Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology > Bone-Alex > Flashcards

Bone-Alex Flashcards

1
Q

What type of CT is bone?

A

specialized

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

Bone can be _ or _

A

compact or spongy

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

What is compact and spongy bone made up of?

A

Compact: made of osteons
Spongy: trabeculae

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

What is bone covered by?

A

Periosteum> dense irregular CT

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

Mineralied matrix is made up of what?

A

Calcium phosphate (hydroxyapatite crystals)

KNOW BOTH TERMS

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

What are the matrix components?

A
  • Calcium phosphate (hydroxypatite crystals)
  • Type I collagen> produced by osteoblasts
  • Ground substance= PG+GAGs (keratin/chondroitin sulfate)+glycoproteins (laminin and fibronectin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • What is the end of the long bones called?
  • What are they made up of?
  • What do they contain
A
  • Epiphysis
  • Made up of spongy bone
  • Contains red marrow> produce RBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • What is the epiphyseal line?
  • What is it made up of ?
A
  • Growth plate
  • made up of hyaline cart> replaced with compact bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  • What is the shaft of long bones?
  • What is it made up of?
  • What does it contain?
A
  • The shaft of long bones
  • made up of compact bone
  • contain the medullary cavity=site of BM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of tissue is periosteum?

A

dense irregular CT

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

Bone marrow can be _ or _

A

red or yellow

Red: RBCs
Yellow: adipose cells-> only in adults

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

What is the layers of the bone from outer to inner?

A
  1. Periosteum
  2. Compact bone
  3. Endosterum
  4. Bone Marrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Compact bone is made up of what?

A

lamellae=rings of thin bone
* Outer circumferential lamellae
* Haversian systems
* inner circumferential lamellae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • What is the haversian system?
  • What is it made up of?
  • What cells does it contain?
A
  • Lamellae around a central canal
  • Made up of osteons=lamellae around haverian canal
  • Contains osteoblasts (or osteoclasts if remodeling)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is haversian cannals and volkmann canals

A
  • Haversian: run parallel to the axis of bone
  • Volk: runs perpendicular to connect systems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • What is endosteum?
  • What cell does it contain?
A
  • inner CT lining the medularry cavity
  • Contain osteoblasts
17
Q

What is the basic unit of compact bone?

A
  • osteons=lamellae (rings of thin bone) around a central (haverian) canal
18
Q

What are canaliculi?
What is the purpose?

A
  • Small tunnels in the bone matrix
  • Connect neighboring cells in lacunae for cell-cell communication via gap junctions
19
Q

How do we end up with partial lamellae ?

A
  • As bone remodels, parts of the haversian system get resorbed+replaced so it results in partial lamelaae (w/o haversian canal)
20
Q
  • What does osteoblasts secrete?
  • Mitoically active?
A
  • type one collagen fibers
  • yes, further divide to form osteocytes and more osteoblasts
21
Q
  • What is osteocytes housed in?
  • What is their fxn?
  • Mitotically active?
A
  • Lacunae surrounded by matrix
  • Maintain bone matrix and help resorb Ca2+ into the blood with PTH
  • NO because they are fully differentiated
22
Q
  • What is the fxn of osteoclasts?
  • What is it housed in?
A
  • Bone remodeling cells
  • Housed in Howship’s lacunae with enzymes to digest bone

clasts are fully differentiated

23
Q
  • What activates and inhibits osteoclasts?
  • What happens to the Ca2+?
A
  • PTH activates clasts-> increases Ca2+
  • Calcitonin inhibits clasts->decreases blood Ca2+
24
Q

Osteoclasts digest bony matrix of an area->

A

resorption bay

25
Q

What follows behind clasts?
What does it deposit?

A
  • Osteoblasts
  • deposit new bony matrix
26
Q

Where does intramembranous bone formation happen?

A
  • occurs in mesenchyme (embryonic CT)> mesenchymal cells turn into osteoblasts
27
Q

Explain the intramembranous bone formation?

A
  • Osteoblasts secrete boney matrix (=osteoid)-> creates bony spicules
  • As boney spicyles enlarge, they become interconnected-> forming trabeculae
  • The newly developed bone expands by appostitional growth (i.e. mediated bone growth)-> bone is added to the surface; this is the only way bone grow
28
Q

Where does endochondral bone formation occurs?

A

hyaline cartilage-> mesenchymals cells turn into osteoblasts

29
Q

Explain endochondral bone formation

A

hyaline cartilage-> mesenchymals cells turn into osteoblasts @ bony collar near diaphysis
* The bony collar is formed by intramembranous bone formation via osteoblasts
* The bony collar cuts off supply to the cartilage, thus the chondrocytes die

Chondrocytes within the cartilage hypertrophy-> secrete alkaline phoshate-> then calcify

Osteoblasts cover the calcified cartilage w/its own unclacifed bony matrix (=osteoid)
* Calcified cartilage stains purple
* osteoid stains pink

30
Q

explain endochondral ossification

A
  1. Perichondrium gets vascularized-> periosteum
  2. Mesenchymal cells surrounding hyaline cartilage differentiate into osteoblasts
  3. Ostroblasts (near diaphysis) cover cartilage w/bony matrix (osteoid)->forms bony collar
  4. Chondrocytes hypertrophy-> secrete alkaline phosphate-> calcifies cartilage-cells dies
  5. Osteoclasts erode the calcified cartilage-> produce holes where vessels invade-> forms periosteal bud
  6. Osteoblasts secrete bony matrix (osteoid) around remaining cartilage-> forms traceculae
  7. Clasts resorb bone (breakdown trabeculae)-> leaves an enlarged cavity for marrow
  8. Final stage is marked by the appearance of secondary ossification centers @epiphysis
31
Q

Explain fracture healing

A

Step 1: Hematoma formation
* Blood clot forms+ cells deprived of nutrients die

Step 2: fibrocartilage callus formation
* capillaries form+deliver fibroblasts to the area
* Collagen fibers close the fractured bone
* Fibroblasts turn into chondrocytes-> produces cartilage
* cartilage undergoes bone formation process

Step 3: bony callus formation
* Osteoblasts create trabeculae-> forms spongy bone

Step 4: bone remodeling
* Osteoclasts+ blasts replace spongy bone with compact bone

Histology (39 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions