Lecture 5 - Epithelial Tissue Flashcards Preview

Structures > Lecture 5 - Epithelial Tissue > Flashcards

Flashcards in Lecture 5 - Epithelial Tissue Deck (19):

Germ layers of epithelial tissue

All three layers. Ectoderm --> epidermis, endoderm --> lining of GI tract and respiratory tract, mesoderm --> endothelium, mesothelium


Two types of epithelial tissue

Membranous epithelia, glandular epithelia


Five functions

protection/containment, absorption, secretion, sensation, contractility


apical vs. basal

apical --> uptake, secretion, protection; basal --> cell-substrate contact


Simple Epithelial Tissue

Just one layer of cells


Simple squamous tissue

Flat tissue; Found in lungs, blood vessels, cavities; serves as site of diffusion of fluids and gasses.


Simple Cuboidal Epithelium

cube-ish cells, centrally located nucleus; Found in ducts of the kidney, thyroid glands, salivary glands; serves as site of excretion, secretion, absorption (good surface:volume ratio)


Simple columnar epithelium

height>width, nucleus basal; found in intestine; good for absorption


Simple columnar ciliated epithelium

Columnar with cilia; oviduct/respiratory tract; propel ovum over cell surface, towards uterus


Pseudo-stratified columnar ciliated epithelium

Ciliated columnar cells w/ nuclei at different heights; Trachea; propel mucus and trapped particles


Stratified epithelial tissue

2 or more layers; serves as protection


Stratified squamous epithelium

many layers, top one squamous, lower ones more cuboidal; oral cavity, esophagus, cervix, vagina; serves to withstand chronic abrasion


Stratified Squamous keratinized epithelium

like stratified squamous with surface layer of keratin (dark pink H&E); epithelial surface of the skin; also withstands chronic abrasion


Stratified cuboidal epithelium

1-2 layers cuboidal cells; larger excretory ducts of exocrine glands (salivary glands); provide thicker lining


transitional epithelium

many layers of cells, surface layer large, round pillow shaped; urinary tract; withstands toxicity and accommodates stretch


types of glandular epithelia

1. Exocrine, stays connected to surface epithelia during development, when epithelial cells invade connective tissue
2. Endocrine, after epithelia cells invade connective tissue the duct cells break down and the gland is surrounded by connective tissue. Two types
2a. Endocrine glands that secrete into capillaries
2b. Follicular endocrine glands, secrete into interior lumen


Types of exocrine glands

Merocrine --> No loss of membrane so glands not exposed to lumen (goblet cell)
apocrine --> secretory product in vesicles
Holocrine --> whole cell broken for discharge of products (sebaceous glands)


Synthesis of mucigen

Protein component made in RER, carb. part attached in Golgi


Goblet cell function

Upper GI --> protective coat
Lower GI --> lubrication
Respiratory --> prevent drying, humidifies air, act as a sticky surface to trap potential irritants