slide deck 2

joint

pivot point between 2 bones that articular along with their internal structures

synarthroses

very little movement

• fibrous or cartilaginous

• stable joints

Diarthroses

mod/extensive movement

• synovial fluid-filled cavity → thick gel like

• synovial joints

What the 7 parts of a Diarthrosis Synovial joint?

1. ligament

2. joint capsule (external dense CT)

3. Synovial membrane (inside)

4. Articular cartilage (covered)

5. blood vessels

6. nerve

7. synovial fluid (inside)

Intrinsic ligaments

thickening of capsule (MCL)

Extrinsic ligaments

more cordlike outside the capsule (LCL)

Disc/menisci

congruence and disperse forces

Labrum

deepen concave surface of joint

Fat pads

absorb force, fill recesses b

bursa

outgrowth of synovium (fluid filled)

synovial plicae

synovial folds that decrease tension

won’t know unless is goes wrong

convention of naming a synovial joint according to the shape of the ____ member on the ______ member

distal on proximal

Hinge joint

1degree of freedom

flexion/extension

ex: humeroulnar joint of elbow and interphalangeal joints of digits

pivot

1 degree of freedom

supination/pronation and atlantoaxial joint (C1-C2)

Spin motion occurs parallel to axis of rotation (muscle acts perpendicularly)

Ellipsoid joint

2 degrees of freedom → blocks 1 degree (resistant)

flexion/extension, abduction/adduction

radoiocarpal joints

ball-and-socket joints

3 degrees of freedom

glenohumeral joint, acetabulofemoral joint

planar joints

formed by 2 flat surfaces

no axis to rotate on

facet joints in spine

translation and rotation

Examples of Planar joints

CMC joints (II-V) → long bones in hand

intercarpals, intertarsals, facet joints

again, no true axis of rotation, supported by muscle and ligaments

Saddle joint

represent the trapezium

2 degrees of freedom

depends on plane the CV+CC can flip

1st CMC and SternoClavicular joint

CV on CV in one plane flip for the other plane

Condyloid joint

2 degrees of freedom (3rd degree limited by ligaments and bony incongruence)

tibiofemoral joint, occipitotlantal, MCP joints

Ovoid surface

imperfect sphere

• one concave and one convex surface

• most synovial joint

  • saddle surface

Axis of rotation

GENERALLY IN CV MEMBER

is dynamic and perp to plane of motion

Connective tissue

forms the basic structure of joints

Main types of tissue in body

CT

Muscle

nerve

epithelium

Types of CT

capsule

ligament

tendon

articular cartilage

fibrocartilage

bone

Type 1 collagen

resist tension

• joint capsule, lig, tendons

Type II collagen

resist compression

• articular cartilage, thinner

Elastin

return to original shape after deformation

• articular cartilage

• fibrocartilage

  • ligaments

ground substance

water-saturated matrix or gel

• GAGS

• water

• solutes

Fibrous proteins

lie within the ground substance and resist tension

GAGs

are hydrophilic that swell and repel

fibrous proteins and GAGs provide

structure and give CT great ability to resist forces over time

Dense CT are

ligaments

tendons

joint capsules

regular dense CT

DRY SPAGETTI

• tendons and ligaments near parallel oritentation of fibers

irregular dense CT

COOKED SPAGETTI

• fibrous capsule (multidirectional) -fascia

ligaments provide

immediate tension restraint to undesirable motion between bony partners

articular cartilage

specialized form of hyalline cartilage

located over load-bearing surfaces of bones

neural, avascular → get nutrition by synovial fluid (milking)

articular cartilage function

decrease friction between joint surfaces

fibrocartilage

• mixture of dense ct and articular cartilage

• resilience and shock absorption of articular cartilage

• tensile strength of ligaments and tendons

vascularized outermost fibers only

bone

• type 1 collagen

• osteoblasts

• ground substance

compact bone = highly organized

highly vascularized and innervated

constantly being remodeled

what is bone

specialized CT comprising most skeletal and supports entire body

movement

blood cells

storages Ca2+ “reservoir”

bone basics

diaphysis = shaft

metaphysics = growth plate

epi[hysis = wider areas at distal bone structures → form articular surfaces

helps distribute load from joint surfaces

cancellous bone

resists high compressive loads

compact bone

Wolff’s law

bone is laid down in areas of high stress and reabsorbed in areas of low stress

follows function at the micro and macro levels

joint form

provided by tissues designed to resist specific directional forces

stability of joint