Day 6 Flashcards
What are the three types of cartilage?
hyaline
Elastic
Fibrocartilage
What is the primary fiber in Hyaline cartilage?
collagen
what is the primary fiber in Elastic cartilage
elastin
What is the primary fiber in fibrocartilage?
collagen with a regular arrangement
Hyaline cartilage in synovial joints
what is absent in hyaline cartilage in joints?
there is no perichondrium
its nourishment and support comes from synovial fluid
What are the functions of Elastic cartilage?
support and tolerates distortion
has memory and is able to return to original shape
where are the locations of Elastic cartilage?
pinna of auricle of external ear
epiglottis
cuneiform cartilage of larynx
auditory tube
What does Fibrocartilage contain?
lots of collagen and a little elastin
follows stress lines- regularly arranged
what are the locations in Fibrocartilage?
intervertebral discs between vertebrae
pads within knee joints (menisci)
between pubic bones (pubic symphysis)
What are the functions of Fibrocartilage?
shock absorption
resists compression
prevents bone-to-bone contact
limits relative movements
In the intervertebral disc- annulus fibrosus is an example of what?
an example of fibrocartilage
What are the two types of bone tissue?
compact bone
spongy (trabecular bone)
What are the four types of bone cells?
osteoblasts
osteocytes
osteoclasts
osteoprogenitor cells
What are Osteoblasts?
young active bone forming cells that produce protein fibers
what are osteocytes?
mature and less active bone cells
What are osteoclasts?
bone remodelling cells
what are osteoprogenitor cells?
stem cells
what is the Martix of bone made of?
Matrix = Osteoid
Made of ground substance that has mineralized plus fibers
the fibers are made of collagen and some elastin
they came from osteoblasts
What are the characteristics of compact bone?
dense packed matrix (no apparent space) highly organized vascular structures forms thick walls of shaft (diaphysis) in long bone surrounds medullary cavity covers epiphyses
What are the characteristics of Trabecular (spongy of cancellous) bone
plates, bars, sheets of intersecting bone –Trabeculae
It is vascular!
red marrow often found here
light but strong
What are the three special structures that are associated with bone formation and growth
lucunae
lamellae
canaliculi
What is the Lacunae?
a pocket for cells in bone
What is the lamellae?
concertric ring of cells
what is the canaliculi?
“little canals” inter lamellar cell connections
Connective tissue around bone:
the periosteum contains what?
contains outer (fibrous) and inner (cellular) layer. collagen fibers of the periosteum are continuous with those of the bone, adjacent joint capsules and attached tendons and ligaments
what will exercise do for bones?
it will increase bone mass
What is endochondral ossification?
process used in formation of most, but not all bones
related to cartilage embryonic model
ENDO – Chondral
What is the first step in Endochondral Ossification?
as the cartilage enlarges through appositional and interstitial growth, chondrocytes near the center of the shaft increase greatly in size. the martix is reduced to a series of small struts that soon begin to calcify. The enlarged chondrocytes then die and disintegrate, leaving cavities within cartilage
What is step two in in Endochondral Ossification?
blood vessels grow around the edges of the cartilage, and the cells of the perichondrium convert to osteoblasts. The shaft of the cartilage then becomes ensheathed in superfilial layer of bone
what is the third step in Endochondral Ossification?
Blood vessels penetrate the cartilage and invade the central region. Fibroblasts migrating with the blood vessels differentiate into osteoblasts and being producing spongy bone at a primary ossification center. Bone formatioon then spreads along the shaft toward both ends.
what is the forth and in Endochondral Ossification?
remodeling occurs as growth continues creating a marrow cavity. The bone of the shaft becomes thicker, and the cartilage near each epiphysis is replaced by shafts of bone. Further growth involves increases in both length and diameter
what is the fifth step in Endochondral Ossification?
capillaries and osteoblasts migrate into the epiphyses to create secondary ossification centers
what is the sixth step in Endochondral Ossification?
soon each epiphysisis filled with spongy bone. an articular cartilage remains exposed to the joint cavity; over time it will be reduced to a thin superficial layer. At each metaphysis, an epiphyseal cartilage separates the epiphysis from the diaphysis
