Lecture 10 Flashcards
(24 cards)
Hyaline cartilage
T2 collagen fibres, proteoglycans which repel each other spreading the molecules over a wide space. GAGs hold lots of H2O and it’s how cells get nutrients.wast diffused. Has perichondrium layer then chondroblast layer followed by the chondrocytes.
Elastic cartilage
elastic fibres, elastic lamellae, collagen proteoglycans
fibrocartilage
T1 collagen fibres, proteoglycans. More cartilage than hyalin and had fibroblasts.
cells in hyalin cartilage
chondroblasts (cells that rapidly divide)
chondrocytes (cells that eith slowly or dont divide).
chondrocytes can give rise to other chondrocytes. Perichondrium, growing area and chondrocytes in lacuna is indicative of hyalin cartilage. Found in: bone precursor, epiphyseal plate, synovial joint surface (minus perichondrium), end plates and respiratory tract.
Isogenous group
multiple chondrocytes in one lacuna due to division.
Characteristics of elastic cartilage
surrounded by perichondrium. Located in ear and epiglottis. Pliant and resilient.
Characteristics of fibrocartilage
found in intervertebral disks, pubic symphysis, knee menisci, wrist disks, temporomandibular joint. No perichondrium. Chondrocytes surrounded by matrix and have round nuclei. Fibroblasts have flat nucleus surrounded by collagen and arranged in rows. Combination of dense regular CT and hyaline cartilage. Function is to absorb energy and hold joints.
Bone
Compound tissue: periosteum, bone tissue (cells+matrix), endosteum, marrow, supply and cartilage. Has osteoprogenitors, bone lining, osteoblasts, osteocytes and osteoclasts. Ground substance is hydroxyapetite.
Lamellae types
circumferential (goes around bone), concentric (around Haversion canals) , interstitial (those in the middle) and spongey bone which don’t have Haversion systems.
compact bone
dense, harder outer shell, strength
spongey bone
trabeculae or cancellous. Provides strength and lightness.
Haversian System (osteon)
A cylindrical unit of bone tissue. Consists of a central Haversian canal surrounded by concentric layers of lamellae. Provides structural support and strength to the bone. The Haversian system is the microscopic structural unit of compact bone. On bone that transfer lots of weight
Haversian canals
A central, tubular channel within the Haversian system. Contains blood vessels, nerves, and lymphatic vessels. Serves as a pathway for nutrients and waste exchange between the blood and the osteocytes. Lay vertical.
Volkmann’s canals
small channels in compact bone that connect Haversian canals to each other and the periosteum, allowing blood vessels and nerves to pass through and supply the bone tissue. Lay horizontal.
Periosteum
A fibrous layer composed of dense connective tissue that allows for the attachment of muscles, tendons, and ligaments. Has fibrous, cellular and bone component.
Perichondrium
the connective tissue that envelops cartilage where it is not at a joint.
Endosteum
thin layer of connective tissue composed primarily of osteoblasts, osteoclasts and osteoprogenitor cells. has cellular level
Endosteum vs periosteum vs perichondrium
Endosteum and periosteum are associated with bone while perichondrium is associated with cartilage.
Endosteum lines the INNER surface of bone while periosteum lines the OUTER surface of the bone
Canaliculi
Where osteocytes communicate with each other.
Difference in bone cell appearance
Osteoprogenitor cells and bone lining cells are flat, osteoblasts are cuboidal, osteoclasts are big and multinucleated and osteocytes are within the lamellae.
osteoblats
make bone, cuboidal in shape. Secretes collagen and matrix minerals. Calcifies bone matrix. Communicate via gap junctions with each other. Form a single layer along forming bone face. Respond to mechanical stimuli.
osteocytes
Enclosed by matrix. Mature bone cells. Maintains bone matrix and helps maintain Ca homeostasis. In lacunas. Cytoplasmic processes extend through canaliculi in the matrix to contact other cells via gap junctions
Osteoclasts
Different cell line (haemopoietic progenitor cells). Large dome shaped, multinucleated. Ruffled boarder against the bone. Plasma membrane infoldings increase SA. Sits in hemilacuna
Synovial membrane
produces synovial fluid (lubrication and nourishment). A membrane comprised of a mixture of cells incl. synoviocytes. Fernestrated capillaries, sensory nerve fibres. Lack TJs and basal lamina. Not on articular surfaces, surrounds rest of joint space.
