Synathroses, diarthroses, fibrous joint, synovial joint, etc.

Synathroses joints characteristics

- permit slight to no movement; immovable joint; not differentiated for movement
- Reinforced by a combo of fibrous and cartilaginous connective tissues.
- joint space is filled in with something (thick ligs, cartilage, etc. --> restrains movement.

two types of synathroses joints

fibrous joints and cartilaginous joints

synathroses (fibrous joints)

sutures of the skull
distal tibiofibular joint (syndesmosis/interosseus membrane)
interosseous membrane - reinforcing radio-ulnar joints

synathroses (cartilaginous joints)

pubic symphysis (fibrocartilage)
interbody joint of spine (including intervertebral discs) - fibrocart)
manubriosternal joint (in young; articular cartilage)

INTERVENING LAYER OF TISSUE = CARTILAGE

Suture

synathroses/fibrous joint.
2 bony components united by a thin layer of dense connective tissue, found only in skull, small amount of movement

Gomphosis

synathroses/fibrous joint
surface of bony compartments are configured like a peg in a hole (bone-conn tiss-bone)
intervening layer of fibrous connective tissue
ex: tooth and mandible or maxilla.

syndesmosis

synathroses/fibrous joint
bone-dense connective tissue-bone
bony compartments are directly connected by a ligament, cord, or aponeurosis.

Ampiarthroses (cartilaginous joints) examples

symphysis or synchondrosis

synchondrosis (def and ex)

bone- articular cartilage-bone
bony components connect by hyaline cartilage
ex: joint b/tw manubrium and rib

symphysis (def and ex)

bone-fibrocartilage-bone
bony components connected by fibrocartliage
ex: intervertebral discs or pubic symphysis

Diarthroses characteristics and examples

posses a synovial fluid-filled cavity; permit moderate to extensive movement
ex: glenohumeral joint, apophyseal (facet) joint of spine, knee (tibiofemoral joint), ankle (talocrural joint)

Elements that are ALWAYS assoc w/diathroses (synovial joints)

synovial fluid, articular cartilage, joint capsule (strong capsular ligaments), synovial membrane (lines joint capsule), ligaments (extracapsular - collateral/cruciate ligs of knee), blood vessels & sensory nerves in joint capsule (s: where proprioception comes from/transduce info of touch)

joint cavity - have space where synovial fluid always is.

elements that are SOMETIMES assoc w/diathroses (synovial joints)

intra-articular discs or menisci, peripheral labrum, fat pads, bursa (fluid filled sacs provide lubrication in areas of high friction), synovial plicae

Joint capsule + name of layers

double-layered structure surrounding joint cavity
stratum fibrosum (outer layer)
stratum synovium (inner layer)

stratum fibrosum

outer layer of joint capsule
provide structural support and opposing forces
portion of joint capsule that resists deformation (changes shape), STRETCHES

stratum synovium

inner layer of joint capsule
maintain internal environment
has A cells and B cells

A cells of stratum synovium

A cells = synovial macrophages, absorb and degrade cellular debris. wander around ange eat things, phagocytose foreign objects
more superfical, facing joint cavity.
recycle proteins within matrix of joint

B cells of stratum synovium

deeper; facing capsular ligament
fibroblast-like
secrete collagens and hyaluronic acid for synovial fluid (spit out components of synovial fluid)

Synovial fluid

-ulta-filtrate of blood plasma
-hyaluronate (hyaluronic acid): maintains viscosity of fluid and reduces friction
-chicken shots lol; take h.a from head of rooster to treat osteoarthritis
- lubricin: cartilage on cartilage lubrication -> glide better
super slippery, lowers coeff of friction (so more energy could go toward promoting/maintaining movement than reducing friction)

Classification of synovial joints (what types)

plane, uniaxial (pivot and hinge), biaxial/ellipsoid (saddle and condyloid), triaxial (ball and socket)

Plane (synovial joint)

no axis of rotation, 2 flat surfaces conjoining one another, provide for more motion than other fibro/cart joints but NOT much movement.
ex: foot and ankle; b/tw tarsal bones tiny joints

Uniaxial (synovial joint)

occuring around one axis, 3D movement around one plane
pivot: joint b/tw c1-c2 (c1 pivots around c2)
hinge: knee, elbow

biaxial/ellipsoid (synovial joint)

movement occurs around 2 axes , 2 planes
saddle - b/tw 1st metacarpal and trapezium
condyloid - b/tw radius and carpal bones of wrist; or finger joints (metacarpophalangeal)

triaxial (synovial joint)

3 axes joints, movement in three planes
ball and socket: shoulder and hip