BIOL 1160 Chapter 9: Joints

any point where two bones meet, whether or not the bones are movable at that interface

joints (articulation)

science of joint structure, function, and dysfunction

arthrology

the study of musculoskeletal movement

kinesiology

joint names are typically derived from

the names of the bones involved

ex: radioulnar joint involves the radius and ulna

joints can also be classified according to the manner in which the bones are bound to each other. name the four major joint categories.

bony joints

fibrous joints

cartilaginous joints

synovial joints

an immobile joint formed when the gap between two bones ossifies, and the bones become, in effect, a single bone

bony joint or synostosis

bony joints are also called

synostosis

(think osto like osteo means bone --> bony joints)

examples of bony joints

left and right mandibular bones in infants

attachment of first rib and sternum with old age

frontal bone (fusion of metopic suture)

adjacent bones are bound by collagen fibers that emerge from one bone and penetrate into the other

fibrous joint or synarthrosis

fibrous joints are also called

synarthrosis

name the three kinds of fibrous joints

sutures, gomphoses, syndesmoses

immobile or slightly mobile fibrous joints in which short collagen fibers bind the bones of the skull to each other

sutures (fibrous joint)

sutures can be classified as

serrate, lap (squamous), plane (butt)

interlocking wavy lines

ex: coronal, sagittal, and lambdoid sutures

serrate sutures

overlapping beveled edges

ex: temporal and parietal bones

lap (squamous) sutures

straight, non-overlapping edges

ex: palatine processes of the maxillae

plane (butt) sutures

attachment of a tooth to its socket

gomphosis (fibrous joint)

held in place by fibrous periodontal ligament, which allows the tooth to move a little under the stress of chewing

gomphosis (fibrous joint)

in gomphoses, what type of fibers attach tooth to jawbone?

collagen fibers

a fibrous joint at which two bones are bound by long collagen fibers

syndesmosis (fibrous joint)

example of a very mobile syndesmosis

interosseus membrane joining radius to ulna allowing supination and pronation

example of a less mobile syndesmosis

joint between tibia to fibula

two bones are linked by cartilage

cartilaginous joint or amphiarthrosis

cartilaginous joints are also called

amphiarthroses

name the two types of cartilaginous joints

synchondroses and symphyses

bones joined by hyaline cartilage

synchondrosis

example of synchondrosis

temporary joints in the epiphyseal plates in children (bind epiphysis to diaphysis)

first rib attachment to sternum (other costal cartilages joined to sternum by synovial joints)

two bones joined by fibrocartilage

symphysis

example of symphysis

pubic symphysis joints right and left pubis bones with interpubic disc

bodies of vertebrae joined by intervertebral discs (only slight movement between adjacent vertebrae)

joint in which two bones are separated by a joint cavity

synovial joint or diarthrosis

synovial joints are also called

diarthrosis

which joint type is the most familiar type of joint, most are freely mobile, and most structurally complex type of joint?

synovial joint or diarthrosis

layer of hyaline cartilage that covers the facing surfaces of two bones in a synovial joint

articular cartilage of a synovial joint

separates articular surfaces of synovial joints

joint (articular) cavity of a synovial joint

slippery lubricant in joint cavity of synovial joints

synovial fluid of a synovial joint

what makes up the synovial fluid of synovial joints?

rich in albumin and hyaluronic acid

connective issue that encloses the cavity and retains the fluid of synovial joints

joint (articular) capsule of a synovial joint

synarthrosis

no movement

amphiarthrosis

some movement

diarthrosis

free movement

in a few synovial joints, what grows inward from the joint capsule

fibrocartilage

forms a pad between articulating bones that crosses the entire joint capsule (in synovial joints)

articular disc made of fibrocartilage

ex: found in temporomandibular joint (TMJ, jaw)

moon-shaped cartilage in knee; in each knee, extend inward from the left and right

meniscus

these cartilages absorb shock and pressure; guide bones across each other and improve their fit together; stabilize joints, reducing the chance of dislocation

meniscus

strip of collagenous tissue attaching muscle to bone

tendon

strip of collagenous tissue attaching one bone to another

ligament

fibrous sac filled with synovial fluid, located between muscles, where tendons pass over bone, or between bone and skin

bursa (rounded shape)

cushions muscles, helps tendons slide more easily over joints (reduces friction), modifies direction of tendon pull

bursa

elongated cylindrical bursa wrapped around a tendon, found in hand and foot

tendon sheath

all synovial joints are moveable, but

some may not be moveable in as many planes as others

name the six classes of synovial joints

ball-and-socket, condylar, saddle, plane, hinge, pivot

smooth, hemispherical head fits within cup-like socket; only multiaxial joints in body

ball-and-socket joints

examples of ball-and-socket joints

shoulder and hip

oval convex shape of one bone fits into a complementary-shaped depression on the other; biaxial joints- movement in two planes

condylar (ellipsoid) joints

examples of condylar (ellipsoid) joints

radiocarpal joint, metacarpophalangeal joints

both bones have an articular surface that is shaped like a saddle, one concave, the other convex; biaxial joints

saddle joints

examples of saddle joints

trapeziometacarpal (opposable thumb), sternoclavicular joint

flat articular surfaces, bones slide over each other; usually biaxial joints

plane (gliding) joints

examples of plane (gliding) joints

between carpal bones of wrist; between tarsal bones of ankle; also between articular processes of vertebrae

one bone with convex surface fits into a concave depression of another bone; monoaxial joints - move freely in one place

hinge joints

examples of hinge joints

elbow, knee, joints within fingers, toes

a bone spins on its longitudinal axis; monoaxial joints

pivot joints

examples of pivot joints

atlantoaxial joint (C1 and C2), radioulnar joint at the elbow

movement that decreases joint angle; common in hinge joints

flexion

movement that straightens a joint and returns a body part to the zero position

extension

extension of a joint beyond the zero position

hyperextension (not available at all joints)

movement of a body part in the frontal plane away from the midline of the body

abduction

movement in the frontal plane back toward the midline

adduction

primarily forearm movements

supination and pronation

forearm movement that turns palm to face anteriorly or upward

supination

the forearm is _______ in anatomical position

supinated

during supination, what is the position of the radius?

the radius is parallel to the ulna

forearm movement that turns palm to face either posteriorly or downward

pronation

during pronation, what is the position of the radius?

the head of the radius spins and the radius crosses the stationary ulna like an X

articulation of the condyle of the mandible with the mandibular fossa of the temporal bone

temporomandibular (jaw) joint (TMJ)

hemispherical head of humerus articulates with glenoid cavity of scapula

glenohumeral (humeroscapular) joint

the glenohumeral joint is also called

humeroscapular joint

the most freely mobile joint in the body

glenohumeral (humeroscapular) joint

the shallow glenoid cavity and loose shoulder joint capsule sacrifices

stability for freedom of movement

fibrocartilage ring that deepens glenoid cavity

glenoid labrum

how many principle ligaments support the shoulder?

5

how many bursa occur at the shoulder? name them.

4

subdeltoid, subacromial, subcoracoid, and subscapular bursae

a hinge that includes the humeroulnar and humeroradial joint

elbow

trochlea of the humerus joins trochlear notch of ulna

humeroulnar joint

capitulum of humerus meets head of radius

humeroradial joint

head of femur inserts into acetabulum of hip bone

coxal (hip) joint

which joint bears weight, has deeper sockets, and is more stable than the shoulder?

coxal (hip) joint

horseshoe-shaped ring of fibrocartilage that deepens the hip (coxal) joint socket

acetabular labrum

note: dislocations of the hip joint are rare

ligaments supporting hip joint

arises from fovea capitis and attaches to lower margin of acetabulum; contains artery that supplies blood to head of femur

round ligament (ligamentum teres)

largest and most complex diarthrosis of the body

tibiofemoral (knee) joint

the knee is stabilized by what features?

quadriceps tendon in front of thigh, tendon of semimembranosus muscle on rear of thigh, and lateral meniscus and medial meniscus

c-shaped cartilages within joint capsule; absorb shock and prevent side-to-side rocking

lateral meniscus and medial meniscus

posterior region of knee

popliteal

intracapsular ligaments cross each other to form an X

anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL)

prevents hyperextension of knee when pulled tight; common sight of knee injury

anterior cruciate ligament (ACL)

prevents femur from sliding off tibia

posterior cruciate ligament (PCL)

includes two articulations: medial joint and lateral joint

talocrural (ankle) joint

joint between tibia and talus

medial joint

joint between fibula and talus

lateral joint