1
Q
How do the joints of the skeletal system contribute to homeostasis?
A
- by holding bones together in ways that allow for movement and flexibility
- by acting as fulcrums that act as fixed point of stability
2
Q
what is a joint?
A
articulation
arthrosis
- a point of contact between bones, cartilage and bones, or teeth and bones
3
Q
what is kinesiology?
A
the study of motion of the human body
4
Q
what is arthrology?
A
the scientific study of joints
5
Q
what are the three principal types of joints?
A
- synovial
- cartilaginous
- fibrous
6
Q
what are fibrous joints?
A
A joint in which the articulating bones are held together by dense irregular connective tissue (mainly collagen fibres) and allows little to no movement
7
Q
what does the degree of movement in fibrous joints depend on?
A
on the length of the collagen fibres that join the articulating bones
the longer the collagen fibres, the more movable
the shorter the collagen fibres, the more immovable
8
Q
what are the subtypes of fibrous joints?
A
- sutures
- syndesmoses
9
Q
what are cartilaginous joints?
A
A joint without a synovial cavity where the articulating bones are held together by hyaline or fibrous cartilage, allowing little to no movement
10
Q
what are the subtypes of cartilaginous joints?
A
- synchondroses
- symphyses
11
Q
what is a synovial joint?
A
A slightly movable to fully movable joint in which a lubricated articular cavity is present between the articulating bones which are united by a two-layered articular capsule
12
Q
what is the lubrication in synovial joints supplied by?
A
the inner layer of the articular capsule
13
Q
what are the subtypes of synovial joints?
A
- Ball-and-socket
- Ellipsoid
- Hinge
- Pivot
- Plane
- Saddle
14
Q
what is a suture?
A
an immovable fibrous joint composed of a thin layer of dense irregular connective tissue that joins skull bones
15
Q
why are sutures strong and unlikely to fracture?
A
due to their irregular, interlocking edges
- can absorb shock
16
Q
what is a synostosis?
A
a fibrous joint in which the dense irregular connective tissue that unites bones at a suture has been replaced by bone, resulting in complete fusion across the suture line
17
Q
what is a syndesmosis?
A
a slightly movable fibrous joint in which the articulating bones are united by dense irregular connective tissue
18
Q
how is a syndesmosis different from a suture?
A
- generally a greater distance between the articulating surfaces than in sutures
- more dense irregular connective tissue than in sutures
19
Q
what are the different types of syndesmoses?
A
- interosseous ligament
- interosseous membrane
- gomphosis
20
Q
what is an interosseous ligament?
A
a syndesmosis that has fibrous connective tissue arranged as a ligament that permits limited movement
21
Q
what is an interosseous membrane?
A
a syndesmosis with a substantial sheet of dense irregular connective tissue that binds neighbouring long bones and permits slight movement
- plays important role in defining range of motion btwn the neighbouring bones
- provides increased attachment surface for muscles
22
Q
what is a gomphosis?
A
a fibrous joint in which a cone-shaped peg fits into a socket with a small amount of dense irregular connective tissue
- permits minute shock-absorbing movements
23
Q
what is the thin periodontal ligament?
A
The dense irregular connective tissue between a tooth and its dental alveolus
24
Q
what is a synchondrosis?
A
cartilaginous joint in which the connecting material is a solid piece of hyaline/fibrous cartilage that allows little or no movement
25
what is an epiphyseal cartilage?
a type of synchondrosis that is actually an hyaline cartilage growth center during endochondral bone formation, not a joint associated with movements
- immovable joint
ex. epiphyseal growth plate in growing long bones
26
what does damage to the epiphyseal cartilage lead do?
Breaks in a bone that extend into the epiphyseal plate and damage the cartilage of the synchondrosis can affect further growth of the bone, leading to **abbreviated development** and a bone of shortened length
27
what happens to epiphyseal cartilages when bone elongation ceases?
bone replaces the hyaline cartilage, and becomes a synostosis, a bony joint
28
what is a symphysis?
a **slightly movable** cartilaginous joint in which the ends of the articulating bones are covered with **hyaline cartilage**, but a broad, flat disc of **fibrous cartilage** connects the bones
29
what is the main characteristic that distinguish synovial joints from other joints?
presence of articular cavity btwn articulating bones
30
what is an articular cavity?
The space between the articulating bones of a synovial joint, filled with **synovial fluid**
- surrounded by an articular capsule that attaches the articulating bones
31
what does the presence of an articular cavity permit?
a wide range of movements from slightly movable to freely movable
32
what is articular cartilage?
layer of **hyaline cartilage** that covers the surface of articulating bones within a synovial joint
33
what is the function of the articular cartilage?
- covers the articulating surfaces of the bones with a **smooth, slippery surface** but does not bind them together
- reduces **friction** between bones in the joint during movement
- absorbs **shock**
34
what is autologous chondrocyte implantation?
healthy chondrocytes taken from a femoral condyle area that is not weight-bearing and cultured to generate between 5 million and 10 million cells
- cultured chondrocytes are injected under the periosteum after damaged area prepped by removing dead cartilage
- patient can put the full weight of the body on the knee in about 10 to 12 weeks
- candidates for ACI have cartilage damage due to acute or repetitive trauma, not arthritis
35
what is an articular capsule?
A sleevelike structure of a synovial joint that encloses the articular cavity and units the articulating bones; composed of an **outer fibrous layer** and an **inner synovial membrane**
36
what is the outer fibrous layer of the articular capsule?
layer consisting of **dense irregular connective tissue** that attaches to the periosteum of the articulating bones (thickened continuation of the periosteum btwn the bones)
37
what does the flexibility of the articular capsule's fibrous layer do?
permits considerable movement at a joint
38
what does the tensile strength of the articular capsule's fibrous layer do?
tensile strength (resistance to stretching) helps prevent the bones from dislocating
39
what is a ligament?
parallel bundles of **dense regular connective tissue** that attaches bone to bone and are highly adapted to **resisting strains**
40
what is the inner synovial membrane of the articular capsule?
inner layer that is composed of **areolar connective tissue** with collagen and elastic fibers
41
what are articular fat pads?
accumulations of adipose tissue in synovial membranes
42
do "double-jointed" people really have double joints?
NO
- they have greater flexibility in their articular capsules and ligaments
- increased **range of motion**
- less structurally stable
- easily dislocated
43
what is synovial fluid?
a viscous (gel-like), clear or pale yellow fluid secreted by the synovial membrane and forms a thin film over the surfaces within the articular capsule
44
what does synovial fluid consist of?
- **hyaluronic acid** secreted by synoviocytes in the synovial membrane
- **interstitial fluid** filtered from blood plasma
45
what are the functions of synovial fluid?
- reduces **friction** by lubricating the joint
- absorbs **shocks**
- supplies O2 and nutrients to the chondrocytes
- removes CO2 and metabolic wastes from the chondrocytes
- contains **phagocytic cells **that remove microbes and debris from normal wear and tear
46
What is one benefit of warming up before exercise when it comes to synovial fluid?
stimulates the production and secretion of synovial fluid; within limits, more fluid means less strain on the joints during exercise
47
what happens when a synovial joint is immobile for a time?
the fluid becomes quite viscous, but as joint movement increases, the fluid becomes less viscous
48
what are extracapsular ligaments?
accessory ligaments that lie outside articular capsule
49
what are intracapsular ligaments?
accessory ligaments that occur within the articular capsule but are excluded from the articular cavity by folds of the synovial membrane
50
what are menisci?
*articular discs*
crescent-shaped pads of **fibrous cartilage** that lie between the articular surfaces of the bones and are attached to the fibrous layer of the articular capsule
51
what is the function of the menisci?
- bind strongly to the inside of the fibrous layer and usually subdivide the synovial cavity into two spaces, **allowing separate movements** to occur in each space
- shock absorption
- better fit btwn articulating bony surfaces
- providing adaptable surfaces for combined movements
- weight distribution over a greater contact surface
- distribution of synovial fluid across the articular surfaces of the joint
52
what is a labrum?
found in ball-and-socket joints
ring-like **fibrous cartilage** lip that extends from the circumference of the joint socket
53
what is the function of a labrum?
- helps deepen the joint socket
- increases the area of contact between the socket and the ball-like surface
54
what are bursae?
saclike structures that are strategically situated to alleviate friction in some joints by cushioning the movement between these body parts against one another
- walls consist of an outer fibrous layer of thin, dense irregular connective tissue lined by a synovial membrane
- filled with synovial fluid
55
what is a torn cartilage?
A tearing of an articular disc (meniscus) in the knee
56
what is arthroscopy?
minimally invasive procedure for examining the interior of a joint, usually the knee, by inserting an arthroscope into a small incision; used to determine extent of damage, remove torn cartilage, repair cruciate ligaments, and obtain samples for analysis
57
what is a menisectomy?
removal of an entire meniscus
58
what are tendon sheaths?
tubelike bursae that wrap around certain tendons that experience considerable friction as they pass through tunnels formed by connective tissue and bone
59
what are the inner and outer layer of the tendon sheaths called?
inner - visceral (attached to surface of tendon)
middle - cavity w/ synovial fluid
outer - parietal (attached to bone)
60
what is the function of tendon sheaths?
reduce friction around joints
- protects all sides of a tendon from friction as the tendon slides back and forth
61
what are the four main categories of movements at synovial joints?
1. gliding
2. angular
3. rotation
4. special movements
62
what is gliding?
- nearly flat bone surfaces move back-and-forth and from side-to-side with respect to one another
- limited in range due to the structure of the articular capsule and associated ligaments and bones
- can be combined with rotation
63
Where do gliding movements occur?
- intercarpal joints
- intertarsal joints
64
what are angular movements?
an increase or a decrease in the angle between articulating bones
65
What are two examples of flexion that do not occur along the sagittal plane?
- flexion of the thumb towards opposite side of palm
- movement of trunk sideways at the waist (lateral flexion)
66
what is hyperextension?
a clinical condition associated with injury, used to describe a movement beyond the normal range of motion
ex. may occur at joints such as the elbow, interphalangeal joints, and knee joint
67
what is circumduction?
movement of the distal end of a body part in a circle
- not an isolated movement by itself but rather a continuous sequence of the other movements
- does not occur along a separate axis or plane of movement
68
what is rotation?
Movement of bone around longitudinal axis
69
what is a plane joint?
*arthrodial joint*
articulating surface of bones are flat or slightly curved
- primarily permit back-and-forth and side-to-side movements between the flat surfaces of bones, but they may also rotate against one another
- many are **biaxial**
70
what is a hinge joint?
a joint where convex surface of one bone fits into the concave surface of another bone
- produce an angular, opening-and-closing motion
- many are **uniaxial**
71
what is a pivot joint?
*trochoid joint*
- rounded or pointed surface of one bone articulates with a ring formed partly by another bone and partly by a ligament
- **uniaxial**
72
what is an ellipsoid joint?
*condylar joint*
- convex oval-shaped projection of one bone fits into the oval-shaped depression of another bone
- **biaxial** (F-E, Ab-Ad) limited circumduction
73
what is a saddle joint?
*sellar joint*
- articular surface of one bone is saddle-shaped, and the articular surface of the other bone fits into the “saddle” as a sitting rider would sit
- **biaxial** (F-E, Ab-Ad) limited circumduction
74
what is a ball-and-socket joint?
*spheroidal joint*
- ball-like surface of one bone fitting into a cuplike depression of another bone
- **triaxial** (F-E, Ab-Ad, rotation)
75
What are the factors that affect contact and range of motion at synovial joints?
1. structure&shape of articulating bones
2. strength&tension of joint ligaments
3. arrangement&tension of muscles
4. contact of soft parts
5. hormones
6.disuse
76
what is range of motion?
amount of movement, measured in degrees of a circle, through which the bones of a joint can move
77
how does structure and shape of articulating bones affect ROM at synovial joints?
The structure or shape of the articulating bones determines how closely they can fit together
78
how does strength and tension of joint ligaments affect ROM at synovial joints?
The different components of an articular capsule are tense or taut only when the joint is in certain positions
- Tense ligaments not only restrict the range of motion but also direct the movement of the articulating bones with respect to each other
79
how does arrangement and tension of the muscles affect ROM at synovial joints?
Muscle tension reinforces the restraint placed on a joint by its ligaments, and thus restricts movement.
80
how does contact of soft parts affect ROM at synovial joints?
The point at which one body surface contacts another may limit mobility.
81
how do hormones affect ROM at synovial joints?
hormones can induce changes in the cartilages and ligaments changing the function of the joint
(ex. relaxin, a hormone produced by the placenta and ovaries, increases the flexibility of the fibrous cartilage of the pubic symphysis and loosens the ligaments, permitting expansion of the pelvic outlet, which assists in delivery of the baby.)
82
how does disuse affect ROM at synovial joints?
Movement at a joint may be restricted if a joint has not been used for an extended period. Disuse may also result in decreased amounts of synovial fluid, diminished flexibility of ligaments and tendons, and muscular atrophy, a reduction in size or wasting of a muscle.
83
what are the movements that the temporomandibular joint can make?
- depression-elevation
- protraction/retraction
- slight rotation
84
Why does the glenohumeral joint have more freedom of movement than any other joint of the body?
The glenohumeral joint is the most freely movable joint in the body because of the looseness of its articular capsule and the shallowness of the glenoid cavity in relation to the size of the head of the humerus.
85
what movements can the glenohumeral joint make?
- flexion-extension
- abduction-adduction
- medial/lateral rotation
- circumduction
86
what is rotator cuff injury?
- a strain or tear in the rotator cuff muscles
- due to shoulder movements that involve vigorous circumduction
- wear and tear, aging, trauma, poor posture, improper lifting, and repetitive motions
87
why is the glenohumeral joint the most commonly dislocated joint in adults?
its socket is quite shallow and the bones are held together by supporting muscles
88
what is a separated shoulder?
an injury to the acromioclavicular joint due to partial/complete tearing of ligaments
89
what is a torn glenoid labrum?
fibrous cartilage labrum may tear away from the glenoid cavity. This causes the joint to catch or feel like it’s slipping out of place
90
what movements can the elbow joint make?
flexion and extension
91
what is a tennis elbow?
pain at or near the lateral epicondyle of the humerus, usually caused by an improperly executed backhand. The extensor muscles strain or sprain, resulting in pain
92
what is a little league elbow?
inflammation of the medial epicondyle, typically develops as a result of a heavy pitching schedule and/or a schedule that involves throwing curve balls
93
what is dislocation of the radial head?
head of the radius slides past or ruptures the radial annular ligament
- most apt to occur when a strong pull is applied to the forearm while it is extended and supinated, for instance, while swinging a child around with outstretched arms
94
what movements can the hip joint make?
flexion, extension, abduction, adduction, lateral rotation medial rotation, and circumduction of the thigh
95
why is the hip joint so stable?
- very strong articular capsule and its accessory ligaments
- fovea capitis stabilizes the manner in which the femur fits into the acetabulum
96
what is the function of the anterior cruciate ligament?
limits hyperextension of the knee and prevents the anterior sliding of the tibia on the femur
97
what is the function of the posterior cruciate ligament?
prevents the posterior sliding of the tibia (and anterior sliding of the femur) when the knee is flexed. This is very important when walking down stairs or a steep incline.
98
why are ACL injuries more common in females?
may be related to less space between the femoral condyle in females so that the space for ACL movement is limited; the **wider pelvis of females that creates a greater angle between the femur and tibia** and increases the risk for an ACL tear; female hormones that allow for greater flexibility of ligaments, muscles, and tendons but which do not permit them to absorb the stresses put on them, thus transferring the stresses to the ACL; and females’ lesser muscle strength, causing them to rely more on the ACL to hold the knee in place
99
what is the function of the medial and lateral menisci?
help compensate for the irregular shapes of the bones and circulate synovial fluid
100
what is the function of the fibular collateral ligament?
strengthens the lateral aspect of the joint
101
what movements can the knee joint make?
flexion, extension, slight medial rotation, and lateral rotation of the leg in the flexed position
102
why is the knee joint the most vulnerable joint to damage?
- is a mobile, weight- bearing joint and its stability depends almost entirely on its associated ligaments and muscles
- no complementary fit between the surfaces of the articulating bones
103
why do knees become swollen after an injury?
- initial swelling due to escape of blood from damaged blood vessels adjacent to areas of injury, including rupture of the anterior cruciate ligament, damage to synovial membranes, torn menisci, fractures, or collateral ligament sprains
- Delayed swelling due to excessive production of synovial fluid, a condition commonly referred to as “water on the knee”
104
why is the firm attachment of the tibial collateral ligament to the medial meniscus clinically important?
because tearing of the ligament typically also results in tearing of the meniscus
- Such an injury may occur in sports when the knee receives a blow from the lateral side while the foot is fixed on the ground
- The force of the blow may also tear the ACL, which is also connected to the medial meniscus
105
what is a dislocated knee?
the displacement of the tibia relative to the femur
- most common type is dislocation anteriorly, resulting from hyperextension of the knee
- A frequent consequence is damage to the popliteal artery
106
what is the effect of aging in joints?
- decreased production of synovial fluid in joints
- articular cartilage thinner
- ligaments shorten and lose flexibility
107
what is rheumatism?
any painful disorder of the **supporting structures of the body**—bones, ligaments, tendons, or muscles—that is not caused by infection or injury
108
what is arthritis?
a form of rheumatism in which the joints are swollen, stiff, and painful
109
what is osteoarthritis?
- a degenerative joint disease in which joint cartilage is gradually lost and new osseous tissue are deposited on exposed bone ends in a misquided effort to protect against increased friction
- wear-and-tear arthritis
110
why are spurs from osteoarthritis bad?
spurs decrease the space of the articular cavity and restrict joint movement
111
how is osteoarthritis and rheumatoid arthritis different?
- osteoarthritis affects mainly the articular cartilage
- osteoarthritis first afflicts the larger joints (knees, hips) and is due to wear and tear
- rheumatoid arthritis in its early stage first strikes smaller joints (interphalangeal of the hands and feet) and is an active attack on the cartilage
112
what is rheumatoid arthritis?
- autoimmune disease in which the immune system of the body attacks its own tissues—in this case, its own cartilage and joint linings
- inflammation of the joint, which causes swelling, pain, and loss of function.
- occurs bilaterally
- inflammation of the synovial membrane
113
what is pannus?
abnormal granulation tissue produced by synovial membrane that adheres to the surface of the articular cartilage and sometimes erodes the cartilage completely. When the cartilage is destroyed, fibrous tissue joins the exposed bone ends. The fibrous tissue ossifies and fuses the joint so that it becomes immovable
114
what is gouty arthritis?
- sodium urate crystals are deposited in the soft tissues of the joints
- crystals irritate and erode the cartilage, causing inflammation, swelling, and acute pain, eventually destroying all joint tissues
- if untreated, the ends of the articulating bones fuse, and the joint becomes immovable
115
what is the bacteria that causes Lyme disease?
Borrelia burgdorferi
116
what is a sprain?
- forcible wrenching or twisting of a joint that stretches or tears its ligaments but does not dislocate the bones
- ligaments are stressed beyond their normal capacity
117
what is a strain?
a stretched or partially torn muscle or tendon. It often occurs when a muscle contracts suddenly and powerfully
118
what is tenosynovitis?
- an inflammation of the tendons, tendon sheaths, and synovial membranes surrounding certain joints
- condition often follows trauma, strain, or excessive exercise
119
Katie loves pretending that she’s a human cannonball. As she jumps off the diving board, she assumes the proper position before she pounds into the water: head and thighs tucked against her chest; back rounded; arms pressed against her sides while her forearms, crossed in front of her shins, hold her legs tightly folded against her chest. Use the proper anatomical terms to describe the position of Katie’s back, head, and limbs.
Katie’s vertebral column, head, thighs, lower legs, lower arms, and fingers are flexed. Her forearms and shoulders are medially rotated. Her thighs and arms are adducted.
120
During football practice, Jeremiah was tackled and twisted his leg. There was a sharp pain, followed immediately by swelling of the knee joint. The pain and swelling worsened throughout the remainder of the afternoon until Jeremiah could barely walk. The coach told Jeremiah to see a doctor who might want to “drain the water off his knee.” What was the coach referring to and what specifically do you think happened to Jeremiah’s knee joint to cause these symptoms?
The knee joint is commonly injured, especially among athletes. The twisting of Jeremiah’s leg could have resulted in a multitude of internal injuries to the knee joint but often football players suffer tearing of the anterior cruciate ligament and medial meniscus. The immediate swelling is due to blood from damaged blood vessels, damaged synovial membranes, and the torn meniscus. Continued swelling is a result of a buildup of synovial fluid, which can result in pain and decreased mobility. Jeremiah’s doctor may aspirate some of the fluid (“draining the water off his knee”) and might want to perform arthroscopy to check for the extent of the knee damage.
121
After lunch, during a particularly long and dull class video, Antonio became sleepy and yawned. To his dismay, he was then unable to close his mouth. Explain what happened and what should be done to correct this problem.
The condylar processes of the mandible passed anteriorly to the articular tubercles of the temporal bones, and this dislocated Antonio’s mandible. It could be corrected by pressing the thumbs downward on the lower molar teeth and pushing the mandible backward.
122
why is the glenohumeral joint the most freely movable joint in the body?
because of the looseness of its articular capsule and the shallowness of the glenoid cavity in relation to the size of the head of the humerus
123
what is an unhappy triad?
a knee injury that involves damage at the same time to the:
1. tibial collateral ligament
2. medial meniscus
3. anterior cruciate ligament
124
what is treatment for knee injuries if no surgery needed?
PRICE
P - protection
R - rest
I - ice
C - compression
E - elevation
