tissue part 1 Flashcards
covers the external surfaces of the body, lines the internal surfaces of the body and forms exocrine glands.
epithelial tissue
serves as support soft body parts and bind structures together
connective tissue
forms the muscular wall of tubular organs and the flesh of the body movement
muscle tissue
conducts impulses used to help control and coordinate body activities.
nervous tissue
components of tissue
cells, intracellular substance, fluid
the living components of a tissue and vary in number, shape and arrangement depending on type of tissue
cell
the liquid component of a tissue that occurs in between cells where it is known as extracellular fluid and in blood where it is called plasma
fluid
the non-living materials produced by cells, such as fibroblast (connective tissue cells), chondroblast (cartilage cells) and osteoblast (bone cells),
intracellular substances
organic body material in animals made up of large numbers of cell that are similar in form and function and their related intercellular substances
tissues
major component of ct
intercellular substance
2 types of intercellular substance
amorphous substance and formed
Amorphous substance literally means
without form
difficult to observe with routine paraffin technique. It is viscous, gel-like and binds to large quantities of water. It forms the ground substance matrix of tissue and occupies areas not occupied by cells and forms intercellular substance.
amorphous substance
amorphous substance is chemically composed of
glycoproteins or proteogycans
acts as barrier to bacteria and shock absorber in tissues.
amorphous substance
are fibrous in nature and chemically composed of neutral mucosubstances glycoproteins).
formed elements
3 types of formed elements
collagen fiber, elastic and reticular
the predominant fiber in most proper connective tissues
collagen fibers are
likened to a “biological rope” because of its immense strength as it provides high tensile strength and prevent over-distension.
collagen fiber
In embryonic connective tissue, they are fine filamentous materials stained glassy pink in H&E.
individual collagen fiber
in adult animals, these are like tendon’ individual fibers are widely glassy bands with smooth edges
connective tissue
In stretch preparation , the fibers appear as wavy thick bands of indefinite length and random arrangement
of areolar connective tissue
Adult collagen fiber is composed of
collagen fibrils
composed of overlapping tropocollagen molecule laid together in triplets like a braid of hairs.
collagen fibrils
the most common protein in animals
collagen
a type of collagen that is banded; most abundant; present in skin, bone and tendon;
type 1
type of collagen that is unbanded; present in cartilage
type 2
type of collagen thats make up the reticular fibers,
type 3
tye of collagen that is unbanded, major component of the basement membrane
type 4
strands or sheet and provides springiness and stretchability to the tisse.
elastic fiber
this is difficult to observe in H&E sections
elastic fibers
In dense regular elastic connective tissue like ligamentum nuchae, elastic fibers are
individual fibers are long, narrow, straight and branched bands with rough edges.
In In stretch preparation of loose (areolar) connective tissue, elastic fibers are
thinner than collagen fibers and may have a corkscrew appearance.
Each elastic fiber consists of a
protein elastin (amorphous substance) surrounded by microfibrils
chemically made up of type III collagen, a very fine collagen fiber. Not visible with routine H & E but stains well with silver and periodic acid schiff (PAS)
Reticular fibers
short, black, wiry, branched structures that interconnect with each other to form the characteristic netlike arrangement.
silver stained individual reticular fibers
the principal role of reticular fibers is
to form a delixate scaffolding to anchor blood vessels and nerve fibers to the more robust surrounding CT
epithelium comes from greek roots _____
epi=upon
thele=breast
aggregation of cells which are in apposition over a large part of their surfaces, having very little intercellular space and resting on basement membrane and which are specialized for absorptive, secretory, protective, or sensory activities.
epithelial tissue
defined as a relatively avascular and almost wholly cellular (i.e., having little or no connective tissue associated with it)
epithelila tissue
tissue similar to epithelium but lack basal lamina
epithelioid
Epithelial chief components are____ which are generally similar in structure and function.
cells
the cellsclosely joined together laterally and/basally by junctional complexes.
epithelium
presents a free surface that faces a canal or cavity or lumen and may present special modifications, such as microvilli or cilia that enhance the function of the epithelium.
epithelium
increase the surface area for absorption or secretion.
microvilli
move secretions and other substances across the epithelium.
cilia
Rests on a basement membrane that attaches it to the underlying connective tissues.
epithelium
what is a basement membrane
when the epithelial cells lie on the reticular lamina which is bound to another ct called areolar cells
since epithelium is avascular, how are cells nourished?
by diffusion of nutrients from capillaries in the underlying connective tissue.
exihibit polarity since they have apex and base where different activities take place (
epithelial cells
Epithelial tissue embryonic origin mostly comes from
ectoderm, endoderm, and few from mesoderm
(lining epithelium of digestive tube, parenchyma of the liver, pancreas and other digestive glands
endoderm
(lining epithelium of urinary organ (ureter) and reproductive tracts
mesoderm
have high ploriferation and turnover rates. they are short-lived, typically days to weeks and dead or damage cells are regularly replaced by mitosis of younger cells.
epithelial cells
functions of epithelia
secretions
gas exchange
nutrient absorption
UV barrier
physical barrier
pigmentation (for camouflage)
excretion
stimulis reception
secretory sheets of epithelial tissue is found in
reproductive tract, conjuctiva, GI tract
examples of epithelial cells that has secretory functions
goblet cells of epithelial sheets(secretes mucinous material)
