Skeletal System Flashcards
Specialized CT include _______.
Bone, Cartilage, Blood
Bone is a type of _____________.
Connective tissue
Connective tissue is made of ________
Cells, ECM (Ground Substance + Collagen fibers)
Cartilage is a type of ___________. What are its functions?
Specialized Connective tissue
- Embryonic skeleton (bone growth), airways are held open
- Shock absorption, resisting compression via intervertebral discs, menisci,
- Smooth gliding surfaces as articular surfaces of bones within joints.
_________ has a disc made of _________.
Dental Application
TMJ has a disc made of cartilage
What are the three types of cartilage?
Which one is most abundant?
Hyaline Cartilage - Most Abundant
Fibrocartilage
Elastic Cartilage
Where can hyaline cartilage be found?
Pubic Symphysis
Articular cartilage of joint
Meniscus
Costal (Rib)
Nose
Where can fibrocartilage be found?
Intevertebral discs, near knee joints
Where can elastic cartilage be found?
External ear, epiglottis
Bones have a ______ precursor.
cartilage
What is responsible for the synthesis of cartilage-specific ECM-components?
Chondrocytes
What are chondroblasts?
ChondroCYTE precursors capable of forming cartilage specific ECM material not yet encased within the matrix
(They transition to chondrocytes)
What structures do you expect to be abundant in cells that produce lots of proteins?
RER- Collagen
Golgi Body- Proteoglycans
What is the ECM of cartilage made of?
Type II collagen
Proteoglycans
Chondrocytes originate from _________ which can give rise to _________.
What is required for the expression of __________ to differentiate from _______ progenitor cells to chondrocytes.
mesenchymal stem cells, osteoblasts, myoblasts, adipocytes
Type II, mesenchymal
Sox9!
What is Sox9?
A transcription factor required to activate the differentiation of mesenchymal stem cells to chondrocytes.
What can mesenchymal stem cells make?
Chondrocytes
Osteoblasts
Myoblasts
Adipocytes
Fibroblasts
Cartilage ECM components are _________ and _________
- Ground substance containing large proteoglycan aggregates (Aggrecan) in a hyaluronic acid core that interact with collagen
- Glycosaminoglycans which are negatively-charged chains on proteoglycans that bind water.
What do GAGs contain that make then _______-charged?
negatively
Chondroitin sulfate and keratin sulfate
What is the purpose of the ECM of cartilage
Create shock absorber due to stiffness and elasticity
Describe the arrangement of the cartilage ECM
Network of Type II collagen fibril is interwoven with a long hyaluronic acid chain with several proteoglycan aggregates that interact with the collagen.
GAGs are located on the collagen fibril that contain chondroitin sulfate and keratin sulfate.
Why is it important that GAGs bind ______?
Water allows diffusion of things through the cartilage matrix
How does cartilage get its nutrients and oxygen?
Cartilage is AVASCULAR so it nutrients and oxygen must diffuse through the ECM.
This limits cartilage growth and repair.
Chondrocytes have a ______ metabolic rate and do not require __________ to perform.
low, high oxygen
What is perichondrium?
A sheath of DCT surrounding most cartilage.
It contains vasculature, nerves and lympathic vessels
From the outer to inner layer approaching the matrix, what is the perichondrium made of?
Outer layer: Fibroblasts will differentiate into chondroblasts and also provide the vasculature
Inner Layer: Chondroblasts
How does a perichondrium appear on a histological section?
A thick pink layer with a few cells. There is NO clear border but will end close to where there is an abundance of cells laying down the matrix.
What are fibroblasts?
Cells that can differentiate into chondroblasts and osteoblasts as well as produce collagen ECM.
Growth and cartilage is attributed to two processes. What are they?
The first is appositional growth. This is where cells differentiate from the perichondrium to become chondroblast cells. This is the most common way that cartilage increases girth postnatally.
The second is interstitial growth within the ECM. This is the mitotic division of pre-existing chondrocytes.
Where does interstitial growth occur?
Epiphyseal plate for increasing longbone length, articular cartilage regeneration because it lacks a perichondrium.
KNOW FOR EXAM
__________ cartilage lacks a perichondrium.
Articular and Fibrocartilage
Hyaline cartilage is the most common. True or false?
True
Where is hyaline cartilage found?
What fibers are found in it?
What is its growth pattern?
Pubic Symphysis
Costal (ribs)
Nose
Joints of knees
Growth Plates
Walls of large respiratory passages
Type II Fiber
Interstitial and appositional
What does the cartilage matrix look like on a histological sample?
Large mass of purple cells (basophilic)
Chondrocytes sit in _______ in the ECM.
Lacunae
Articular cartilage is a form of ________.
Hyaline Cartilage
Where is articular cartilage found?
Articular surfaces of bones
Articular cartilage lacks a _________. How does it replace the function of this structure?
Perichondrium
It diffuses oxygen and nutrients from synovial fluid.
Where is elastic cartilage found?
What fibers are found in it?
What is its growth pattern?
Ear, Walls of auditory canals, Epiflottis, Eustachian tubes
Elastic fibers and Type II collagen
Appositional and Interstitial
How does elastic cartilage stain?
Elastin fibers will stain as thin wispy lines. It will be BLUE
Chondrocytes will exist
Where is fibrocartilage found?
What fibers are found in it?
What is its growth pattern?
Intervertebral discs, attachments of certain ligaments, pubic symphysis, menisci, TMJ!!
Type I collagen and small amounts of Type II collagen
Interstitial