Week 2 Lecture: Test 1 Flashcards
what are synarthroses
joints with little to no motion
type of periarticular tissue
what are the types of synarthroses
fibrous; dense connective tissues i.e. skull or distal tip/fib joint
cartilaginous; stabilized by fibrocartilage/hyaline cartilage, often midline of body i.e. symphisis pubis or manubriosternal joint
what are diarthroses
“synovial joints” that allow moderate to extensive movement
majority of joints
cavity lined with synovial fluid
give an example of a gomphosis joint
root of tooth in socket
name the 7 elements associated with the synovial or diarthrodial joints
Articular cartilage (covering articular surface of bone)
Blood vessels (penetrate joint capsule)
Ligaments
Synovial membrane
Sensory nerves (receptors for pain/proprioception)
Capsular ligaments
Joint capsule (dense external layer and internal synovial membrane)
what is synovial fluid
clear/yellow
slightly viscous
hyaluronan/other lubricating glycoproteins
function = coat articular surface, reduce friction, and provide nourishment
describe the difference between intra and extra capsular ligaments
capsular = thickening of capsule or deeper part of ligament; broad sheets that resist mvmt in 2-3 planes
extra = cordlike; partially/completely separated from capsule
what are the elements that are SOMETIMES associated with synovial joints
intra articular discs/menisci
peripheral labrum
fat pads
bursa
synovial plicae
describe a hinge joint
movement at right angle to “pin” or axis; rotation and sliding
i.e. humeroulnar joint or interphalangeal
describe a pivot joint
cylindrical pin surrounded by larger cylinder
mobile member oriented parallel to AOR
produces spin (like a door knob)
i.e. humeroradial joint or atlanto-axial joint
describe an ellipsoid joint
convex elongated surface and similarly elongated concave surface
elliptic surface restricts spin
biplane motions: flexion/extension and abd/add
i.e. radoiocarpal joint
describe a ball and socket joint
spherical convex compared with cupcake socket
3 plans of motion; spin CAN occur (unlike ellipsoid)
i.e. glenohumeral joint and coxofemoral joint
describe a plane joint
pairing of 2 flat or slightly curved surfaces
slide/rotation; lack a definitive axis of rotation
tension in muscles and ligaments cause or restrict the motion
i.e. carpometacarpal joints 2-5 and some inter carpal/inter tarsal joints as well
describe saddle joints
2 surfaces (1 concave and one convex) oriented at right angles (reciprocally curved)
i.e. carpometacarpal joint of the thumb
2 planes of ample motion, limited spin
describe condyloid joints
similar to ball and socket except the concave portion is shallow
i.e metacarpophalangeal, tibiofemoral, and Atlanto-occipital
2 degrees of freedom
ligaments and the bony shape is what restricts the 3rd degree of motion, but this depends on the joint (i.e. knee still has some abd/add)
what is the evolute
the path of serial locations for the instantaneous axis of rotation
when is the path of an evolute more complex
when opposing joint surfaces are less congruent or there are greater differences on their radii of curvature
what are the 4 primary types of tissue found in the body
connective
muscle
nerve
epithelium
describe the 3 types of fascia
superficial= adipose tissue/loose connective tissue immediately deep to skin
deep fascia = dense connective tissue; forms strong internal framework
subserous fascia = loose connective tissue; between deep fascia and serious membrane
what does endomysium do
form continuous 3D matrix
links adjacent fibers
coordinates force transmission
what are the fundamental materials that comprise all connective tissues in the body
fibrous proteins (collagen and elastin)
ground substances (glycominoglycans, water, and solutes)
cells (fibroblasts and chondrocytes)
describe collagen
high tensile strength
poor stretch
most abundant protein in body
comprises 70-90% of dry weight of tendons and ligaments
what are the 2 main types of collagen
type I thick fibers; little elongation; stiff and string (i.e. tendons, ligaments, fibrous capsules, and fascia)
type II; thinner and less tensile strength; provide general shape for structures (i.e. hyaline cartilage)
what is collagen synthesized by
white fibroblasts
how many types of collagen have been identified
28; Type I is most common
what gives the fibrils in the body strength
cross links between collagen molecules and fibril levels
describe the cross links in newly formed collagen
relatively few and are reducible
as collagen ages total number of reducible cross links decreases to a minimum number and a large number of stable non-reducible cross links are formed
why does it take a great deal of energy to separate collagen molecules
their alignment is staggered and they are oppositely charged
how do fibroblasts align
in rows between bundles along axis of a ligament or tendon
what is the function of elastin in the body? where can it be found?
affords tissue recoil/extensibility (up to 130% initial length), however resilience changes when temperature drops
in skin, tendons, lungs, lining go arteries, and some ligaments
structures with high elastin can do what
readily return to original shape
where is fibronectin (type of fiber) found
plasma
what does reticulin (fiber type) do?
forms a flexible yet durable meshwork (viscera)
where can laminin be found
connects to the basement membrane
where is the fiber type chondronectin found
cartilage
what are the 2 basics elements of connective tissue
cells and extra cellular matrix made of fibrous components and ground substance
the glue that holds us together
what types of cells are found in connective tissue? (x11)
fibroblasts
macrophages
monocytes
fibrocyte
adipocyte
melanocyte
lymphocytes
mast cells
plasma cells
R and W blood cells
microphages
what determines the composition/ role of the matrix
the stress that impacts the cell
what are the functions of the matrix
large water quantity enables diffusion of nutrients and waste products as well as friction free movement of fibers
what gives ground substance/the matrix physical resilience
glycominoglycans (GAGs)
describe the structures of a proteoglycan
large sugar protein complex with water binding properties
made up of glycosaminoglycan (GAGs) and core proteins
linked to hyaluronan molecule via linker protein to form large proteoglycan complex
where can you find fibroblasts
;ligaments, tendons, and other supportive tissues
where can you find chondrocytes
hyaline cartilage and fibrocartilage
what conducts “maintenance and remodeling” in the cells
synthesizing ground substance and fibrous proteins
describe the key components of dense connective tissue
in external layer of capsule, ligaments, and tendons (most non muscular soft tissue around joint
few cells (fibroblasts)
abundance of tightly packed type I collagen
moderate to low proteoglycans/elastin
limited blood supply/low metabolism
how do you differentiate between irregular and regular dense connective tissue
based on the spatial orientation of collagen fibers
i.e. fibrous later of a joint capsule is irregular; ligaments and tendons are regular
what are sharpey’s fibers
collagen fibers extending deep into the bone material
what is articular cartilage
special type of hyaline cartilage
creates load bearing surfaces that disperse forces and reduce friction
classified as avascular, but recent research shows it may contain some nerve endings
no perichondrium
how are chondrocytes spread throughout articular cartilage
spread throughout
flattened near articular surface, parallel to collagen to resist abrasion
perpendicular to collagen near bone to act as an anchor
what is the tidemark
diffusion barrier in periarticular tissue
how do nutrients and gases travel in periarticular tissue
nutrients and gases must pass from synovial fluid to all chondrocytes
what is perichondrium
covers the surface of hyaline and elastic cartilage (but not fibrocartilage)
dense connective tissue composed of fibroblasts and type I collagen fibers
contains blood vessels
why is there no perichondrium in articular cartilage
allows opposing surfaces to form load bearing surfaces
examples of fibrocartilage
intervertebral discs
labrum
pubic symphysis
TMJ disc
knee menisci
describe fibrocartilage
mix of dense connective tissue + articular cartilage
has resilience and shock absorption of articular cartilage and tensile strength go ligaments/tendons
some blood supply to outer rims
support/stabilize/guide motion and dissipate forces
what is a structural sub unit of a bone called
osteon or Haversian canal
what type of bone acts like a series of struts to redirect forces along the bone
cancellous bone
where is bone laid down/absorbed
laid down in areas of high stress and reabsorbed in areas of low stress
thus the importance of weight bearing exercises for bone health
what causes bone spurs
aka osteophytes
may form from increases spinal stresses (distal or instability)
what are the effects of immobilization on the body
changes in structure/functuon of connective tissue (lost mall, volume, and strength)
reduced mechanical strength
happens within days, but recovery is slow and often incomplete
what are some of the general accompaniments in the joints that come with age
slowed rate of fibrous proteins and proteoglycan replacement
slow repair rates in periarticular tissue and bone
loss of ability to restrain and disperse forces (micro traumas)
