Anatomy and Physiology Articulations Anatomy and Physiology

I. Classification of joints Articulation – point where 2 bones meet (joint) Joints are classified according to amount and type of movements 3 general types of joints Immovable (synarthrosis) Slightly immovable ( amphiarthrosis) Freely movable (diarthrosis)

II. Immovable joints (synarthrosis) Joints fused together 4 types Sutures Gomphoses Synchondroses synostoses

a. Sutures Between bones of skulls Interlocked Bound together by dense connective tissue

b. gomphoses teeth to bony sockets held into socket by periodontal ligament

c. Synchondroses cartilage bridge between 2 articulating bones ex. Ends of vertebrosternal rib and sternum

d. synostosis rigid immovable bones fused together with no line of demarcation as to where it starts or ends. Ex. Hip, coccyx

III. Slightly movable (amphiarthrosis) Permits more movement than syntarthrosis, but stronger than freely movable joints 2 types 1. syndesmosis 2. symphysis

a. Syndesmosis (sin-dez-MO-sis) bones connected by a ligament   ex. Tibia and fibula

b,. symphysis bones separated by wedge or pad of fibrocartilage ex. Vertebrae – vertebral disks pubic bones – pubic symphysis

IV. Freely Movable (diarthroses) a. Aka – synovial joints Allow large range of motion Synovial joint surrounded by capsule and synovial membrane lines the cavity Found end of long bones Surface slippery and smooth which decreases friction Contains synovial fluid

b. 3 functions of synovial fluid i. lubricant the viscous fluid acts to lubricate the joints ii. nutrient distribution circulates to provide nutrients and rids waste products moves every time joint moves iii. shock absorption cushions distributes pressure across the joint which lessens shock on the surfaces of joint

c. arthritis affects syovial joints damages to articulating cartilages caused by injury, virus, bacteria, physical stress 2 types arthritis i. Osteoarthritis – Degenerative Results from cumulative wear and tear of joint surfaces Genetic factors 60 + older   ii. Rheumatoid arthritis Inflammation Due to immune system mistakenly attacking joint tissue Allergies, bacteria, virus, and genetics contribute to triggering

iii. Treatment of arthritis Exercises Physical therapy Meds (anti-inflamatory) Replacement of joint

V. Accessory Structures of synovial joints Fat pads Cartilage pads Ligaments Tendons bursea

a. Fat pads structure: adipose tissue covered by layer of synovial membrane superficial to joint capsule function – protect articulating cartilage act as packing material for joint by filling in spaces created as joint cavity moves.

b. Cartilage pads structure: fibrocartilage pad situated between bones within synovial joint ex. Meniscus function : channel synovial fluid flow absorb shock subdivide synovial cavity  

c. ligaments i. Accessory: thickenings of capsule reinforces and strengthens capsule limits rotation at joint ii. extracapsular connect articulating bones passes across outside of capsule support wall of joint ex. Lateral collateral and medial collateral ligaments of knee iii. Intracapsular inside capsule prevents extreme movements that could hurt joint   ex. ACL , PCL iv. other (ligaments of knee) popliteal patellar 

d. tendons Connect muscle to bone Across and around joints to provide strength to joints Tendonitis – inflammation of tendon

e. bursea structure Small fluid filled sacs in connective tissue Contain synovial fluid and lined by synovial membrane Found where tendons and ligaments rub against other tissues   Function – Decrease friction Absorb shock Bursitis – inflammation of bursae Pain when move tendon or ligament Associated with repetitive motion Golfers, swimmers, pitchers, tennis

VI. Types of Movements Gliding Angular Rotation Special movements

a. gliding Sliding past one another Carpal bones B/t tarsal bones b/t clavicle and sternum movement in any direction – but very slight Ex: touch process on clavicle and turn shoulders in – feel sliding

b. angular Change in angle between shaft and joint Flexion – decrease in angle ex. Chin to chest, touch toes, bend wrist Extension – increase in angle Ex. Straightening leg or arm Hyperextension – extension beyond anatomical position ex. Look at ceiling (hyperextend neck)

ex. Moving arm away from body, spreading fingers Abduction – movement of appendage AWAY from long axis of body (along frontal plane) ex. Moving arm away from body, spreading fingers Adduction – movement appendages TOWARD long axis of body (along frontal plane) Ex. Moving arm toward body, fingers together Circumduction – Distal end of appendage moves in circle Ex. Baseball wind up

c. Rotation in referent to anatomical position depends on part moving ex. Head rotation – move chin to right or left (say NO)   ex. Limb rotation – medial – inward lateral – outward   Lower arm rotation pronation – move palm toward back supinate – move palm from back toward front

d. Special movements FOOT: inversion twisting motion of foot that turns sole inward eversion twisting motion of foot that turns sole outward dorsiflexion flexion of ankle and elevation of sole of foot (dig heel into ground) plantar flexion extend ankle and elevate heel (stand on tip toes)

Special mvmts. cont…. opposition thumb to fingers protraction moving body part anteriorly in horizontal plane ex. Sticking out tongue retraction opposite of protraction elevation structure moves superiorly ex. Shrug shoulders, close mouth, depression structure move inferior open mouth   lateral flexion vertebral column bends to one side ex. Side stiches, move ear toward shoulder

VII. Types of Synovial Joints Each synovial joint permits different type and range of motion Gliding Hinge Pivot Ellipsoidal Saddle Ball and socket

a. Gliding Aka planar joints Flattened or slightly curved faces Flat articulating surfaces Slight movement Ex. Clavicle, carpals, tarsals, between vertebrae

b. Hinge joint Angular movement in single plane (monaxial joint) Monaxial joint (only flexes or extends in one plane) Ex. Occipital condyle and atlas Elbow, knee, interphalangeal joints , wrist

c. Pivot Monaxial Permits rotation only Ex. Atlanto-axial joint (atlas and axis) Radioulnar joint

d. Ellipsoidal Aka condyloid joint Nestles with in a depression Angular motion in 2 planes – biaxial (flexion/extension and abduction/adduction ex. Metacarpal phalangeal joint metatarsalphalangeal joint wrist – radiocarpal joint

e. Saddle Aka sellaris joint Articulating faces look like saddles Angular motion – biaxial Circumduction and angular motion (flexion /extension, etc) Ex. Carpometacarpal joint (base of thumb – twiddle thumbs)

f. Ball and socket round head of bone fits in cup shaped depression of another bone multiaxial – rotate, circumduction, angular movements) ex. Shoulder , hip

VIII. Major Joints in Human Body Shoulder joint: greatest range of motion also most frequently dislocated most stability provided by ligaments and muscles around joint contain bursae to decrease friction between tissue

Shoulder joint cont… rotator cuff: supraspinatus infraspinatus subscapularis teres minor primary support for shoulder joint and limits range of motion. Injury to rotator cuff usually due to severe stress on shoulder, repetition (pitchers, swimmers, quarterbacks , etc..)

b. elbow olecranon joint hinge (flexion and extension) diarthrosis muscles that extend elbow attach at olecranon process (triceps) muscles that flex elbow – attach at radial tuberosity stable joint due to the fact that humerus and ulna interlock has thick articular capsule and ligament reinforcement

c. hip diarthrosis flexsion / extension, abduction/adduction, circumduction and rotation contains large muscles to help with stability of joint ligaments around the hip include iliofemoral pubofemoral ischiofemoral transverse acetabular ligament ligamentum teres

d. knee Hinge joint Flexion / extension (monaxial) Limited rotation Medial and lateral menisci lie between femoral and tibial surface Cushions, gives lateral stability,

Knee cont. Ligaments of knee Patellar ligament Patella is within patellar tendon, continuation of this tendon = patellar ligament which attaches to anterior surface of tibia (tuberosity) Popliteal ligaments (2) Between femur and heads of tibia and fibula Supports posterior surface   Anterior and Posterior Cruciate Inside joint capsule Criss cross inside capsule Limit anterior and posterior movement of femur and maintain alignment of femoral and tiaeal condyles. Tibial (medial ) collateral (MCL) Reinforces medial surface of knee Fubular (lateral) collateral (LCL) Reinforces lateral surface of knee

IX. Male vs. Female Skeleton General differences: Males bones larger than female Males have larger muscle attachment surfaces Males have larger Joint surfaces Skull : Males have shorter forehead Males mandible and maxillae larger Males facial area is more pronounced Pelvis: Males pelvis narrower Males pelvis deeper Males pelvic outlet smaller Males subpubic angle less than 90 degrees

X. Common Disorders of Skeletal System 1. Arthritis – inflammation of joint, pain stiffness Osteoarthritis – wear and tear Rheumatoid - 2. Bunion Bony bump that forms on the joint at the base of your great toe. Wearing tight or narrow shoes can form bunions. Sometimes just inherent structural defect. 3. Bursitis Inflammation of fluid filled sac Overuse or repetitive movement 4. Gout Missing enzyme causes uric acid build up in joints Common in toe, knee 5. Herniated disc When vertebral disk “pops” out from between vertebrae

Disorders cont….. 6. Luxation 7. Subluxation 8. Sprain 9. Strain Full dislocation of a joint Usually from fall or unusual movement Shoulder, knees, shoulder, fingers, jaw 7. Subluxation Partial dislocation of a joint 8. Sprain Overstretching or tearing of connective tissue, ligaments and tendons 9. Strain Overstretching or over use of muscle