Final Exam Flashcards
Connective tissue function is primarily determined by ___
Its extracellular components
Fibroblasts
basic cell of most connective tissues, produce extracellular matrix, creates type 1 collagen
Chondroblasts
Make cartilage, produce mostly type 2 collagen
Osteoblast
make bone, produces type 1 collagen and hydroxyapetit
Osteoclast
Monocyte derived, bone resorption
Tenoblasts
Make tendon, produce type 1 collagen
Interfibrillar component
Composed of PG’s and GP’s, responsible for attracting and binding water, forming a supportive substance for fibrous and cellular components
Fibrillar component
Collagen (mainly type 1 or 2), elastin
Type 1 collagen
90% of collagen in body, found most in connective tissues, responsible for TENSILE strength and stress of tissues
Type 2 collagen
Found mainly in cartilage and intervertebral discs (nucleus pulposus), structures associated with WEIGHT BEARING
Type 3 collagen
Mostly found in HEALING tissues
Structure of collagen
Triple Helix. tropocollagen –> microfibrils –> fibrils –> fascicles –> fiber(surrounded by endotenon)
Types of GAG’s
chondroitan sulfate, keratin sulfate, dermatin sulfate, hyaluronon
Chondroitan Sulfate
Compressive forces
Dermatin Sulfate
Tensile forces
Keratin Sulfate
Found in cartilage
Hyaluronon
non-sulfated, no protein core, free GAG
Function of PG’s
attract water, create tension to resist forces, regulates collagen fiber size, forms reservoir for nutrients and growth factor determining amnt of collagen in matrix.
Aggrecan is mostly composed of which GAG to resist TENSILE forces?
Dermatin sulfate
Aggrecan is mostly composed of which GAG to resist COMPRESSIVE forces?
Chondroitan Sulfate (or keratin sulfate)
Types & fucntion of Glycoproteins
Lamimin, fibronectin: form scaffolding for the cells, hold receptors in place, adhesion.
Which has more type 1 collagen? Tendons or ligaments.
Tendons
Which is the primary PG in tendons & ligaments?
Dermatin sulfate
Fibrocartilaginous Tendon Attachments
Gradual change of tendon to bone - 4 zones. Exposed to compressive and tensile forces.
Myotendinous junction
Comprises interdigitation between muscle cells and collagen fibers. Strong attachment.
Hyaline Cartilage
Non-vascular, nutrition from diffusion, doesn’t heal well, very low coefficient of friction.
Articular cartilage
Alot of type II collagen (resist compressive forces)
Which GAGs are associated with Aggrecan?
Keratan sulfate and chondroitan sulfate (less chondroitan as you age and less keratan)
Layers of Articular Cartilage
Zone I (parallel collagen fibers), Zone II & III (transitional & radiate stratum) less organized, Calcified (fibers perpendicular to structure and going into subchondral bone)
Where do osteoblasts come from?
Periosteum
SAID
Specific Adaptations to Increased Demand
Elastic Region
No permanent deformation
Yield point
Exits the elastic region
Plastic region
Deformation is permanent after the load is removed
Stress
force per cross sectional unit of material (S = F/A)
Strain
percentage change in length or cross section of a structure. ((L2-L1 )/L1). Deformation of a structure that may accompany stress
Stress Strain Curves are flatter in more elastic or stiffer materials?
Elastic
Hysteresis
difference in energy applied and recovered
Is more or less force required to deform when loaded rapidly?
More
Synarthroses
Minimal movement, fibrous (suture, gomphoses, syndesmoses), cartilaginous (symphyses, synchondroses)
Diarthroses
Synovial, moving
Things always associated with a synovial joint
Synovial Fluid, articular cartilage, capsule, synovial membrane, capsular ligaments, blood vesels, sensory nerves
Stratum fibrosum
outer layer of synovial capsule, more type 1 collagen, resist compressive forces, attach to bone, poorly vascularized but richly innervated
Stratum synovium
inner layer of synovial capsule, lines the joint space, layered with synoviocytes, (type A & B), highly vascuarized, highly innervated
Has intima & subsynovial tissue
Synoviocytes
Type A: macrophages
Type B: inhibit macrophages
both synthesize hyaluronon. Allow repair or removal of damage.
What are the two joint lubrication theories?
Fluid-film (layer of fluid between) & boundary (lubricin coats the surface)
Ruffini
Sensitivity: Stretch (usually at extremes of motion)
Location: fibrous layer of joint capsule on flexion side of joint, periosteum, ligaments, and tendons
Pacini
Sensitivity: compression or changes in hydrostatic pressure and joint movements
Location: throughout the joint capsule, particularly in deeper layer and in fat pads
Golgi
Sensitivity: pressure and forceful joint motion into extremes of motion
Location: inner layer (synovium) of joint capsules, ligaments and tendons
Detect tension and when tension is too high they relax (inhibit) the muscle
Unmyelinated free nerve endings
Sensitivity: non-noxious & noxious mechanical or biomechanical stress
Location: around the blood vessels in synovial layer of capsule and in adjacent fat pads and collateral ligaments, tendons, and the periosteum
Ostekinematics
the movement of a particular bone in space through plane, voluntary
Arthrokinematics
articular surface movement on the joint surfaces, not voluntary in nature, accompany the osteokinematics.
Effects of Immobilization on Ligament and Tendon
decrease collagen content & cross linking between collagen fibers. Loses interdigitation, 50% loss in tensile strength (8 weeks)
Effects of Immobilization on Articular surfaces & Bone
proliferation of fatty tissue in the joint space, adhesions in synovium, atrophy of cartilage, regional osteoporosis, weakening of ligaments at insertion, decrease in PGs, increase in H2O content of articular cartilage, thinning and softening of articular cartilage, swelling (inhibits and weakens the muscles surrounding the joint)
What is needed to restore tendon and ligament strength?
Gradual loading
Effects of decreased load on tendon and ligaments
decreased: collagen concentration, cross linking, tensile strength
Effects of increased load on tendon and ligaments
Increased: cross sectional area, collagen concentration, cross linking, tensile strength, stiffness
Effects of decreased load on bone
decreased: collagen synthesis, bone formation
increased: bone resorption
Effects of increased load on bone
Denser bone, increases synthesis of collagen and bone
Effects of decreased load on cartilage
disordered collagen fibrils, abnormal crosslinking
Effects of increased load on cartilage
increased PG synthesis, maybe increased volume (unverified)
Prevention of changes w/ immobilization
CPM, dynamic splinting, reduce time, use healthy tissues, graded loading of forces, extend the treatment
Class One Lever
Axis between the Effort & Resistance, mechanical advantage varies
Class Two Lever
Resistance between the axis and effort, mechanical advantage > 1
Class Three Lever
Effort between the axis and Resistance, mechanical advantage < 1
Mechanical Advantage
EA/RA
Desmin
Helps with the transmission of forces
Titin
Helps maintain the position of myosin within the sarcomere
What structure releases the calcium that plays a role in muscle contraction
Sarcoplasmic Reticuluum
Concentric
thin filaments slide toward and past thick filaments with formation and reformation of cross bridges. Sarcomere shortens and tension is generated. Bridges formed, broken, formed, etc
Eccentric
Thin filaments pulled away from thick filaments and cross bridges broken as muscle lengthens. Tension generated as cross bridges are reformed. Bridges broken, re-formed, broken.
Large Motor Units
Large axon, many fibers (mainly type II), recruited in forceful contractions
Small Motor Units
Small axon, fewer fibers (primarily type 1), recruited first in most activities
Layers of muscle connective tissue
Endomysium –> perimysium –> epimysium
Superficial Fascia
encloses muscles, loose, right under the skin, skin mobility, insulates and contains the muscles
Deep Fascia
compact connective tissue, regularly arranged, (tracts, retinacula, bands, aponeuroses) Not completely within the muscle.
Parallel elastic component
the connective tissues that surround the muscle, plus the sarcolemma, titin, nerves and blood vessels. When a muscle lengthens or shortens the tissues also lengthen and shorten because they function in parallel with the muscle contractile unit
Active tension can be increased by
Neural (frequency, number and size of motor units firing) & Mechanical properties (isometric length/tension relationship and force/velocity relationship)
When are multi-joint muscles recruited?
To control the fine regulation of torque during dynamic movements involving eccentric more than concentric muscle actions. Complex motions around multiple axes.
Muscle Spindle
Have intrafusal and extrafusal fibers. Stimulated when the muscle is stretched rapidly. Causes contraction of the muscle.
Muscle immobilization
Increase epi and perimysium, increases the ratio of the CT to muscle tissue making the muscle stiffer. The muscle tissue itself atrophies. Decrease in the force production. Change in the sarcomeres.
How do we increase the tension in a muscle?
Increase frequency, number or type of motor units firing (neurological controls)
Put them in the optimal (different) position in order to get more tension.
Use a different type of contraction (eccentric (most), concentric (third), isometric (second))
Change the speed of the contraction (velocity). The slower the greater the force.
Reverse Action
When you stabilize the distal segment and move the proximal segment (push-up)
As the clavicle elevates and depresses the disc is part of the
Manubrium
As the clavicle protracts and retracts the disc is part of the
Clavicle
What provides the primary restraint to Ant/Post translation at the SC joint?
The posterior capsule
Costoclavicular ligament
Anterior & posterior lamina: Limit elevation of lateral end of clavicle & help facilitate inferior glide of medial clavicle. (limit upward rot.) Stabilize the clavicle so muscles that attach there can contract on a stable base
Function of AC ligaments
Approximate the structures (acromion and clavicle), Limit anterior force to lateral clavicle. Superior stronger than inferior.
Coracoclavicular
Trapezoid and conoid: provide superior and inferior stability, limit upward rotation of the scapula at the AC joint, couple the posterior rotation of the clavicle to scapula rotation during arm elevation
Trapezoid portion of coracoclavicular
More lateral. primary restraint to translatory motion caused by superior directed forces applied to lateral clavicle
Conoid portion of coracoclavicular
More medial. primary restraint to translatory motion caused by posterior directed forces applied to distal clavicle. Prevents medial displacements of the scapula on clavicle
Type 1 AC sprain
Sprain of AC ligament but coracoclavicular is intact
Type 2 AC sprain
Rupture of AC ligament and sprain of Coracoclavicular ligament
Type 3 AC sprain
complete rupture of AC and coracoclavicular, separation between the structures and get a step off.
Resting position of the scapula
30-45 IR, 10-20 upward rotation
starts at T2, inferior aspect is at T7
Angle of inclination
Between the shaft of the humerus and head/neck of humerus (130-150 degrees)
Angle of torsion
Between the condyles and head/neck of humerus (30 degrees of retroversion)
If retroversion of the humeral head increased you get more ____ but less _____
ER, IR
If retroversion of the humeral head decreased (anteversion) you get more ____ but less _____
IR, ER
Rotator cuff interval
superior capsule, superior GH ligament, coracohumeral ligament
Middle GH ligament function
Limit anterior translation w/ arm at side - 60 ABd
Inf pouch – primary for ant and inf when arm goes up in abd
Ant and post bands – resist ER and IR
Ant resists ant translation when arm rises bc it moves ant in abd (arm ER when abd)
Post – for inf bc moves to inf when arm abd, and post when arm comes down
Components of Inferior Glenohumeral Ligament Complex (IGHLC)
Inferior pouch, anterior/posterior bands
Passive stabilization of the GH joint
Superior capsule/Sup GH lig/Coracohumeral lig, negative intraarticular pressure, superior tilt of glenoid fossa (bony block), supraspinatus passive tension
Functions of MCL
STABILIZE AGAINST VALGUS TORQUE, LIMIT ELBOW EXTENSION AT THE END OF THE RANGE, GUIDE JOINT MOVEMENT THROUGH FLEXION KEEP IT FROM GOING TO MEDIAL DIRECTION, SOME RESISTANCE TO LONGITUDINAL DISTRACTION
Functions of the anterior bundle of the anterior band of the MCL
Primary restraint to valgus at 30, 60, and 90 degrees of flexion and coprimary up to 120 degrees
Which ligament is ALWAYS disrupted with elbow dislocation?
lateral collateral ligament
Functions of LCL complex
Limit VARUS, and resist varus w/ supination so the radius doesn’t “roll off”, Stabilize radial head for rotation, stabilize in medial/lateral and posterior/anterior direction and compressive distractive.
Prevent subluxation of humerus by securing ulna to the humerus, & prevents forearm from rolling off when you go into valgus with supination.
Reinforces joint to resist distraction
Limits to elbow flexion
limited by coronoid in coronoid fossa, muscle bulk, excess tissue, maybe radial head in radial fossa.
Resists valgus in extension
medial collateral and anterior joint capsule and bones equally
Resists valgus in flexion
anterior MCL
Resists varus in extension
50% LCLC 50% joint capsule (more ligamentous than flexion)
Resists varus in flexion
osseous components mostly, some capsule & ligaments
Which ligaments limit supination
palmar radioulnar, quadrate, maybe oblique cord
Which structures limit pronation
dorsal radioulnar ligament, quadrate & if in extension maybe biceps, approximation of radius and ulna
Inferior radioulnar joint is a _____ surface on a ______ surface
Concave on convex
Superior radioulnar joint is a _____ surface on a ______ surface
convex on concave
Most ADLs require functional range of the elbow from ____
30 degrees to 130 degrees flexion, 50 degrees supination and pronation both.
Compression of ulnar nerve/Cubital tunnel syndrome
ulnar nerve compressed between the two heads of the FCU, radiation of pain into the fingers with numbness and tingling in the 4th and 5th digits and weakness of the intrinsics (thumb too). or can be compressed in the cubital tunnel.
Which nerve is compressed in the Pronator Teres
Median
Which nerve is compressed in the Supinator
Radial
Which tendon is ulnar to listers tubercle?
EPL
Radiocarpal joint is a ___ surface on a _____ surface
Convex on concave
Function of the TFCC
increase congruency on ulnar side, tether ECU, increase stability, absorb forces
Which muscle tendon does the pisiform lay within?
FCU
How much of the radiocarpal joint is in contact at any one point?
20-40%
With axial loading, what percentage of force goes through the radius to the scaphoid and lunate?
80%: of that 80% –> 60% scaphoid, 40% lunate
Effects of ulnar negative variance
thicker TFCC, different dispersion of forces, lack of forces on the lunate = poor nutrition or too much compression = necrosis.
Keinbocks disease
Avascular necrosis of the lunate
Effects of ulnar positive variance
Thin TFCC, aborbs less forces, main problem is with impingement = pain.
What is the only muscle that attaches to the proximal carpals?
FCU
Capitate and Hamate on Lunate/Triquetrum is a _______ surface on a _________ surface
convex on concave
Trapezoid and trapezium on scaphoid is a _______ surface on a _________ surface
concave on convex
Midcarpal joint favors which motions?
Extension and radial deviation
Extrinsic Volar wrist ligaments
Volar Radiocarpal, Radial Collateral, Ulnocarpal Complex
Volar radiocarpal ligaments
Radioscapholunate, Radiolunate, Radiocapitate: limit extension, provide support to bones
Ulnocarpal complex
Ulnar Collateral, Ulnolunate, TFCC
Intrinsic Volar wrist ligaments
Scapholunate interosseous, lunotriquetral interosseous: largely avascular, important for stability (esp of the scaphoid)
Dorsal radiocarpal ligaments
dorsal radiocarpal ligament, dorsal intercarpal: Support, prevent excessive flexion, try to prevent dorsal glides
Which proximal row carpal shows the most movement? Least?
Scaphoid. Lunate.
Radial Deviation
proximal row moves ulnarly on radius, proximal carpals flex, distal carpals extend
Ulnar Deviation
proximal row moves radially on radius, proximal carpals extend, distal carpals flex
Function wrist ROM
60 degrees extension, 54 flexion, 40 ulnar deviation, 17 radial deviation
DISI
dorsal intercalated segmental instability: scapholunate dorsal interosseous not present or ruptured. Scaphoif flexes, lunate and Tq extend. distal carpals flex.
SLAC
Scapholunate advanced collapse : capitate migrates down between lunate and scaphoid, very painful.
VISI
volar intercalated segmental instability: lunotriquetral ligament is injured. Lunate and scaphoid into flexion, and Tq and distal row into extension
Degrees necessary for maximum grip force
20-25 degrees extension, 5-7 ulnar deviation
Which two muscles do NOT pass under the flexor retinaculum.
Palmaris longus, FCU
Compartments of the extensor retinaculum
1: ABPL, EPB
2: ECRL ECRB
3: EPL
4: EDC, EI
5: EDM
6: ECU
Proximal carpal arch is maintained by
transverse carpal, intercarpal, small intrinsics
Distal carpal arch is maintained by
deep transverse MC, CMCs
What is the only muscle that acts only at the CMC
Opponens Digiti Minimi
How do anatomic pulleys affect the magnitude and direction of a muscle force?
They change the direction, without changing the magnitude of the applied force. Increases the moment arm.
What factors can cause the net torque on a segment to change?
change the moment arm, the angle of application of force, change the magnitude of the force