epithelial tissue ET

Name the characteristics of ET (4) and the two main types

Cellularity, polarity, avascular yet innervated, and highly regenerative.

Epithelia and glands

What is the basement membrane?

Interface between ET and CT

What is the function of the basement membrane?

Attach epithelium to CT and serve as a barrier to the movement of large molecules between ET and CT

What are the two layers of the basement membrane

Basal lamina and reticular lamina

What is the basal lamina made of?

Collagen, and proteins and carbohydrates (proteoglycans)

What is the reticular lamina made of?

Reticular fibers, proteins and carbohydrates

What are junctions?

Points of contact between adjacent cell membranes

What are the 4 types of junctions?

Tight, adhering, desmosomes, and communicating (or gap)

Tell me about tight junctions

Fluid tight seal near apical surface

Tell me about adhering junctions

Forms completely around the cell that stabilizes the cell and maintains tissue integrity

Tell me about desomoes junctions

Like snap buttons between calls. Long thin strands that run from one plasma membrane to the other. Resistance to mechanical stress, stretch without tearing

Tell me about communicating (gap) junctions

Little tunnels that connect the intercellular space between two cells. Rapid diffusion and communication

What’s the biggest difference between covering and lining ET and Glandular ET

ET is vascular, the other is not

What are the functions of ET

Protection, transport, selective permeability, misc (page 6 notes for more details)

What are the number of layers called in ET?

Simple, stratified, pseudo-stratified

What are the cell shapes at the free surface of ET?

Squamous, cuboidal, columnar, transitional

What are possible modifications in ET?

Goblet cels, cilia, microvili, flagella

Cilia is ONLY on what type of cell shape?

Columnar

Microvilli are never on what cell shape?

Squamous

Transitional cells are always what shape and #of layers?

Cuboidal and stratified

Where would I find simple squamous ET in the body?

Blood vessels, lymph vessels, lung alveoli

Where would I find simple cuboidal ET in the body?

Ducts of small glands

Where would I find simple cuboidal with microvili?

Kidney tubule

Where would I find simple columnar ET in the body?

Ducts of small glands, stomach, intestines

Where would I find stratified squamous ET in the body?

Mouth, esophagus, vagina, anus

Where would I find transitional ET in the body?

Bladder, urethra, parts of the ureter

Where would I find pseudo-stratified ET in the body?

Nasal cavity, trachea, bronchi

What is the function of Glandular ET?

To secrete, tissue is modified and specialized for secretions

What are the 2 types of glandular ET cells?

Endocrine and exocrine

what does an endocrine cell do?

Release hormones into blood

What does an exocrine cell do and where would you find them?

Release substance via ducts to a free surface or lining. Mucus, sweat, oil, saliva, enzymes

What’s a goblet cell?

Single cell glands, secrete mucus to lubricant surfaces

What is mucus and where would you find it?

A lubricant to reduce wear and tear. Respiratory, GI, Reproductive tracts

Name the 3 classifications of exocrine glands

Merocrine, apocrine, Holocene

What’s a merocrine exocrine gland and where would you find it

Cells release product by exocytosis. Pancreas

What’s an apocrine exocrine glad and where would you find it?

A pics portion of cell pinched off with product

What’s a holocrine exocrine glad and where would you find it?

While cells are released with their contents. sebaceous glands