Connective Tissue Flashcards
Describe mesenchymal cells.
A type of stem cell. irregularly shaped with multiple processes. Usually found adjacent to blood vessels
Describe fibroblasts.
Fibroblasts are active, long and branched cells with an pvoid nucleus. Synthesize fibers and ground substance
Fribrocytes are resting, rounded cells.
Describe myofibroblasts.
Can actin filaments and participate in wound healing.
Describe reticular cells.
Stellate-shaped with a spherical nucleus and basophilic cytoplasm. Produce reticular fibers.
What are the two types of adipocytes? Describe them.
Unilocular adipocytes are filled with large lipid droplets so the nucleus is displaced to the periphery.
Multilocular adipocytes have multiple lipid droplets and a centrally located nucleus. Have a lot of mitochondria. aka brown fat
Describe pericytes.
Elongated cells located near blood vessels and can differentiate. Contain actin and myosin to participate in wound healing.
Describe mast cells.
Found in loose connective tissue and around blood vessels. Can be spherical or ovoid with granules, release histamine and heparin (anticoagulant).
Stain with toludine blue to make the granules appear red.
Describe plasma cells.
Spherical or ovoid with an eccentric nucleus that looks like cart-wheel-like appearance. Cytoplasm is intensely basophilic. Produce antibodies.
With what can you stain collagen fibers?
Stained red with Van Gieson’s Method and blue with Mallory’s and Masson’s Trichrome stain.
Where can you find reticular fibers?
Liver, endocrine, and lymphatic organs.
With what can you stain reticular fibers?
Silver impregnation or PAS reagent.
What is the basic unit of reticular fibers?
Type III collagen coated with proteoglycans and glycoproteins.
Where can elastic fibers be found?
Aorta, muscular arteries, nuchal ligament, pinna of the ear, and lungs.
With what can you stain elastic fibers?
Hematoxylin and Eosin (stains light pink) or orcein and resorcin-fuchsin.
What is the basic unit of elastic fibers?
Elastin protein, covered by glycoprotein (fibrillin).
What are the two types of embryonic connective tissue?
Mesenchymal and mucous/gelatinous connective tissue.
Describe mesenchymal connective tissue.
Composed of mesenchymal cells and fluid-filled ground substance.
Describe mucous/gelatinous connective tissue.
Composed of fibroblasts and viscous ground substance and collagen fibers.
Describe loose/areolar connective tissue.
Predominantly ground substance, some scattered cells, and collagenous, reticular, and elastic fibers.
Where can loose/areolar connective tissue be found?
Beneath the epithelium (lamina propria, hypodermis), around blood vessels and nerves, and in serous membranes.
Describe dense connective tissue.
Composed of thick collagenous fibers and few fibroblast cells,
Where is dense irregular connective tissue found?
Capsules of the organs and deep layers of the dermis.
Where is dense regular connective tissue found?
Tendons, ligaments, and aponeurosis.
Describe elastic tissue.
Regularly or irregularly arranged elastic fibers.
Give an example of elastic tissue.
Nuchal ligament and vocal ligament.
Give an example of reticular tissue.
Spleen, lymph node, and liver.
Describe adipose tissue.
Adipocytes wuth loose connective tissue of mesenteries.
Where can adipose tissue be found?
Around blood vessels and nerves.
Does cartilage have blood supply?
Only around the peripheries.
How can you tell apart a chondroblast from a chondrocyte?
Chondroblast cells are oval shaped and are found on the peripheries where cartilage deposition occurs.
Chondrocytes are located within lacunae deep in the tissue.
Describe cartilage matrix.
Composed of fibers and ground substance with chondroitin sulphate, keratin sulphate, hyaluronic acid, chondronectin, and fibronectin (adhesive molecules).
Describe Hyaline cartilage.
Chondrocytes in lacuna or clusters (isogenous groups), ground substance with type II collagen (same refractive index as ground substance), surrounded by perichondrium with collagen fibers on the exterior but not interior.
Where can hyaline cartilage be found?
Articular surfaces of the bones, nose, and trachea.
Describe elastic cartilage.
Large amount of elastic fibers with ground substance, surrounded by perichondrium with a fibrous outer layer.
Where can elastic cartilage be found?
Pinna and epiglottis.
Describe fibrocartilage.
Predominantly type I collagen fibers, lack a distinct perichondrium but surrounded by collagen fibers.
What shape do osteoblasts take?
They vary from columnar to squamous.
Describe osteoblasts.
Found at the surface of the bone, nucleus is located in the basal region
What do osetoblasts secrete?
Osteoid
Where can fibrocartilage be found?
Intervertebral discs and menisci.
Describe osteocytes.
Lie in lacuna surrounded by interstitial matrix, which they secrete. Have long processes that extend to other adjacent osteocytes.
Describe osteoclasts.
Multinucleated with a ruffled cell border. Secrete acid and lysosomal enzymes for bone resorption.
What makes up the periosteum?
Fibrous and osteogenic layers.
Where is periosteum located?
On bone surfaces, except on the articular surfaces an where tendons and ligaments insert on the bone.
Where is endosteum located?
Lines the marrow cavity in a single layer of squamous cells, osteoblasts and osteoclasts.
What is the composition of spongy bone?
Bony plates and spicules.
Where can intramembranous ossification be observed?
In the skull bones, except the base of the skull.
Where can endochondral ossification be observed?
In the appendicular skeleton, vertebral column, and base of the skull.
