C6

Question 1

CARTILAGE TISSUE:
Perichondrium:

Answer 1

CARTILAGE TISSUE: “chondro”; avascular, non-innervated connective tissue.
Perichondrium: outer layer of dense irregular CTP; inner layer of chondroblasts.

Question 2

CELLS:

Answer 2

1. Chondroblasts: form most of the matrix.
2. Chondrocytes: fully differentiated cells in lacunae, capable of division; maintain matrix.

Question 3

MATRIX:

Answer 3

ground substance: GAG’s (hyaluronic acid, chondroitin sulfate). Fibers: collagen, elastic.

Question 4

TYPES:

Answer 4

1. Hyaline “glassy”; fibers=fine collagen fibrils. Locations: embryonic skeleton, larynx, tracheal
   cartilages, outer nose, costal, articular, epiphyseal plates.
2. Elastic: elastic fibers dominant. Locations: “e” : epiglottis, outer ear (auricle), ear canal.
3. Fibrocartilage: large collagen fibers present. Locations: “discs” : anulus fibrosus of intervertebral,
   interpubic discs; articular discs (menisci of knee joint).

Question 5

GROWTH:

Answer 5

1. Appositional: chondroblasts deposit matrix.
2. Interstitial: chondrocytes deposit matrix.

Question 6

BONES

Answer 6

BONES=OSSEOUS TISSUE: vascular, innervated connective tissue

Question 7

FUNCTIONS

Answer 7

support, movement, protection, mineral storage (calcium, phosphate), hematopoiesis (blood cell
formation), fat storage (yellow marrow), energy metabolism (osteoblasts secrete osteocalcin
to stimulate pancreas to synthesize more insulin and adipose cells to reduce fat storage.)

Question 8

BONE TISSUE

Answer 8

Components. Organic=osteoid: 35%: collagen fibers and ground substance.
Inorganic: 65%: hydroxyapatite mineral salts-mainly calcium phosphate

Question 9

CELLS:

Answer 9

1. Osteoblasts: in periosteum and endosteum; synthesize most of the matrix; become osteocytes.
2. Osteocytes: maintain matrix. Cell bodies in lacunae; filopodia extend into canaliculi.
3. Osteoclasts: in periosteum and endosteum; multinucleate, mobile, secrete HCl to resorb bone.

Question 10

MEMBRANES:

Answer 10

1. Periosteum: covers bone externally, except for articular surfaces; attaches to bone via
   Shapey’s fibers; dense irregular CTP + cell layer of osteoblasts and osteoclasts.
2. Endosteum: lines internal cavities; cell layer only (osteoblasts and osteoclasts).

Question 11

BONE MARROW

Answer 11

Red=hematopoeitic, marrow spaces of axial skeleton; prox epiphyses of humerus, femur.
Yellow adipose tissue in medullary cavities and marrow spaces not containing red marrow.

Question 12

LONG BONE MORPHOLOGY:

Answer 12

Epiphyses=articular ends covered by articular (hyaline) cartilage.
Diaphysis=shaft: cylinder covered by periosteum; medullary cavity lined by
endosteum and containing yellow marrow.
Nutrient foramina: contain blood vessels, nerves.

Question 13

OSSEOUS TISSUE TYPES

Answer 13

1. Compact=dense: diaphysial cylinder, outer epiphyses, skull plates. Osteon=Haversian system:
   Haversian=central canal surrounded by concentric lamellae. Lacunae with osteocytes located between
   lamellae. Volkmann’s canals connect central canals.
2. Spongy=trabecular: core of epiphyses and dipole between skull bone plates; trabeculae with incomplete
   lamellae and osteocytes and intervening marrow spaces lined by endosteum.

Question 14

OSTEOGENESIS=OSSIFICATION

Answer 14

1. Intramembranous: skull bones, clavicle. mesenchymal membrane gives rise to osseous tissue.
2. Endochondral: ossification of all other bones: hyaline cartilage model replaced by bone tissue;
   epiphyseal plates of cartilage replaced by epiphyseal lines (Ex. anatomical neck of humerus).