Structural Organisation in Animals Test 1

• Ciliated pseudostratified columnar epithelia are found in the linings of the trachea as well as the upper respiratory tract.
• Non-ciliated pseudostratified columnar epithelia are located in the membranous part of male vas deferens.
• Most of the respiratory passageways, from the nasal cavity through the bronchi, are lined by ciliated, pseudostratified columnar epithelium with goblet cells.

Transitional epithelium is a special type of epithelium which has the property of stretchability, it is found in places which requires strechibility as a function such as urinary bladder,ureter etc.

• A brush border is the microvilli-covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body.
• The brush borders of the small intestinal lining are the site of absorption.
• 

The luminal surface of the tonsils are covered with a stratified squamous epithelium (in common with the oral epithelia). The epithelial cells are able to phagocytose bacteria, and transfer them to macrophages, which then present the foreign antigens to B-cells, which are activated (with the help of T cells).

• 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 cells called endothelial 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.

The tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. 

Marie François Xavier Bichat was a French anatomist and physiologist, who is best remembered as the father of modern histology and descriptive anatomy. Despite working without a microscope, he was the first to introduce the notion of tissues as distinct entities, and maintained that diseases attacked tissues rather than whole organs or the entire body, causing a revolution in anatomical pathology.

Lining of buccal cavity and oesophagus contain non keratinised, where as the rest of the alimentary canal is lined by cuboidal epithelium.

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 non keratinized, stratified squamous epithelial cells, which are held together by tight junctions, to form an effective barrier against fluid loss and pathogen penetration.

Ectoderm: The epithelial cells of the skin and oral cavity (epidermis) are derived from ectoderm. Epithelial cells covering the cornea and lens, as well as sensory receptors of the eyes, ears, and nose, are also ectodermal in origin.

Mesoderm: The epithelial lining of blood vessels (endothelium) is derived from mesoderm. The epithelial lining of the pleural and peritoneal cavities (mesothelium) also originate from mesodermal cells.

Endoderm: The epithelial lining of the respiratory system and digestive tracts - as well as the functional cells (parenchyma) of the liver, pancreas, gallbladder, thyroid, and parathyroid, are derived from endoderm.

The basement membrane is composed of two layers, the basal lamina and the underlying layer of reticular connective tissue. The clear layer closer to the epithelium is called the lamina lucida, while the dense layer closer to the connective tissue is called the lamina densa.

Simple columnar cells are found In major organs like stomach as it plays a very important role in secretion and absorption.

The simple squamous epithelial tissues are present in the skin. These cells are present in the inner surface of the cheek. These cells are the single layer of cells placed on the basement membrane in the form of tiles. They are compactly arranged without the intercellular spaces similar to the packing and arrangement of tiles.

Hence, option D is correct.

The pharynx is a part of the digestive system which is the conducting zone of the respiratory system. The pharynx makes up the part of the throat situated immediately posterior to the nasal cavity, posterior to the mouth and superior to the esophagus and larynx. The pharynx is lined by non-keratinised squamous stratified epithelium also called as compound squamous epithelium.

• If the epithelium is composed of one layer of cells, it is referred to as simple squamous epithelium and if it possesses multiple layers, it is referred to as stratified squamous epithelium.
• The peritoneum is the serous membrane that forms the lining of the abdominal cavity or coelom. It covers most of the intra-abdominal (or coelomic) organs and is composed of a layer of mesothelium supported by a thin layer of connective tissue.  The mesothelium is a membrane composed of simple squamous cells that form the lining of several body cavities like peritoneum.

Hence the correct option is D.

• Cilia can be defined as the hair-like structures that sit on top of a tissue. They wave back and forth which help move things. 
• 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.

The cellular covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. It consists of cells joined by small amounts of cementing substances. Epithelium is classified into types on the basis of the number of layers deep and the shape of the superficial cells. Cuboidal epithelium epithelium whose cells are of approximately the same height and width, and appear square in transverse section.

A stratified squamous epithelium consists of squamous (flattened) epithelial cells arranged in layers upon a basal membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity.

Inner lining is also known as endothelium.tunica intima(endothelium)of a artery will normally appear wavy because of the partial constriction of the smooth muscle in the tunica media, the next layer of blood vessel walls.

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.

The mucus that lines the nasal cavity and controls the ionic milieu of the olfactory cilia is produced by secretory specializations (called Bowman's glands) distributed throughout the epithelium.This entire apparatus—mucus layer and epithelium with neural and supporting cells—is called the nasal mucosa.

• The basement membrane is a thin, fibrous, extracellular matrix of tissue that separates the lining of an internal or external body surface from underlying connective tissue in metazoans. 
• 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.

• Transitional epithelium is a type of tissue consisting of multiple layers of epithelial cells that contract and expand.
• Transitional epithelium is stretchable and waterproof.
• The cells of transitional epithelium are highly keratinized and contain tight junctions or virtually impenetrable junctions, that seal together the cellular membranes of neighboring cells.
• This barrier prevents reabsorption of toxic wastes and pathogens by the bloodstream.

• The mesothelium is a membrane composed of simple squamous cells that form the lining of several body cavities, the pleura, peritoneum and pericardium.
• Mesothelial tissue also surrounds the male internal reproductive organs and covers the internal reproductive organs of women.
• Mesothelium that covers the internal organs is called as visceral mesothelium, while the layer that covers the body walls is called as the parietal mesothelium.
• Mesothelium is the epithelial component of serosa.

Line of brain ventricle is called ependymal epithelium.
All of the ventricular system and the central canal of the spinal cord are lined with ependyma, a specialized form of epithelium connected by tight junctions that make up the blood-cerebrospinal fluid barrier.

Ruysch created the term from the Greek word 'epi', which means on top of, and 'thele', which means nipple.

He used it to describe the type of tissue he found while dissecting the lip of a cadaver.

The exoskeleton is originated from the epithelial cell and after origin, it's keratinized.

• The epididymis is a tube that connects a testicle to a vas deferens in the male reproductive system.
• The stereocilia of the epididymis help in absorption. They are long cytoplasmic projections that have no motility.

The basal layer of the stratified squamous epithelium is the cuboid layer which forms the other layer known as germinativum layer.

Unicellular Glands: Goblet Cells. Remember that unicellular cells are single-celled secretory cells.
The only major example in humans would be goblet and mucous cells that are found in the conducting airways and GI tract, respectively.