Review of Histology (P) Flashcards
What is tissue?
It is a grp of cells w/ similar structure and function
What is histology?
It is the study of tissue structure
What are the 4 basic tissue types?
1) Epithelial tissue
2) Connective tissue
3) Muscle tissue
4) Nervous (Neural tissue)
What are the characteristics of epithelial tissue?
1) It also forms glands
2) It is also found throughout the body covering tissues
What is the classification of epithelia based on number of layers and its corresponding cell shape?
Number of Layers: Cell Shape
Simple (1 layer): Squamous; Cuboidal; Columnar
Pseudostratified (a modified form of simple epithelium): Columnar
Stratified (more than 1 layer): Squamous; Keratinized;
Nonkeratinized (moist)
Transitional (a type of stratified epithelium): Roughly cuboidal to columnar when not stretched and squamous like when stretched
*What is simple squamous epithelium?
What is the purpose of simple squamous epithelium?
To prevent abrasion bet organs
How can simple squamous epithelium prevent abrasion bet organs?
By covering them and by secreting a lubricating fluid
*What is simple cuboidal epithelium?
*What is simple columnar epithelium?
What is pseudostratified columnar epithelium?
It is a modified simple columnar w/c appears to have more than 1 layer
What is the function of pseudostratified columnar epithelium and what is the action of this function?
Secretes mucus that covers its free surface
What are the characteristics of stratified cuboidal epithelium?
1) It is composed of 2 or more layers of cuboidal cells
2) It is relatively rare
3) It is found in sweat gland ducts, ovarian follicular cells, and salivary glands
What are the characteristics of stratified columnar epithelium?
1) It is also rare
2) It consists of more than 1 layer of epithelial cells, but only the surface is columnar
3) It is found in ducts in the breast, larynx, and portions of the male urethra
What is transitional epithelium?
It is a special type of stratified epithelium that can be stretched
*What is the characteristic of transitional epithelium?
*It has umbrella cells (dome cells) on the surface
What is the characteristic of connective tissue?
It is characterized by a large amt of extracellular mat separating the cells
What are the 3 components of the extracellular matrix of connective tissue?
1) Protein fibers
2) Ground substance consist of non-fibrous protein
3) Fluid
What are the 3 types of protein fibers (in connective tissue)?
1) Collagen fibers
2) Reticular fibers
3) Elastic fibers
What is ground substance (in connective tissue)?
It is the bg where the cells and protein fibers are seen
What is the characteristic of the ground substance (in connective tissue)?
It is made up of proteoglycans
How are connective tissue cells named?
They are named accdg to their functions
What are the connective tissue cells that are named accdg to their functions?
1) Blast: produces the matrix
2) Cyte: maintains the matrix
3) Clast: destroys the matrix
Provide exs of connective tissue cells that are named accdg to their functions
Osteoblast, osteocyte, osteoclast, fibroblast, and fibrocyte
What is the action of embryonic connective tissue?
It gives rise to 6 major connective tissue types
What is the action of extracellular matrix?
It determines the function of each connective tissue type
What are the diff classifications of connective tissues?
Loose (areolar) connective tissue
Adipose tissue
Dense connective tissue
A) Dense collagenous connective tissue
a) Collagen fibers arranged in the same direction
b) Collagen fibers arranged in many directions
B) Dense elastic connective tissue
a) Elastic fibers arranged in the same direction
b) Elastic fibers arranged in many directions
Cartilage
A) Hyaline cartilage
B) Fibrocartilage
C) Elastic cartilage
Bone
Blood
What are the characteristics of loose (areolar) connective tissue?
1) Extracellular matrix is composed mostly of collagen fibers and few elastic fibers
2) It is loosely distributed throughout the body
3) Basement membrane often rests in loose connective tissue
4) It is widely distributed throughout the body; substance on w/c epithelial basement membranes rest; packing bet glands, muscles, and nerves. Attaches the skin to underlying tissues
5) In terms of its structure, it is a fine network of fibers (mostly collagen fibers w/ a few elastic fibers) w/ spaces bet the fibers. Fibroblasts, macrophages, and lymphocytes are located in the spaces
What are the functions of loose (areolar) connective tissue?
1) It fills spaces bet glands, muscles, and nerves
2) Loose packing, support, and nourishment for the structures w/ w/c it is associated
What are the characteristics of adipose tissue?
1) It has very little extracellular matrix composed of collagen and elastic fibers
2) The cells are large and closely packed together, and appear empty under light microscope
- > each cell is filled w/ lipids
3) It is a connective tissue w/ special properties
4) In terms of structure, it has a little extracellular matrix surrounding cells. The adipocytes, or fat cells, are so full of lipid that the cytoplasm is pushed to the periphery of the cell
5) This is located predominantly in subcutaneous areas, mesenteries, renal pelves, around kidneys, attached to the surface of the colon, mammary glands, and in loose connective tissue that penetrates into spaces and crevices
What are the functions of adipose tissue?
1) Packing mat
2) Thermal insulator
3) Energy storage
4) Protection of organs against injury from being bumped or jarred