberosity
Tibial collateral ligament: flat ligaments of medial surface that attached to medial meniscus
Fibular collateral ligament : rounded ligament on lateral surface that attaches to fibula
ACL: limits hyperextension of prevents anterior sluing of the tibia and femur
PCL: prevents posterior sliding of the tibia when knee is flexed (important for walking down inclines)
Medial (c-shaped fibrocartilage) & lateral (O-shaped fribocartlilage) miniscus: attached to tibia
Rheumatism
Any painful disorder of the supporting structures of the body – bones, ligaments, tendons, or muscle – that is not caused by infection of injury
Arthritis is a form of rheumatism in which joints are swollen, stiff, and painful
Osteoartritis
degenerative joint disease in which joint cartilage is gradually lost restricting movement
Most common arthritis referred to as ‘wear-and-tear’
Progressive disorder of synovial joints
Rheumatoid arthritis (RA)
autoimmune disease in which the immune system attacks cartilage and joint linings
Attacks small joints first
Gouty arthritis
sodium urate crystals are deposited in the soft tissues of the joint especially the joints of the feet and base of big toe
Lyme disease
a bacteria transmitted mainly by deer ticks that typically causes a bulls-eye target rash -Other symptoms include joint stiffness, nausea, and low back pain
