BioMech4 Test 1 Flashcards
What is the most common joint in the extremities?
Synovial Joint.
What is the biomechanical triad?
muscles, skeleton, joints.
What makes up scar tissue and why is it different than regular tissue?
Fibroblasts make up the scar tissue and it is different from regular tissue because they orient themselves according to stress placed on them.
What cell will make scar tissue?
Fibroblasts.
How will fibroblasts lay scar tissue?
They orient themselves according to stress placed on them.
What is the diaphysis?
Diaphysis- shaft or body of the long bone.
What is the metaphysis?
Metaphysis- Between diaphysis and the epihyseal plate.
What is the epiphyseal plates?
Epipyseal plate- growing lines.
What is the epiphysis?
Epiphysis- Top part of the long bone.
What is the name for a secondary growth center on a long bone (ie: for tubercles or other muscle/ligament attachments?
Apophysis.
Epiphyseal plate is aka?
Physis.
What is a closed physis?
Where the epiphyseal plate was but the cartilage is gone and growth has stoped, but a line is still there.
Perisoteium is continous with what?
Fibrous capsule.
What is the bone called that is deep to the articular cartilage in a synovial joint?
Subchondral bone.
What is articular cartilage like in synovial joints?
Blue, slippery caps of adjacent bone ends and lines the bone
Where is intra-articular cartilage found at? What type of cartilage is it?
Discs and menisci and it is fibrous cartilage between bones.
What inner lining part of the synovial joint that lines the synovial cavity?
Synovial membrane.
What is the synovial cavity?
Joint Cavity
What does the synovial cavity contain?
Synovial fluid
What is synovial fluid?
Viscous fluid in joint cavity
What is the periosteum?
Membrane lining outer bone
Will synovial joints have a perichondrium?
No.
Where is synovial fluid secreted from?
The innermost layer (intima) of the synovial membrane.
How much synovial fluid is there in synovial joints?
Just enough to form a film.
What is synovial fluid like?
Transparent high viscosity rich in glycosaminoglycans (GAG’s).
What is the major GAG in synovial fluid?
Hyaluronic acid.
Hyaluronic acid injections are used to treat what in synovial joints?
Osteoarthritis.
What are the functions of synovial fluid? (4)
Shock absorber, lubrication, supplies nutrients to cartilage, removes waste from cartilage.
How many layers are there for synovial membranes?
two, Intima and sub-intima.
What layer of the synovial membrane is closest to the synovial fluid and which layer is closest to the bone?
Intima- closest to the fluid. Sub-intima- closest to the bone.
What is the intima like?
Epithelioid layer (like epithelium), but not epithelium.
What is the sub-intima like?
Connective tissue that is a thicker outer layer.
What are the 3 different types of sub-intima?
Areolar, fibrous, adipose.
Is the synovial membrane innervated and vascularized?
Yes, but only the subintima not the intima.
What are the functions of the synovial membrane?
Produce and resorbe synovial fluid and provide immunity to the joint cavity.
What is found in the transition zones of cartilage?
Villi and fibrocartilage.
Name the cells found in synovial membranes?
macrophages, secretory, fibroblast, lipocytes.
What are synovial membrane capillaries like and why?
Fenestrated to increase the fluid exchange.
Will Synovial membranes have lymphatic vessels?
Yes even the intima has lymphatic vessels as it needs to extract fluid from the synovial joint
What is the function of the fibrous capsule of synovial joints?
Support, guide/ limit movement, absorb shock.
What are the different cell types of the synovial membrane cells?
macrophages, secretory, fibroblast, lipocytes.
What are fenestrated capillaries and what is the significance of them in the synovial joint?
Increase fluid exchange
Other than synovial joints, where else are fenestrated capillaries also found?
Kidneys for fluid exchange
With joint support what is the difference between dynamic and static?
Dynamic- muscles. Static- inter-locking bones and joint capsules.
What happens when the fibrous capsule has scar tissue?
It will have abnormal wear and tear.
What are extracapsular ligaments?
Those that are independent of the joint capsule. (don’t develop in the capsule)
What are sharpey’s ligaments?
Ligaments that go into bone.
What is Wolff’s law?
Bones grow from tension, the more tensile force on bone the more growth of bone occurs
What is the innervation like for fibrous capsules?
well innervated with lots of proprioception.
What is the vascularization like for fibrous capsules?
Not well vascularized, but is vascularized.
If a joint has lots of bleeding or brusing involved what should be thought of?
Blood might come from a fracture, or muscle injury since bones and muscles are well vascularized.
What is Bursae?
Synovial membrane lined extra-capsular pockets or pouches.
Bursae communicate with what?
Synovial cavity, Thru passages/defects in the capsule. Others are separate.
What are the 2 functions of bursae?
Lubricate and pad.
What is another synovial membrane lined structure besides bursae that lines extra-capsular pockets or pouches?
Gastrocnemius and popliteus bursae.
What is the purpose of gastrocnemius and popliteus bursae?
To help guide and lubricate tendons.
What is the fluid like with bursae?
Thin film or fluid.
What is the most common type of articular cartilage?
Hyaline cartilage.
What is the leaste common type of articular cartilage and where is it found at?
Fibro-cartilage only 3.5 joints; AC, TMJ, 1/2 SI.
What are the 3 things articular cartilage is made of?
water, collagen, GAG.
What is the main component of articular cartilage?
H2O.
What are the 2 parts of articular cartilage?
wet and dry parts.
H20 makes up what % of total weight of articular cartilage?
80%.
What makes up what % of the total dry weight of articular cartilage?
Collagen- 60-70%. GAG- 30-40%.
What is the function of collagen in articular cartilage?
Holds things together and resists shear.
What will give articular cartilage the rigid characteristics?
Strong water attraction from GAG’s.
What is needed to make Collagen?
Vitamin C and amino acids.
How are collagen fibers oriented at the articular surface?
Parallel.
How will articular cartilage receive nutrition?
Synovial fluid, deep layers receive from bone diffusion. NO NUTRITION FROM BLOOD VESSELS.
Name 2 important GAG’s in synovial joints?
chondroitin sulfate and glucosamine sulfate.
Name 2 other GAG’s in synovial joints?
Keratin sulfate, hyaluronic acid.
What is a dietary source of GAG’s?
Connective tissue, shellfish, cartilage.
How will GAG’s pull water inside the articular cartilage?
It will attract H2O with the negative charged Sulfate and Carboxyl groups. This is why the Chondroitin sulfate and glucosamine sulfate GAG’s are important in articular cartilage.
Synovial joint boundary lubrication is like what?
Teflon.
What are small compressive loads of synovial joints like?
Weak inoic bonding and GAGs lubricate the surface.
What are large compressive loads of synovial joints like?
Squeeze fluid film out of the cartilage.
Why are slow oscillations of synovial joints good?
Fluid exchange.
Why would rapid or no oscillations of synovial joints be bad?
Decreased fluid exchange.
What happens to synovial joints with DJD?
Decreased cell # which leads to decreased GAGs and increased serous fluid which leads to decreased lubrication, which leads to increased calcification.
subchondral or cancellous bone is aka?
Spongy bone.
subchondral / cancellous / spongy bone is tuff stuff that does what?
Shock absorption.
What happens with subchondral bone aka cancellous aka spongy bone with DJD?
Increases calcification which increases rigidity which increases thickness and impedes nutrient delivery, which decreases shock absorption.
What is cartilage innervation in general like?
It is not innervated, but intra-articular cartilage is in the outer 1/3.
What are the different types of intra-articular cartilage?
- Disc. 2. Meniscus.
Name 4 examples of disc intra-articular cartilage?
AC (in early 20s), SC, TMJ, Ulnocarpal (triangular fibrocartilage).
Name 2 joints made of meniscus intra-articular cartilage?
Knee, AC (late 20’s to early 30’s).
Intra-articular cartilage is made of what?
Fibrocartilage.
What is the function of intra-articular cartilage?
Increases shock absorption, increases congruency(fits better), increases stability, decreases friction, increases motion.
What type of innervation will intra-articular cartilage have?
Outer 1/3 transition with capsule, but has proprioception, nociception.
What is the vascularizatino of intra-articular cartilage like?
Outer 1/3 is and inner 2/3 is avasular.
In which part of the intra-articular carilage is it the furthest away from the nutrient source?
Middle of the intra-articular cartilage
What happens to intra-articular cartilage with age?
Meniscus tear easier as we get older.
How does intra-articular cartilage age?
Similar to IVD, increase vascularization, decrease chondrocytes, decrease GAGS, decrease collagen, increase collagen fiber size (more brittle_, decrease shock absorption, decrease flexibility
Chiropractors are human ______.
Joint experts.
Name the parts of synovial joints?
synovial membrane, fibrous capsule, articular cartilage, intra-articular cartilage, subchondral bone.
What is the Number 1 disability encountered by the medical profession?
Joint disease.
Synovial joint extends from where to where?
Metaphysis to metaphysis.
Forces exerted on synovial joints and the tissues that provide support are generated how?
Partly by body weight, and mainly by muscle contraction across the joint.
Synovial joints originate from what?
Mesenchymal “articular discs” between the primoridla bones.
What happens to the mesenchyme in the zones where the joint will later appear?
It is replaced by cartilage.
After the mesenchyme is replaced by cartilage what happens?
The cartilage plate then cavitates.
Synovial fluid is secreted by what?
Cells of the synovial membrane.
What are the 2 functions of the synovial membrane?
secrete and remove synovial fluid.
What are the 2 groups of cells in the synovial membrane and what do they do?
A or F- Rich in hyalurionic acid. B or M- immune cells.
What is the fibrous capsule of synovial joints like?
A barrel shaped sleeve around the joint that is reinforced by thickenings called capsular ligaments.
From what will the fibrous capsuel develop?
Perichondrium of the embryonic cartilaginous model and remains attached to the periosteum.
What is the main cellular component of articular cartilage?
Chondrocytes.
What are chondrocytes responsible for?
Maintenance and repair of the cartilage matrix.
What are chondrocyte life cycles like?
They are long lived in normal adult cartilage there is no further mitosis and growth subsides. Repair and regeneration of articular cartilage will predictably diminish with age.
What happens when 2 cartilage surfaces are rubbed together?
An interposed film of synovial fluid that is 40 times more slippery than teflon occurs.
What are the 2 types of lubrication and what are they used for?
Boundary- small loads. Hydrostatic- high loads.
What is subchondral bones stiffness like?
100 times less stiff than cortical bone.
What is the purpose of subchondral bone being less stiff?
It forms an intermediate zone that protects both articular cartilage and the diaphysis.
Why would it be better for subchondral bone to be injured vs. articular cartilage?
Bone can heal better.
Intra-articular cartilage developed from what?
Mesenchyme.
What happens when intra-articular cartilage is torn?
It is rarely abosorbed and becomes a foreign body that can accelerate wear and tear on articular cartilage surface and should be removed.
When intra-articular cartilage is removed what happens?
It is replaced by a dense fibrous connective tissue.
What is the vascularization like for synovial joints?
They are highly vascularized around each joint there is a plexus called a rete or periarticular plexus.
What are the 3 groups of arteries or veins that reach the joint area?
- Epiphysis/metaphysis. 2. Fibrous joint capsule. 3. Synovial membrane.
Why will the articular, intra-articular cartilage and synovial cavity be avascular?
They contain a substance that specifically inhibits the incursion of blood vessels and only in diseased and dying cartilage will blood vessels invade.
Will synovial joints have lymphatics?
Yes and they help with the removal of synovial fluid.
What is the innervation of large joints like?
They receive pain fibers from several spinal levels and the pain may be poorly localized or even deceptive.
Active protection of a synovial joint is done by muscle contraction and joint motion and this active protection is called what?
Negative work.
Negative work is the most important factor in what?
Sparing synovial joints from excessive loading.
80% of cases of idiopathic osteoarthritis at the hip joint are due to what?
Defects that produce joint incongruity and uneven or increased impact loading.
What happens to Proteoglycan with lack of compression in synovial joints?
This will result in decreased proteoglycan synthesis and abnormal binding.
What will excersise do to ligaments?
Hypertrophy and increased strength.
Osteoarthritis is not associated with what?
Systemic phenomena that are features of primary inflammatory joint diseases like RA.
Deterioratin is most common in what joints?
Those that are subjected to abnormal loads.
What is the specific healing agent with osteoarthritis?
None aside from reducing the source of irritation which may allow healing to occur.
Most extremity synovial joints are what type of joint?
diarthroidal and highly mobile.
What are the 3 types of joints according to the # of articulations?
- Simple- 2 articular surfaces (1 articulation). 2. Compound- 2 or more articulations. 3. Complex- 1 or more articulation plus intra-articular disc/meniscus.
What is an example of a simple joint?
DIP joint
What is an example of a compound joint?
tibiofemoral, subtalar, patellofemoral joint
What is an example of a complex joint?
Knee, ulnocarpal, AC, SC, TMJ, knee joint & radiocarpal joint
What is a joint complex?
Several joints acting together as a functional group. Like the knee, shoulder, wrist, elbow.
What are the 6 types of joints based on anatomical/ morphological classifications?
- Spheroid- ball and socket. 2. Ellipsoid- condyloid. 3. Arthroid- planar(gliding). 4. Sellar- saddle. 5. Ginglymus- hinge. 6. Trochoid- pivot.
What is an example of a spheroid joint?
shoulders and hip (more moveable than ellipsoid
What is an example of an ellipsoid joint?
Knee and occipital axial joint (spheriod in shape but moves in pairs)
What is an example of a arthroid joint?
Planar = flat, radioulnar joint
What is an example of a sellar joint?
First carpal metacarpal joint
What is an example of a ginglymus joint?
knee, elbow, intercarpal joint
What is an example of a trochoid joint?
humeral-radius joint at the capitellum
What are the 4 joint motion classifications?
- angular. 2. Translational. 3. Rotational. 4. Circumduction.
What is angular motion?
Flexion, extension, abduction, adduction.
What is translational motion?
Primarily gliding non-angular.