Chapter 9 Flashcards
articulations
where two bones meet
joint classification
joints can be classified according to both structure and function
synarthroses
immovable joints
amphiarthroses
slightly movable joints
diarthroses
freely movable joints
structural classification
based on the binding material between the bones, and whether or not a joint cavity is present (fibrous, cartilaginous, synovial)
fibrous joints
bones are connected by fibrous tissue
no joint cavity
most are synarthrotic
suture (type of fibrous joint)
between bones of the skull
syndesmoses (type of fibrous joint)
bones are connected by ligaments (longer than those in sutures)
some are synarthrotic, while others are amphiarthrotic
gomphoses (type of fibrous joint)
between teeth and their sockets
cartilaginous joints
bones are united by cartilage
no joint cavity
most are amphiarthrotic (a few are synarthrotic)
synchondroses (type of cartilage joints)
bones are united by hyaline cartilage
examples: the epiphyseal plates of long bones, and the joint between the first rib’s costal cartilage and the manubrium of the sternum
typically are synarthrotic
symphyses(type of cartilage joints)
bones are united by fibrocartilage
amphiarthrotic
examples: intervertebral discs and the pubic symphysis
synovial joints
the most movable joints (all are diarthrotic)
have a joint cavity
includes most of the joints in the body (all of the joints in the limbs)
articular cartilage (structure of synovial joint)
hyaline cartilage covering the ends of bones
joint (synovial) cavity (structure of synovial joint)
space around the joints
articular capsule (structure of synovial joint)
two-layered capsule that surrounds the joint cavity (outer fibrous capsule and inner synovial membrane)
synovial fluid (structure of synovial joint)
reduces friction in the joints
reinforcing ligaments (structure of synovial joint)
serve to support and strengthen some synovial joints
nerves and vessels (structure of synovial joint)
richly applied with nerved and blood
menisci
fibrocartilage discs located in the temporomandibular joints, sternoclavicular joints, and constant, the knees
factors influencing the stability of synovial joints
- shape of the articulating surfaces (shallow joint sockets vs deep sockets (or grooves)
- ligaments (number and position of ligaments
- muscle tone (a constant low level, of contractile force generated by a muscle even when it is not causing movement (especially important in knees and shoulders)
bursae and tendon sheaths
- closed sacs of synovial fluid that are associated with synovial joints and some tendons
- serve to reduce friction in areas where there is high abrasion and/or high degrees of mobility
three basic types of movements
gliding, angular, and rotation
gliding
slipping of bone surfaces across each other
angular
changes the angle between two bones
-includes: flexion and extension, abduction, and adduction, and circumduction
look at pictures
understand movements
special movements of synovial joints
supination and pronation dorsiflexion and plantar flexion inversion and eversion protraction and retraction elevation and depression opposition
supination and pronation
movements of the radius and ulna
dorsiflexion and plantar flexion
movements of the foot at the ankle
inversion and eversion
movements of the foot
protraction and retraction
nonangular movements in anterior and posterior directions
elevation and depression
movements of the mandible when chewing
opposition
only occurs in the thumb
synovial joints classified by shape
plane joints, hinge joints, pivot joints, condyloid joints, saddle joints, and ball-and-socket joints
plane joints
allow gliding motions
Examples: intercarpal (wrist) intertarsal (ankle) and intervertebral (not discs)
hinge joints
allow movement in one place (uniaxial)
flexion and extension
Examples: elbows, knees, and interphalangeal joints
pivot joints
allow rotation (uniaxial) Examples: proximal radioulnar joints
condyloid joints
allow movement in two planes (biaxial)
(frontal )abduction and adduction, and flexion and extension (sagittal)
Examples: metacarpophalangeal joints (knuckle) and wrist joints
NO TRANSVERSE PLANE
saddle joints
biaxial joints
the first carpometacarpal joints (base of thumb)
ball-and-socket
allows movement in all three planes (multiaxial)
circumduction (flexion, extension, abduction, and adduction) and rotation
examples: shoulders and hips
joint injuries
sprains, dislocations (luxations) and torn cartilage
sprains
the ligaments reinforcing a joint are stretched or torn
take a long time to heal because of their poor blood supply
dislocations (luxations)
occurs when the bones of a joint are forced out of alignment
the bones must be reduced or returned to their normal position
torn cartilage
especially common in the menisci of the knees
joint arthritis
describes over 100 kinds of inflammatory or degenerative diseases of joints
very commons, especially old people
types of arthritis
osteoarthritis, rheumatoid arthritis, and gouty arthritis
osteoarthritis
chronic degenerative disorder
caused by normal wear-and-tear on a joint
the most common type
affects articular cartilage (hyaline) causing it to soften, fray, crack, and erode
rheumatoid arthritis
chronic inflammatory disorder
autoimmune disease that effects women three times more than men
can lead to joint fusion
gouty arthritis
characterized by a buildup of uric acid crystals in the blood (due to purine metabolism
attacks are periodic and normally manifest themselves in joints of the lower limbs (often at the base of the hallux)
more common in males
may indicate a dietary problem or kidney dysfunction
