Epithelial tissues lie on the basement membrane. It is made up of -
Basal Lamina: It is outer thin layer (near the epithelial cells), composed of mucopolysaccharides and glycoproteins, both secreted by epithelial cells. It is visible only with the electron microscope.
Fibrous or Reticular Lamina: It is inner thick layer, composed of collagen or reticular fibres of the underlying connective tissue. It is visible with light microscope. The basement membrane provides elastic support. It also allows selective chemical exchange between epithelial tissues and surrounding blood vessels.
Simple epithelium is not effective in -
Simple epitheliumIt is found generally on secretory and absorptive surfaces. It covers surfaces exposed to mechanical or chemical abrasions because it is not effective in protecting the underlying tissues. It is formed of a single layer of cells resting on the basement membrane.
Which of the following epithelium forms the inner lining of lung alveoli, blood vessels and peritoneum of body cavity ?
Squamous epithelium: Squamous epithelium consists of cells, which are thin, flat and polygonal having a prominent round or oval nucleus. The cells have irregular boundaries that fit closely into those of neighbouring cells. Its main function is protection of the underlying tissues. It forms the inner lining of lung, alveoli, blood vessels and peritoneum of the body cavity.
Which of the following mammalian tissues is associated with filteration and diffusion ?
A simple squamous epithelium is a single layer of flat cells in contact with the basal lamina (one of the two layers of the basement membrane) of the epithelium. This type of epithelium is often permeable and occurs where small molecules need to pass quickly through membranes via filtration or diffusion.
The simple squamous epithelium lining the blood vessels is called as
This epithelium is present in/the terminal bronchioles and alveoli of the lungs, walls of Bowman's capsules and descending limb of loop of Hen Ie. In the blood vessels and heart it is called endothelium. In coelom, it is called as mesothelium.
Ciliated columnar epithelium called as ependymal are present in the lining of -
The ventricular system is a set of communicating cavities within the brain. These structures are responsible for the production, transport and removal of cerebrospinal fluid, which bathes the central nervous system.
Curved portion of the Henle’s loop of the nephrons are lined by
The loop of Henle is the U-shaped portion of the nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. The curved portion of Henle's loop is lined by squamous epithelium. The squamous epithelium enables rapid diffusion of blood and diffusion of small molecules.
So, the correct answer is 'Squamous epithelium'.
Ciliated epithelium occurs in -
The trachea and bronchi are lined by stratified ciliated epithelium. The height of the epithelium decreases as the bronchial tree branches. Four different cell types can be found in the epithelium: basal cells, ciliated cells, goblet cells, and clear cells, which belong to the diffuse neuroendocrine system or amine precursor uptake and decarboxylation (APUD) system.
Germinal epithelium of testis and ovary is made up of
The Germinal epithelium or epithelial cells are the ones present in the reproductive organs of animals, such as testis and ovary. These are the cells which divide and redivide itself to form the male and female gametes.
All the statements about stereocilia are correct except -
There is a structural difference between a kinocilium (which is a true cilium, having a 9+2 microtubule arrangement), and stereocilia (which don't have microtubules, instead they have actin cores).
Which of the following epithelium covers the inner linings of trachea, large bronchi and helps to remove mucus ?
Pseudo-stratified epithelium : It is the simple columnar epithelium in which the regular arrangement of the cells is distorted. The cells of this type of epithelium are also twisted with respect to each other giving a false appearance. Cells are arranged in single layer, but appear multi-layered. This type of epithelium is present in the inner linings of trachea, large bronchi and helps to remove mucus.
The epithelium found in the lining layer of stomach and intestine is -
A simple columnar epithelium is a columnar epithelium that is uni-layered. In humans, a simple columnar epithelium lines most organs of the digestive tract including the stomach, small intestine, and large intestine. Simple columnar epithelia line the uterus.
The adjacent epithelial cells are held together by means of
A desmosome, also known as a macula adhaerens, is a cell structure specialized for cell-to-cell adhesion. They are transmembrane proteins that bridge the space between adjacent epithelial cells by way of homophilic binding of their extracellular domains to other desmosomal cadherins on the adjacent cell.
Pavement epithelium is the name of -
Squamous epithelium (labelled c) is composed of large flat cells whose edges fit closely together like the tiles in a floor, hence it is also called pavement epithelium or tessellated epithelium. The cells rest on a thin basement membrane. If the cells are seen from the surface, they seem to be polygonal in shape.
Pseudostratified non-ciliated columnar epithelial tissue is found in -
Pseudostratified columnar epithelium : It is found in certain segments of human male urethra and parotid salivary gland, vasa deferentia and epididymis.
Epithelium of bronchi is
Bronchi are tube like structures that allow air to be transported from the surrounding atmosphere to the lung. The respiratory system (airways) consists of the trachea (essentially a large bronchi) that branch off into smaller and smaller bronchi before reaching the most distal lung alveoli, where oxygen can be transferred to the blood.
The respiratory bronchus is lined by respiratory epithelium comprising an admixture of pseudostratified ciliated columnar epithelium, goblet cells (mucin producing cells also termed mucous cells) and basal cells that function as progenitor cells for both the ciliated columnar cells and goblet cells.
Which of the following epithelium is much thinner and more stretchable than the stratified epithelium and covers the inner surface of urinary bladder and ureter ?
Transitional epithelium is much thinner and more stretchable than the stratified epithelium. It has a single layer of cuboidal cells at the base, two to three middle layers of a large polygonal or pear-shaped cells and a superficial layer of large, broad, rectangular or oval cells.
Which of the following cells are specialised for sensory functions, e.g., cells of taste bud ?
Histologists have recognized two more types of epithelia, which cannot be included in any of the types of covering epithelia. One is the neuroepithelial cell of epithelial origin. These cells are specialised for sensory functions, e.g. cells of taste bud. The other one is myoepithe-lial cell, which are branched cells, which con-tain muscle proteins, such as myosin and actin.
Cells of peritoneum comprise -
The peritoneum consists of two layers that are continuous with each other: the parietal peritoneum and the visceral peritoneum. Both types are made up of simple squamous epithelial cells called mesothelium.
Which of the following match is incorrect ?
Mammary glands, which secrete milk, are apocrine type. Apical end of the cells accumulate secretory material and cell apex gets pinched off to release the product.It loses part of its cytoplasm in their secretions. Apocrine secretion is less damaging to the gland than holocrine secretion (which destroys a cell) but more damaging than merocrine secretion (exocytosis). An example of true apocrine glands is the mammary glands, responsible for secreting breast milk.
Human mammary glands belong to one of the following types of glands -
Each breast is made up of 15- 25 secretory lobes, embedded in adipose tissue. The mammary gland is like a modified sweat gland. Each of these lobes is a compound tubular acinar gland. The acini empty into ducts that are lined by cuboidal, or low columnar epithelial cells, and surrounded by myoepithelial cells.
Apocrine secretion of gland means -
Which of the following tissue is present in maximum amount, joins different tissues, forms the packing between them and helps to keep the organs in place and normal shape ?
The areolar tissue joins different tissues and forms the packing between them and helps to keep the organs in place and in normal shape.
Epithelium covering the tongue is –
A stratified squamous non-keratinized epithelium lines the oral surface of the lips, cheeks, floor of mouth, and covers the ventral surface of the tongue In slide 114 (human) and 114M(monkey) of the lip, note that skin (stratified, keratinized squamous epithelium with hair follicles) covers the external surface, skeletal muscle (orbicularis oris muscle) forms the core, and a mucosal epithelium(stratified, non-keratinizing squamous epithelium) covers the internal surface.
Pseudostratified epithelium is present in -
Transitional Epithelium is found in -
Transitional epithelium is a stratified tissue made of multiple cell layers, where the cells constituting the tissue can change shape depending on the distention in the organ. When the organ is filled with fluid, cells on the topmost layer of this epithelium can stretch and appear flattened. Alternately, they can also appear cuboidal with a rounded shape when the fluid pressure is low.
This epithelium is found lining the urinary bladder, ureters and urethra, as well as in the ducts of the prostrate gland.
Columnar Epithelium with micro villi or Brush Border is present in -
The epithelial lining of the gall bladder consists of simple columnar cells specialized for absorption, with an apical brush border of microvilli, very similar to intestinal absorptive cells. However, unlike intestinal epithelium, gall bladder epithelium includes only this single cell type; it has no goblet cells.
Stratified squamous epithelium with micro villi or Brush Border is present in -
M cells are classically found in the simple columnar epithelium of the intestines, their presence in the stratified epithelium of the conjunctiva is similar to their occurrence in the stratified squamous epithelium of the rabbit’s palatine tonsil.
The internal lining of blood vessels in called as -
Endothelium refers to cells that line the interior surface of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. It is a thin layer of simple, or single-layered, squamous cellscalled endothelial cells. Endothelial cells in direct contact with blood are called vascular endothelial cells, whereas those in direct contact with lymph are known as lymphatic endothelial cells.
Epithelial lining of bartholins duct is composed of which type of cells -
Cuboidal epithelia have a cube-like shape; that is, their width is approximately equal to their height. They may exist in single layers or multiple layers depending on their location in the body.
The Bartholin's glands (also called Bartholin glands or greater vestibular glands) are two pea-sized compound racemose glands which are located slightly posterior and to the left and right of the opening of the vagina. They secrete mucus to lubricate the vagina. They are composed of cuboidal epithelium.
Term tissue is coined by (for animal anatomy)
Non Keratinised stratified squamous epithelium is found in -
A stratified squamous epithelium consists of cells arranged in layers upon a basal membrane. Only one layer is in contact with the basement membrane; while the other layers are adhered to one another to maintain structural integrity.
This type of epithelium is well suited to areas in the body subject to constant abrasion, as it is the thickest layer. Additionally, this layer can be sequentially sloughed off and replaced before the basement membrane is exposed. It forms the outermost layer of the skin and the inner lining of the mouth, esophagus and vagina. Non-keratinised surfaces must be kept moist by bodily secretions to prevent them from drying out. Examples of non-keratinized stratified squamous epithelium include cornea, lining mucosa of the oral cavity, esophagus, anal canal, vagina and the internal portion of the lips.
Epithelial lining of cornea is composed of
The corneal epithelium is the outermost layer of the cornea. It is composed of a single layer of basal cells and 4-5 cell layers of nonkeratinized, stratified squamous epithelial cells, which are held together by tight junctions, to form an effective barrier against fluid loss and pathogen penetration.
Epithelial tissue originated from
Epithelial tissues are derived from all of the embryological germ layers:
However, it is important to note that pathologists do not consider endothelium and mesothelium (both derived from mesoderm) to be true epithelium. This is because such tissues present very different pathology. For that reason, pathologists label cancers in endothelium and mesothelium sarcomas, whereas true epithelial cancers are called carcinomas. Additionally, the filaments that support these mesoderm-derived tissues are very distinct. Outside of the field of pathology, it is generally accepted that the epithelium arises from all three germ layers.
Basement membrane is composed of
Basement lamina consists of two layers -
(a) BASAL LAMINA - Toward epithelium and its is made up of glycoprotein, which is secreted by epithelium cells.
(b) FIBROUS LAMINA - Towards connective tissue, in which collagen and reticular fibres are suspended in muccopolysaccharide which is matrix of connective tissue. Muccopolysaccharide is presented in the form of hyaluronic acid.
Inner lining of gut, stomach & liver is made up of
Simple columnar epithelium
Cells are elongated and column-shaped. Their nuclei are elongated and are usually located near the base of the cells.
Columnar epithelium is found in the following:
The lining of the stomach and intestines.
Some columnar cells are specialized for sensory reception such as in the nose, ears and the taste buds of the tongue.
Also have surface modifications such as cilia and microvilli and
Goblet cells (unicellular glands) are found between the columnar epithelial cells of the duodenum.
Function: secretion and absorption.
Epithelial tissue with thin flat cells appearing like packed tiles occurs on –
Squamous epithelial cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and helps to identify the type of epithelium. Squamous cells, for example, tend to have horizontal flattened, elliptical nuclei because of the thin flattened form of the cell. They form the lining of cavities such as the mouth, blood vessels, heart and lungs and snake up the outer layers of the skin.
Compound squamous epithelium occurs in
They are found in lining of mouth cavity, tongue, pharynx, oesophagus and vagina. Keratinized stratified epithelium- This tissue is found on outer dry surfaces of body like skin, hair claws and nails. The outer surface layer consists of deadepithelial cells.
Cells of Peritoneum comprise
Ciliated Epithelium occurs in frog
Ciliated epithelium performs the function of moving particles or fluid over the epithelial surface in such structures as the trachea, bronchial tubes, and nasal cavities.
A ciliated columnar epithelium lines the lumen of the uterine tube, where currents generated by the cilia propel the egg cell toward the uterus. They are also present in the buccal cavity of frog.
Germinal Epithelium of ovary is formed of
Simple cuboidal epithelium consists of a monolayer of epithelial cells that appear to be square-shaped in cross section. With large, rounded, centrally located nuclei, all the cells of this epithelium are directly attached to the basement membrane.
A monolayer of cuboidal epithelial cells covers the ovary and forms the ovarian surface epithelium. It plays a role in repairing the damage caused during every ovulation event and may also support the formation of an ovum.
Epidermis of skin of vertebrates comprises
Epidermis of the skin of vertebrates comprises stratified epithelium. Stratified epithelia are cover the exterior body surfaces and lining portions of the body tracts, where friction occurs. A multilayered epithelium allows deeper cells to replace the most superficial cells, as they are damaged or cast off from the epithelial surface.
lnner lining of Blood vessels and heart is tesseleted Epithelium. Which is
Tessellated epithelium is another term used for simple squamous epithelium also called pavement epithelium due to its flat appearance. It is mainly present in the alveoli and blood capillaries and performs the function of diffusion.
Lining of larynx is
Larynx is lined by ciliated pseudostratified columnar epithelium except vocal cords (lined by stratified squamous epithelium). The wall of larynx is reinforced by cartilage tissue. Large cartilages (cartilago thyroidea, cartilago cricoidea) and part of cartilago arytenoidea are composed of hyaline cartilage. Small cartilages (cartilagines corniculatae, cuneiformes et arytenoides) are composed of elastic cartilage tissue. Laryngeal inlet is protected by epiglottis consisting of elastic cartilage. Epiglottis is covered by nonkeratinized stratified squamousepithelium with transition to ciliated pseudostratified columnar.
Germinal Epithelium is
Germinal epithelium : Specialized cuboidal cells capable of producing gametes as found in gonads. Germinal epithelium produces gametes e.g., ova (Female gametes) and sperms (Male gametes)