Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
UKCD Histo Lec 4
learning objectives from histo for cartilage and joints
| Question | Answer |
|---|---|
| For which specific function is cartilage designed? | Ability to bear weight and provide rigidity yet exhibit some variable flexibility. |
| What are the 3 main components of cartilage? | Cells, fibers, and amorphous ground substance. |
| What is the perichondrium and which two layers comprise it? | A CT layer that surrounds cartilage not attached to bone. It is composed primarily of collagen(ic) fibers and is composed of two layers: the outer fibrous and inner chondrogenic layer. |
| When are these two layers most evident? | During cartilage formation. |
| What is the predominant cell type in each layer of the perichondrium? | Fibroblasts/cytes predominate in the fibrous portion; chondrogenic cells in the chondrogenic layer. |
| Where do chondrogenic cells come from and what do they become? | Chrondrogenic cells arising from mesenchymal cells of the inner layer to become chondroblasts. |
| What is the function of a chondroblast? | They secrete the fibers and amorphous ground substance of cartilage. |
| Identify the type of growth that occurs at the surface of the cartilage? | Appositional growth. |
| Appositional growth can be attributed to which cells doing what? | results from chondrogenic cells differentiating into chondroblasts which divide to form other chondroblasts, all secrete cartilage, amorphous ground substance and fibers, enlarging cartilage mass, occurs primarily at the surface under the perichondrium. |
| What is a lacunae? | The space within the cartilage matrix occupied by the cell body of the chrondroblast/ chondrocyte. |
| What is a cell nest (isogenous group)? | A group of mature chondrocytes that arose from the cell division of a single chondrocyte – all occupying the single lacuna of that original cell. |
| What is a chondrocyte? | A mature chondroblast trapped within it’s own lacuna and now unable to secrete any further serious amounts of cartilaginous matrix. |
| What is territorial matrix and how does it differ from interterritorial matrix? | matrix immediately surrounding the lacunae, interterritorial matrix is that matrix separating adjacent lacunae. Territorial matrix has a higher concentratioon of cartilage ground substance chemicals (chondroitin sulfate/hyaluronic acid). |
| Which specific fiber types are found in the matrix of cartilage? | Collagen(ic) – although elastic fibers are found in elastic cartilage. |
| What are the four steps involved in cartilage development embryologically? | Undifferentiated mesenchymal cells differentiate into precartilage cells that continue differentiation to become chondroblasts that then become chondrocytes that are finally housed in an isogenous group (cells nest). |
| How does appositional growth differ from interstitial growth? | A- formation of new cartilage at surface of cartilaginous mass, occurs throughout life I- growth due to secretion of matrix by chrondroblasts w/in cartilaginous mass, occurs during embryonic development |
| Which cell type is responsible for each type of growth? | Continued differentiation of chondroblasts from chondrogenic cells are primarily responsible for appositional growth, continued division of chondroblasts responsible for interstitial growth Both growths result from accumulation of new matrix |
| What are the two major components within the ECM of cartilage? | Amorphous ground substance and fibers. |
| What are the three major GAC's of the extracellular matrix of cartilage? | Hyaluronic acid, chondroitin sulfate and keratin sulfate. |
| How is a proteoglycan monomer formed? | Chondroitin sulfate and keratan sulfate (prominent GACs of cartilage) join to a core protein to form a proteoglycan monomer. |
| What is a hyaluronic proteoglycan aggregate? | A single hyaluronic acid molecule associated with approximately 80 proteoglycan monomers forms hylauronic proteoglycan aggregates that bind to fibrous components of the cartilage matrix by cross-linking proteins. |
| In which forms is water present in this matrix and what is the function of each form? | Tightly bound water (resilience) and loosely bound water (diffusion medium) are the two forms of water in the highly hydrated (60-70% net weight) cartilage matrix. |
| What are the three types of cartilage? | Hyaline, elastic and fibrocartilage. |
| Give an example of where each can be found. | Hyaline- entire fetal skeleton (long bones), comprises the tracheal rings and skeleton of the larynx in the postnatal condition; elastic comprises the epiglottis and pinna of the ear; fibrocartilage comprises the pubic symphysis and intervertebral discs. |
| Which type of collagen fibers is most abundant in hyaline cartilage? | Predominantly type II collagen fibers. |
| Does hyaline cartilage have a perichondrium? Where might it be lacking? | Yes. Over surfaces that are not attached to bone. |
| Does hyaline cartilage normally calcify? Why might it? | In the general adult situation - no. However, in old age, lack of blood supply can cause costochondral and laryngeal cartilages to calcify. |
| Which fiber type is found in elastic cartilage? | Chiefly elastic fibers, but some collagen type II is present. |
| Does elastic cartilage ever calcify? | No, it never calcifies. |
| What is the function of elastic cartilage? | Resilience - its ability to spring quickly back into its original shape. |
| Does elastic cartilage have a perichondrium? Is it complete? Why/why not? | Yes, always exhibits a complete perichondrium as it is never attached to bone but found embedded within CT. |
| Does fibrocartilage have a perichondrium? If not, why? | No, it is adherent to bone |
| Which specific fiber type is found in its matrix? | Large bundles of Type I collagen. |
| What is the function of fibrocartilage? | Resistance - due to the large, thick bundles of the toughest form of collagen (type I). |
| Why are the chondrocytes aligned in rows in fibrocartilage? | They are “pushed/squeezed” into rows by the large bundles of parallelly-arranged collagen fibers. |
| Which component of a synovial joint might be composed of fibrocartilage? | The intra-articular disc. |
| What is articular cartilage? | Condensed hyaline cartilage – less ground substance, more fibers per unit area. |
| Where is articular cartilage found? | Lining the articulating surfaces of bones within an articulation (synovial joint). |
| From what type of cartilage does articular cartilage arise? | Hyaline cartilage |
| How is articular cartilage nourished? | By diffusion from the blood vessels of the marrow space of the underlying bone and by diffusion from the surrounding CT capsule via synovial fluid. |
| How responsive is articular cartilage to regeneration after damage? | Non-responsive due to lack of sufficient vascularization that results in lack of sufficient nutrients by diffusion to facilitate/promote regeneration. |
| Name one type of pathological process related to articular cartilage. | Osteoarthritis |
| What is the prognosis for cartilage repair in young children and in adults? | Good in children due to lots of surrounding vascularization; less common in adults as they age due to decreased surrounding vascularization. |
| After a cartilage injury in an adult, which tissue type might replace the damaged? | Bone. |
| How would bone replace cartilage? Why would this occur? | Through endochondral ossification. The lack of blood supply initiates the process. |
| Which features are used to determine structural classification of joints? | The presence/absence of a synovial cavity. |
| How is a synovial joint classified functionally? | Freely moveable (diarthritic). |
| Does it have a joint cavity? | Yes. All synovial joints have a joint cavity. |
| What is used to hold the articulating bones together? | Ligaments (dense regular CT) anchor bone-to-bone. The joint capsule (fibrous CT) also assists. |
| What is the function of an intra-articular disc? | They assist in guiding the articulating surfaces. |
| Name a joint that contains an intra-articular disc. | The temporomandibular, knee and sternoclavicular joints. |
| What are the regions seen in a section through the synovial membrane? | The synovial membrane proper (single layer of cells) and an underlying layer of subsynovial CT. |
| What is the function of the synovial membrane? | Secrete synovial fluid (fibroblast-like Type II or B cells modify fluid from underlying capillaries of the CT layer); and 2. keep the cavity free of debris (the macrophage-like Type I or A cells) phagocytose particulate matter within the synovial cavity. |
| What are three types of synovial membranes and how do they differ? | Areolar (overlies loose CT); fibrous (overlies the dense regular CT capsule, tendons and ligaments); and adipose (surrounded by adipose tissue of the superficial fascia ie. bursae). |
Created by:
wiechartm
Popular Histology sets