Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Human Histology > Unit 5: Cartilage and Bone > Flashcards

Unit 5: Cartilage and Bone Flashcards

(70 cards)

Start Studying
1
Q

What are the cells that make up cartilage?

A

chondroblasts, chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the origin, location, and function of chondroblasts?

A

Paraxial mesoderm origin
Peripheral location
Matrix producing during chondrogenesis and appositional tissue growth
• Active or inactive metabolic states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the origin, location, and function of chondrocytes?

A

Chrondroblast origin
Central/deep location
Primary matrix producing/maintaining cells within mature cartilage resulting in interstitial tissue growth
• Active or inactive metabolic states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the components of extracellular matrix that make up cartilage? What does it not consist of?

A

mostly ECM and a semi-solid portion

avascular and aneural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the semi-solid part of ECM of cartilage?

A

firm yet pliable via the “mesh like” interaction of GAGs & PGs
crucial for diffusion and chondrocyte survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the semi-solid part of ECM of cartilage composed of?

A

Aggrecan-hyaluronan aggregates
Cartilage-specific collagen molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the aggrecan-hyaluronan aggregates?

A

Highly hydrated for resilience and diffusion
Binding of signaling molecules and growth factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the cartilage-specific collagen molecules composed of?

A

Type II collagen and VI, IX, X, and XI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of the avascular and aneural part of ECM for cartilage?

A

tolerates intense stress but has limited ability to heal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Are the components of cartilage uniformly distributed?

A

no
fibrocartilage can be somewhat uniformly distributed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are lacunae?

A

(void spaces)
in the ECM that accommodate chondrocytes within the semi-solid matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do chondrocytes appear in tissue?

A

seen singularly or in isogenic groups (IGGs), representing cells that have recently divided

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the capsular (pericellular) matrix? How does it stain?

A

high concentration of PGs, GAGs, MAPs surrounding cell
directly surrounds lacunae

dense micromolecues stain this darkest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where is the territorial matrix? How does this stain?

A

surrounds isogenic groups

stains to a medium opacity (less than capsular but more than interterritorial)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is the interterritorial matrix? How does it stain?

A

occupies space between IGGs

stains very opaque (light)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the types of cartilage?

A

hyaline cartilage, fibrocartilage, elastic cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where is hyaline cartilage?

A

Articular surfaces of synovial joints, costal cartilages, cartilages of nasal cavity, larynx (thyroid, cricoid, arytenoid), trachea, bronchi, fetal skeletal tissue, epiphyseal plates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is fibrocartilage?

A

Intervertebral discs, pubic symphysis, articular discs, menisci of knee joints, triangular fibrocartilage complex (wrist joint), insertions of tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is elastic cartilage?

A

Pinna of external ear, external acoustic meatus, auditory tube, larynx (epiglottis, corniculate, cuneiform)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the differentiating factors of hyaline cartilage?

A

Most common type of cartilage
Weakest
Surrounded by perichondrium
Type II collagen (pressure), GAG, PGs, GPs
Staining appears homogenous
Can undergo calcification (endochondral ossification at epiphyseal plate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the differentiating factors of fibrocartilage?

A

Less cellular than other cartilage types
NOT surrounded by perichondrium
Type II collagen, GAGs, PGs, GPs
Type I collagen (tension)
Some uniformity to tissue distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the differentiating factors of elastic cartilage?

A

Surrounded by perichondrium
Type II collagen, GAGs, PGs, and GPs
Elastic fibers & lamellae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the cells that compose bone?

A

osteoblasts, osteocytes, osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the origin, location, and function of osteoblasts?

A

Mesoderm (most) or Ectoderm (specialized)
• Paraxial or Neural Crest
Located on bone surface
Bone Formation
• Osteoid secretion & mineralization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the origin, location, and function of osteocytes?
Osteoblast origin (fuses with osteoid) Located in lacunar spaces Mechanosensation • Lacunar-canalicular network
26
What is the origin, location, and function of osteoclasts?
Lateral mesoderm (hematopoietic) origin - fusion of multiple preosteoclasts (multinucleated) Located on bone surface Bone resorption
27
What is the extracellular matrix composition of bone?
organic (1/3) inorganic (2/3) vascular and neural -via branching of nutrient arteries into central and perforating canals
28
What is the composition and function of the organic part of the ECM of bone?
Type I collagen (90% on bone protein) BMPs, CBPs, MAPs, ALP Stretch resistant
29
What is the composition and function of the inorganic part of the ECM of bone?
Calcium phosphate • Hydroxyapatite crystals [Ca10(PO4)6(OH)2] Compression resistant
30
How do osteoblasts mineralize?
Calcium binding proteins (CBPs) like osteocalcin bind extracellular Ca2+ which stimulates OBs to secrete alkaline phosphatases (ALPs) ALP increases local concentration of PO4 ions which further increases the local Ca2+ concentration OB ectosomes (matrix vesicles) accumulate Ca2+ & PO4 and assemble hydroxyapatite crystals Bone matrix proteins (BMPs) contribute to the formation of a ECM collagen scaffold for mineral deposition Hydroxyapatite crystals exit the matrix vesicles and develop as mineralized nodules within the ECM collagen scaffold
31
What are the regions of osteoclast resorption?
ruffled border, clear/sealing zone, basolateral region
32
What is the function of the ruffled border during osteoclast resorption?
increase surface area - increases proton secretion (decalcification) - increases hydrolytic enzyme exocytosis (Casthepsin K: collagen degredation)
33
What is the function of the clear/sealing zone during osteoclast resorption?
tight seal “sealing zone” between OC plasma membrane and bone matrix
34
What is the function of the basolateral region during osteoclast resorption?
exocytosis of bone debris
35
What is the etiology and presentation of osteoporosis?
bone resorption > bone formation Occurs due to an imbalance in the bone producing osteoblasts and bone resorbing osteoclasts Results in decreased bone strength and a significant increase risk of fracture
36
What are the types of bone ossification?
endochondral, intramembranous
37
How does endochondral ossification occur?
Mesoderm → Paraxial mesoderm → Somites → Cartilage → Bone 1. Cartilage model 2. Periosteal bony collar 3. Cartilage matrix mineralized 4. Blood vessel formation & Periosteal migration 5. Cartilage matrix resorbed and replaced with bone matrix
38
What bones does endochondral ossification form?
Most axial and appendicular skeleton (gestational 12 weeks)
39
How does intramembranous ossification occur?
Ectoderm → Neural Crest → Mesenchyme → Bone Unlike most axial and appendicular skeleton, much of the bone, cartilage, and CT of the head (skull, jaw, hyoid) have a unique embryonic origin from Neural Crest Cells (an ectoderm population derived during neurulation)
40
What bones does intramembranous ossification form?
flat bones of skull and face (8th week gestation)
41
What are the types of bone growth?
interstitial, appostitional
42
What is interstitial growth?
Cartilage resorption & bone deposition aka lengthening via growth plate
43
What is appositional growth?
Uncoupled bone resorption & formation “Bone modeling” osteoblasts + osteoclasts work independently changes shape (diameter) of bone
44
What can bone remodeling be described as?
stochastic, targeted it is a coupled process in which osteoclasts and osteoblasts work together
45
What are the staining zones for bone tissue?
articular cartilage[ [superficial (tangential) zone [intermediate (transitional) zone [deep (radial) zone [calcified zone bone{ {subchondral bone {cancellous bone
46
What happens in osteoarthritis to the cells?
↓PGs = ↓H2O (no hyaluron) ↑ IL-1 & TNFα = ↓ Collagen II ↑ IL-17 = ↑ OC (osteoclastogenesis = absorb cartilage)
47
What are bone-lining cells?
quiescent osteoclasts
48
What is the periosteal layer of bone?
(similar to perichondrium) fibrous + cellular outer layer of bone innervated attachment of muscles and tendons
49
What is the intracortical layer of bone?
the majority of compact bone with osteons circular with central canals and perforating channels to perfuse tissues
50
What is the endocortical layer of bone?
(endosteum) has osteoblasts and osteoclasts lining the surface
51
What is the cancellous layer of bone?
extension of the endocortical layer “spongy” layer filled with marrow
52
What is stochastic bone remodeling?
random along endosteal surface for Ca++ regulation
53
What is targeted bone remodeling?
microdamage/cracks in mineralized matrix osteoclasts bore hold to let osteoblasts fix damage and fill back in
54
What are the steps of bone remodeling?
osteoblast (A-activation) ->RANKL osteoclast (R-resorption) ->coupling osteoblast (F-formation)
55
What does bone maintenance require?
mechanical stimulation disuse = osteoclast bone loss = fracture overuse = osteoblast bone formation -> too quickly = woven bone formation = bone fracture
56
What does bone fracture repair require?
inflammatory response (unlike microfractures) results in haematoma around site of fracture
57
What are the epiphyseal growth plate (interstitial growth via endochondral ossification) zones?
zone of reserved cartilage, zone of proliferation, zone of hypertrophy, zone of calcified cartilage, zone of resorption
58
What does TRAP stain for?
osteoclasts
59
Where does the PTHR1 bind?
osteoblasts to activate RANKL (activation)
60
Where does RANK bind?
pre osteoclasts (resorption)
61
What kind of ossification happens in the calvaria?
intramembranous
62
What is the differential diagnosis for polyarticular joint pain and what is the next diagnostic step?
infectious arthritis, osteoarthritis (OA), RA, crystal-induced arthritis, Lyme disease, hemochromatosis, and systemic lupus erythematosus (SLE). Most likely OA or RA (given family history) order conventional radiographs of the lumbar spine, bilateral hands, wrists, and right knee. OA and RA have distinct findings on conventional radiographs. Ultrasound is a used in cases of gout, OA, and RA. screening rheumatoid factor (RF) antibody, anti-citrullinated protein antibody (ACPA), and routine lab work is indicated, including complete blood cell counts (CBC), comprehensive metabolic panel (CMP), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).
63
What is the epidemiology and pathogenesis of the differential diagnosis?
OA is the leading cause of joint disease worldwide. affects 10% of men and 18% of women over 60. leading risk factor is age; increases exponentially after 50. degenerative joint disease primarily affecting the articular cartilage of weight-bearing joints such as the hips, knees, spine, and fingers. pathogenesis of OA involves the entire joint: cartilage, subchondral bone, and soft tissues, including the synovium. cartilage integrity lost by biomechanical stress; but genetics can contribute.
64
Describe the images and the notable findings of osteoarthritis pre-mortem
radiograph of right hand: osteophyte formation, joint space narrowing, supchondral sclerosis radiograph of right knee: advanced tricompartmental OA with joint space narrowing and osteophyte formation radiograph of lumbar spine: multilevel degenerative changes characterized by disc space narrowing
65
What are bisphosphonates?
group of drugs used to treat bone problems, called osteopenia or osteoporosis, conditions associated with thin or fragile bones at increased risk for fracture. medications for low bone density or with a history of fragility bone fractures in the hip, arm, wrist or spine. Oral: Alendronate (Fosamax), risedronate (Actonel), and ibandronate (Boniva) IV: Pamidronate, ibandronate and zoledronic acid (Reclast/Zometa)
66
Define osteoporosis.
bone disease that develops when bone mineral density and bone mass decreases, or when the structure and strength of bone changes. Typically, due to an imbalance of bone forming osteoblasts and bone resorbing osteoclasts
67
How do bisphosphates function in order to treat osteoporosis?
inhibit osteoclastic bone resorption. attach to hydroxyapatite binding sites on bony surfaces, especially surfaces undergoing active resorption. When osteoclasts begin to resorb bone that is impregnated with bisphosphonate, the bisphosphonate released during resorption impairs the ability of the osteoclasts to form the ruffled border, to adhere to the bony surface, and to produce the protons necessary for continued bone resorption. Bisphosphonates also reduce osteoclast activity by decreasing osteoclast progenitor development and recruitment and by promoting osteoclast apoptosis.
68
Describe Bone Remodeling.
69
How does one explain an increase in atypical bone fractures as a result of long-term bisphosphonate treatment?
Microfractures repaired by targeted bone remodeling are not able to be repaired efficiently by osteoclasts so they accumulate
70
Describe the images and the notable findings of osteoarthritis post-mortem
intervertebral disc: narrowing of joint space, osteophytes histology: loss of proteoglycans from hyaline cartilage = decreased metachromatic staining, chondrocytes die leaving empty lacunae

Human Histology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions