Chapter 8: articulations Flashcards
what do joints do?
Joints hold bones together but MAY permit movement
what are the three points of contact?
between 2 bones
between cartilage and bone
between teeth and bones
what is arthrology?
the study of joints
what is Kinesiology?
the study of motion
what are the three classifications of joints? briefly describe them (based on movement)
Synarthrosis = immovable Amphiarthrosis = slightly moveable Diarthrosis = freely moveable
what are the three classifications of joints? (based on anatomy)
Fibrous (collagen fibers)
Cartilaginous (cartilage)
Synovial (joint capsule & accessory ligaments)
describe fibrous joints
- Lack a synovial cavity
- Bones held closely together by fibrous connective tissue
- Little or no movement (synarthroses or amphiarthroses)
what are the three structural types of fibrous joints?
sutures
syndesmoses
gomphoses
what is a suture?
are sutures moveable?
- Thin layer of dense fibrous connective tissue unites bones of the skull
- No they are immovable (synarthrosis)
if sutures fuse completely in adults this is known as what?
synostosis
describe syndesmoses
whats an example?
Fibrous joint bones united by ligament Slightly movable (amphiarthrosis)
example: Anterior tibiofibular joint and interosseous membrane
describe gomphoses
Ligament holds cone-shaped peg in bony socket
Immovable (synarthrosis)
Teeth in alveolar processes of maxillae or mandible
describe cartilage joints
Lacks a synovial cavity
Allows little or no movement
Bones tightly connected by fibrocartilage or hyaline cartilage
what are the two types of cartilage joints?
synchondroses
symphyses
describe synchondroses and give an example
Connecting material is hyaline cartilage
Immovable (synarthrosis)
example is Epiphyseal plate or joints between ribs and sternum
describe symphyses and give an example
Fibrocartilage is connecting material
Slightly movable (amphiarthroses)
example is Intervertebral discs and pubic symphysis
What are two features of synovial joints?
1) 2 bones separated by fluid-filled cavity
2) Joint capsule has 2 layers
- synovial membrane
- articular cartilage
what are the components of synovial fluid?
blood filtrate
hyaluronic acid
glycoproteins
what are the functions of synovial fluid?
lubricate joint surface
nourish chondrocytes
shock absorber
what two things do ligaments do?
reinforce & strengthen joint capsule
Connect bone to bone with dense regular CT
what are the two types of ligaments? where is each located and give an example of each
extracapsular ligaments:
outside joint capsule
Collaterals (ex. TCL)
intracapsular ligaments:
within capsule
Cruciates (ex. ACL)
what are articular disks? give an example
Pads of fibrous cartilage that subdivide a cavity
Ex: ulnolunate joint; knee joint
articular disks are also known as what?
Menisci
what are the functions of articular disks?
Channel flow of synovial fluid Modify articular surfaces Restrict movements at joint Cushion articulating surfaces Help distribute body weight
what are fat pads? give an example
Adipose tissue surrounding the synovial capsule
Ex: tibiofemoral joint
what are the functions of fat pads?
Protect articular cartilage
Packing material
Fills spaces when joint changes shape
what are bursae?
small, fluid filled pockets of connective tissue
what is the function of bursae?
cushion and support, aid movement of tendons
where is bursae located?
hypodermis; between tendons/ ligaments & bones
describe gliding movement
Two opposing surfaces slide past one another
describe angular movement
A change in angle between the shaft and the articular surface
describe circumduction movement
A type of angular motion
Rotation of the shaft while changing the angle
describe rotation
Spinning of the shaft without changing the angle
what are the five types of angular movement?
Abduction Adduction Flexion Extension Hyperextension
what are the two types of rotation?
supination
pronation
slides 27 and 28 for other special movements
synovial joints are trade off between flexibility and stability because…….
Shape of articulating surfaces
Tightness of ligaments
Presence of accessory ligaments
Other factors: other bones, muscles or fat pads
what are the 6 types of synovial joints?
Plane, hinge, pivot, condylar, saddle, ball-and-socket
describe a plane joint and give an example
Bone surfaces are flat or slightly curved Side to side movement only Rotation prevented by ligaments Examples: intercarpal or intertarsal joints sternoclavicular joint vertebrocostal joints
describe a hinge joint and give an example
Convex surface of one bones fits into concave surface of 2nd bone
Uniaxial like a door hinge
Examples:
Knee, elbow, ankle, interphalangeal joints
what types of motion do hinge joints allow?
flexion = decreasing the joint angle extension = increasing the angle hyperextension = opening the joint beyond the anatomical position
describe a pivot joint and give an example
Rounded surface of bone articulates with ring formed by 2nd bone & ligament Uniaxial since it allows only rotation around longitudinal axis Examples: Proximal radioulnar joint (supination) (pronation_ Atlanto-axial joint (turning head side to side “no”)
what happens in a condylar joint?
Oval-shaped projection fits into oval depression
condylar joints are biaxial… what does this mean? examples?
Biaxial = flex/extend or abduct/adduct is possible
Examples:
wrist and metacarpophalangeal joints for digits 2 to 5
how does a saddle joint work?
One bone saddled-shaped; other bone fits as a person would sitting in that saddle
is a saddle joint biaxial? describe
- Circumduction allows tip of thumb travel in circle
- Opposition allows tip of thumb to touch tip of other fingers
where is a saddle joint located?
trapezium of carpus and metacarpal of the thumb
how does a ball and socket joint work?
Ball fitting into a cuplike depression
is a ball and socket joint biaxial? describe
no it is Multiaxial
- flexion/extension
- abduction/adduction
- rotation
what are some examples of a ball and socket joint?
shoulder joint and hip joint
describe the temporomandibular joint
Hinge joint
between condylar process of mandible & mandibular fossa
Condyles slide back & forth along joint socket
2 synovial joints
slide 37
:)
what do intervertebral discs do?
Allows flexion, extension, lateral flexion & rotation
what are the two parts to the intervertebral disc?
Anulus fibrosus (fibrocartilage) Nucleus pulposus (composed of 75% water, hyaluronic acid, reticular and elastic fibers)
what is a herniated disk?
- ‘slipped disc’
- Nucleus pulposus breaks through annulus fibrosus
- Movements of vertebral column compresses nucleus
what is the glenohumeral joint?
Head of humerus meets glenoid cavity
shoulder joint
in the glenohumeral joint, the glenoid cavity is covered by glenoid labrum. What is this?
A ring of dense irregular connective tissue attached to the margin of the glenoid cavity
there are two joints that make up the elbow joint. what bones make up these joints and what motions do they allow?
1.) Humerus and Ulna Hinge Flexion/extension 2.) Ulna and Radius Pivot Pronation/supination
What are the five wrist and hand joints?
radiocarpal intercarpal carpometacarpal metacarpophalangeal interphalangeal (look at slide 42-43 for all details)
for the hip joint, the _______ meets the ______ of the pelvis. The________ extends the size of the acetabulum
femoral head, acetabulum, labrum
The knee joint must do four things…. what are they?
Support body mass
Have up to 160° motion
Be unobstructed by muscle (like hip)
Lack strong yet limiting ligaments (like ankle)
what are the two knee joints? describe their ROM
1.) Tibiofemoral joint Hinge (Flexion/extension) (Some rotation-less stable than most hinge joints) 2.)Patellofemoral joint Plane (sliding)
the talocrural joint is the what joint?
what other joints are associated with this one?
ankle
tibiotalar
tibiofibular
fibulotalar
what ROM does the ankle joint/s allow for?
dorsi/plantiflexion
what are the four joints in the foot? describe briefly
Intertarsal: plane joints between tarsals
Tarsometatarsal: plane joints between tarsals and metatarsals
Metatarsophalangeal: condylar joints between metatarsals and digits
Interphalangeal: hinge joints in digits
