chapter 8 articulations Flashcards
(85 cards)
1
Q
What is the trade-off between strength and mobility in a joint?
A
The greater the mobility of a joint the weaker it is?
* Example: more mobility (as in the shoulder joint) means less strength, which is why it is much easier to damage the tissues of the shoulder when compared to the hip
2
Q
What factors influence mobility?
A
- the shapes of the articulating bony surfaces
- the presence or absence of other bones, muscles, or fat pads around the joint
- accessory ligaments and fibers of the joint capsule
- tension of muscles and/or tendons which insert or originate at the joint
3
Q
Three types of classification exist for the connective tissue types within joints that have no cavity
A
bone joints
fibrous joints
cartilaginous joints
4
Q
Bone joints
A
there is no cavity and there is fusion of bones
- example) fusion of the frontal suture and the the epiphyseal line in the growth of a long bone
5
Q
fibrous joints
A
there is no cavity and dense regular connective tissue binds the bones together
- little or no movement (Synarthrosis or Amphiarthrosis)
- example) sutures (S), syndesmosis (A), gomphoses (S)
6
Q
Cartilaginous joints
A
there is no cavity and cartilage (hyaline or fibrocartilage) holds the bones together
- little or no movement (Synarthrosis or Amphiarthrosis)
- example) synchondrosis (S), symphysis (A)
7
Q
synovial joint
A
name given to joints that have a cavity between the bones (most joints in a human body are synovial)
8
Q
Name the three types of joints classified by movement.
A
- Immovable Joints: Synarthroses
- Partially movable: Amphiarthrosis
- Moveable: Diarthroses
9
Q
Synarthroses
A
- immovable joint between two bones
- Synarthroses containing bone: synostoses
- Synarthroses held together by fibrous tissue: sutures (ex: sutures of skull) or gomphoses
- Synarthroses held together by cartilage: synchondroses (ex: epiphyseal growth cartilage or joints between ribs and sternum which cannot move)
10
Q
Amphiarthrosis
A
- joints that allow partial movement (like interosseous membrane between tibia/fibula and ulna/radius)
- amphiarthrosis held together by fibrous tissue: syndesmosis (ankle)
- amphiarthrosis held together by cartilage: symphysis (ex: symphysis pubis & intervertebral discs)
11
Q
Diarthrosis
A
- joints that are freely movable
- also synovial joints are diarthrosis
- monaxial, biaxial, triaxial movement
12
Q
Why would it be important to have a symphysis at the articulation of the pubic bones of the os coxae? The intervertebral discs? What function does fibrocartilage provide in these joints?
A
os coxae: to allow the pubic symphysis to become more mobile to allow the pelvis to change shape slightly as the fetus passes through the birth canal
intervertebral discs: the collective movements of all the intervertebral discs afford the spine considerable flexibility
Function of fibrocartilage: resist both compression and tension stress and acts a resilient shock absorber
13
Q
Name the structures in a synovial joint.
A
synovial cavity
articular cartilage
articular/joint capsule
synovial membrane
synovial fluid
accessory structures: sensory nerves & blood vessels
14
Q
Synovial Cavity:
A
lies between two articular cartilages that are the hyaline cartilage remnants of endochondral bone formation
15
Q
Articular cartilages
A
made of hyaline cartilage which decreases friction between bones while the matrix absorbs shock
16
Q
Articular/Joint capsule
A
- Surrounds joint/diarthrosis
- Encloses synovial cavity and resists mechanical stress
- Unites articulating bones
- Has two layers
- outer fibrous layer: contains ligaments that help hold the bones together
- inner synovial membrane: secretes synovial fluid
- flexibility of fibrous capsule permits movement and tensile strength helps prevent bone dislocation
17
Q
Synovial membrane
A
- Inner lining of articular capsule
- Secretes a lubricating synovial fluid which provides nutrients to the articular cartilages
18
Q
Synovial fluid
A
- Slippery hyaluronic acid
- Provides shock absorption, as well as lubrication in the join
- Vehicle for nutrients/oxygen/waste: provides nutrients to articular cartilage
- Circulation driven by joint movement: use it or lose it
19
Q
Accessory structures in simple synovial joints
A
Sensory nerves
Blood vessels
20
Q
Found in complex joints
A
- Has everything found in simple synovial joints but also has…
- Bursae
- Tendon sheaths: allow tendon to move without adhering to surrounding fascial layers
- Retinacula: large areas around the ankle and wrist, which hold tendinous sheaths to minimize friction
- Accessory ligaments/structures: separate from the joint capsule (cartilage/fat pads/menisci)
- Intrinsic (capsular) ligaments: help support, strengthen, reinforce joints
21
Q
What are the functions of synovial fluid and why is it important to keep joints moving?
A
- Provides shock absorption, as well as lubrication in the joint
- flexibility of the fibers capsule and synovial fluid permit movement, the strength of the capsule and ligaments prevent dislocation
- Use it or lose it applies to joints because joint movement drives the circulation of synovial fluid, helps prevent arthritis
22
Q
What are the functions of bursae?
A
- Sac like structures between structures
- found in more complex joints
- Found in joints where there is contact between skin and bone, tendon and bone, ligament and bone
- Composed of outer connective tissue layer that reduces friction in areas that are not part of a joint, but are still moving and creating friction
- Some bursae cushion bony structures
- Some bursae surround tendons
23
Q
Types of movement allowed at a synovial joint:
A
- Gliding (linear) movement
- Angular movement
- Rotational movement
- Special movement
24
Q
Gliding (linear/planar) movement
A
- Occur when relatively flat bone surfaces move back-and-forth from side to side
- No significant alteration of angle between bones
- Slight movement and almost any direction
*Carpals, tarsals, sternoclavicular joint
25
Angular movement
* Cause increase or decrease in angle between articulating bones
* Example) flexion, extension, hyperextension, adduction, abduction, circumduction
26
Rotational movement
* Bone revolves around its own longitudinal axis
* Pronation, supination, internal/external rotation,
* Pivot (axis and atlas) and ball and socket joint have rotational movement
27
Special movement
* only occur at specific joints
* Foot: eversion, inversion, dorsiflexion, plantar flexion
* Shoulder & temporomandibular joints: protraction, retraction, elevation, depression
* Opposition: allowed at joint between trapezium and metacarpal one, also called a saddle joint; thumb moves across the palm to touch the tips of each digit, allows hand to grasp objects
* Pronation and supination are rotational movements, but can also be considered special movements since they only occur in forearm
28
flexion
a decrease in the angle between the bones
29
lateral flexion
movement of the trunk to the right or left at the waist; movement occurs in the frontal plane between the intervertebral joints
30
extension
and increase in the angle between articulating bones, usually returning a flex body part to its original position
31
hyperextension
a continuation of extension beyond the anatomical position, usually prevented by the arrangement of bones and ligaments at the joint
32
abduction
movement of the bone away from the midline
33
adduction
movement of the bone toward the midline
34
circumduction
movement of the distal end of a body part in a circle; result of a continuous sequence of flexion, abduction, extension, and abduction
35
eversion
movement of the soles laterally
36
inversion
movement of the soles medially
37
dorsiflexion
pointing the toes upward
38
plantarflexion
pointing the toes downward
39
protraction
shoulders or jaw moved forward
40
retraction
shoulders and jaw moved backwards
41
elevation
movement upwards (closing mouth or shrugging shoulders
42
depression
movement downwards (opening mouth or putting down shoulders)
43
opposition
thumb moves across the palm to touch the tips of the digits
44
6 types of synovial joints
Plane
Hinge
Pivot
Condylar
Saddle
Ball and socket
45
Planar joint
* gliding joints
* Bone services are flat or slightly curved
* Side to side movement only
* Rotation prevented by ligaments
* Example: intertarsals & intercarpals joint, Sternoclavicular joint, and sternoclavicular joints
46
hinge
* Monaxial, permit only flexion and extension
* Movement in one plane
* Elbow, knee, ankle, joints between the flanges of the digits
47
pivot
* Monaxial, rotational joint
* Atlanto-axial joint (“no” joint) and the radio-ulnar joints for pronation and supination
48
condylar
* biaxial
* Oval shaped projection fits into oval depression
* Concave depression of one bone fits into the convex projection of another bone
* Allow flexion/extension and abduction/adduction, examples include the radius with the scaphoid and lunate of the wrist
* Wrist and metacarpophalangeal joints for digits 2-5
49
saddle
* multiaxial or biaxial
* Only one joint in the body is a saddle joint; the thumb
* Allows flexion and extension and abduction and abduction, as well as opposition
50
ball and socket
* multiaxial
* Allows flexion/extension, abduction/adduction, and rotation
* Hip and Glenohumeral (most movable joint in the body)
51
Which joint allows opposition?
Saddle joint between metacarpal I and the trapezium allows a movement called opposition of the thumb-the action taken when you touch your thumb to the tips of the other fingers on the same hand. It is opposition that makes the human hand such a fine tool for grasping and manipulating objects.
52
Which type of synovial joint is the most moveable?
Shoulder (glenohumeral joint)
* ball and socket joint
* Head of humerus and glenoid fossa of scapula
* Allows flexion, extension, abduction, adduction, medial rotation, lateral rotation, and circumduction of arm
* The most movable, but also the most susceptible to dislocation
53
Know the structures which stabilize the glenohumeral joint/rotator cuff
* this is the shoulder joint
* must be stabilized by ligaments, tendons, bursae, and muscles
* four muscles that stabilize rotator cuff: supraspinatus, infraspinatus, teres minor, and subscapularis
54
Know the structures which stabilize the acetabulofemoral joint
* this is the hip joint
* Formed by head of femur and acetabulum of innominate bone
* iliofemoral ligament: from iliac bone to femur; strongest in body and prevents hyperextension of femur
* ischiofemoral ligament: from ischium to femur; prevents hyperextension of femur
* pubofemoral ligament: from pubis to femur; prevents excess abduction and extension
* One of strongest structures in the body in despite its mobility
55
Why are two different types of movement allowed at the TMJ?
* this is the temporomandibular joint
* two synovial joints in one articular capsule separated by articular disc
* Superior joint cavity: allows gliding movements (protraction, retraction, and lateral/medial movement)
* Inferior joint cavity: is a hinge joint, allowing depression and elevation (chewing)
56
Know the ligaments and structures that stabilize the knee joint.
* accessory ligaments: help support strengthen and reinforce the joint
* Lateral (fibular) collateral ligament & medial (tibial) collateral ligament stabilize the knee on each side
* Patellar ligament (quadriceps ligament): stabilize anterior aspect of knee
57
Stability of the knee joint is increased by…
* Two intracapsular ligaments
* Anterior cruciate (ACL): prevents tibia from sliding anteriorly on femur & also prevents hyperextension of knee
* Posterior cruciate (PCL): prevents tibia from sliding posteriorly on femur
* Named for where they attach on the tibial intercondylar eminence
* 13 bursae and fat pads to protect structures
58
Knee joint:
* Tibiofemoral joint
* largest and most complex joint in human body
* Consists of three separate joints within a single synovial cavity
* Allows for flexion extension, slight medial rotation, and slight lateral rotation when leg is flexed
* Complexity is due to the fact that the condyles of the femur and tibia do not fit together well and structures need to be placed to stabilize the joint
59
Why is it important that the ACL and the PCL are taut when the leg is extended?
* Anterior cruciate (ACL): prevents tibia from sliding anteriorly on femur & also prevents hyperextension of knee
* Posterior cruciate (PCL): prevents tibia from sliding posteriorly on femur
* Overall, it is to provide stability and prevent excessive movement in the knee joint
60
What is the function of the patella in terms of the knee joint?
* is a sesamoid bone within the quadriceps tendon
* Helps stabilize the joint anteriorly
61
What is the function of The menisci in terms of the knee joint?
* Consists of fibrocartilage discs within the joint
* C-shaped medial meniscus
* Almost circular lateral meniscus
* Attach to articular capsule and assist in transferring the load from the femur to the tibia
* Prevent condyles of femur from sliding off the tibia during flexion and extension of the knee
62
Understand the factors affecting movement at a joint and how they change
* structure and shape of the articulating bone
* strength and tautness of the joint ligaments
* arrangement and tension of the muscles or tendons which insert or originate at a joint
* contact of soft parts
* hormones (ex: relaxin during pregnancy)
* disuse
* aging
- decrease production of synovial fluid
- thinning of articular cartilage
- loss of ligament length and flexibility
- due to genetic factors as well as wear and tear on joints
63
Function of appendicular skeleton:
movement
64
Six main components of the appendicular skeleton:
* pectoral girdle
* brachium (arm)
* antebrachium (and hand)
* pelvic girdle
* thigh
* leg (and foot)
* all of the bones within these six main components
65
Radius and Ulna
* radius is lateral
* ulna is medial
* interosseous membrane lies between them and provides stability
66
Interosseous membrane:
tough thin sheet of connective tissue that helps distribute the compression stress ur loads placed on the hand and forearm between the two bones (ulna and radius)
67
How are joints classified?
* classification by structure: the presence or absence of a cavity between the bones and the connective tissue holding the bones together
* classification by movement
68
Plane movement of synovial joints
Monaxial : one plane
Biaxial: two planes
Triaxial: three planes
69
Sutures
* thin layer of dense fibrous connective tissue uniting bones of the skull
* Immovable (synarthrosis)
* If fused completely an adult = synostosis
70
Syndesmosis
* fibrous joint (bones united by a ligament)
* Slightly movable (amphiarthrosis
* Anterior tibiofibular joint
* Interosseous membrane
71
gomphosis
* Fibrous joint: ligament anchors cone-shaped peg in bony socket
* Immovable (synarthrosis)
* Teeth/alveolar processes
72
Synchondrosis
* Hyaline cartilage
* Immovable (synarthrosis)
* Epiphyseal plate or joints between ribs and sternum
73
Symphysis
* fibrocartilage
* Slightly movable (amphiarthrosis)
* Intervertebral discs and pubic symphysis
74
Bursitis/Sprain/Strain
bursitis: chronic inflammation of a bursa
Sprain: twisting of a joint, stretches, or tears ligaments, no dislocation of bones, may damage nearby blood vessels/muscles/tendons, swelling & hemorrhage from blood vessels
Strain: less serious injury, overstretched or partially torn muscle
75
Skeletal system:
bones provide protection and support for all systems, bone remodeling provides homeostasis of calcium
76
Skeletal system and integumentary system:
the skin provides vitamin D for bone remodeling, bones support muscles and overlying skin
77
Skeletal system and muscular system:
* components of skeletal system (bones, cartilage, and joints) provide an internal framework to support muscle attachment and movement
* calcium stored in bone is required for muscle contraction
78
Skeletal system and nervous system system:
* skull protects brain while vertebrae protect spinal cord
* calcium stored in bone is required for normal function of components of the nervous system
79
Skeletal system and endocrine system
* calcium is required for exocytosis of hormones from endocrine organs
* many hormones also use calcium as a second messenger
80
Skeletal system and cardiovascular system
* thoracic cage protects the heart
* red bone marrow produces blood cells through hematopoiesis
* calcium stored in bone is required for a contraction of heart muscle
81
Skeletal system and lymphatic/immune system
red bone marrow produces white blood cell cells
82
Skeletal system and respiratory system
* thoracic cage protects lungs and trachea
* diaphragm touches two ribs and vertebrae for breathing
* ribs assist diaphragm in creating a larger thoracic cavity for breathing
83
Skeletal system and urinary system
pelvis protects urinary bladder
84
Skeletal system and digestive system:
* teeth and dental alveoli of maxillae and mandible provide a mechanical breakdown of food
* thoracic cage protects esophagus, stomach, and liver, while the pelvis protects inferior portions of intestines and rectum
85
Skeletal system and reproductive system:
pelvis protects reproductive organs in both male and female
