Term | Definition |
Cartilage | A connective tissue made of cells, fibers and matrix. It is tough, resilient, avascular gel, capable of fast growth. |
Hyaline cartilage | Most common. Made of collagen fibers. Flexible and tough but yet the weakest. The matrix doesn't stain well so its almost transparent. (Ex: part of nasal septum, ribs, sternum, joint surfaces and developing bone.) |
Elastic cartilage | Elastin fibers. Darker under microscope. (Ex: external ear, tip of nose and alar cartilages and larynx.) |
Fibrocartilage | Densely inter-woven collagen fibers (Ex: pubic symphysis, intervertebral disks) Can absorb shock and resist compression. Very pink. Heals very poorly and slowly. |
Ligament | Connect bone to bone, cartilage to cartilage and bone to cartilage. Lots of elastic fibers and collagen fibers and is moderately stretchy. |
Areolar CT | Deep in the dermis, covered by epithelial lining of the digestive, respiratory and urinary tract between muscles and around blood vessels. Provides support but permits independent movement. |
Adipose CT | Deep in skin; side , buttocks, breasts and padding around eyes. Cushion shocks, insulates and stores energy. |
Osteon | Mature bone, made up of osteoblasts, osteoclasts and osteocytes. |
Lamellae | Matrix layers |
Lacuna(e) | Osteocytes occupy lacunae (lakes) sandwiched between layers of matrix. |
Canaliculi | Channels that radiate through the matrix from lacuna to lacuna. |
Haversian canal | Central canal brings nutrients to bone. |
Matrix | Makes up most of connective tissue. Jobs: structural framework, transporting fluids and dissolving material, protecting delicate organs, interconnecting tissues. |
Fibroblasts | Avascular gel. |
Chondroblast | Turn into chondrocyte. Produce fibers and matrix. Trapped in lacunae. |
Bone | Is a connective tissue. Made of osteocytes, collagen fibers, calcium phosphate matrix. Dynamic living tissue: self-repair, adjusts to new loads. Stores calcium, fat and makes blood cells. Vascular: numerous blood vessels (transport) Innervated. |
Functions of bone tissue | STRUCTURAL SUPPORT for the entire body. STORAGE OF MINERALS (calcium) and lipids (fat). BLOOD CELL PRODUCTION (hematopoiesis). PROTECTION (rib cage, skull, spinal column). LEVERAGE (muscle attachment=movement) |
Bone tissue has 4 types of bone cells | FIBROBLASTS (undifferentiated), OSTEOBLASTS (produce new bone matrix), OSTEOCYTES (mature cells surrounded by their own matrix, cycle/recycle calcium levels in the bone matrix) OSTEOCLASTS (remove bone matrix (osteolysis)) |
Neurovascular | NAVL (each produce each other) small nerve, artery, vein & lymphatic. |
Long bone structure | Diaphysis (tubular shaft), epiphysis (expanded area at the ends of bone), metaphysis (zone btw. diaphysis & epiphysis. |
Long bone structure (cont.) | Epiphyseal line ( remnant of metaphysis/ growth plate. Nutrient foramen (hole in diaphysis for blood vessel) medullary (marrow) cavity (cavity within diaphysis) |
Yellow bone-marrow | Contains fat cells |
Red bone-marrow | Contains blood cells (hematopoiesis) |
Periosteum | Membrane on external surface of the bone. Outer fibrous layer: muscle attachment. 2 active cell types reside btw bone and periosteum (osteoclasts remove bone, osteoblasts make bone) |
Endosteum | Membrane on inner walls of the medullary cavity. (single layer of epithelial cells, osteoclasts & osteoblasts sit btw bone & endosteum) |
Vascular supply of bone | NUTRIENT A/V: bone marrow in medullary cavity, METAPHYSEAL A/V: assoc. w/ metaphyses and epiphyses. |
Compact bone | Compact bone appears solid. Osteon is a functional unit, holes btw. lamellae (lacunae) filled w/ osteocytes. Osteocytes talk via canaliculi. Haversian canals carry n./a./v.'s through osteon. Perforating (Volkman's) canals carry n./a./v.'s btw. osteon. |
Trabecular bone | Appears 'spongy', this bone type is very strong for its weight. Haversian canals & osteons are modified/ reduced. Osteocytes & canaliculi are found throughout the trabeculae. Osteocytes get nutrition via diffusion from the bone marrow. |
Diaphyses are typically made of compact bone. Epiphyses are typically made of trabecular bone. | |