Epithelium and connective tissue

What are the 4 basic tissues of all organs

1. epithelium

2. connective tissue

3. muscle

4. nervous tissue

What are the primary functions of epithelial cells

1. protect the tissue underneath

2. regulate exchange

3. secrete hormones

What are the shared characteristics of epithelial cells

1. close apposition of cells

2. free surface of epithelial cells is adjacent to space

3. basal surface is adjacent to connective tissue

4. sheets of epithelial cells may be modified into tubes forming glands

5. absence of blood vessels

How would you morphologicaly classify epithelia

1. # of layers

2. shape of cells at free surface

3. function of epithelium

4. surface modifications

what are the 3 shapes of epithelia

• squamous

• cuboidal

• columnar

what type of epithelia is most likely the outer covering for organs

simple squamous epithelia; mesothelium

What type of epithelia is most likely the covering for blood vessels

simple squamous epithelia; endothelium

how does pseudostratified differ from stratified

in pseudostratified each cell still connects to the basement membrane

what is the only shape of cell can pseudostratified epithelia be in

columnar

what are the two functions of epithelia

• lining

• secretory

what are the 2 types of secretory epithelia

• endocrine

• exocrine

what are the 3 types of exocrine secretion

• holocrine

• apocrine

• merocrine

Holocrine secretion work

the whole cells dies and sloughs off allowing for the substrate to be swept into the lumen

how does merocrine secretion work

exocytosis of secretory vesicles to the lumen

how does apocrine secretion work

budding vesicles off the epithelial cells into the lumen

what is an endocrine gland

secretes products into extracellular space which enters the blood stream

what two modifications can be made to the epithellium

• microvilli

• cillia

What is the cell junction called that facilitates cell to cell connection

desmosome

What is the cell junction called that facilitates cell to basement membrane connection

hemidesmosome

what are the fiber types that make up connective tissue

• collagen fibers

• reticular fibers

• elastic fibers

what are ground substances

a gel like substance that occupies the space between cellular and fiber elements in the extracellular matrix

what is the most common cellular component in connective tissue

fibroblasts

what other cells are present in connective tissue

• macrophages

• neutrophils

• eosinophils

• b & t cells

• brown and white adipocytes

what are the 4 classifcations of connective tissue

• loose irregular tissue

• dense irregular tissue

• dense regular tissue

• embryonic connective tissue

what fiber makes up a majority of embryonic connective tissue

reticular fibers

where can pseudostratified columnar epithelium mostly be found

respiratory tract

what distinction must be made if identifying stratified squamous epithelia

the presence of keratin

what collagen is part of hyaline and elastic cartilage

type 2 collagen

what type of collagen in part of the smooth muscle and healing wounds

type 3

what type of collagen is found in the basement membrane of epithelial cells

type 4

what type of collagen is found in placental basement membranes and interstitial tissue

type 5