Connective Tissue Flashcards
Responsible for providing and maintaining form in the body
Connective Tissue
Connective tissue divided into several types depending on;
✓ period of occurrence
✓ amount of intracellular substance
✓ arrangement of fibers
✓ presence of specific features
General characteristics of connective tissue
✓ made up of fewer cells that are set far apart
✓ supported by abundant intercellular substance
✓ contain connective tissue fiber
✓ different contents of intercellular substance, CT cells and fibers account
General functions of Connective Tissue
✓ provide a matrix that serves to connect and bind the cells and organs
✓ give mechanical support to the body
✓ storage of fat and certain minerals like calcium and bones
✓ exchange of metabolites between blood and tissues
✓ significant role in the repair and healing of wounds
✓ for protection against infection
functions of connective tissues
✓ CONNECT one tissue to another
✓ SUSPEND organs from the body wall
✓ INSULATE organs from mechanical damage
✓ account for the FORM of the organs
✓ serve as NUTRITIVE function as well
✓ aid in SUPPORT AND LOCOMOTION in conjunction with other tissues
Connective Tissue Proper
✓ loose CT
✓ Dense CT - regular & irregular
special properties of connective tissue
✓ adipose CT
✓ elastic CT
✓ hematopoietic CT
✓ mucous CT
supporting connective tissue
✓ cartilage
✓ bone
composition of connective tissue
✓ CT cells
✓ CT fibers
✓ intercellular or ground substance
✓ blood vessels - except in mucous CT and in cartilage
are immigrant cells usually from blood or bone marrow.
wandering cells
some retain their original characteristics and may take up permanent residence there;
✓ mast cells
✓ plasma cells
✓ pigment cells
✓ blood leukocytes
are native to the tissue in which they are found;
- undifferentiated mesenchymal cells
- fibroblast
- macrophages
- fat cells
eight resident cells
✓ fibroblasts
✓ mast cells
✓ pericytes
✓ fat or adipose cells
✓ macrophages
✓ mesenchymal cells
✓ foreign body giant cells
✓ reticular cells
remain undifferentiated in adult CT and constitute a reserve population of stem cells.
adventitial cells
often located along the walls of blood vessels
perivascular cells
capable of differentiation either into the usual cell types or into other cell type such as smooth muscle cells
pluripotential cells
unspecialised mesodermal tissue
mesenchymal CT
a more advanced stage of mesenchymal CT. Present in the Wharton’s jelly of the umbilical cord, comb, wattle of birds and lamina propria of omasum.
mucoid CT
intercellular substance - amorphous matrix and ground substance appears granular in proper fixation
principal component
fine collagen and elastic fibers and cells and mesenchymal cells.
minor component
Fibroblast classified as?
✓ lamellar or pyriform-shaped (youngest)
✓ spindle or fusiform (intermediate in age)
✓ stellate or star-shaped (mature)
Macrophages may either be?
✓ fixed or resting
✓ free, wandering
act as scavengers engulfing extravasated blood cells, dead cells, bacteria and foreign bodies.
macrophages
fully differentiated cells and are incapable of mitotic division
fat cells
found in most of the bulk of the human body
yellow or white
concerned with heat production, particularly important in newborn and young animals
brown fat cells
seven transient cells of CT
✓ plasma cells
✓ monocytes
✓ basophils
✓ pigment cells
✓ neutrophils
✓ lymphocytes
✓ eosinophils
plasma cells
✓ “activated” B lymphocytes
✓ very common cellular component of CT
✓ oval with eccentrically placed nucleus
✓ present in inflammatory sites, lymphatic organs, and in the lamina propria of the Gut
✓ differentiate from circulating blood CT
✓ principal producers of antibodies (immunoglobulins) that participate in the body’s humoral defense against infection
pigment cells or melanocytes
✓ pigment-containing cells of loose CT
✓ numerous in pigmented loose CT like in the core or the iris, ciliary body and ciliary process of the eye
✓ resemble the fibroblast but whose cytoplasm contains pigment granules that never invade the nucleus
found in the dermis of the skin, retina, choroid and iris of eyeball
dermal chromatophore
found in common mole and are responsible for the manufacture of melanin granules
epidermal melanocytes
smallest, with rounded nucleus which occupies most of the cytoplasm. Concerned with antibody production
lymphocytes
first line of defense, seen in regions of acute inflammation. have a segmented nucleus (3-5 lobes) having fine granules which are purple or violet in color.
neutrophils
largest, they have a kidney-shaped nucleus and are considered as the phagocytes of the blood
monocytes
Colorless, transparent and homogenous. Fills the space between cells and fibers of the CT. It is viscous and acts as lubricant and also as a barrier to the penetration of the tissues by foreign particles.
ground substance
Connective tissue Fibers
- collagen - formed by the protein collagen
- reticular - most abundant protein in the body
- elastic - composed mainly of the protein elastin
Collagen Fibers
✓ most numerous fiber in CT
✓ fibers are colorless stands, but when present in great numbers, they cause the tissue in which it is lie to be white
✓ are inelastic and a tensile strength greater than steel
✓ imparts a unique combination of flexibility and strength to the tissues in which it lies
most abundant and has a widespread distribution. Found in the dermis of the skin, tendons, bone, teeth and virtually all CT.
collagen type I
present mainly in hyaline and elastic cartilage. only very thin fibrils are formed
collagen type II
often found in association with type I and is probably the major collagenous components or reticular fibers. can copolymerize with other types of collagen
collagen type III
is the major collagen type in basal lamina. does not form fibrils or fibers
collagen type IV
present in fetal membranes and blood vessels and in small amounts in other tissues
collagen type V
affinity to silver salts
argyrophilic fibers
are extremely thin, with a diameter between 0.5 and 2 um. not visible in hematoxylin and eosin stains but can be easily stained black by impregnation with silver salts
reticular fibers
Elastic Fibers
✓ consists of an albuminoid protein called elastin
✓ range in diameter from 0.1 to 10 um
✓ contains few charged amino acids so it stains poorly with standards ionic dyes
✓ special stains such as verhoeff’s stain anf Weigert’s resorcin-fushsin stains.
✓ are extremely pliable and elastic
✓ can be stretched to 150% of their length without breaking
Adult connective tissue
✓ fibrous Connective Tissue/Proper CT
✓ Special Connective Tissue
✓ Supportive Connective Tissue
✓ Blood
most numerous and important resident cell of loose CT. shape depends upon the location of the cells.
fibroblast
process of scar formation
fibrosis
fibroblast in a quiescent phase are termed?
fibrocytes
is an anticoagulant (prevents blood clotting)
heparin
increases vascular permeability and smooth muscle contraction.
histamine
oval cells with a small oval nucleus and coarse.
mast cells (tissue basophils)
Macrophages (histiocytosis or clasmatocytes)
✓ very common phagocytic wandering cells in loose CT
✓ present in many organs to deal with routine contaminants
✓ highly specialized for phagocytosis of cells
✓ contain degradation products of cells
✓ derived from circulating blood monocytes that migrate to the CT
Fat or Adipose cells
✓ white fat cells
✓ brown fat cells
any cell type that occur around capillaries or small vessels where they intimately contact with the lining endothelium. cells are contractile having control on the size of the vascular lumen.
pericyte
rare in loose CT; if present, could be fibroblast that have de-differentiated.
mesenchymal cells
Dense Connective Tissue
✓ principal component is fiber
✓ fibers are arranged tightly together to make the CT thick or dense
✓ based on fiber orientation, is classified as irregular and regular.
numerous fibers runs parallel to each other, an arrangement that confers tensile strength and stretch resistance.
regular dense CT
a coarse network of collagen fibers arranged at RANDOM. More fibers and fewer cells that loose CT. also contain blood vessels and nerves bundle and ganglia. occurs in the reticular layer of the dermis of skin and in capsules of organs
irregular dense white CT
another variant of areolar CT.
adipose tissue
White adipose tissue
✓ wide distribution
✓ white adipose cells occur in cluster and may be angular in shape due to pressure they exert on each other
✓ chicken wire appearance
Hematopoietic tissue
✓ variant of loose CT
✓ blood cells in various stages of development and maturation
✓ classified as myeloid and lymphatic tissues
produces majority of blood cells
myeloid tissue
highly cellular tissue blood cells in various stages of development, blood vessels and sinuses filled with erythrocytes
red bone marrow
Features of Megakaryocytes
✓ actually a resident of the red bone marrow
✓ give rise to platelets
✓ large cell with a single large lobulated nucleus
yellow bone marrow
✓ similar in location to red bone marrow
✓ white adipose cells
✓ developing cells
✓ similar to white adipose tissue except that it is located in the intertrabercular or interosseous spaces.
produces the lymphocytes
lymphatic tissue
dark peripheral zone of NLT that contains small lymphocytes with small dense nuclei and plasma cells.
Corona
central area of NLT that contains B lymphocytes, lymphoblast and large lymphocytes with large pale nuclei
germinal center
classified as solitary and aggregated NLT
Nodular lymphatic tissue
occurs in the lamina propria of tubular organs or in parenchyma of solid organ
solitary lymphatic nodule
three or more NTL’s that consolidated in the lamina propria and or t. submucosa of certain organs
aggregated lymphatic nodules
two form of aggregated lymphatic nodules
✓ tonsil
✓ Peyer’s patches
also called the intestinal tonsil
peyer’s patches
