Pl. III · Simplex columnaris — simple columnar

The plate

The specimen, drawn

Pl. III

The tissue as you will meet it on the slide.

Habitat & range

Where it lives

Body map

Where this tissue is found.

Range

• Stomach lining — surface mucous cellsThe basic structural and functional units of life.
• Small intestine (jejunumThe middle section of the small intestine, primarily responsible for nutrient absorption., ileumThe last section of the small intestine, responsible for absorbing vitamin B12 and bile salts.)
• Large intestine
• Gallbladder
• Uterine tubes (ciliated)

Collection record

• Slide 029 — simple columnar
• Small intestine, cross-section
• Bronchi slide 130 — ciliated, for comparison

Niche

What it does for a living

Absorption with a surface-area problem to solve. Height gives room for the machinery; microvilliTiny projections on the surface of epithelial cells that increase surface area for absorption. multiply the surface; goblet cells keep it wet. This is the lining of a border crossing that is also a marketplace.

field collected specimen

How to know it on sight

• One row of tall cells standing like a picket fence.
• Nuclei low, near the basement membrane, and all at the same level.
• A brush borderA dense layer of microvilli on the surface of certain cells, increasing surface area for absorption. of microvilli on the free surface.
• Goblet cells punched into the row like white thumbprints.

Specimen 1

Specimen 2

Specimen 3

People keep calling her by the wrong name

Look-alikes

Three plates. Read the line underneath each one before you decide.

Pseudostratified columnar

Tell them apart by the nucleiClusters of neurons in the CNS responsible for processing information.. One tidy row = simple. Scattered heights, every cell still touching the membrane = pseudostratified.

Simple cuboidal

Tell them apart by height against width, and where the nucleusThe control center of the cell that contains DNA and directs cellular activities. sits — centred in cuboidal, low in columnar.

Stratified columnar

Tell them apart by looking underneath. A second row of short cells below the tall ones means stratified.

Examine it yourself

The virtual slide

Zoom in until you can see the surface of the cells, then find the basement membrane underneath.

Virtual slide courtesy of Histology Guide.

Field notes

Why this animal

The flamingo’s bill is lined with about a hundred lamellae — an actual brush border — and it feeds with the bill upside down, straining shrimp out of the lake. Tall, narrow, nucleus down by the boots, fuzzy on top.