MindMap Gallery Biology - Epithelial Tissue
This is a mind map about epithelial tissue, including covering epithelium, glandular epithelium and glands, The specialized structure of epithelial cells, etc.
Edited at 2023-12-15 14:44:44Avatar 3 centers on the Sully family, showcasing the internal rift caused by the sacrifice of their eldest son, and their alliance with other tribes on Pandora against the external conflict of the Ashbringers, who adhere to the philosophy of fire and are allied with humans. It explores the grand themes of family, faith, and survival.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
Avatar 3 centers on the Sully family, showcasing the internal rift caused by the sacrifice of their eldest son, and their alliance with other tribes on Pandora against the external conflict of the Ashbringers, who adhere to the philosophy of fire and are allied with humans. It explores the grand themes of family, faith, and survival.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
epithelial tissue (Epithelial/Polar/With nerves but without blood vessels)
Covering epithelium
single layer epithelium
Single layer squamous epithelium (single layer squamous epithelium/egg-shaped/oval nuclei)
Mesothelium (surface of pleura/peritoneum/pericardium)
Others (renal cyst wall layer and alveolar epithelium, etc.)
Endothelium (luminal surface of heart/blood vessels/lymphatic vessels)
Single-layer cuboidal epithelium (mainly distributed in certain ducts, renal tubules, thyroid follicles, etc., with absorptive and secretory functions)
Single layer columnar epithelium (the cell nucleus is oval, close to the base/mainly distributed in the luminal surface of the stomach, intestine, gallbladder, uterus and fallopian tube, its main function is absorption and secretion)
columnar cells
The single-layer columnar epithelium of the intestine contains these two types of cells, which are not mentioned elsewhere.
Goblet cells (the nucleus is triangular or half-moon-shaped, located at the base/there are mucin granules/mucin on the upper part of the cell, which is water-soluble and can protect and lubricate)
Pseudostratified ciliated columnar epithelium (composed of columns, cones, spindles, and goblet cells/with swinging cilia on the free surface/mainly distributed in the luminal surface of the respiratory tract, and goblet cells can secrete)
stratified epithelium
Stratified squamous epithelium (stratified squamous epithelium/new cells gradually differentiate from the base to the surface/located in the skin, oral cavity, esophagus, vagina, anus, cornea, etc./the junction between this epithelium and deep connective tissue is uneven, increasing the contact area , conducive to nutrient supply, fixed/stratified squamous epithelium has mechanical protective effects such as resistance to friction and preventing foreign body invasion, and has strong regeneration and repair capabilities after injury)
Unkeratinized stratified squamous epithelium (lining luminal surfaces such as the mouth and esophagus)
Keratinized stratified squamous epithelium (the nuclei of the stratified squamous epithelial cells located in the skin disappear, the cytoplasm is filled with keratin, and the cells are dry and hard and continue to fall off)
Stratified columnar epithelium (mainly found in the conjunctiva, male urethra and large ducts of some glands)
Migrant epithelium (mainly distributed in the renal pelvis, renal calyces, ureters, bladder and other luminal surfaces/cover cells/cells with variable shape and size)
glandular epithelium and glands
Types of exocrine (single layer, stratified × tubular glands, alveolar glands, tubuloalveolar glands/mucinous acini, serous acini, mixed acini)
Glandular epithelium (the epithelium composed of glandular cells with mainly secretory function is called glandular epithelium/the organ or structure composed of glandular epithelium as the main component is called gland)
specialized structure of epithelial cells
free surface
Microvilli (tiny finger-like protrusions/containing longitudinal microfilaments, which play a supporting role, extend downward from the top, and are connected to the terminal network arranged parallel to the top of the cytoplasm/columnar cells of the small intestinal epithelium and the epithelial cells of the proximal tubule of the kidney) Microvilli are numerous and long, each cell can have thousands of them and are neatly arranged. Under the light microscope, they appear as striated borders or brush borders/microvilli increase the cell surface area and improve the cell's absorption function)
The terminal mesh is a mesh of microfilaments in the cytoplasm at the base of the microvilli that is parallel to the cell surface and contains myosin. Its contraction can make the top of the cell bulge and spread the microvilli.
Cilia (thick and long protrusions/ciliated epithelium mainly found in the respiratory tract, each cell has about 300 cilia/rhythmic directional swings)
Under the electron microscope, there are two separate longitudinal microtubules in the center of the cilium, surrounded by 9 groups of doublet microtubules/the base of the cilium has a dense particle called the basal body. Tubes are connected, and the doublet microtubules may consist of a basal body. Two short dynein arms extend from one side of each set of doublet microtubules. It has ATPase activity. After decomposing ATP, the dynein arms attach to adjacent doublet microtubules, causing displacement or sliding between the microtubules, resulting in overall ciliary movement/motile cilia syndrome patients lack dynein arms.
side
Among the above four types of connections, if 2 or more of them exist immediately adjacent to each other, they are called connection complexes. The connections and changes of cells often change with the different developmental stages and functional states of organs and pathological changes.
Tight link (closed junction/near the top/viewed from the top of the cell, surrounds the cell in a hoop shape/under an electron microscope, the outer layers of two adjacent cell membranes are simply fused together, tightly adhered by the mosaic proteins of the two membranes) Together, they form a network of ridges/This connection can prevent macromolecular substances from entering the tissue from outside the cell through the intercellular space. It is the basis of various barriers in the body and can limit the diffusion of substances)
Adhesive zonules (middle connections/beneath the tight links, are strips of varying lengths that surround the top of epithelial cells, adhering adjacent cells together/maintaining cell shape/transmitting cell contractility)
Under an electron microscope, there is a gap of 15 to 20 nm between adjacent cells. In the gap, there are filaments with low electron density connecting the membranes of adjacent cells. There are transmembrane cell adhesion molecules on the inner surface of the cytoplasm of the membrane, called cadheres. Protein, with microfilaments from the cytoplasm, which form the terminal network
Desmosomes (focal adhesions/are located deep in the middle connection, are spot-shaped or button-shaped, and vary in size/desmosomes are a strong connection that connects target cells like rivets, in areas such as the skin and esophagus that are susceptible to friction. Especially developed in stratified squamous epithelium)
Under the electron microscope, there is a gap of 20 to 30 nm between adjacent cells. In the gap, there are filaments with low electron density composed of the extracellular part of cadherin. There is a dense middle line in the center, which is made of intertwined filaments. of. On the inner surface of the film on both sides of the gap, there is an elliptical patchy structure composed of thicker dense material, called an attachment plate. Intermediate filaments in the cytoplasm extend into the attachment plate and then fold back into the cytoplasm to serve as a fixation and support
Gap junctions (communication connections/widely distributed in various tissues/deep in the sides of epithelial cells, in the form of spots of varying sizes)
Under the electron microscope, the cell membranes between two adjacent cells formed intermittent fusion. There was a 2nm gap between the cells at the unfusion point, and there were small tubes connecting the cells at the fusion point. /Research on freeze etching has proven that there are many regularly distributed columnar particles called connectosomes on adjacent cell membranes. Each connectosome is composed of 6 rod-shaped connexin molecules with a small tube in the center and a diameter of 1.5 to 2 nm. Adjacent connecting bodies are connected to each other, and the central tubules are also connected to each other, becoming a direct connection between cells. The pipes can be retracted and unfolded.
basal surface
Basement membrane (a thin film between the basal surface of epithelial cells and deep connective tissue/basement membrane = basal plate + reticular plate, basal plate = transparent layer + dense layer / The basal plate is formed by epithelial cells, and the reticular plate is composed of reticular fibers and Matrix composition, produced by fibroblasts/supports, connects and fixes/semi-permeable membrane/facilitates material exchange between epithelial cells and deep connective tissue/guides the movement of epithelial cells and affects cell proliferation and differentiation)
It is very thin and cannot be distinguished by HE staining, but the basement membrane of pseudostratified ciliated columnar epithelium and stratified squamous epithelium is thicker and can be seen in pink. The base membrane is dyed black with silver plating
The infoldings of the plasma membrane (the thin film on the basal surface of epithelial cells, are many folds formed by indentations into the cell). There are a large number of mitochondria arranged in longitudinal rows in the cytoplasm between the infoldings. The cytoplasm is eosinophilic and can be seen under a light microscope. There are longitudinal striations at the base. The infoldings of the plasma membrane expand the surface area of the cell base, which is beneficial to the transport of water and electrolytes, and is mainly distributed in the proximal tubule of the kidney)
Hemidesmosomes (half of the desmosome structure/there is also an attachment plate in the plasma membrane, keratin filaments are attached to it, folded into loops and returned to the cytoplasm/strengthen the connection between the cell and the basement membrane/mainly found in the basal layer of complex squamous epithelial cells)
central theme
theme
theme
theme