Epithelial Tissue Flashcards
It is composed of closely aggregated polyhedral cells adhering strongly to one another and to a thin layer of ECM
Epithelial Tissue
What are the functions of Epithelium?
- Covering, lining, and protection
- Absorption
- Secretion
- Filtration
What characteristics are these; squamous, cuboidal, and columnar?
Shape
What characteristics are these; oval, spherical, and flattened?
Nuclei
What characteristics are these; basal pole, apical pole, and lateral surfaces?
Polarity
It is a thin extracellular, felt-like sheet of
macromolecules. A SEMIPERMEABLE FILTER for substances reaching epithelial cells from below.
Basement Membrane
What are the two parts of the Basement Membrane?
- Basal Lamina
- Reticular Lamina
It is composed of the cells responsible for the organ’s specialized functions, wherein the CELLS HAVE A SUPPORTING ROLE IN THE ORGAN.
Parenchymal and Stroma
What are the functions of Basement Membrane?
- Physical Support
- Cell Attachment
- Filter
- Guide Cell Migration
SEALS ADJACENT CELLS TO ONE ANOTHER, controlling the passage of molecules between them; separate apical and basolateral membrane domains.
Tight Junction (Zonula Occludens)
PROVIDES POINTS LINKING THE CYTOSKELETON OF ADJACENT CELLS; strengthens and stabilizes nearby tight junctions.
Adherens Junction (Zonula Adherens)
Resembles a single “Spot-weld”, PROVIDES POINTS OF STRONG INTERMEDIATE FILAMENT coupling between adjacent cells, strengthening the tissue.
Desmosome (Muscula Adherens)
ANCHORS CYTOSKELETON to the basal lamina.
Hemidesmosome
ALLOWS DIRECT TRANSFER OF SMALL MOLECULES and ions from one cell to another.
Gap Junction (Nexus)
What are the MAJOR TRANSMEMBRANE LINK PROTEINS of Tight Junction (Zonula Occlodens)?
Occludins, Claudins, and ZO Proteins
What are the MAJOR TRANSMEMBRANE LINK PROTEINS of Adherens Junction (Zonula Adherens)?
Cadherin and Catenin
What are the MAJOR TRANSMEMBRANE LINK PROTEINS of Desmosome (Macula Adherens)?
Desmogleins and Desmocollin
What is the MAJOR TRANSMEMBRANE LINK PROTEINS of Hemidesmosome?
Integrins
What is the MAJOR TRANSMEMBRANE LINK PROTEINS of Gap Junction (Nexus)?
Connexin
It is SMALL MEMBRANE PROJECTIONS with cores of ACTIN FILAMENTS.
Microvilli
Where are Microvilli found in the body organs?
Small Intestine
It INCREASES THE SURFACE AREA AVAILABLE FOR ABSORPTION; a motion-detecting function best seen on the absorptive epithelial cells lining the male reproductive system.
Stereocilia
Where are Stereocilia found in the body organs?
Epididymis, Vas Deferens, and the Inner Ear
It is LONG, HIGHLY MOTILE APICAL STRUCTURES. It has at least one short projection called a PRIMARY CILIUM.
Cilia
Where are Cilia found in the body organ?
The Respiratory System (Trachea, Lungs, Digestive Tract, etc.)
Are classified according to the number of CELL LAYERS and the CELL MORPHOLOGY in the outer layer.
Covering or Lining Epithelia
A single-layer of FLAT CELLS with DISC-SHAPED NUCLEI wherein molecules can easily pass (diffusion & filtration).
Simple Squamous Epithelium
Where is Simple Squamous Epithelium located?
- Renal Corpuscles
- Alveoli Lungs
- Lining of Heart, Blood, and Lymphatic System
- Lining of Ventral Cavity (serosae)
A single-layer of CUBE-LIKE CELLS with LARGE, SPHERICAL CENTRAL NUCLEI that can produce secretion and absorption.
Simple Cuboidal Epithelium
Where is Simple Cuboidal Epithelium located?
- Kidney Tubules
- Secretory Portion of Small Glands
- Ovary
- Thyroid Follicle
A single-layer of COLUMN-SHAPED (rectangular) CELLS with OVAL NUCLEI that can produce ABSORPTION, SECRETION OF MUCUS, ENZYMES, and OTHER SUBSTANCES.
Simple Columnar Epithelium
Where is Simple Columnar Epithelium located?
- Digestive Tract
- Gall Bladder
- Ducts of Some Glands
- Small Bronchi
- Uterine Tubes
- Uterus
What does Pseudostratified Columnar Epithelium function?
- All cells originate at basement membrane
- Only tall cells reach the apical surface
- It may contain goblet cells and bear cilia
- Nuclei lie at varying heights within cells
- Gives a false impression of stratification
- Secretion of mucus; propulsion of mucus by cilia
Where is the Pseudostratified Columnar Epithelium located?
- Ducts of Male Reproductive Tubes and some Large Glands
- Lines of Trachea and most of the Upper Respiratory Tract
It consists of MANY LAYERS of cells but the APICAL PART of the tissue is a squamous epithelium.
Stratified Squamous Epithelium
It contains the PROTECTIVE PROTEIN KERATIN.
Keratinized
It forms the MOIST LINING of BODY OPENINGS.
Non-Keratinized
Where is Keratinized located?
Epidermis
Where is Non-Keratinized located?
- Esophagus
- Vagina
- Mouth
Transitional Epithelium also known as?
Urothelium
What do goblet cells produce?
Mucus
Basal cells are usually CUBOIDAL or COLUMNAR, superficial cells are DOME-SHAPED or SQUAMOUS.
Transitional Epithelium
Where is Transitional Epithelium located?
- Ureters
- Urinary Bladder
- Part of Urethra
Epithelial cells that function mainly to PRODUCE and SECRETE various macromolecules may occur in epithelia with other major functions or comprise specialized organs.
Glands
It REMAINS CONNECTED with the surface epithelium. It HAS DUCTS that lead to another organ or the body surface.
Exocrine Glands
It LOSES CONNECTION to its original epithelium for PROTEIN or STEROIDS HORMONE SYNTHESIS and it has NO DUCTS.
Endocrine Glands
It is the MOST COMMON METHOD of PROTEIN or GLYCOPROTEIN SECRETION
Merocrine Glands
It RELEASES THE PRODUCT and CELL DEBRIS into the GLAND’S LUMENS
Holocrine Glands
It RELEASES THE PRODUCT together with small amounts of CYTOPLASM and CELL MEMBRANE
Apocrine Glands
Types of Exocrine Glands
- Simple
* Tubular (Simple, Branched & Coiled)
* Acinar (Simple & Branched) - Compound
* Tubular
* Acinar
* Tubuloacinar
Types of Endocrine Glands
- Autocrine
- Paracrine
Type of tissue that LINES OF SURFACE or BODY CAVITIES; glandular secretion
Epithelial Tissue
Type of tissue that SUPPORTS and PROTECTION TISSUES and ORGANS
Connective Tissue
Type of tissue that is STRONG CONTRACTION; BODY MOVEMENTS.
Muscle Tissue
Type of tissue that TRANSMITTED TO A NERVE IMPULSE
Nervous Tissue
What is called the FORMATION of cilia built around a sophisticated microtubule bundle?
Axoneme
Skin
Skin
