Quiz 2 Flashcards
what are the three components of connective tissue
- Cells 2. Ground Substance 3. Fibers
What kind of cells make up cartilage connective tissue
- chondroblasts 2.chondrocytes
What 4 things are in cartilage ground substance
- GAGs 2.proteoglycans 3.glycoproteins
What are 2 examples of GAGs in cartilage
hyaluronic acid and chondroitin sulfate
What is an example of a glycoprotein in cartilage?
chondronectin
What are the two main fibers found in cartilage
collagen elastic
What are the four main functions of cartilage
- structure support for soft tissue (eg ear, nose) 2.Shock absorption in joints 3.Reduce friction between joint surfaces 4.Role in growth and development of long bones
What are the 3 different kinds of cartilage
- hyaline 2. elastic 3.fibrocartilage
Which kind of cartilage is the most common?
hyaline
What is the most prevalent type of fiber in hyaline cartilage?
type 2 collagen
In terms of growth/development, what are hyaline cartilages two main functions?
- temporary skeleton in embryo 2.Is in the epiphyseal plates of long bones
Where are the three main places in the body where hyaline cartilage is found?
- articular surfaces of joints 2.end of ribs 3. respiratory passages
What type of fibers make up elastic collagen
type II and elastic
What is the main function of elastic cartilage
providing flexible support
What is distinct about elastic cartilage’s appearance?
yellow in color due to elastin
What are the three main places in the body where elastic cartilage is found?
- auricle of the ear 2. Eustachian/ Auditory tube 3. epiglottis of the larynx
Fibrocartilage is made up of primarily what type of fiber?
type 1 collagen
What allows fibrocartilage to resist compression and shearing forces?
At the edges it blends into dense collagenous connective tissue
Where are the 3 main locations in the body where fibrocartilage is found?
1.Intervertebral and articular disks 2. Menisci of knee joint (incomplete articular disks) 3.pubic symphysis
Mesenchymal cells differentiate into chondroblasts when which transcription factor is expressed
SOX-9
Which kinds of cartilage do not have perichondrium
articular and fibrocartilage
What is osteoarthritis?
Breakdown and loss of cartilage on articular surfaces in joints
T/F Osteoarthritis is the most common type of arthritis
T
What are 5 risk factors for osteoarthritis?
- >45 years old 2. Obesity 3. Being female 4. Previous Joint Injury 5.Hereditary conditions such as defective cartilage
What are 3 treatments for osteoarthritis
- meds for pain/inflammation 2.exercise and weight reduction 3.joint replacement
What are the 4 types of cells that make up bone tissue
osteoprogenitor, osteoblasts, osteocytes, and osteoclasts
What are the two main types of substances that make up the ground substance in bone?
proteoglycans and glycoproteins
what are the two main types of glycoproteins in bone?
osteonectin and osteocalcin
What kind of fibers are found in bone tissue
type 1 collagen
General Functions of Bone
- supportive framework 2. site of attachment for muscles 3. Protects vital organs 4. Site of hematopoiesis 5. Regulates blood calcium and phosphate
Bone the organ is comprised of what 6 things
- bone tissue 2.hematopoietic tissue 3. adipose tissue 4. Cartilage 5. Blood vessels 6. Nerves
What are the 4 different shapes bones can be classified by
- Long bone 2. Short bone 3. flat bone 4. irregular bone
label
what anchors the periosteum to the bone?
Sharpey’s fibers
2 places in bones where osteoprogenitor cells are found
periosteum and endosteum
Where do osteoclasts come from
hematopoietic stem cells/ fusion of monocytes
What is hte organic component of the bone matrix called?
osteoid
Active osteoblasts have _____ shape and inactive ones have a _____ shape
rounded
flat
What is the major enzyme that induces calcification of bone?
alkaline phosphatase
Osteoblasts only deposit new matrix on the side of the cell that is….
facing the existing bone
How do osteocytes communicate with one another?
gap junctions in canaliculi
What is the main functionof osteocytes
maintain the bone matrix
Ruffled border of osteoclast is
region that contains infoldings of the plasma membrane and is directly involved in resorpstion of bone
clear zone of osteoclast is
surrounds perophery of ruffled border and is where the osteoclast firmly adheres to the bone matrix; devoid of organelles, rich in actin filaments
What are the two categories for gross/ macroscopic oragnization?
compact
spongy/(cancellous) bone
What are the two categories of microscopic organization of bone?
Immature and mature
spongy bone resists______
compact bone resists ______
compression
bending
Vertebrae are what percentage spongy/compact bone
75
25
long bone are what percentage spongy/compact bone
95 compact
5 spongy
Are outer/inner layers of lamella laid down first?
outer
How are blood vessels of adjacent Haversion systems interconnected?
transversely running canals called Volkman’s canals
What is the difference between lamellar bone just beneath the periosteum and endosteum and lamellar bone that is not on the periphery
just beneath the periosteum and endosteum the lamella are parallel to the bone surface and surround the entire bone in a circumferential manner ie circumferential lamellae
function of Volkmann’s canals
connect the Haversion canals with teh periosteum and marrow cavity
What are names of the two processes of bone formation
intramembrenous ossification and endochondral ossification
In both mechanisms of bone formation, primary bone is first produced in a ___ ___
trabelcular network
Which type of bone formation is responsible for the formation of flat and some irregular bones?
Intramembranous
Which type of bone formation is occuring in the periosteum and endosteum
intramembranous
what is the enzyme that leads to calcification of bone
alkaline phosphatase
What 3 mains things are secreted by hypertrophic chondrocytes to promote calcification and vasuclar invasion?
- type X collagen
- Alkaline Phosphatase
- VEGF vascular endothelial growth factor
proliferation of cartilage occurs on the _____ side of the plate, while bone deposition occurs on the ____ side
epiphyseal
diaphyseal
Calcitonin
- Where is it produced
- What does it do to osteoclastic activity
- What does it do to blood calcium levels
thyroid
- decreases
- decreases
Parathyroid Hormone
- Where is it produced
- What does it do to osteoclastic activity
- What does it do to blood calcium levels
- parathyroid
- increase
- increase
What does PTH do to GI tract and kidneys?
stimulates GI tract to absorb calcium
- reduces Ca excretion from kidneys
Calcitonin is released in response to ____ Ca levels
PTH is released in response to _____Ca levels
high
low
