30 Questions
What is the primary function of cilia in pseudo-stratified columnar ciliated epithelium?
To move substances in one direction
Which type of epithelium is found in the uterus and fallopian tube?
Simple columnar ciliated
What is characteristic of pseudo-stratified columnar epithelium?
Cells are crowded, with nuclei at different levels
What is the function of simple columnar epithelium in the stomach, intestine, and convoluted tubule of the kidney?
Secretion or absorption
What is the name given to the type of epithelium that appears stratified due to nuclei at different levels, but is actually a single layer of cells?
Pseudo-stratified epithelium
Where is pseudo-stratified columnar ciliated epithelium found?
In the respiratory system
What is the shape of the top layer of cells in stratified squamous epithelium?
Flat squamous
How is stratified epithelium classified?
According to the shape of the cells in the top layer
What is a characteristic of epithelial tissue?
It is formed mainly of cells with few intercellular substances
Which type of epithelium is responsible for secretion and reabsorption?
Simple cubical epithelium
What is the function of simple squamous epithelium in the lungs?
Gas exchange and filtration
Where is simple columnar epithelium found?
In the thyroid follicle
What is a characteristic of glandular epithelium?
It is involved in secretion
What is the origin of epithelial tissue?
It may be ectodermal, endodermal, or mesodermal
What is the function of simple squamous epithelium in the serous membranes?
Facilitating the flow of fluids
What is a characteristic of neuroepithelium?
It is highly innervated
What is the primary function of neuro-epithelial cells?
Reception of stimuli
What type of epithelial cell is responsible for contraction in exocrine glands?
Myoepithelial cells
Which of the following functions is NOT associated with epithelial tissue?
Muscle contraction
Where are myoepithelial cells typically found?
Around secretory cells in exocrine glands
What is the primary function of epithelial cells in the intestinal epithelium?
Absorption of nutrients
What is the term for the type of epithelial cells that are modified to be contractile?
Myoepithelial cells
What is the main function of epithelial tissue?
Protection
Which type of epithelial tissue is found in the ducts of sweat glands?
Stratified cuboidal epithelium
What is a characteristic of stratified columnar ciliated epithelium?
Its top layer has cilia
What is the name of the epithelial tissue that can change its shape according to the state of the organ?
Transitional epithelium
In an empty bladder, what is the characteristic of transitional epithelium?
It consists of 5-8 layers of cuboidal cells
What is the classification of glands based on the presence or absence of ducts?
Exocrine and endocrine
What is the characteristic of apocrine glands?
The apical part of the cell is lost with the secretion
What is the characteristic of holocrine glands?
The whole cell is lost with the secretion
Study Notes
General Characteristics of Epithelium
- Epithelial tissue may be ectodermal, endodermal, or mesodermal in origin.
- It is formed mainly of cells with few intercellular substances.
- The cells rest on a basement membrane.
- Epithelial tissue is avascular (no blood or lymphatic vessels penetrate it).
- It is highly innervated.
- It has a high power of regeneration.
Types of Epithelium
- Surface epithelium
- Glandular epithelium
- Neuro-epithelium
- Myo-epithelium
Simple Epithelium
- Formed of a single layer of cells
- Types:
- Simple squamous epithelium
- Simple cubical epithelium
- Simple columnar epithelium
- Simple columnar ciliated epithelium
- Pseudo-stratified columnar epithelium
- Pseudo-stratified columnar ciliated epithelium
Simple Squamous Epithelium
- Formed of a single layer of flat cells with flat nuclei
- Site: lining heart and blood vessels, lining serous membranes, lining lung alveoli, Bowman's capsule, and thin loop of Henle in the kidney
- Function: acts as a thin, smooth surface facilitating the flow of fluids, easy movement, gas exchange, filtration, and diffusion
Simple Cubical Epithelium
- Formed of a single layer of cube-like cells with central rounded nuclei
- Site: secretory units (thyroid follicle, secretory acini of salivary glands, pancreas, and sweat gland), convoluted tubules of kidney
- Function: responsible for secretion or reabsorption
Simple Columnar Epithelium
- Formed of a single layer of tall cells with basal oval nuclei
- Site: stomach, intestine, convoluted tubule of the kidney
- Function: secretion or absorption
Simple Columnar Ciliated Epithelium
- Formed of a single layer of tall cells with basal oval nuclei and cilia on the surface
- Site: uterus, fallopian tube, bronchioles of lung
- Function: the cilia beat in one direction to move substances
Pseudo-Stratified Columnar Epithelium
- Formed of a single layer of crowded columnar cells with nuclei at different levels
- Site: large ducts of salivary glands, upper part of male urethra
- Function: no specific function mentioned
Pseudo-Stratified Columnar Ciliated Epithelium
- Formed of a single layer of crowded columnar cells with nuclei at different levels and cilia on the surface
- Site: respiratory system (trachea, bronchi)
- Function: the cilia beat in one direction to remove dust and foreign substances
Stratified Epithelium
- Formed of multiple layers of cells
- Types:
- Stratified squamous epithelium
- Stratified cuboidal epithelium
- Stratified columnar epithelium
- Stratified columnar ciliated epithelium
- Transitional epithelium
Stratified Squamous Epithelium
- Formed of multiple layers of cells with a flat surface layer
- Site: skin, oral cavity, cornea, vagina
- Function: protection
Stratified Columnar Epithelium
- Formed of multiple layers of cells with a columnar surface layer
- Site: conjunctiva of the eye, male urethra, large ducts of glands
- Function: no specific function mentioned
Stratified Columnar Ciliated Epithelium
- Formed of multiple layers of cells with a columnar surface layer and cilia
- Site: fetal esophagus, soft palate
- Function: no specific function mentioned
Stratified Cuboidal Epithelium
- Formed of 2-3 layers of cuboidal cells
- Site: ducts of sweat glands
- Function: no specific function mentioned
Transitional Epithelium
- Site: urinary system (ureter and urinary bladder)
- Function: allows for stretching and compression of the bladder
- Histological picture in empty bladder: 5-8 layers of cells with a non-clear, non-wavy basement membrane
- Histological picture in full bladder: 2-3 layers of flat cells due to gliding of cells over each other by mucous-like intercellular substance
Glandular Epithelium
- Formed of epithelial cells modified to give secretion
- Classification:
- Presence or absence of ducts: exocrine, endocrine, or mixed glands
- Number of cells: unicellular or multicellular
- Mode of secretion: merocrine, apocrine, or holocrine
- Type of secretions: serous, mucous, fatty, waxy, or watery
- Shape of secretory part: tubular, alveolar, or tubuloalveolar
Neuro-Epithelium
- Definition: specialized type of epithelial tissue formed of epithelial cells modified to receive stimuli
- Consists of: hair cells, tall supporting cells, and basal cells
- Site: taste buds in tongue, olfactory epithelium in nose, organ of Corti in ear
- Function: sensation
Myo-Epithelium
- Definition: specialized type of epithelial tissue formed of epithelial cells modified to be contractile
- Site: present around secretory cells in exocrine glands (salivary and mammary gland)
- Function: contraction helps secretory cells to squeeze and evacuate secretion
Functions of Epithelium
- Protection
- Secretion
- Absorption
- Sensation
- Reproduction
- Excretion
Test your knowledge of the general histological characters of epithelial tissue, including its origin, composition, and different types such as surface epithelium, neuroepithelium, myoepithelium, and glandular epithelium.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
