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Simple Squamous Epithelium
Simple Cuboidal Epithelium
Simple Columnar Epithelium
Pseudostratified Columnar Epithelium
Stratified Squamous Epithelium
Stratified Cuboidal Epithelium
Stratified Columnar Epithelium
Transitional Epithelium
Glandular Epithelium
Connective Tissues – Embryonic/Fetal
Connective Tissues – Adult
Connective Tissues – Supporting
Connective Tissues – Transport
Muscles Tissues
Nervous Tissues

Organ Systems

Integumentary System
Cardiovascular System
Lymphatic System

Digestive System Part I – Oral Cavity and Salivary Glands

Digestive System  Part II – Esophagus and GI Tract

Digestive System  Part III – Liver, Gall Bladder and Pancreas

Respiratory System
Urinary System
Endocrine System
Reproductive System

Sensory System:  The Eye And Internal Ear


Respiratory System

Nasal Septum Rat Frontal Sec 40X

Perpendicular plates of the delicate ethmoid bone (blue arrows), together with hyaline cartilage (Hc), form the nasal septum that separates the right and left nasal cavities.  Most of the surface area of each cavity is lined with respiratory mucosa consisting of pseudostratified ciliated columnar epithelium (pink arrow) with goblet cells.  The underlying, highly  vascularized lamina propria (Lp) contains numerous darkly stained seromucous glands. Simple cuboidal cells line the excretory ducts (Ed).  The lamina is attached to the periosteum of the ethmoid bone.

Nasal Concha(Turbinate Bone) Frontal Sec Rat 40X

The micrograph displays one of three scroll-like conchae or turbinate bones in the left nasal cavity (NC).  These bones project into each nasal cavity from the lateral wall of the ethmoid bone (blue arrow).  The conchae are covered with respiratory mucosa (green arrow).  Their presence increases the surface area of the mucosa, and enhances its ability to warm inspired air and trap particulates in mucous that covers the epithelial surface.  Blood vessels, mucoserous glands, and excretory ducts can be identified in the image.

Trachea Wall 40X

The lumen of the trachea is lined with pseudostratified ciliated columnar cells.  Clear, mucous-secreting goblet cells can be seen interspersed in the epithelium (Ep).  Cilia are visible on the luminal surface of the cells.  The lamina propria (Lp) with elastic connective tissue underlies the epithelium.  Mucous and seromucous glands (arrows) are in the submucosa (Sm).  The tracheal ring (Tr) is composed of hyaline cartilage.  The perichondrium (Pc) consisting of fibrous connective tissue surrounds the tracheal ring.

Terminal Bronchiole 100X

Branches of intrapulmonary bronchi called bronchioles supply air to pulmonary lobules of the lung.  Observe that the cartilaginous plates and glands are absent.  A circularly arranged  band of smooth muscle (arrow) is present in the wall of the bronchiole.  Simple ciliated columnar epithelium lines the lumen of the air passageway.  A branch of the pulmonary artery (Bv) is present.  Lung tissue with alveoli (AL) surrounds the bronchioles, but there is no gas exchange between the alveoli and the bronchioles.

Alveoli 100X

Polyhedral alveoli are present in the figure.  Interalveolar septa (arrows) of varying degrees of thickness surround and separate alveolar air spaces.  Darkly stained nuclei of simple squamous cells are visible in the walls of the alveoli.


Nasal Region  Rat  Frontal Section  20X
Nasal Cavity  Respiratory Mucosa  400X   1000X
Nasal Cavity  Olfactory Mucosa  100X
Paranasal Sinus  Frontal Section  40X
Epiglottis  LS  20X   40X
Larynx  Ventricular + Vocal Fold  20X
Trachea  Inner Wall  400X
Trachea  Goblet Cells  400X
Intrapulmonary Bronchus  40X   100X
Terminal Bronchiole  40X
Alveolar Capillaries  400X
Alveolar Epithelium  400X