Lecture 5 - Bone and Cartilage Flashcards
What is cartilage made of?
Dense regular connective tissue, Types II Collagen
Chondrocytes
mature form of chondroblast; secrete collagen type II, have large golgi (washed out). Inside a space within the matrix called lacunae.
What is it called when there are multiple cells in lacunae?
Isogenous groups
Interstitial growth
from cell division of pre-existing chondrocytes; occurs only in early stages of cartilage formation = “cell nest.” Results in articular cartilages and epiphyseal plates of long bones.
Appositional growth
from chondrogenic cells in perichondrium. Results in formation of chondroblasts and or new chondrocytes. Results in new layer of cartilage matrix at periphery.
Where is hyaline found?
articular cartilage (joints), costal (ribs), fetal skeleton tissue, larynx, rings of trachea
What is hyaline composed of?
60-80% water
15% type II collagen for tensile & shear strength
10% proteoglycans for compressive strength
5% multiadhesive glycoproteins
and 5% chondrobalsts, chondrocytes, fibroblasts
What does hyaline have?
Perichondrium make up of dense irregular CT that makes membrane around hyaline and elastic cartilage. Perichondrium also has a cellular layer (chondrogenic layer) where chondroblasts reside.
What is the progression from fibroblast to isogenous groups?
Fibroblasts differentiate into chondroblasts
Chondroblasts mature into chondrocytes, which move towards the middle of the hyaline cartilage.
Form Isogenous groups/cell nest
Which is more flexible - hyaline or elastic cartilage?
Elastic
What is Elastic cartilage made of?
Type II Collagen and Elastic Fibers
Which has more isogenous groups - hyaline or elastic cartilage?
Elastic
Where is elastic cartilage found?
external ear, epiglottis, elastic arteries
Fibrocartilage - What is it made of?
Mix of dense irregular connective tissue and hyaline cartilage. Contains fibrocytes (making collagen I) and chondrocytes (making collagen II)
Where is fibrocartilage found?
invertebral discs, annulus fibrosus, meniscus, tendons, ligaments
Is cartilage vascular or avascular?
avascular - limited capacity for repair.
What is bone made of?
Collagen I - Calcified connective tissue forms structural component of bones.
What are the two types of bone in a bone?
Compact bones in the middle, spongy bone at the ends.
What are the functions of bones?
systems of levers, support, protection, bone marrow (in adults, mainly in flat bones), calcium & phosphate reservoir
Epiphysis
end of bone (made of cancellous/spongy/trabecular bone). Can have bone marrow within spaces
Diaphysis
shaft of bone (lamellar/compact bone) marrow cavity, bone marrow is mainly here. filled w/ hemopoetic tissue in kids, adipose tissue in adults (yellow marrow)
Metaphysis
Small flanking region in bone between diaphysis and epiphysis.