Chapter 8- Articulations Flashcards
arthrology
study of joints
articulations
joints
- hold bones together but may permit movement
- point of contact between 2 bones, between cartilage and bone and between teeth and bones
kinesiology
study of motion
classification of joints based on movement
- synathrosis=immovable
- amphiarthrosis=slightly
- diarthrosis=freely
class. based on anatomy
-fibrous=collagen fibers
-cartilaginous=cartilage
-synovial=joint capsule and accessory ligaments
whats in between the joints
fibrous joints
-lack synovial cavity
-bones held closely together by fibrous connective tissue
-little or no movement
Types of fibrous joints: sutures, syndesmosis, gomphosis
sutures
thin layer of dense fibrous connective tissue unites bones of skull
- immovable
- if fused completely in adults=syntosis
syndesmosis
- fibrous joint
- bones united by ligament
- slightly movable
- anterior tibiofibular joint and interosseous membrane as EX.
gomphosis
- ligament hold cone-shaped peg in bony socket
- immovable
- teeth in alveolar processes of maxillae or mandible
- something else shoved into bone with ligament as protection
cartilage joints
- lacks synovial cavity
- allows little-no movement
- bones tightly connected by fibrocartilage or hyaline cartilage
- 2 types
- -synchondroses
- sympheses
synchondrosis
- connecting material is hyaline cartilage
- immovable
- epiphyseal plate or joints between ribs and sternum
- when fusion occurs it becomes synostosis
symphysis
- fibrocartilage is connecting material
- slightly movable
- intervertebral discs and pubic symphysis
- built to cushion
- resist compression+tension
synovial jint: features
- 2 bones separated by fluid filled cavity
- joint capsule has 2 layers
- -synovial membrane
- -articular cartilage
synovial fluid components and functions
no blood vessels components -blood filtrate -hyalurnic acid -glycoproteins synovial fluid functions -lubricate joint surface -nourish chondrocytes -shock absorber
synovial joint:accessory structures: ligaments
ligaments
- reinforce and strengthen joint capsule
- connect bone to bone with dense regular connective tissuel
ligament types
extracapsular ligaments
-outside joint capsule (collaterals) ex=tcl
intracapsular ligaments
-wth capsule (cruciates) ex=acl
synovial joint: accessory structure:articular discs
- pads of fibrous cartilage that subdivide a cavity
- also known as menisci
- ex. ulnolunate joint; knee joint
articular disc funtions
channel flow of synovial fluid
- modify articular surfaces
- restrict movements at joint
- cushion articulating surfaces
- help distribute body weight
synovial joint: accessory structures: fat pads
-adipose tissue surrounding the synovial capsule
fat pad functions
protect articular cartilage
- packing material
- fills spaces when joint changes shape
synovial joint: accessory structures: bursae function, location, what is it
- small fluid filled pockets of connective tissue
- location: hypodermis; between tendons/ligaments and bones
- function: cushion and support; aid movement of tendons
- connective tissue bag with synovial like fluid inside, reduce friction, aids movement
types of movement: gliding
- two opposing surfaces slide past one another
- same angle/orientatio the whole time
circumduction movement
- type of angular motion
- rotation of the shaft while changing the angle
- ex: humerus+scapula
- circle
angular motion
- a change in angle between the shaft and articular surface
- no movement, just angle changing
rotation
spinning of the shaft without changing the angle
-ex: atlas and axis
types of angular movement
- abduction-away from midline
- adduction-towards midline
- flexion-foward movement from lateral view, reduce angle between two bones
- extension-decrease angle between two bones
- hyperextension-past angle of movement, injury based sometimes
types of rotation
- supination (anatomical position of hands, palm up)
- pronation= flipping hand palm down
Special Movements
- Eversion (ankle ouwards)
- Inversion (ankle inwards)
- dorsiflexion (ankle up/flexed)
- plantar flexion (ankle down/extended)
- lateral flexion (ear to shoulder)
- protraction (chin thrust forward)
- Retraction (chin thrust back)
- opposition (thumb to pinky)
- elevation (jaw closed)
- depression (jaw opening)
synovial joints
-trade off between flexibility and stability
due to:
-shape of articular surfaces
-tightness of ligaments
-presence of accessory ligaments
-other factors: other bones, muscles, fat pads
types of synovial joints
- plane
- hinge
- pivot
- condlar
- saddle
- ball-and-socket
plane joint
- bone surfaces are flat or slightly curved
- side to side movement only
- rotation prevented by ligaments
- ex:sternoclavicular joint
hinge joint
- convex surface of one bone fits into concave surface of 2nd bone
- uniaxial like a door hinge
- -knee, elbow, ankle
movements produced by hinge joint
- flexion (decrease joint angle)
- extension (increasing the angle)
- hyperextension (opening joint beyond anatomical position
pivot joint
rounded surface of bone articulates with ring formed by second bone and ligament
- ex= proximal radioulnar joint (supination/pronation)
- atlanto-axial joint (turning head “no”)
condylar joint
- oval shaped projection fits into oval depression
- biaxial=flex/extend or abduct/aduct is possible
- ex=wrist and metacarpophalangeal joints (2-5)
saddle joint
- one bone saddle shaped, other bone fits as a person would in saddle
- biaxial
- circumduction allows tip of thumb travel in circle
- opposition allows tip of thumb to touch tip of fingers
- ex=trapezius of carpus and metacarpal of thumb
ball-and-socket joint
-ball fitting into a cuplike depression
-multiaxial
ex= shoulder joint
-hip joint
types of motion for ball and socket
- flexion/ extension
- abduction/adduction
- rotation
temporomandibular joint
TMJ
- hinge joint
- between condylar process of mandle and madibular fossa
- condyles slide back and forth along joint socket
- 2 synovial joints
intervertebral articulations: facets of articulation (where)
- vertebrae articulate at superior and inferior articular processes
- plane joint
- restricts lateral movement
intervertebral articulations; discs (what are they, made of what)
-allows flexion, extension, lateral flexion and rotation
anulus fibrosus
fibrocartilage in joints of vertebrae
nucleus pulposus
nucleus inbetween vertebrae and inside cartilage
- made of water (75%)
- hyaluronic acid
- reticular and elastic fibers
intervertebral articulations: herniated disc
- slipped disc
- nucleus pulposus breaks through annulus fibrosus
- movements of vertebral column compresses nucleus
shoulder joint
- glenohumeral joint
- head of humerus meets glenoid cavity
- gelnoid cavity covered by glenoid labrum
- ring of dense irregular connective tissue attached to margin of glenoid cavity
elbow joint
- two joints: humerus and ulna (hinge, flexion/extension)
- humerus and radius (pivot, pronation/supination)
wrist and hand joints
radiocarpal joint intercarpal joints capometacarpal joints metacarpophalangeal joints -interphalangeal joints
radiocarpal joint
- radius and 3 proximal carpels
- flexion/extension
- abduction/adduction
- circumduction
intercarpal joints
sliding
carpometacarpal joints
- thumb (saddle)
- other digits (plane=sliding)
metacarpophalangeal joints
hand to fingers (condylar)
- adduction/abduction
- flexion/extension
interphalangeal joints
fingers (hinge)
-flexion/extension
hip joint
- femoral head meets acetabulum of pelvis
- ball and socket
- labrum extends the size of the acetabulum
knee joint must..
- this joint must
1. support body mass
2. have 160 degrees motion
3. be unobstructed by muscle (like hip) - lack strong yet limiting ligaments (like ankle)
knee joints
tibiofemoral joint
-hinge (flexion/extension, some rotation)
patellofemoral joint
-plane (sliding)
ankle joints
ankle (talocrural joint) -tibiotalar -tibiofibular -fibulotalar dorsi/plantiflexion
foot joints
- intertarsal
- tarsometatarsal
- metatarsophalageal
- interphalangeal
intertarsal
plane joints between tarsals
tarsometatarsal
-plane joints between tarsals and metatarsals
metatarsophalangeal
-condylar joints between metatarsals and digits
interphalangeal
-hinge joints in digits
Types of fibrous joints
Sutures
Syndesmosis
Gomphosis
