Lecture 18: Joints and Articulation Flashcards
what is a joint?
a junction between 2 bones
what are key aspects of a joint?
movable and fixed
Name one fixed joint
skull
what is the skull like at birth?
the skull bones are not joined together, there’s a anterior and posterior gap
when do the gaps in the skull close?
first is posterior (1-2 months) then anterior (9-18 months)
Name 3 bones found in the skull?
frontal bone
parietal bone
occipital bone
Give 3 example of movable joints
knee
elbow
finger
Nam two types of joints
fibrous joints
cartilaginous joints
what is a fibre joint?
Fixed joint between two bones
How is a fibrous joint held together ?
connective tissue
do fibrous joints have a cavity?
no cavity
Give one example of a fibrous joint?
skull
cartilaginous joint has ________ movement
limited
cartilaginous joints are he’d together by what?
- fibro-cartilaginous discs
- ligaments
Give an example of a cartilaginous joint
pubic symphysis ribs
what are synovial joints?
two or more bones which are covered with a layer of articular cartilage and can transfer land between bones
list the joints from least movement to most
fibrous joints
Cartilaginous joint
synovial joints
whats an articular capsule?
connects bones
creates a cavity
whats a cavity n a synovial joint filled with?
synovial fluid
what does Articular cartilage/hyaline cartilage do?
covers end of bone
prevents friction
absorbs compression on joint
protects the joint
How is a joint capsule formed?
an outer tough fibrous layer and an inner synovial membrane.
what does a joint capsule do?
increase stability
what does a synovial membrane produce?
synovial fluid
where can synovial fluid be found?
joint cavity
whats the function of synovial fluid?
reduces friction between cartilage
Nourishes cartilage
gets rid of any waste debris
what does synovial fluid consist of ?
hyaluronic acid
interstitial fluid
what does synovial fluid contain?
phagocytes
what are ligaments
fibrous connective tissue arranged in a parallel form
what do ligaments do?
- strong
- resist repeated strain
- helps prevent dislocation.
- connects bone to bone
name two accessory ligaments
extracapsular, intracapsular
where are Intracapsular ligaments
located inside the articular capsule
what’s an example of a Intracapsular ligament ?
cruciate ligament
what are tendons?
Strong connective tissue that connects muscle to bone
what is a sprain, give an example?
ligament tear
eg:ankle sprain
what is a strain, give an example?
Tendon or muscle tear
e.g. hamstring muscle tear
what is a bursa and what does it do?
A pad of fat provide cushioning between fibrous capsule and bone or muscle, that acts as shock absorbers
what is Bursitis ?
When the Bursa swells as its accumulating synovial fluid
what are the different types of synovial joints?
Ball and Socket hinge Joint Pivot Joint Gliding Joint Saddle Joint Condyloid Joint
where can you find a Ball and socket joint?
hip or shoulder
where can you find a hinge joint?
knee or elbow
where can you find a pivot joint?
vertebrae of the neck
where can you find a gliding joint?
in the Hand between carpels
where can you find a saddle joint?
thumb joint
where can you find a condyloid joint ?
wrist joint
what are the 4 types of movement ?
gliding, flexion/extension, abduction/adduction, circumduction
what type of movement is gliding?
No rotary or angular motion
what type of movement is flexion/extension?
decrease/increasing angle between bones
what type of movement is Abduction/adduction?
Movement of bone away/towards midline
what type of movement is Circumduction?
Combination of flexion/extension and abduction/adduction in succession, resulting in circular motion
which joints are triaxial ?
ball and socket
Name a uniaxial joint
hinge joint
what is elevation/depression?
moving the jaw up and down
what is Protraction/retraction?
Pushing chin out/ pulling chin into neck
what is Inversion/eversion?
Moving soles of feet inwards or outwards
what is Dorsiflexion/plantar flexion?
Bending foot towards shin/towards sole
what is Supination/pronation ?
Palm turned upwards/downwards
why s the forearm more mobile than the lower leg?
radius/ulna are further apart compared to the tibia/fibula
why are ball and socket joints triaxial?
because of rotation
extension
adduction
shoulder also circumduction
what is uniaxial movement ?
Movement in a single plane
what is hyperextension?
when someone is double jointed
what features do double jointed joints have?
hyperflexible
hyperextensible
hypermobile
what does a pivot joint look like?
Bone fits in a circle
What is a pivot joint formed by?
formed by articulating bone and ligament
what movement does a pivot joint have?
monoaxiol (rotation only)
medial and lateral rotation
does a gliding joint allow twisting?
no
what kind of joint is a saddle joint?
Modified ellipsoidal joint
what kind of movement does saddle joints allowed?
Allows side-side, back-forth movements. Biaxial and allows circumduction. Allows opposition.
what is opposition?
when the thumb can touch
each finger
what movement do condyloid joints have?
biaxial - forward bak and side to side
what is Osteoarthritis (OA)
?
wear and tear
wat is Rheumatoid arthritis (RA)?
inflammatory, Autoimmune disease
what is a gout?
sodium urate crystals in the joint
what type of arthritis is OA?
degenerative
non-inflammatory
progressive
weight bearing joints
what happens when there’s a Degeneration of articular cartilage?
bone is exposed
bumps of osseous tissue deposited
restricts joint movement
reduction in joint cavity
how does osteoarthritis affect the spine?
narrow disks and bone spur
what inflames due to Rheumatoid Arthritis ?
The synovial membrane
thickens and fluid accumulates
what is panes ?
abnormal granulation tissue
responsible for deformation of joints
sticks to and erodes articular cartilage
How does Rheumatoid Arthritis lead to joints being immobile?
Cartilage degraded
bones join together by fibrous tissue
ossifies and fuses – joint now immobile
RA leads to hyperplasia of _______ _____ _____
synovial stromal cells
RA causes the infiltration of?
T and B cells
what is Rheumatoid factor?
autoantibody, binds to other antibodies found in 80% of patients.
what’s a dietry treatment for OA/RA ?
antioxidants (vitamins C, E) chondroitin sulphate collagen hydrolysate glucosamine Ginger, evening primrose, fish oil
what medication is taking to treat OA/RA?
painkillers
Immunosuppression (methotrexate)
Anti-TNF therapy for RA (adalimumab, etanercept and infliximab )
Anti- B cell therapy ( Rituximab)
what other treatment is there for OA/RA?
surgery - relieves pain and improves function
what causes Gout?
excess of uric acid (hyperuricemia) due to dysfunctional purine metabolism
what other conditions are linked to gout?
Obesity
Diabetes
renal insufficiency
hypertension
is there a clear correlation with diet and gout?
no
How is Uric acid formed from hypoxanthine ?
enzyme xanthine oxidase
turns hypoxathine into xanthine and then xanthine into uric acid
How is Uric acid formed from guanine ?
enzyme guanosine deaminase
turns guanine into xanthine and then xanthine oxidase turns xanthine into uric acid
In Gout what does uric acid react with?
sodium
(gout) what’s formed from uric acid and sodium ?
sodium urate crystals form and accumulate in joints
what happens to cartilage hone someone has gout?
it erodes
come back too
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