Connective tissue (Bone) Flashcards Preview

Histology > Connective tissue (Bone) > Flashcards

Flashcards in Connective tissue (Bone) Deck (26)
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1
Q

what are the 3 key cell types?

A
  1. osteoclasts
  2. osteoblasts
  3. osteoclasts
2
Q

bone has a typical _______ organization

A

lamellar

3
Q

__________ secrete the matrix that then hardens by calcification, trapping the differentiating cells now called osteocytes in individual lacunae

A

Osteoblasts

4
Q

__________ maintain the calcified matrix and receive nutrients from microvasculature in the central canals of the osteons via very small channels called canaliculi that interconnect the lacunae

A

Osteocytes

5
Q

The ____________ consists of dense connective tissue, with a primarily fibrous layer covering a more cellular layer

A

periosteum

6
Q

Bone is vascularized by small vessels that penetrate the matrix from the periosteum. __________ covers all trabeculae around the marrow cavities

A

Endosteum

7
Q

________ osteoblasts are more flattened and cover the bony surface

A

inactive

8
Q

________ are located within lacunae surrounded by matrix

A

osteocytes

9
Q

Osteoblasts secrete _________containing collagen type I, proteoglycans and other molecules, and matrix vesicles

A

osteoid

10
Q

As osteoid undergoes calcification, hardens, and traps the osteoblasts, these cells differentiate further as _________

A

osteocytes

11
Q

how are osteoclasts made?

A

produced by the fusion of blood monocytes, where they reside on bondy surfaces and erode the matrix during bone remodeling

12
Q

________ secrete type I collagen, several glycoproteins, and proteoglycans

A

osteoblasts

13
Q

Osteoblasts also release very small membrane-enclosed _______ ________ with which alkaline phosphatase and other enzymes are associated

A

matrix vesicles

14
Q

what is an osteoclast?

A

large cell with several nuclei derived by the fusion in bone of several blood-derived monocytes

15
Q

In living tissue the compact bone is covered externally with ______________ and all trabecular surfaces of cancellous bone are covered with ____________

A

periosteum, endosteum

16
Q

describe the development of an osteon

A

During remodeling of compact bone, osteoclasts act as a cutting cone tunneling into existing bone matrix. Behind the osteoclasts, a population of osteoblasts enters the newly formed tunnel and lines its walls. The osteoblasts secrete osteoid in a cyclic manner, producing layers of new matrix (lamellae) with cells (osteocytes) trapped in lacunae. The tunnel becomes constricted with multiple concentric layers of new matrix, and its lumen finally exists as only a narrow central canal with small blood vessels

17
Q

where does osteogenesis: endochondral ossification take place?

A

within a piece of hyaline cartilage whose shape resembles a small version of bone be formed.

18
Q

Calcified cartilage matrix are __________ and devoid of chondrocytes and become enclosed by more lightly stained osteoid and woven bone produced by active osteoblasts.

A

basophilic

19
Q

The large and growing primary ossification center in long bone diaphyses and the secondary ossification centers in epiphyses are separated in each developing bone by a plate of cartilage called the _____________ __________

A

epiphyseal plate

20
Q

what are the five general zones of bone elongation?

A
  1. reserve of normal hyaline cartilage
  2. cartilage with proliferating chondroblasts aligned as axial aggregates in lacunae
  3. degenerating cartilage in which the aligned cells are hypertrophic and the matrix condensed
  4. an area in which the chondrocytes have disappeared and the matrix is undergoing calcification
  5. a zone in which blood vessels and osteoblasts invade the lacunae of the old cartilage, producing marrow cavities and osteoid for new bone
21
Q

bone matrix consists of?

A
  1. calcium hydrocyapatite
  2. type 1 collagen
  3. proteoglycan and osteonectin
22
Q

what is periosteum and endosteum?

A

surround the bone on outside and inside, respectively. Nourishment and growth.

23
Q

what are the types of bone?

A

Compact or Cancellous. Lamellar or Woven

24
Q

osteogenesis consists of?

A

Intramembranous (flat bone) and endochondral ossification (long bone).

25
Q

bone remodeling consists of ?

A

Osteoclasts (breakdown), osteoblasts (rebuild).

→ Osteoporosis

26
Q

describe joints

A

regions where adjacent bonds are capped and held together firmly by connective tissue. Example diarthrose joints (knee) capped with hyaline cartilage.