joints

the junction between bones

joints

study of joints

the smooth bony surfaces that come together to form freely movable joints

• immovable fibrous joints
• slightly movable cartilaginous joints
• freely movable synovial joints

fibrous joints

cartilaginous joints

synovial joints

fibrous joints

immovable. bones firmly united by fibrous tissues

• sutures in skull
• splint bones of horse

cartilaginous joints

slightly movable. rocking movement

• intervertebral disks
• pubic symphysis 
• mandibular symphysis

synovial joints

freely movable

• shoulder joint (humerus&scapula)
• stifle joint (tibia/fibula&femur)
• elbow (ulna/radius&humerus)
• hip (femur&acetabulum) 

• articular surfaces covered with articular cartilage
• fluid-filled joint cavity enclosed by a joint capsule
• ligaments may be present to stabilize

bands of fibrous connective tissue present in and around many synovial joints. connect bone to bone

thin, smooth layer of hyaline cartilage that lies on the tip of articular surface of a bone

(to reduce friction/aid in smooth movement)

fluid filled potential space between the joint surfaces. a multilayered joint capsule surrounds it. the outer layer of the joint capsule is fibrous tissue, the lining layer is synovial membrane. synovial membrane produces the synovial fluid that lubricates the joint surfaces.

• normally transparent
• viscosity of medium-weight motor oil

joint "tap" often performed. presurgical skin prep, insert needle into joint cavity and withdraw synovial fluid for examination, analysis, and possible bacterial culture

• flexion
• extension
• adduction
• abduction
• rotation
• circumduction

decrease angle between two bones

increases angle between two bones

movement of an extremity toward the median plane

movement of an extremity away from the median plane

twisting movement of a part on its own axis

(hold arm out with palm down, move it so palm is up)

movement of an extremity so that the distal end moves in a circle

(extend arm, move hand in a circle)

• hinge joints
• gliding joints
• pivot joints
• ball-and-socket joints

also called ginglymus joints

• one joint surface swivels around another
• only movements possible are flexion and extension

• elbow joint
• atlantooccipital joint

(flexion&extension of atlantooccipital joint moves the skull up and down in a nodding "yes" motion)

arthrodial joints

• joint surfaces relatively flat. movement between them is rocking motion.
• main movements possible are flexion and extension, but some abduction and adduction may also be possible.

carpus (wrist)

trochoid joints

• one bone pivots or rotates on another
• only movement possible is rotation

atlantoaxial joint

only movement allows is the rotation of the head back and forth saying "no"

(only one true pivot joint in most animals: joint between first and second cervical vertebrae)

spheroidal joints

allows most extensive movement (allow all the synovial joint movements)

permits flexion, extension, adduction, abduction, rotation, circumduction

shoulder and hip joints

• rickets
• osteomalacia
• hypervitaminosis A
• scurvy

calcium and phosphorus 

UV hits skin, vitamin D3 in skin, UV turns D3 into D1 to absorb calcium&phosphorus in diet

freely movable synovial joints

synarthroses 

fibrous joints

diarthroses

hinge joints&gliding joint

ball-and-socket

medial&lateral collateral ligaments

anterior&posterior cruciate ligaments

anterior cruciate ligament

swelling of bursa sacs (becomes infected or inflamed)

fibrous tissue

synovial membrane

transudate

medial and lateral collateral ligaments

anterior and posterior cruciate ligament


(help prevent bones of stifle from sliding back and forth as the joint bends and strengthens)