Trachea is a fibro cartilaginous tube that allow expansion in width and extension during inspiration. In trachea histology, you will find the same histological features of general tubular organs with some special characteristics features.
Hope you are looking for the best guide to learn trachea histology along with their proper identification points. Great, you are now in the right platform where you are going to learn histological features of trachea with real slide images and labeled diagram.
After finishing this article you will able to identify the trachea histology slide under light microscope easily at laboratory.
The histological structure of trachea and extrapulmonary bronchi are almost same. You will find extrapulmonary bronchi structure in the lung histology slide. I have already published article on lung histology including extrapulmonary bronchi here in anatomy learner.
Okay, let’s get into the main part of today’s article – trachea histology layers with labeled diagram and real slide images.
You know trachea is called the windpipe and largest in diameter and length of respiratory tubes That provides the passageways between larynx and bronchi. In trachea histology you will find the four different coats, similar to the general organizational pattern of a hollow organ (as I mentioned before).
You will find the following four different layers in trachea histology slide –
#1. Tunica mucosa layer of trachea
#2. Tunica submucosa layer of trachea
#3. Muscularis mucosa layer of trachea structure and
#4. Adventitia of trachea structure
I will discuss details on these four different layers of trachea structure; but now I would like to enlist the important structure that you might identify from the trachea slide under light microscope.
#1. Pseudostratified ciliated columnar epithelium along with goblet cells in trachea
#2. Lamina propria of trachea structure
#3. Tracheal gland
#4. Hyaline cartilage of trachea
#5. Trachealis muscles
#6. Adventitia layer of trachea structure
Trachea histology slide identification
Do you want to identify the trachea histology slide under light microscope? Well, I will show you the real trachea slide picture with the identification points.
#1. Presence of four different layers – mucosa, submucosa, muscularis mucosa (cartilage layer) and adventitia in the provide sample tissue.
#2. The mucosa of the smaple tissue is folded and lined by pseudostratified ciliated columnar epithelium along with numerous goblet cells
#3. Presence of moderate numbers of seromucous gland in the submucosa of the sample tissue (actually tracheal gland)
#4. C shaped hyaline cartilage present in the muscularis layer (next to the submucosa layer or tracheal gland) and gap between the C shaped ring fills with smooth muscles (known as trachealis muscle)
#5. Presence of fibroelastic connective tissue in the adventitia of the provided tissue sample
So, the provided tissue smaple is a trachea slide.
Trachea histology layers with labeled diagram
You know there are four different layers in trachea histology structure. Now I am going to describe these four layers of trachea structure.
Trachea lining epithelium
The mucosa of trachea consists of respiratory lining epithelium and lamina propria. In the trachea lining epithelium you will find different types of cells –
#1. Pseudostratified ciliated columnar epithelium cells – these are tall, densly packed cell having apical cilia (most predominant in domestic mammals)
#2. Goblet cells – these are the mucous secrating cells in trachea that located at the basal part of mucosa layer
#3. Basal cells – they are rounded cells located at the basal area of mucosa of trachea
#4. Brush cells – these are columnar type of cells and have apical microvilli located at mucosa of trachea
#5. Small granule cell or dense granule cells of mucosa that contain different secretory granules
#6. Clara cells – these clara cells are present in the lower part of the trachea and found more in bronchi histology. These clara cells have smooth apical surface and contain secretory vesicle and smooth endoplasmic reticulum.
These clara cells are responsible for secration of phospholipid rich lipoprotein surfactant that help to reduce the surface tension in the air passageways of respiratory system.
All these cells are known as the respiratory epithelium of trachea.
Lamina propria of trachea histology slide contains thin layer of loose fibro elastic connective tissue and diffuse or nodular lymphoid tissue (sometimes). Actually there is no clear demarcation in between lamina propria and tunica submucosa of trachea as there the lamina muscularis is absent in trachea histology layer. So, you may called this layer as propria submucosa layer in trachea structure.
Propria submucosa layer of trachea structure
Deep to the lamina propria you will find dense connective tissue, longitudinally oriented elastic fibers and different cells (fibrocytes, lymphocytes, plasma cells and mast cells). In this layer you will also find tubule acinar seromucous tracheal gland that opens into the lumen of trachea through ducts that lines with ciliated cells.
Tubular portion of the tracheal gland lines with mucous secrating cells and the acinar part lines with serous secretory cells. In all domestic mammals, these tracheal glands are numerous in the proximal part of trachea.
Tunica muscularis or cartilage layer of trachea
In this layer you will find more distinct features in the tracha histology layer. You will find rough C shaped or U shaped tracheal ring (hyaline cartilage) in most of the animals. This ring is dorsally free and connected by the band of smooth muscle (usually known as trachealis muscle).
In most animals, this smooth muscle band attached the pericondrium of hyaline cartilage on the internal side; but in carnivores this attachment is on the external aspect of the cartilage.
Tunica adventitia of trachea structure
The adventitia of trachea histology made with fibroelastic connective tissue along with neurovascular structures.
Trachea histology drawing
Do you need the trachea histology drawing images? Well, I am going to share simple trachea drawing slide image with you.
If you need more updated labeled pictures of trachea slide then you may follow anatomy learner at social media (get more updates on trachea slide pictures).
You might also read other different article related to histology of respiratory organs from anatomy learner –
#1. Histological features of animal lung with slide image and labeled diagram
#2. Identification of epiglottis under light microscope
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