Chapter 9: Joints Flashcards
joint (articulation or arthrosis)
what does it attach?
POA btween 2 or more bones
- also btwn teeth and bones
how are bones structurally classified?
based on:
- presence or absence of a synovial joint cavity
- type of connecting tissue (fibrous, cartilaginous, synovial)
how are bones functionally classified?
based on the degree of movement permitted (synarthroses, amphiarthroses, diarthroses)
description of fibrous joints
lack a synovial cavity, aticulating bones are held together by fibrous CT
- synarthroses

what kind of movement do synarthroses joints have?
allow little or no movement
3 types of fibrous joints
- suture
- sydesmosis
- gomphosis

suture
description
function
- fibrous joint composed of thin layer of dense fibrous CT (sutural ligament)
- united skull bones
- slight movement, only in skull

description of synostosis joint
- suture joint that has ossified
- ex: suture btwn frontal and parietal (coronal suture)
- 10% ossified

how is a synostosis functionally classified?
as a synarthrosis which allows little or no movement
description of syndesmosis
example
- fibrous joint in which 2 bones are separated by thick dense fibrous CT (interosseous membrane or ligament)
- ex: joint btwn distal tibia and fibula (anterior tibiofibular ligament)

ligament
bone to bone

gomphosis (dentoalveolar)
- fibrous joint in which cone shaped peg fits into a socket (alveolar socket)
- ex: periodontal ligament

description of cartilaginous joints
- lacks a synovial cavity
- articulating bones connected by either fibrocartilage or hyaline cartilage
- synarthroses

2 types of cartilaginous joints
synchondroses, symphysis

synchondrosis
description
example
- cartilaginous joint
- connecting material is hyaline cartilage
- ex: epiphyseal plate of a bone

symphysis
- cartilaginous joint in which connecting material is a white broad disc of fibrocartilage
- ex: pubis symphysis

range of motion for amphiarthrosis joint
slightly moveable

description of synovial joints
have a synovial joint cavity btwn articulating bones

description of diarthroses joints
freely moveable joint (several types of movement)

articular cartilage (fibrocartilage/hyaline)
location
function
- covers the end of bones at synovial joints
- function = decrease friction produced by moving bones and absorb shock

articular capsule
location
parts
- encloses the synovial cavity and unites the articulating bones
- 2 layers:
- outer fibrous capsule
- inner synovial membrane

outer fibrous capsule
tupe of tissue
location
- dense irregular CT attached to periosteum
- some of these are arranged in parallel bundles called ligaments

inner synovial membrane
type of tissue
elastic areolar CT

synovial fluid
functions (5)
- secreted by the synovial membrane
- lubricates joint
- decreases friction
- supply nutrients
- removes wastes given off by chondrocytes
- phagocytes to remove debris accumulated from joint wear & tear

why warm up?
stimulates production and secretion of synovial fluid
what is the function of accessory ligaments and articular discs? Why?
- alter the shape of joint surfaces of articulating bones to allow
- tighter fit
- increased joint stability
- distributes synovial fluid to areas of stress in joint

articular discs
functions
- menisci
- perform 3 functions
- maintain joint stability
- distribute synovial fluid
- allow tighter fit

what occurs during a sprain?
forcible wrenching or twisting of a joint that stretches or tears its ligaments but doesnt dislocate

what is a strain?
stretched or partially torn muscle

bursae
description
function
location
- synovial fluid filled saclike structures that cushionthe movement of 1 body part over another
- located btwn bone and skin where skin rubs over bone btwn tendons and bones within articular capsule

gliding movements
- when flat bone surface moves back and forth against each other
- no alteration of the angle btwn bones
- occur at plantar joints

angular movements
- inc/dec in the angle btwn articulating bones
- principle angular movements are:
- flexion
- extension
- hypertension

flexion
- dec in the angle btwn articulating bones
- ex: cervical spine, chin to chest, foot plantar/dorsi flexion

extension
inc in the angle btwn articulating bones

lateral flexion
- movement of the trunk sideways to the right/left at waist
- movement occurs in the frontal plane and involves the intervertebral joints (spine)

hyperextension
- continuation of extension beyond the anatomical position
- usually prevented by the arrangement of ligaments and the anatomical alignment of bones

abduction
movement of bone away from midline

adduction
movement of bne toward midline of body

opposition
- movement of thumb ONLY at the carpometacarpal joint
- thumb moves across the palm to touch the tips of the finger on the same hand

dislocation
displacement of a bone from a joint
- bones lose anatomical relationship

luxation
loses position but doesn’t lose anatmical relationship

planar joints
- permit gliding movements
- non axial
- include intercarpal, intertarsal, sternoclavicular, acromioclavicular, sternocostal, vertebrocostal joints

hinge joint
- contains convex surface of 1 bone fitting into a concave surface of another
- movement is primarily flexion or extension in a single plane (monoaxial)
- ex: elbow, knee, ankle, interphalangeal joints

pivot joint
- round/pointed surface of 1 bone fits into ring of another bone and a ligament
- movement is rotational and monoaxial
- ex: atlas, palms, anterior/posterior

condyloid joint
- oval shaped condyle of 1 bone fits into a elliptical cavity of another
- movements are flexion-extension, abduction-adduction, circumduction
- ex: joint btwn carpals and radiul

saddle joint
- contains 1 bone whose articular surface is saddle-shaped and another that is shaped like a rider on a saddle
- movements are flexion-extension, abduction-adduction, curcumduction
- ex: thumb joint

ball and socket joint
- ball shaped surface of 1 bone fits into cup depression of another
- movements are flexion-extension, abduction-adduction, rotation, circumduction
- ex: shoulder, hip joint

shoulder joint
- ball and socket (humerus and glenoid cavity of scalpula)
- movements include flexion-extension, abduction-adduction, medial-lateral rotation, circumduction of arm
- more freedom of movement in exchange of stability

common injuries to shoulder
- rotator cuff
- dislocation
- separation
knee joints (3)
movements
- largest, most complex joint of body
- consists of 3 joints in synovial cavity:
- patellofemeral
- lateraltibiofemural
- medialtibialfemoral
- movements include flexion-extension, slight medial rotation, lateral rotation of leg in a flexed psition

common injuries to knee
rupture of the tibial collateral ligament and dislocation
rotator cuff muscles
- supraspinatus
- infraspinatus
- terrismajor
- subscalpularis

function of patella
- holds tendon of quad forward
- increase effectiveness of quad in extending knee
what would happen without a patella?
30% more effrt to extend knee
ligaments in knee
- tibial collateral
- fibular collateral
- medial lateral meniscus
- anterior/posterior cruciate

rheumatism
description
any painful state of the supporting structures of the body, bones, ligaments, joints, tendons, muscles

rheumatoid arthritis
description
symptoms
- autoimmune disease in which the bodys immune system attacks its own cartilage and joint linings
- results in swelling + loss of joint function
osteoarthritis
description
what does it affect?
- degenerative joint disease
- wear and tear arthritis
- deterioration of articular cartilage and bone spur formation
- noninflammatory
- affects weight bearing joints: knees, ankles, hips, spine
gouty arthritis
description
symptoms
tx
- when sodium urate crystals are depposited in soft tissues of joints
- causes inflammation, swelling, pain
- bones will eventually fuse, rendering joints immobile
- patients told to eliminate red meat (digested red meat-nucleic acids turn to urate)