Exam 1 9/13 Davenport Intro to Connective Tissue Flashcards
Definition of connective tissue
Forms a continuum with other epithelial tissue, muscle and nervous tissue, and other components of connective tissue to maintain a well integrated body
Where does most connective tissue derive from?
Mesoderm
Where does cranio-facial connective tissue derive from?
Ectomesenchyme
CT composition
cells, ECM (fibers + ground substance)
What type of fibers are found in CT ECM?
collagen, reticular, elastic
What are the components of ground substance in CT ECM?
GAGs, proteoglycans, glycoproteins, extracellular fluid
What GAGs are found in ECM ground substance?
Hyaluron, chondroitin-4 & -6-sulfate, dermatan sulfate, keratin sulfate I and II, heparin sulfate
Where is hyaluronic acid found?
most connective tissue, synovial fluid, cartilage, dermis, vitreous humor, umbilical cord
Where is keratan I and II found?
Keratan sulfate I - cornea
Keratan sulfate II - cartilage
Where is heparan sulfate found?
Blood vessels, lung, basal lamina
Where is chondroitin-4-sulfate found?
Cartilage, bone, cornea, blood vessels
Where is chondroitin-6-sulfate found?
Cartilage, Wharton’s jelly, blood vessels
Where is dermatan sulfate found?
Heart valves, skin, blood vessels
CT cells have 2 major groups, which are:
Fixed cells; transient cells
Examples of fixed cells CT
fibroblasts, myofibroblasts, pericytes, adipose cells, mast cells, macrophages
What do fibroblasts do?
help maintain fibrous components of ground substance
Pericytes
associates with blood vessels
How do fibroblasts stain?
Pale staining nucleus but defined nucleolus
How do adipocytes stain?
Circular, white cells - most of cytoplasm has fat
Where can you find adipocytes?
Around neurovascular bundles; ex mentioned is a fat pad around the kidneys as a shock absorber
Difference between brown and white fat cells
Brown - droplets of fat within cytoplasm
In white adipose, these droplets coalesce to form bigger cells
How does mast cell stain?
Lots of blue secretory granules
Histamine
Vasodilator; increases vascular permeability, causes contraction of bronchial smooth muscle, increases mucus production
Those with allergies have higher number of:
IgE antibodies on basophil cells
____ is an anticoagulant and inactivates histamine
Heparin
What does macrophage look like?
Very large, kind of amoeboid
Examples of transient cells CT
plasma cells, leukocytes (neutrophils, eosinophils, lymphocytes)
Where do plasma cells derive from?
B lymphocytes that have interacted with antigen
Plasma cells produce and secrete:
antibodies
True or false: elastin fibers in the periodontal ligament stains
False - there is no elastin, the microfibrils stain
Collagen vs elastin structure
Collagen - axial periodicity, elastin has soft elastin core and intertwined microfibrils
Functions of CT
structural support, medium of exchange, defense and protection, storage of fats
Classification of CT (3)
Embryonic CT, CT proper, Specialized CT
Types of Embryonic CT
mesenchymal, mucous
Types of CT proper
Loose, Reticular, adipose, dense
Types of specialized CT
Cartilage, mineralized CT, blood
Mineralized CT examples
bone, cementum, dentin
Where is mesenchymal CT found?
embryo
Where is mucous CT found?
umbilical cord
Where is reticular fibers found?
stroma, liver, lymph
Types of cartilage
Hyaline, Elastic, fibrocartilage
Cartilage definition
form of connective tissue composed of cells called chondrocytes and highly specialized ECM
Hyaline cartilage - describe matrix and what type of collagen?
homogenous amorphous matrix of Type II collagen
Elastic cartilage has what type of collagen and fibers?
Elastic fibers and lamellae, Type II collagen
_____ has large bundles of Type I collagen between rows of chondrocytes
Fibrocartilage
Where is hyaline cartilage found?
Articular ends of long bones, ventral rib cartilage, templates for endochondral bone formation, trachea
Where is elastic cartilage found?
Pinna of the ear, auditory canal, laryngeal cartilages
Where is fibrocartilage found?
Intervertebral discs, pubic symphisis
In hyaline cartilage, chondrocytes are found in:
Lacunae
Describe structure of hyaline cartilage
Thin collagen fibrils (type 2), normally does not exhibit 67-68nm banding, arranged in felt-like pattern. Does not have axial periodicity, hard to see
Which GAGs are in hyaline cartilage?
hyaluronic acid, chondroitin sulfate, keratan sulfate
Describe hyaline cartilage matrix
- chondroitin and keratan sulfates are joined to a core protein (proteoglycans form)
- hyaluronate proteoglycan aggregates are bound to thin collagen fibrils
- highly hydrated
True or false: in hyaline cartilage, ground substance components are uniformly distributed
False - higher concentration of GAGs closer to cell because matric is hard to diffuse through
Perichondrium
Firmly attached connective tissue in inner cell layer and outer fibrous layer
Where is perichondrium found?
Around cartilage
Describe elastic cartilage
presence of elastin in the matrix, contains cells in lacunae and a perichondrium
Fibrocartilage components
Consists of chondrocytes and their territorial matrix in combination with dense connective tissue; NO perichondrium
Cartilage arises from:
mesenchyme
Cartilage is capable of what kinds of growth?
Appositional, interstitial
True or false: cartilage has extensive ability to repair
False - ability is limited
Calcification
generally replaced by bone
