36 



EPITHELIAL TISSUES 



2. Columnar. 



(4) Neuro-epi- 

 thelium. 



(a) Eye the rod and cone cells 

 of the retina. 



(b) Ear in the cristse and mac- 

 ula of the labyrinth and in Cor- 

 ti's organ. 



(c) Nose in the olfactory mucous 

 membrane (true neuron). 



(d) Tongue in the taste buds. 



II. COMPLEX (STRATIFIED) EPITHELIA those whose cells 

 \ form several superimposed layers. 



Forms the epidermis of the skin, 

 and covers the free surface of 

 those mucous membranes which 

 clothe all orifices in direct con- 

 nection therewith viz., the con- 

 junctiva and cornea; the exter- 

 nal auditory canal; part of the 

 nasal mucous membrane ; mouth, 

 pharynx, and esophagus; epi- 

 glottis and vocal cords; anus, as 

 high as the internal sphincter; 

 vagina and external portion of 

 the urethra. 



1. Squamous. 



2. Columnar 

 (Pseudo- 

 stratified 

 columnar) 



Superficial cells, 

 squamous; 

 deeper, polyhe- 

 dral; the deep- 

 est, columnar 

 in shape. 



Superficial cells, 

 columnar; 

 deeper cells, 

 polyhedral or 

 spindle-shaped. 



(a) Non-ciliated 

 (rare) 



(b) Ciliated. 



(a) Part of ductus deferens. 



(b) Respiratory tract; nasal mu- 

 cous membrane and passages 

 connected therewith, tear-ducts, 

 auditory tube, etc., larynx, 

 trachea, and bronchi. 



Genital tract; epididymis and vas 

 deferens. 



3. Transitional. 



Superficial cells 1 

 only somewhat 

 flattened; next 

 deeper layer, 

 pear-shaped; 

 deepest layers, 

 polyhedral. 



Found only in the urinary system 

 viz., pelvis of the kidney, ure- 

 ter, bladder, and first portion of 

 the urethra. 



