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Illustration shows cells, shaped like slices of pie, arranged in a circle. The hub of the circle is empty. Three of these circles of cells cluster together.
Simple cuboidal epithelial cells line tubules in the mammalian kidney, where they are involved in filtering the blood.

Columnar epithelia

Columnar epithelial cells are taller than they are wide: they resemble a stack of columns in an epithelial layer, and are most commonly found in a single-layer arrangement. The nuclei of columnar epithelial cells in the digestive tract appear to be lined up at the base of the cells, as illustrated in [link] . These cells absorb material from the lumen of the digestive tract and prepare it for entry into the body through the circulatory and lymphatic systems.

Illustration shows tall, columnar cells arranged side-by-side. Each cell has a nucleus located near the bottom, and cilia extending from the top. Two oval goblet cells are interspersed among the columnar epithelial cells. The goblet cells, which are shorter than the columnar cells, are in direct contact with the intestinal lumen. Beneath the columnar cells is a layer of horizontal cells.
Simple columnar epithelial cells absorb material from the digestive tract. Goblet cells secret mucous into the digestive tract lumen.

Columnar epithelial cells lining the respiratory tract appear to be stratified. However, each cell is attached to the base membrane of the tissue and, therefore, they are simple tissues. The nuclei are arranged at different levels in the layer of cells, making it appear as though there is more than one layer, as seen in [link] . This is called pseudostratified    , columnar epithelia. This cellular covering has cilia at the apical, or free, surface of the cells. The cilia enhance the movement of mucous and trapped particles out of the respiratory tract, helping to protect the system from invasive microorganisms and harmful material that has been breathed into the body. Goblet cells are interspersed in some tissues (such as the lining of the trachea). The goblet cells contain mucous that traps irritants, which in the case of the trachea keep these irritants from getting into the lungs.

Illustration shows columnar cells arranged side-by-side. The cells are wide at the top, and thin at the bottom. Shorter columnar cells are interspersed between the lower, thin part of the tall columnar cells. Some of these cells extend to the surface of the epithelium, but they are very thin at the top. The nuclei of the tall columnar cells are located near the top, and the nuclei of the shorter columnar cells are located near the bottom, giving the appearance of two layers of cells. Cilia extend from the top of the tall columnar cells. Oval goblet cells are interspersed among the columnar epithelial cells. Beneath the columnar cells is a layer of horizontal cells.
Pseudostratified columnar epithelia line the respiratory tract. They exist in one layer, but the arrangement of nuclei at different levels makes it appear that there is more than one layer. Goblet cells interspersed between the columnar epithelial cells secrete mucous into the respiratory tract.

Transitional epithelia

Transitional or uroepithelial cells appear only in the urinary system, primarily in the bladder and ureter. These cells are arranged in a stratified layer, but they have the capability of appearing to pile up on top of each other in a relaxed, empty bladder, as illustrated in [link] . As the urinary bladder fills, the epithelial layer unfolds and expands to hold the volume of urine introduced into it. As the bladder fills, it expands and the lining becomes thinner. In other words, the tissue transitions from thick to thin.

Art connection

Illustration shows tall, diamond-shaped cells layered one on top of the other.
Transitional epithelia of the urinary bladder undergo changes in thickness depending on how full the bladder is.

Which of the following statements about types of epithelial cells is false?

  1. Simple columnar epithelial cells line the tissue of the lung.
  2. Simple cuboidal epithelial cells are involved in the filtering of blood in the kidney.
  3. Pseudostratisfied columnar epithilia occur in a single layer, but the arrangement of nuclei makes it appear that more than one layer is present.
  4. Transitional epithelia change in thickness depending on how full the bladder is.

Questions & Answers

hi I'm asking a question about HIV infection, can HIV infection transmitted from Mother to unbron child? please help me I So confused.
Khushboy Reply
what is the difference between primary and secondary active transport in detail? I didn't understand the steps in the textbook specifically
Fathima Reply
you are a doctor?
Mohammed
what is the meaning of connective tissue?
Mohammed Reply
what are the characteristics of living things
Owolo Reply
hi
Mohammed
what's the meaning of connective tissue?
Mohammed
Reproduction, adaptation, interaction, movement, growth, respiration, made of cells, responsive to environment (homeostasis), metabolic action (consumption of food converted into energy)
garret
state two most important factors that favour exponential growth of population of a gazelle in a pack
Eliza Reply
growth
Ben
what are the two types of electron microscope
Sharlom Reply
light microscope and early microscope
Sama
Enzymes are biological catalyst which alter any reaction and protein in nature
Nkoue Reply
Thanks
Gaudi
Your welcome sir
Nkoue
guyz you enjoying
Royd
What is translation and transcription
Nkoue
Transcription is making RNA from DNA. Translation is going from RNA to proteins.
Eric
full meaning of RNA and DNA
Charity
Nkoue what homeostits means?
Mohammed
Mohammed khalfan, In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems.[1] This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid bal
Khushboy
what is the definition of enzymes
Royd Reply
enzymes are biological catalyst that speed up chemical reaction.
Alale
What are enzymes?
Gaudi
Enzymes are made of proteins and lower the energy of activation. In other words, they bring things together which helps to lower the amount of energy for a reaction to go forward.
Eric
they are catalyses that speeds up chemical reaction.... e.g they break down the food we consume.
Azeez
These are catalyst that speeds up the chemical reaction.
Micheal
What is connective tissue?
Mohammed
what homeostits means ?
Mohammed
what is a spirogyra
Talabi Reply
Spirogyra is a filamentous chlorophyte green algae of the order Zygnematales. It is named for the helical or spiral arrangement of the chloroplasts. That is characteristic of the genus. It is commonly found in freshwater habitats. And there are more than 400 species of Spirogyra in the world.
Eric
what is the mean of biology
Bello Reply
what is cell
Bello
A cell is the smallest living unit.
Eric
Hi I'm new in this group can someone please help with the list features shared by plants and charopytes that are not shared with most other eukaryotes
Wendy
iz a basic units of a living thing?
simongc
what is eutrophication
Chinaza Reply
hi.. I'm asking a question about HIV infection.... Can HIV infection transmitted from Mother to unbron child?
Khushboy
Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as: increased production of algae and aquatic plants, depletion of fish species, general deterioration of water quality and other effects that reduce and preclude use.
Khushboy
Show well labeled diagram of female reproductive organs
Lanlege Reply
phenotype is your big head
Amagiya Reply
The phenotype is the physical appearance or things you can see. Or the traits expressed by ones DNA.
Eric
phenotypes are appearance that can be seen and touched
Chidera
example of phenotype
Charity
what is a dichotomous key
Moses Reply
explain the role of
Moses
Dichotomous key : Is the key that is use to classify or group an organism base on their common features
Alale
an amoeba is what kind of cellular organism?
Mercy Reply
It is a protizoa with bilayer membrane bound organelles. Therefore it is eukaryotic.
Eric
what is amoeba
Muhammad
amoeba is a unicellular organisms. Therefore it is made u of only one call.
Alale
what is phenotype
Muhammad
amoeba is a unicellular organism with one cell
Chinaza

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Source:  OpenStax, Biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11448/1.10
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