Epithelium Histology

Question 1

Epithelial tissue rests on a thin extracellular, felt-like sheet of macromolecules called the…

Answer 1

Basement membrane

Question 2

T/F. A semipermeable filter allows passage of nutrients and substance from vasculature of epithelium to basement membrane.

Answer 2

True

Question 3

Epithelium that is primarily involved in secretion is often arranged as ________.

Answer 3

Glands

Question 4

This faces the exterior surface/lumen of an enclosed cavity/tube.

Answer 4

Apical surface

Question 5

This rest on the basement membrane and anchors the cell to underlying CT.

Answer 5

Basal surface

Question 6

This surface communicates/attaches to adjacent cells.

Answer 6

Lateral surfaces

Question 7

This type of intercellular junction is near the apical surface and is impermeable, allowing cells to function as a barrier. The more of these junctions, the less permeability there is.

Answer 7

Tight/Occluding Junctions

Question 8

What are types of tight/occluding junctions?

Answer 8

Occludins

Claudins

Question 9

This type of junction is a fluid-filled channel that connects adjacent cells. It mediates communication and is formed by an aggregate of Connexins.

Answer 9

Gap/Communicating Junctions

Question 10

Gap/Communicating Junctions have channels/pores that typically move ______.

Answer 10

Ions

Question 11

What are the types of anchoring junctions?

Answer 11

Adherens
Desmosomes
Hemidesmosomes

Question 12

This type of anchoring junction involves lateral adhesions involving cadherins that interact with actin filaments.

Answer 12

Adherens

Question 13

This type of anchoring junction involves lateral adhesions involving cadherins that interact with intermediate filaments.

Answer 13

Desmosomes

Question 14

This type of anchoring junction involves basal adhesions involving integrins and intermediate filaments that anchor to basal lamina.

Answer 14

Hemidesmosomes

Question 15

How can Tight Junctions contribute to “food poisoning”?

Answer 15

Bacteria that cause “food poisoning” target Tight Junctions in the intestine, impairing their function. Tissue fluid is then lost into the intestinal lumen, making you sick.

Question 16

How can Tight Junctions contribute to gastric ulcers?

Answer 16

Helicobacter pylori causes gastric ulcers by binding to Tight Junctions in the stomach, increasing permeability. Causes inflammation.

Question 17

How to Desmosomes contribute to oral blisters?

Answer 17

Due to an autoimmune disease called Pemphigus Vulgaris, this causes abnormal desmosome function. There is reduced cell-to-cell adhesion, thus causing blisters of the oral mucosa.

Question 18

This is a specialized sheet of extracellular material located adjacent to the basal domain. Selective barrier between tissues permits diffusion of nutrients.

Answer 18

Basement membrane

Question 19

These are on the apical surface and consists of cytoplasmic processes containing an actin core. They are specialized for absorption and increase surface area by 20-30x. Number and shape correlate to the cell’s absorptive capacity.

Answer 19

Microvilli

Question 20

How are microvilli and Celiac disease related?

Answer 20

Celiac disease is the loss of microvilli on the absorptive cells of the small intestine.

Question 21

These are on the apical surface and are microvilli but of unusual length, making them long and less mobile. It has a microtubule structure with an actin core. They increase surface area for absorption/secretion but are restricted to only two locations: Epididymis and hair cells of inner ear.

Answer 21

Stereocilia

Question 22

Where are stereocilia found?

Answer 22

Epididymis

Hair cells of inner ear

Question 23

These are on the apical surface and are long, highly motile structures containing internal arrays of microtubules. They can either be motile, primary, or nodal.

Answer 23

Cilia

Question 24

This type of cilia beat in a wave-like fashion to propel substances across the tissue.

Answer 24

Motile cilia

Question 25

This type of cilia is immotile, function as chemosensory, osmosensors, and mechanosensors.

Answer 25

Primary cilia

Question 26

This type of cilia is embryonic, and have a role in L/R axis determination.

Answer 26

Nodal cilia

Question 27

Where is simple squamous epithelium found?

Answer 27

Lining of blood and lymphatic vessels (endothelium) Lining of serous membranes (mesothelium) Lining of alveoli in lungs Loop of Henle in kidney Various ducts

Question 28

What is the function of simple squamous epithelium?

Answer 28

Exchange Barrier Lubrication

Question 29

Where is simple cuboidal epithelium found?

Answer 29

Kidney tubules Glands and associated ducts Terminal bronchioles Covering of the ovary

Question 30

What is the function of the simple cuboidal epithelium?

Answer 30

Absorption Barrier Secretion

Question 31

Where is simple columnar epithelium found?

Answer 31

``` Auditory tubes Uterus Oviducts Stomach Small/Large Intestine Gallbladder ```

Question 32

What is the function of simple columnar epithelium?

Answer 32

Absorption | Secretion

Question 33

Where is pseudostratified columnar ciliated epithelium found?

Answer 33

Lining of nasal cavity Lining of pharynx Lining of trachea Lining of bronchi ***Think upper respiratory

Question 34

What is the function of pseudostratified columnar ciliated epithelium?

Answer 34

Absorption Secretion Debris and particulate movement

Question 35

Where is urothelium found?

Answer 35

Urinary bladder Ureters Urethra

Question 36

What is the function of urothelium?

Answer 36

Barrier | Distensible property

Question 37

Where is nonkeratinized stratified squamous epithelium found?

Answer 37

Oral cavity Portions of pharynx, esophagus, anus, vagina, urethra, cornea

Question 38

What is the function of nonkeratinized stratified squamous epithelium?

Answer 38

Barrier | Protection

Question 39

Where is keratinized stratified squamous epithelium found?

Answer 39

Epidermis of skin ***Keratinized = no nuclei, flaking off

Question 40

What is the function of keratinized stratified squamous epithelium?

Answer 40

Barrier | Protection

Question 41

Where is stratified cuboidal epithelium found?

Answer 41

Sweat glands and ducts Ovarian follicles Salivary gland ducts

Question 42

What is the function of stratified cuboidal epithelium?

Answer 42

Barrier and passageway

Question 43

This is epithelial tissue that secretes mucus. It lines many body cavities and tubular organs including the gut and respiratory passages.

Answer 43

Mucous membrane

Question 44

This is epithelial tissue that lines internal body cavities. It forms a smooth, transparent, two-layered membrane that is lubricated by a fluid derived from serum.

Answer 44

Serous membrane

Question 45

What's included in the serous membrane?

Answer 45

Peritoneum Pericardium Pleura

Question 46

This is simple squamous epithelium that comprises part of a serous membrane.

Answer 46

Mesothelium

Question 47

Epithelial cells may produce and secrete a product as individual cells or as specialized organs called _______.

Answer 47

Glands

Question 48

Glands are classified as _______ or _______ according to how their products are released. ________ have a duct, and this is what we are focusing on now.

Answer 48

Exocrine Endocrine Exocrine

Question 49

Gland signals are released via ________ or ________ signaling.

Answer 49

Paracrine | Autocrine

Question 50

These glands are the simplest in structure. They are single, secretory cells distributed among non-secretory cells.

Answer 50

Unicellular glands

Question 51

What is an example of a Unicellular Gland?

Answer 51

Goblet cells

Question 52

These are mucus-secreting cells lining the intestines and respiratory tract. They are Unicellular glands.

Answer 52

Goblet cells

Question 53

These are multicellular glands comprised of secretary cells grouped as an acinus. Product is secreted into a system of ducts for release.

Answer 53

Exocrine glands

Question 54

This is the functional tissue of an organ, it does not include CT and other supporting tissues (in exocrine glands).

Answer 54

Parenchyma

Question 55

In Exocrine Glands, secretory units are supported by a _______ of CT. They have _______ which partitions the gland into lobules and a ________ that encloses the entire gland.

Answer 55

Stroma Septum Capsule

Question 56

This type of gland has secretion that is delivered in membrane-bound vesicles to apical surface where it undergoes exocytosis.

Answer 56

Merocrine gland

Question 57

This type of gland has secretion that accumulates within the cell, then apoptosis occurs. Secretion and cell debris are released.

Answer 57

Holocrine gland

Question 58

This type of gland has secretion that releases the apical portion of the cel, surrounded by cytoplasm within a plasma membrane.

Answer 58

Apocrine gland

Question 59

Glands can be simple (unbranched ducts) or compound (2+ branches). The secretory portions are ________ or ________ and may be branched too, even if the duct is not.

Answer 59

Tubular | Acinar

Question 60

T/F. Compound glands can have branching ducts with numerous secretory portions (tubular, acinar, or tubuloacinar).

Answer 60

True