Lecture 14 Osteogenesis and Joints Flashcards Preview

Histology -- Zach H. > Lecture 14 Osteogenesis and Joints > Flashcards

Flashcards in Lecture 14 Osteogenesis and Joints Deck (46)
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1
Q

Mineralization occurs via ____ ions.

A

Calcium

2
Q

Give some examples of bones that develop by intramembranous ossification.

A
Frontal
Parietal 
part of: 
  - occipital
  - temporal
  - mandible
  - maxilla
3
Q

What 3 things does intramembranous ossification require?

A

1) well-vascularized primitive connective tissue
2) bone formation is not preceded by the formation of a cartilage
3) an aggregate of mesenchymal cells differentiates directly into osteoid-producing osteoblasts

4
Q

True or False:

During intramembranous ossification bone formation is not preceded by the formation of a cartilage.

A

True

5
Q

To begin intramembranous bone formation, an aggregation of mesenchymal cells differentiate into what type of cell?

A

osteoblast

6
Q

Fill in the blank:

Osteoblasts secrete ____, trapping some of the osteoblasts (blastema).

A

osteoid

7
Q

During intramembranous bone formation osteoblasts secrete osteoid (which includes type I collagen & non-collagen proteins) which traps the osteoblasts (blastema). The trapped osteoblasts then turn into osteocytes, in which these osteocytes form what?

A

Osteocytes form a functional syncytium.

8
Q

What type of bone is formed during intramembranous ossification when numerous trabeculae fuse together?

A

Spongy Bone

9
Q

Membrane bone usually consists of two layers of compact bone that enclose a layer of what?

A

Spongy Bone

10
Q

During intramembranous ossification, what type of cells line the surface of the bone blastema?

Hint: this cell type is outlining the functional syncytium made by the interconnected cell processes of osteocytes.

A

Osteoblasts

11
Q

What cell type initiates the modeling of the primary bone tissue?

A

osteoclasts

12
Q

Fill in the Blank:

Although primary bone tissue formation begins as an ______ process, it soon becomes _________ growth.

A

interstitial process, it soon becomes appositional growth.

13
Q

At the surface of the osteoid, osteoblasts continue the appositional deposit of matrix. What are the two main components of this matrix?

A

Type I collagen & Non-collagenous Proteins

14
Q

True or False:

Calcification is a form of mineralization and is ossification.

A

False, calcification is a form of mineralization, but is not ossification.

15
Q

During endochondral bone formation, what is bone replacing?

A

Cartilage

16
Q

Where does the primary ossification center occur in the cartilage model?

A

In the future diaphysis.

17
Q

During endochondral bone formation the network of cartilage matrix is calcified by the deposition of calcium salts. Is this ossification?

A

NO, not ossification.

18
Q

What is happening in the vascular invasion zone?

A

Osteoblasts begin to deposit osteoid along the calcified cartilage.
The osteoid calcifies.

19
Q

How do osteoprogenitor cells, (which are derived from the perivascular mesenchyme) reach the primary ossification center and generate osteoblasts?

A

Vascular invasion zone - thus, osteoprogenitor cells travel into primary ossification center through the blood vessels.

20
Q

What is happening to the chondrocytes in the hypertrophic zone?

A

Chondrocytes become hypertrophic as the ossification front approaches.

21
Q

What is expressed in the proliferative zone?

A

proliferative chondrocytes start expressing Cbfa 1/Runx2 transcription factors.

22
Q

What cell type enlarges the bone marrow cavity?

A

Osteoclasts (osteoclasts “chase”)

23
Q

What is the definition of a joint?

A

A joint is where two bones come together.

24
Q

What are the two types of cartilaginous joints (amphiarthroses)?

A

1) symphysis

2) synchondrosis

25
Q

What is a cartilaginous joint?

A

A joint where bones are joined by hyaline or fibrocartilage.

26
Q

What type of cartilage joins a symphysis type cartilaginous joint? Also, give 2 examples of a symphysis type cartilaginous joint.

A

fibrocartilage - intervertebral discs and pubic symphysis

27
Q

What type of cartilage joins a synchondrosis type cartilaginous joint? Also, give 2 examples of a synchondroses type cartilaginous joint.

A

Hyaline cartilage - epiphyseal plates and the first sternocostal joint.

28
Q

What are the 3 sub-classes of fibrous joints (synarthroses)?

A

1) suture
2) gomphosis
3) syndesmosis

29
Q

What type of join is the fibrous joint (synarthroses)?

A

A join where bones are joined by collagenous and/or elastic fibrous connective tissue.

30
Q

Give an example of a suture type fibrous joint.

A

Examples are the joints between the bones of the calvaria.

31
Q

Give an example of a gomphosis type fibrous joint.

A

This is a “peg-in-the-socket joint such as the teeth in the alveoli.

32
Q

Give an example of a syndesmosis type fibrous joint.

A

Bones are joined by an interosseous fibrous membrane such as the fibrous membrane between the tibia and fibula.

33
Q

What are the 3 types of synovial joints (diarthroses)?

A

1) monaxial
2) biaxial
3) triaxial

34
Q

What is a synovial joint (diarthroses)?

A

These are the movable joints exemplified by a connective capsule surrounding a fluid-filled joint space.

35
Q

What are the two functions that ligaments play with a synovial joint?

A

Ligaments stabilize the capsule and the joint, as well as control and restrict direction and range of motion.

36
Q

What are the different types of synovial joints based on?

A

Based on degrees of freedom of movement.

37
Q

What are two different monaxial types of synovial joints and give an example of each?

A

Hinge Joint -> humeroulnar and knee joints

Pivot Joints -> atlantoaxial and radioulnar joints

38
Q

Give 2 examples of a biaxial type synovial joint and examples found in the body.

A

Condyloid Joint -> metacarpophalangeal and atlantooccipital joints

Saddle (sellaris) Joint -> first carpometacarpal joint

39
Q

Give an example of a triaxial type synovial joint and where it can be found in the body.

A

Ball-and-Socket Joint -> glenohumeral and femoroacetabular joints.

40
Q

In a synovial joint, is the inner synovial portion of the capsule vascularized? Is the outer fibrous portion of the capsule?

A

Yes, inner synovial portion of capsule is vascularized.

No, outer fibrous portion of capsule is innervated but not vascularized.

41
Q

True or False:

The synovial membrane has a basal lamina?

A

False, The synovial membrane does not have a basal lamina.

42
Q

How many layers of synovial cells make up the synovial membrane?

A

1-3 layers of synovial cells.

43
Q

What type of cartilage makes up articular cartilage? Does it have a perichondrium? And is it lined by a synovial membrane?

A

Hyaline Cartilage

Lacks a perichondrium

Not lined by a synovial membrane

44
Q

Is the joint capsule of a synovial joint vascularized by dense connective tissue, lined by synovial membrane, and attached to edges of articular cartilage?

A

Yes, vascularized dense connective tissue

Yes, lined by synovial membrane

Yes, attached to edges of articular cartilage

45
Q

What hyaluronic acid-protein complex does synovial cells produce?

A

mucin, which is in synovial fluid.

** mucin produces slick surface that is more slick than ice on ice.

46
Q

What are the 2 types of synovial cells?

A

type A -> macrophage-like

type B -> fibroblast-like