Connective Tissue Flashcards

Question

Fibrocartilage (Fibrous cartilage) (s, f, l)

Answer 1

Structure: firm, solid tissue that resembles dense connective tissue but has chondrocytes in lacunae; ECM of abundant collage fibers and thick, long strands often in one orientation; No distinct perichondrium Function: provide structural support and rigidity to resist compression and shear forces and absorb shock Location: pubic symphysis, annulus fibrosus of intervertebral disks, menisci

Answer 2

Cartilage is avascular. Thus, it relies on the blood vessels in the perichondrium (and other surrounding tissues) for diffusion of nutrients. Results in slow and limited ability to heal and repair itself when injury occurs.

Answer 3

Occurs mainly before adulthood, slowly decreasing through adolescence. Appositional growth and interstitial growth

Answer 4

Chondroblasts in the perichondrium produce cartilaginous matrix and thicken the cartilage from the periphery. Chondroblasts become encased in the matrix they produced and are then called chondrocytes.

Answer 5

Chondrocytes in the middle of the cartilage divide (become isogenous groups) and then each daughter cells starts secreting its own matrix around itself eventually becoming separated from each other.

Answer 6

a group of chondrocytes that arose from a single chondrocyte during interstitial growth. In the early stage, isogenous groups of chondrocytes can be identified by their close proximity to each other or by a number of chondrocytes in the same lacuna.

Answer 7

Structure: pool of meschymal stem cells, stellate to squamous morpholog, difficult to identify on regular stain Function: give rise to osteoblasts with appropriate stimuli, may differentiate into other types of connective tissue cells Location: mesenchyme, inner most layer of periosteum; endosteum; bone marrow

Answer 8

Structure: active - cuboidal to columnar with basophilic cytoplasm and euchromatic nuclei and distinct nucleoli; inactive - squamous, difficult to identify Function: secrete osteoid (type I collagen and bony matrix proteins) that calcifies Location: innermost layer of the periosteum, endosteum; usually in contact with newly forming bone

Answer 9

Structure: osteoblasts encased in calcified matrix mature and become osteocytes; dendritic morphology Function: maintain bony matrix; mechanotransduction Location: main cell body in lacunae, cell processes in canaliculi

Answer 10

Structure: large, multinucleated macrophage derivative Function: resorb bone tissue Location: resorption bay (Howship lacunae); a concave depression on the bone surface, scattered throughout endosteum and periosteum

Answer 11

Structure: dense connective tissue covering bone Function: deliver neurovascular supply to the bone, allow tight attachment of the muscles and other structures to the bone Location: Outer surfaces of most compact bone

Answer 12

Structure: resembles simple squamous epithelium composed of inactive osteoblasts, Osteoprogenitor cells, and osteoclasts Function: source of new osteoblasts and osteocytes Location: inner surfaces of compact bones, canals; outer surfaces of all spongy bone

Answer 13

Structure: highly organized into osteons Function: mechanical support, protection, weight transfer, mineral storage Location: outer surfaces of the bone

Answer 14

Structure: network of thin plates or branches of bony tissues with spaces in between Function: weight transfer, quick mineral turnover, reduce the weight of the bones, provide large surface area for bone resorption/formation Location: inner portions of the bone; center of diaphysis and epiphysis of long bones and centers of most bones

Answer 15

Structure: spaces filled with erythrocytes and adipocytes Function: site of blood formation and fat storage, lighten the weight of the bone Location: spaces between the sponge bone trabeculae

Answer 16

Structure: cylindrical units within compact bone Function: bear and transfer weight in the long axis Location: throughout compact bone, oriented parallel to the long axis of the bone or in the direction of the force applied

Answer 17

Structure: central channel for vessels and nerves Function: conduct vessels and nerves throughout the length of the osteon Location: center of each osteon

Answer 18

Structure: channel that runs perpendicular to the long axis of the osteon Function: deliver vessels and nerves throughout the thickness of the compact bone Location: varies, run perpendicular to the long axis of the osteon

Answer 19

Structure: concentric layers of bony matrix with collagen fibers in each layer running in opposite direction Function: layered arrangements and fiber orientation allow optimal weight bearing and even weight transfer Location: rings of bony matrix in each osteon

Answer 20

Structure: darker staining line Function: demarks the outer limit of each osteon Location: outer boundary of each osteon

Answer 21

Structure: short, narrow, hair-like channels Function: conduct osteocyte process, allow them to make physical contact and chemical contact via adhesions and gap junctions Location: radiate from each lacuna and often run the width of each lamella

Answer 22

Structure: non-cylindrical layers of bony matrix Function: fill the gap between osteons; weight bearing and transferring; remnant of remodeled osteon Location: in between osteons

Answer 23

Structure: several layers of bony matrix on the outer most side of the compact bone Function: bind the osteons from the outside, site of attachment for periosteum Location: outermost layer of compact bone

Answer 24

Structure: thick, ropy bundles of collagen type I fibers extending from periosteum into the compact bone Function: tightly anchor periosteum to the compact bone Location: extend from periosteum into the outer concentric lamellae and often deeper into the peripheral osteons

Answer 25

Structure: several layers of bony matrix on the inside of the compact bone Function: bind the osteons from the inside site of attachment for endosteum Location: innermost layer of the compact bone

Answer 26

Structure: bony spicule, small think, short bony tissues. In adults, bony matrix is lamellar (layered). No osteons Function: collectively allow weight transfer, source of quick bone absorption and formation Location: throughout the central portion of most bones

Answer 27

Structure: hematopoietic tissue Function: blood cell production Location: most marrow cavities in infants and young children. Marrow cavities of flat bones and vertebrae in adults

Answer 28

Structure: unilocular adipose tissue Function: lipid storage Location: most marrow cavities of long bones in adults

Answer 29

First bone that forms during ossification process. Collagen fibers are unorganized and osteocytes in lacunae are randomly scattered throughout bony matrix. Usually found in embryo and fetus or in adults at healing sites and the alveolar processes of the maxilla and mandible.

Answer 30

Bone tissue that forms through remodeling of woven bone. Collagen fibers are well organized. Osteocytes in lacunae are regularly arranged and spaced throughout matrix. Found in most adult compact and spongy bones.

Answer 31

PTH - released by parathyroid glands, inhibits osteoblasts from producing bony matrix which stimulates osteoclast stimulating factor (OSF) secretion, which increases bone reabsorption by the osteoclasts, ultimately increasing the blood calcium level Calcitonin - released by parafollicular cells (C-cells) of the thyroid and inhibits osteoclasts, thus reducing bone reabsorption and ultimately decreasing blood calcium level

Answer 32

bone formation within the mesenchyme. Osteoprogenitor cells --> osteoblasts --- produce bony matrix ----> become osteocytes. Matrices interconnect and remodel to form compact bone and spongy bone

Answer 33

Bone formation in the cartilage mold. Hyaline cartilage forms from mesenchyme --> hyaline cartilage forms isogenous groups --> and then osteoblasts and eventually osteocytes; zone of rest, zone of proliferation, zone of hypertrophy, zone of calcification, zone of ossification. Occurs in long bones that need to lengthen rapidly without requiring direct blood supply. Occurs at the epiphyseal plate.