Chapter 8 A and P

2. structural classifications

based on anatomical components that make up the joint

1. Functional classifications

based on the range of motion allowed

circumduction

draw around; conical shape or circular motion

iii. periodontal ligament

fibrous connective tissue between a tooth and its socket

d. dorsiflexion

flexion at the ankle joint and elevation of the sole (as when you dig in your heel)

k. supination

in anatomical position, the forearm is supinated with the radius and ulna lying parallel to each other and the palm facing anteriorly (as when holding a bowl of soup)

D. Bursitis

inflammation of the bursa

F. synovitis

inflammation of the synovial membrane

E. Tendonitis

inflammation of the tendon

A. arthritis

inflammatory or degenerative disease of the joint where synovial membranes thicken (called pannus) and fluid production decreases resulting in friction and pain 1. osteoarthritis 2. rheumatoid arthritis 3. gouty arthritis

ii. synovial membrane

inner soft tissue whose network of capillaries leak plasma from the bloodstream to produce the synovial fluid

Articulations

joints where two bones interconnect -only place where bone movement can occur

4. Joint Capsule

laters of dense fibrous connective tissues that enclose the synovial cavity to house the synovial fluid a. fibrous capsule b. synovial capsule

ii. extrinsic ligament

separate from the joint capsule and may pass outside (extracapsular) or inside (intracapsular) the joint capsule

rotation

turning movement of a bone around its own axis

iii. gomphosis

"peg-in-socket" -found on maxilla and mandible where teeth are fixe securely in sockets of alveolar margins -fibrous;synarthrotic

1. Joint Cavity

(Synovial Cavity) -space between articulating bones

i. intrinsic ligament

(capsular ligament) -parallel bundles of fibers creating thickenings within the joint capsule

1. Osteoarthritis

(degenerative arthritis; degenerative joint disease) -generally affects individuals 60+ -can result from cumulative effects of wear and tear on the joint surfaces or from genetic factors affecting collagen formation -in US pop, 25% of woman and 15% of men over 60 show signs of this condition -(from everyday wear and tear)

condyloid joints

(ellipsoid joint) -oval articular surface of one bone fits into a complementary depression in another -biaxial -(matacarpophalanges 2-5(knuckles), radioocarpal joints, and metatarsophalangeal joints

iv. Syndesmosis

-bones connected by interosseous ligaments -ex: between tibia and fibular (tibiolfibular joint) -Fibrous; Amphiarthrotic

plane joints

(gliding joints) -articular surfaces are flat and only allow for short gliding movements -non-axial - (intercarpal and intertarsal joints, sacroiliac joint, vetrebrocostal joint)

C. Dislocation

(luxation) -when reinforcing structures cannot protect a joint from extreme stresses, the articulating surfaces may be forced out of position. The displacement may damage the articular cartilages, tear ligaments, or distort the joint capsule -although inside of joint has no pain receptors, nerves that monitor the cap sue, ligaments and tendons are quite sensitive, so dislocations are very painful. -partial dislocation is called sublaxation

B. cartilaginous joints

- fibrous connective tissues - hyaline cartilage or fibrocartilage -no joint cavity (amphiarthrotic/ synarthrotic)

b. amphiarthrosis

- only slight movement permitted -much stronger then freely moveable joints -simple in structure/direct connections to articulating bones

Range of Motion (ROM)

-amount of movement permitted

saddle joints

-articular surfaces have a concave area on one that fits with the convex area of the other -biaxial -(first carpometacarpal joint in the thumb)

ii. Symphysis

-articulating bones separated by a wedge or pad of fibrocartilage -formed between vertebra where a thick pad of fibrocartilage forms the vertebral discs ex: between two pubic bones -Cartilaginous; Amphiarthotic

2. Rheumatoid Arthritis

-autoimmune disease -can occur at any age but is more common in middle age and in woman -infection, genes and hormone changes may be linked to the disease -usually affects joints on both sides of the body equally -wrists, fingers, knees, feet, and ankles are most common affected body parts -often begins slowly with only minor pain but progressively becomes debilitating

3. Gouty Arthritis

-caused by too much uric acid in the blood -when uric acid in blood is too high it forms hard crystals in your joints -can cause attack of sudden burning pain, stiffness and swelling in joint, usually big toe -attacks can happen over and over unless gout is treated -more common in men

ii. synostosis

-created when two bones fuse and boundary between them disappears. ex: premature ossification of the cranial sutures; radio-ulnar synopsis -fibrous; synarthrotic

C. Synovial Joints

-fibrous connective tissue -hyaline/fibrocartilage -have joint cavity -complex in structure, most numerous type of joint in body (diarthrotic)

a. fibrous joints

-fibrous connective tissues -no cartilage -no cavity between the bones (amphiarthrotic/synarthrotic)

c. diarthrosis

-freely moveable joints -complex in structure, permit greatest range of motion

3. synovial fluid

-largely derived from blood and has a clear, viscous, egg-white consistency -3 primary functions: a. lubrication b. nutrient distribution c. shock absorption

2. articular cartilages

-line the surfaces of articulating bones -composed of hyaline cartilage -lack a perichondrium and the matrix contains more water than hyaline cartilage located elsewhere in the body -provide a slick, smooth surface to the bones which reduces friction during movement

C. Fat Pads

-localized masses of adipose tissue covered by a layer of synovial membrane -commonly superficial to joint capsule -protect the articular cartilages and act as packing material for the joint -when bones move, the fat pads fill in the spaces created as the joint cavity changes shape

i. sutures

-located only between bones of skull -edges of bones are interlocked and bound together at suture -Fibrous; synarthrotic

a. Synarthrosis

-no movement permitted -very strong joints -simple in structure/direct connections to articulating bones

i. synchondrosis

-rigid, hyaline cartilage bridge unites the bones -ex: between ends of first pair of ribs and manubrium of sternum -Cartilaginous; Synarthrotic

B. Bursa

-small, fluid-filled pocket that forms in a connective tissue -contains synovial fluid and is lined by a synovial membrane -often form where a tendon or ligament rubs against other tissues -located around most synovial joints -reduce friction and act as shock absorbers

b. nutrient distribution

-synovial fluid in a joint must circulate continuously to provide nutrients and waste disposal for the chondrocytes of the articular cartilages -it circulates whenever the joint move, and the repressed compression and expansion of the articular cartilages pump synovial fluid into and out of the cartilage matrix

c. shock absorption

-when joint is subjected to compression, the synovial fluid provides a cushion against the shock. -Ex: when you jog, your knees are severely compressed and the synovial fluid distributes that force evenly across the articular surfaces and outward to the joint capsule

a. lubrication

-when part of an articular fluid is compressed during movement, some of the synovial fluid is squeezed out of the cartilage and into the space between opposing surfaces. -in turn, the thin layer of fluid markedly reduces friction between moving surfaces, this is called WEEPING LUBRICATION

B. Movements Provided by Synovial Joints

1. a joint cannot be both highly mobile and very strong. The greater the range of motion at a joint, the weaker it becomes 2. a synarthrotic joint, the strongest type of joint, permits no movement. Where as diarthorsis, such as a shoulder, is far weaker but permits a broad range of motion 3. Axis of motion a. non-axial motion b. uniaxial motion c. biaxial motion d. multi-axial motion

Classes of Synovial Joints

1. anatomical classes of synovial joints are based on the shape of the articulating surfaces of the bones 2. plane joints 3. hinge joints 4. pivot joints 5. condyloid joints 6. saddle joints 7. ball and socket

Components of Synovial Joints

1. joint cavity 2. atriuclar cavity 3. synovial cavity 4. Joint capsule 5. accessory structures of a typical synovial joint

5. Accessory Structures of a typical synovial joint

In complex synovial joints, such as the knee, a variety of accessory structures provide support and additional stability A. Ligaments B. Bursa C. Fat pads D. Meniscus

D. Meniscus

a pad of fibrous cartilage situated between opposing bones within synovial joint. -menisci may subdivide a synovial cavity, channel the flow of synovial fluid, or allow for variations in the shapes of the articular surfaces

m. inversion

a twist motion of the foot that turns the sole inward, elevating the medial edge of the sole (seen in club foo)

4. Types of Motion

a. Gliding b. Angular c. cirumduction d. rotation

c. hyperextension

angular movement where the body part is extended past the anatomical position (looking up at the stars)

a. flexion

angular movement within the anterior-posterior plane that reduces the angle between the articulating elements (lifting dumbbell as in a biceps curl)

f. abduction

angular movement within the lateral-medial plane that moves the body part AWAY from the longitudinal axis (first part of a jumping jack, spreading the fingers, cocking the wrist)

gliding

bones slide across the surface of one another

angular

changing the angle between two bones

hinge joints

cylindrical projection of one bone fits into a trough-shaped surface on another bone; -unaxial -(elbow joint, knee joint, interphalangeal joints)

a. non-axial motion

linear movements where bones slide (vertebrocostal joints, sacroiliac joint, and intercarpal joints)

Common Joint Injuries

listed next

5. Movements relative to anatomical position

listed on next note cards -anatomical position is standing straight up with arounds out straight forward

arthroscopic surgery

may be necessary to treat joint injuries or artificial joints may need to be installed when joint is damaged beyond repair

b. uniaxial motion

movement in one plane (finger joints, elbow, knee) -one direction

d. multi-axial motion

movement in three planes (shoulder joint and hip joint) -any direction

c. biaxial motion

movement in two planes (metacarpophalangeal joint, occipital condyles to atlas) -two direction

o. protraction

moving a body part anteriorly in the horizontal plane (an underbite with the lower jaw)

h. circumduction

moving a limb in a circle creating a cone in space (performing windmill exercises)

b. extension

opposite of flexion; an angular movement within the anterior-posterior plane that increases the angle between the articulating elements. -when in anatomical position, all of the major joints of the axial and appendicular skeleton (except the ankle) are at full extension (lowering the dumbbell back to a starting position)

g. adduction

opposite to abduction; an angular movement within the lateral-medial plane that moves the body part TOWARD the longitudinal axis (second part of jumping jack, bringing fingers together, snapping wrist)

e. plantar flexion

opposite to dorsiflexion, extend the ankle and elevates the heel (as when you point your toes)

j. lateral rotation

opposite to medial rotation; the anterior surface of a limb turns away from the midline of the body (first position in a ballerina stance)

n. eversion

opposite to protraction; moving the body part posteriorly in the horizontal place (an overbite with the lower jaw)

p. retraction

opposite to protraction; moving the body part posteriorly in the horizontal plane (an overbite with the lower jaw)

pivot joints

rounded end of one bone protrudes into a sleeve or ring composed of bone or ligament - uniaxial -(proximal radio-ulnar joint, the dens of the axis to atlas)

ball and socket

spherical end of one bone articulates with a cup like socket of another bone -multiaxial -(shoulder joint and hip joints)

B. Sprain

stretching or tearing of a ligament across the joint capsule

q. depression

structure moves inferiorly (opening the mouth)

r. elevation

structure moves superiorly (closing the mouth)

A. Ligaments

support, strengthen and reinforce synovial joints i. intrinsic ligament ii. extrinsic ligament

i. medial rotation

the anterior surface of a limb turns towards midline of the body (pigeon toe in the leg)

s. opposition

the movement of the thumb toward the surface of the palm or the pads of the other fingers (as in snapping to music)

L. pronation

the shaft of the radius rotates, the distal epiphysis of the radius rolls across the anterior surface of the ulna so that the bones are crossing. The palm faces posteriorly (pro basketball players pronate to dribble the ball)

i. fibrous capsule

thick outer layer continuous with the periosteum around the articulating bones. As a result, this adds strength and helps stabilize the joint