Chapter 9 A&P Joints

9-6: the shoulder joint

aka glenohumeral joint. allows for greatest range of motion of any joint. The most frequently dislocated joint. Ball and socket diarthrosis formed by articulation of head of humerus with glenoid cavity of scapula.

9-1: amphiarthrosis - symphysis

amphiarthrosis category, cartilaginous joint. articulating bones connected by wedge of fibrocartilage, like the pubic symphysis of the two coxal bones.

9-1: amphiarthrosis - syndesmosis

amphiarthrosis category, fibrous joint. bones between are connected by a ligament. Distal end of tibia and fibula = example.

9-4: intervertebral ligaments

attached to the bodies and processes of all vertebrae, binding them together and stabilizing the vertebral column. Includes ligamenta flava (paired ligaments connecting laminae of adjacent vertebrae), posterior longitudinal ligament (fibrous band that parallels the anterior longitudinal ligament and connects the posterior surfaces of adjacent vertebral bodies), interspinous ligaments (made of fibrous tissue that connects spinous processes of adjacent vertebrae), supraspinous ligament (longitudinal fibrous band attached to tips of spinous process of vertebrae from c7 to sacrum) and the ligamentum nuchae (extends from vertebra c7 to the base of the skull, continuous with supraspinous ligament) and finally the anterior longitudinal ligament (wide fibrous band connecting anterior surfaces of adjacent vertebral bodies).

9-1: functional scheme range of moment joint classifications

based on amount of movement. synarthrosis joints (immovable), amphiarthrosis (slighty movable) joints, and diarthrosis joints (freely movable)

9-2: synovial joints - accessory structures: adventitious bursae

bursae that develop in abnormal locations or because of abnormal stresses.

9-4: intervertebral discs

over all, they account for 1/4th of the length of the vertebral column superior to the sacrum. This decreases with age as they lose their ability to bounce back from continuous compression. each has a tough outer layer of fibrocartilage called anulus fibrosus (which contain collagen fibers that connect the disc to the bodies of adjacent vertebrae) that surrounds the nucleus pulposus (soft elastic gelatinous core to give disc resiliency and shock absorption). The superior and inferior surfaces of the disc are almost completely covered by thin vertebral end plates that are composed of hyalin cartilage and fibrocartilage. Displacement of nucleus pulposus from compression during movement permits smooth gliding movements between vertebrae while maintaining their alignment.

9-5: accessory structures of knee joint - quadriceps femoris tendon

passes over anterior surface of joint, responsible for extending knee when muscle contracts. patella is embedded in this tendon.

9-1: amphiarthrosis classification of joints

A slightly movable joint that is either fibrous or cartilaginous depending on the type of connection between the opposing bones. Found largely in the axial skeleton.

9-2: factors that stabilize synovial joints

1 The collagen fibers of the joint capsule and any accessory, extracapsular, or intracapsular ligaments. 2 The shapes of the articulating surfaces and menisci, which prevent movement in specific directions. 3 The presence of other bones, skeletal muscles, or fat pads around the joint. 4 The tension in tendons attached to the articulating bones. The more stable the joint, the more restricted its range of motion. The shoulder joint is the most mobile synovial joint and relies on surrounding ligaments, muscles, and tendons for stability, and is also fairly weak.

9-5: accessory structures of knee joint

A complete dislocation of the knee is very rare, mainly because 7 major ligaments stabilize the knee joint: 1 = quadriceps femoris, 2&3 = popliteal ligaments, 4&5 = anterior cruciate ligament and posterior cruciate ligament, 6&7 = the tibial collateral ligament AKA medial collateral ligament and the fibular collateral ligament AKA lateral collateral ligament.

9-5: accessory structures of knee joint - anterior cruciate ligament and posterior cruciate ligament

ACL and PCL attach the intercondylar area of the tibia to the condyls of the femur. The anterior and posterior in these terms refer to the sites of origin of these ligaments on the tibia as they cross one another to proceed to their destination on the femur. They limit anterior and posterior movement fo the tibia and maintain the alignment of the femoral and tibial condyles.

9-3: types of movements at synovial joints - angular movement

Examples of angular movement include flexion, extension, abduction, and adduction. These movement descriptions are based on reference to an individual in the anatomical position.

9-2: synovial joints - accessory structures: cartilages and fat pads

In several joints, including the knee, pads made of fibrocartilage called a meniscus, plural = menisci, lie between the opposing articular surfaces. The menisci may subdivide a synovial cavity, channel the flow of synovial fluid, or allow for variations in the shapes of the articular surfaces. Fat pads can also lie between opposing articulating surfaces. They are localized masses of adipose tissue covered by a layer of synovial membrane, and are commonly superficial to the joint capsule. They protect articular cartilages and act as packing material for the joint, even as it changes shape with movement.

KNEE

KNOW ALL LIGAMENTS TENDONS AND MENISCI.

9-7: osteoarthritis

Most common type of arthritis, aka degenerative joint disease (DID) and affects people 60 and older usually since its caused by wear and tear. 25% of women and 15% of men over age of 60. regular exercise, physical therapy, and drugs to reduce inflammation can slow the progress of it.

9-6: shoulder joint accessory structures: muscles and the rotator cuff.

Muscles that stabilize shoulder joint originate on trunk, pectoral girdle, humerus, cover the anterior superior and posterior surfaces of the capsule. tendons of the supraspinatus, infraspinatus, teres minor and subscapularis muscles in this. They are the muscles of the rotator cuff. Remember SITS (supraspinatus, infraspinatus, teres minor and subscapularis).

9-1: synarthrosis category of joints

An immovable joint (like skull sutures) that can be fibrous or cartilaginous, depending on the type of connection formed by the two bones on the joint. Over time, these two bones may fuse (ossify) to make a bony joint. Found largely in the axial skeleton. Includes sutures, gomphosis, synchondrosis and synostosis.

9-3: diathroses: the different types of synovial joints allow a wide range of skeletal movements

Describe how the anatomical and functional properties of synovial joints permit movements of the skeleton.

9-2: Diarthroses: synovial joints contain synovial fluid and are surrounded by a joint capsule and stabilizing accessory structures.

Describe the basic structure of a synovial joint, and describe common synovial joint accessory structures and their functions

9-7: with advancing age, arthritis an other degenerative changes often impair joint mobility

Describe the effects of aging on joints, and discuss the most common age-related clinical problems for joints.

9-4: intervertebral joints contain intervertebral discs and ligaments that allow for vertebral movements.

Describe the joints between the vertebrae of the vertebral column.

9-5: The elbow and knee are both hinge joints

Describe the structure and function fo the elbow joint and knee joint.

9-6: the shoulder and hip are both ball-and-socket joints

Describe the structure and function of the shoulder joint and the hip joint.

9-2: synovial joints - synovial fluid's shock absorption

Synovial fluid cushions joints that are subjected to compression from shocks and sudden impacts. because the viscosity of synovial fluid increases increased pressure. When the pressure across a joint suddenly increases, the resulting shock is lessened as the viscosity of synovial fluid increases. As the pressure lessens, viscosity decreases and it regains its lubricating function across the articular surfaces.

9-2: synovial joints - accessory structures

Synovial joints may have a variety of protective and stabilizing accessory structures, including pads of cartilage or fat, ligaments, tendons, and bursae.

9-2: synovial joints - synovial fluid's nutrient distribution

Whenever the joint moves, the compression and expansion of the articular cartilage pumps synovial fluid ) and out of the cartilage matrix to provide a continuous cycle of nutrient and waste exchange.. As the synovial fluid flows through the areolar tissue of the synovial membrane, additional nutrients are delivered and wastes are absorbed diffusion across capillary walls.

9-3: types of movements at synovial joints - circumduction

a complete circular movement, like moving your arm in a loop. When you draw a large circle on a white board, your hand moves but your arm does not rotate.

9-1: diarthrosis classification of joints, all of which are synovial joints

a freely movable joint that can be subdivided functionally according to their plans of movement. Found largely in the appendicular skeleton. Typically at the end of long bones. consisting of a cartilage lined cavity filled with fluid, which is known as a diarthrosis joint.

9-3: special movements at synovial joints - inversion and eversion

a twisting movement of the foot that turns the sole inward, elevating the medial edge of the sole. The opposite movement is eversion.

9-3: angular movement: abduction and adduction

abduction is movement away from the midline of the body in the frontal plane. adduction is movement back to the anatomical position. (Add together is a good way of thinking about it. think of the weight machines for this to remember).

9-3: classification of synovial joints

classified by type and ranges of motion tey permit. Includes plane (gliding), hinge, condylar (ellipsoid), saddle, pivot, and ball-and-socket joints. See figure 9-2c.

9-5: The elbow joint

complex hinge joint involving humerus, radius and ulna. longest and strongest articulation = humero-ulnar joint between trochlea of humerus and trochlear notch of ulna (works like a hinge).This joint is stable because the bony surfaces of humerus and ulna interlocks, the single thick joint capsule surrounds humero-ulnar and proximal radio-ulnar joints, and strong ligaments reinforce the joint capsule. look at figure!

9-1: Joints are categorized according to their structure or range of motion

contrast the major categories of joins, and explain the relationship between structure and function for each category.

9-7: continuous passive motion

degenerative changes comparable to those seen in arthritis may result from joint immobilization, and can be helped by CPM because it improves the circulation of synovial fluid.

9-3: rotational movement: medial rotation and lateral rotation.

describe limb rotation by reference to the longitudinal axis of the trunk. Medial rotation aka internal rotation is the anterior surface of a limb turning toward the long axis of the trunk. The reverse is called lateral rotation.

9-3: special movements at synovial joints - dorsiflexion and plantar flexion

dorsiflexion is the flexion at the ankle joint and elevation of the soul, as when you dig in your heel. Plantar flexion is the opposite movement and extends ankle joint, elevating heal like one would when standing on tip toes.

9-5: accessory structures of knee joint - popliteal ligaments (2 per knee)

extend between femur and heads of the tibia and fibula to reinforce knee joint's posterior surface.

9-1: structural classification of joints

fibrous, cartilaginous, bony, or synovia. Boney joints form when fibrous or cartilaginous joints ossify.

9-3: angular movement: flexion and extension

flection is movement in the saggital plane that decreases the angle between articulating bones. extension occurs in the same plane to increase the angle. example: bring your head toward your chest to flex intervertebral joins of neck. Bringing head back up is extension. When person is in anatomical position, all the major joints of the axial and appendicular skeleton except the ankle, are at full extension.

9-6: the hip joint: ligaments

four broad ligaments to reinforce joint capsule: iliofemoral, pubofemoral, ischiofemoral ligaments are regional thickenings of the capsule. the transverse acetabular ligament crosses the acetabular notch. the fifth ligament called the ligament of the femoral head (ligamentum teres) originates along transverse acetabular ligament to attach to fovea captus, and tenses only when hip is flexed and thigh is undergoing lateral rotation.

9-2: synovial joints

freely movable diathroses, surrounded by an articular capsule (2 layered joint capsule) that is continuous with the periostea of the articulating bones. This capsule has an inner synovial membrane (composed of the secreting areolar tissue covered by an incomplete epithelium), and an outer fibrous capsule. The synovial membrane doesnt cover any articulating surfaces. The diarthrsis is weaker than a synarthrosis joint, but it has a broad range of motion. This means it needs lots of accessory structures to stabilize the joint, which will be listed in a few cards.

9-7: rheumatism

general term for pain and stiffness affecting musculoskeletal system

9-6: shoulder joint capsule and joint cavity

glenoid cavity area increased by fibrocartilaginous glenoid labrum that continues beyond bony rim and deepens the socket. This joint capsule extends from the glenoid labrum of the scapula to the anatomical neck of the humerus. It's oversized so it allows for an extensive range of motion. A dislocation from violent muscle contraction is most likely to happen here, which can tear the inferior capsular wall and the glenoid labrum.

9-3: types of movements at synovial joints

gliding movement, angular movement, circumduction, rotational movement, and special movements.

9-4: structure of intervertebral joints

include intervertebral discs, and intervertebral ligaments.

9-7: rheumatoid arthritis

inflammatory condition that affects .5-1% of the population, usually those between 40-60 years old and women more than men. Immune response mistakenly attacks joint tissue, making it an autoimmune disease.

9-7: arthritis

joint inflammation. encompasses all the rheumatic diseases that affect synovial joints. always involves damage to articular cartilages, but can result from bacterial or viral infection, injury to the joint, decreased viscosity or lack of synovial fluid, metabolic problems, or severe physical stress.

9-4: intervertebral joints

joints between adjacent vertebral bodies (these are symphyses) and joints between adjacent articular processes (these are synovial) along the vertebral column.

9-2: synovial joints - accessory structures: ligaments

localized thickenings that support, strengthen, and reinforce synovial joints. outside joint capsule = extracapsular ligaments. inside the joint capsule = intracapsular ligaments. sprain = stretch of ligament, possibly to the point of tearing collagen fibers. Bones heal quicker than ligaments since they have no direct blood supply and must rely on diffusion to get nutrients for healing.

9-6: shoulder joint accessory structures: tendons

major ligaments help stabilize shoulder joint, including the acromioclavicular, coracoclavicular, coraco-acromial, coracohumeral, and glenohumeral ligaments. A shoulder separation is a common injury involving partial or complete dislocation of the acromioclavicular joint, resulting from a hit to the superior surface of the shoulder. Include the rotator cuff tendons.

9-3: special movements at synovial joints - protraction and retraction

movement of a body part anteriorly in the horizontal plane. retraction is the reverse. jaw protracts to jut the chin forward. jaw retracts when its returned to its normal position.

9-3: special movements at synovial joints - opposition and reposition

movement of the thumb toward the surface of the palm or the pads of other fingers. Lets you grasp and hold objects between thumb and palm. Reposition is movement that returns the thumb and fingers from opposition.

9-3: rotational movement: pronation and supination

movement that turns the palm down = pronation. movement that turns the palm up = supination.

9-2: synovial joints - accessory structures: tendons

not a part of the joint, but do stabilize it by connecting the fleshy parts of muscles to bones that make up the joint, and possibly pass across or around a joint to limit the range of motion to provide support.

9-3: special movements at synovial joints - lateral flexion

occurs when your vertebral column bends to the side. Most pronounced at cervical and thoracic regions.

9-3: ROM

range of motion - the full movement at a particular joint. usually the distance between flexion (decreasing the angle) and extension (increasing the angle). Limited ROM means it cant move through its normal range of movement.

9-2: synovial joints - synovial fluid

resembles interstitial fluid, but contains proteoglycans with a concentration of hyaluronan secreted by fibroblasts of the synovial membrane. They include viscous plsama and hyaluronic acid that include phagocytic cells to remove microbes and debris. synovial fluid within a joint has the following primary functions: Lubrication, Nutrient Distribution, and Shock Absorption.

9-3: types of movements at synovial joints - rotational movement

rotation may involve left and right rotation, medial rotation or lateral rotation, as well as pronation and supination.

9-3: rotational movement: left and right

rotation of the head = left and right rotation.

9-2: synovial joints - accessory structures: bursae

small, thin fluid filled pockets in connective tissue that reduce friction and act as shock absorbers. Contain synovial fluid lined by synovial membrane. May be connected to joint or may be separate. Forms where tendon or ligament rubs against other tissues. They are around most synovial joints like the shoulder. heavy backpacks inflame the bursae.

9-2: synovial joints - articular cartilage

special cartilage that covers articulating surfaces, resembling hyaline cartilage, but is absent of any perichondrium, and contains more water in its matrix than other types of cartilage. Its surface is slick and smooth to reduce friction, and the two articular cartilages of their own side of the joint, never though due to the synovial fluid. Damage to this breaks down the cartilage matrix, causing rough and bristally collagen fibers to cover the articulating surface, increasing friction. USUALLY BLUE ON MODELS

9-1: two classification schemes to categorize joints

structural classification scheme (relies on anatomy of joint) and functional scheme (relies on the range of motion of a joint)

9-6: the hip joint

sturdy ball and socket diarthrosis that permits flexion, extension, adduction, abduction, circumduction, and rotation. acetabulum accommodates head of the femur. acetabulum has articular cartilage that extends like a horseshoe to either side of the acetabular notch. The acetabular labrum is a rim of fibrocartilage that increases the depth of the joint cavity and helps to seal in synovial fluid. joint capsule of hip joint is dense and strong and encloses both the head and neck of the femur to keep the head from moving too far from the acetabulum.

9-6: shoulder joint accessory structures: bursae

subdeltoid bursa, subcoracoid bursa, subacromial bursa and subscapular bursa are the bursae of the shoulder.

9-1: synarthrosis - suture

synarthrosic category, fibrous joint. interlocking line of union between bones connected by dense fibrous connective tissue.

9-1: synarthrosis - synostosis

synarthrosis category, bony joint. created when two bones fuse and the boundary between them disappears, like the rare frontal suture of the frontal bone or the epiphyseal lines of mature long bones.

9-1: synarthrosis - synchondrosis

synarthrosis category, cartilaginous joint. a rigid cartilaginous bridge between two articulating bones, like the connection between the first pair of vertebrosternal ribs and the manubrium of the sternum. Epiphyseal cartilage is used in many of these joints.

9-1: synarthrosis - gomphosis

synarthrosis category, fibrous joint. binds teeth to boney sockets in maxillae and mandible.

9-3: special movements at synovial joints - depression and elevation

take place when we move a structure inferiorly and superiorly. You depress your mandible when you open your mouth and elevate your mandible as you close your mouth.

9-5: accessory structures of knee joint - tibial (or medial) collateral ligament and fibular (or lateral) collateral ligament

the MCL reinforces the medial surface of the knee joint and the LCL reinforrces the lateral surface They tighten only at full extension.

9-8: the skeletal system supports and stores energy and minerals for other body systems

the body undergoes constant remodeling, the balance between osteoblast and osteoclast activity is subject to change. When osteoblasts dominate, bones thicken and strengthen. When osteoclasts dominate, the bones thin and weaken. the balance of formation and recycling of bone varies with age, physical stresses applied to bone, circulating hormone levels, amounts of calcium and phosphorus absorption and excretion, and genetic or environmental factors. bones of skeleton are attachment sites for muscular system which is extensively connected with cardiovascular and lymphatic system and under the control of the endocrine system. the digestive and urinary systems provide the calcium and phosphate minerals needed for bone growth so the skeleton can have a reserve of them once absorbed into blood stream from digestive tract of the dietary minerals.

9-4: vertebral movements

the vertebral column can experience these movements; flexion (bending anteriorly), extension (bending posteriorly), lateral flexion (bending laterally) and rotation.

9-3: types of movements at synovial joints - special movements

these special terms apply to specific joints or unusual types of movement; inversion, eversion, dorsiflexion and plantar flexion, opposition and reposition, protraction and retraction, depression and elevation, and lateral flexion.

9-7: gouty arthritis

too much uric acid in blood causes this. uric acid = waste product of breakdown of purines (ATP and A and G nucleotides) crystals of uric acid form within the synovial fluid of joints, causing an accumulation of crystals of uric acid overtime that interferes with normal movement. its rare but there are other forms of gouty arthritis that are much more common. 30-60% of those over age 85 have some degree of calcium salt deposition.

9-5: the knee joint

transfers the weight of the body from the femur to the tibia. functions as a hinge but is more complex than elbow or ankle. rounded condyls of femur roll across superior surface fo tibia, constantly changing the points of contact. 3 articulations; two between femur and tibia and one between patella and patellar surface of femur. has a thin and in spots, incomplete joint capsule, also have various ligaments and tendons of associated muscles to strengthen it. a pair of fibrocartilage pads (medial and lateral menisci) lie between femoral and tibial surfaces to cushion, conform to shape of articulating surface with changing position, and provides lateral stability.

9-2: synovial joints - accessory structures: synovial tendon sheaths

tubular bursae that surround tendons where they cross bony surfaces.

9-3: types of movements at synovial joints - gliding movements

two opposing surfaces slide past one another in one plane. Occurs between the flat or nearby flat surfaces of articulating carpal bones, between tarsal bones, and between the clavicles and the sternum. Movement can occur in any direction, but amount of movement is slight and rotation is prevented by capsule and associated ligaments.

9-2: synovial joints - synovial fluid's lubrication

when part of an articular cartilage is compressed, some of the synovial fluid is squeezed out of the cartilage like a sponge, and into the space between the opposing surfaces. reduces friction between surfaces, and gets reabsorbed into the cartilage when compression stops.