Question

review sheet
tissues

1. complete the following table:

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$$\begin{tabular}{|l|l|l|l|} \\hline type of epithelium & structure & location & function \\\\ \\hline simple squamous & a. & b. & c. \\\\ \\hline d. & e. & trachea & f. \\\\ \\hline g. & h. & i. & protection from abrasion and friction \\\\ \\hline j. & one layer of tall cells & k. & l. \\\\ \\hline m. & n. & urinary bladder & o. \\\\ \\hline p. & q. & skin & r. \\\\ \\hline s. & one layer of cube-shaped cells & t. & u. \\\\ \\hline \\end{tabular}$$

1. identify the epithelial types illustrated in the diagrams to the right.

a.
b.
c.
d.
e.
f.

Explanation:

🆕 New Concept Discovered: Epithelial Tissue Classification
How structure dictates location and function in tissues.

Step 1: Analyze Simple Squamous Epithelium (Row 1)

* **Structure (a):** Simple squamous epithelium consists of a single layer of flat, scale-like cells.
* **Location (b):** Commonly found where rapid diffusion or filtration is required, such as the air sacs of the lungs (alveoli) or the lining of blood vessels (endothelium).
* **Function (c):** Facilitates diffusion, filtration, and secretion of lubricating substances.

Step 2: Analyze Trachea Epithelium (Row 2)

* **Type of Epithelium (d):** The trachea is lined by pseudostratified ciliated columnar epithelium.
* **Structure (e):** Appears stratified because cell nuclei lie at different levels, but it is a single layer of cells of varying heights, typically ciliated.
* **Function (f):** Secretes mucus (via goblet cells) and propels it upward using cilia to protect the respiratory tract.

Step 3: Analyze Protection from Abrasion (Row 3)

* **Function:** Protection from abrasion and friction.
* **Type of Epithelium (g):** Stratified squamous epithelium (non-keratinized, as it is typically found in moist internal areas subject to wear and tear).
* **Structure (h):** Multiple layers of cells; basal cells are cuboidal/columnar, while apical surface cells are flattened (squamous).
* **Location (i):** Lining of the esophagus, mouth, and vagina.

Step 4: Analyze One Layer of Tall Cells (Row 4)

* **Structure:** One layer of tall cells.
* **Type of Epithelium (j):** Simple columnar epithelium.
* **Location (k):** Lining of the digestive tract (stomach to anal canal) or gallbladder.
* **Function (l):** Absorption of nutrients and secretion of mucus and enzymes.

Step 5: Analyze Urinary Bladder Epithelium (Row 5)

* **Location:** Urinary bladder.
* **Type of Epithelium (m):** Transitional epithelium.
* **Structure (n):** Stratified layers of cells; surface cells are dome-shaped (umbrella cells) when relaxed, but flatten out when stretched.
* **Function (o):** Stretches readily and permits distension of the urinary organ as it fills with urine.

Step 6: Analyze Skin Epithelium (Row 6)

* **Location:** Skin (epidermis).
* **Type of Epithelium (p):** Keratinized stratified squamous epithelium.
* **Structure (q):** Multiple layers of cells; surface cells are dead, flat, and filled with the tough protein keratin.
* **Function (r):** Protects underlying tissues from mechanical damage, pathogens, and dehydration.

Step 7: Analyze One Layer of Cube-Shaped Cells (Row 7)

* **Structure:** One layer of cube-shaped cells.
* **Type of Epithelium (s):** Simple cuboidal epithelium.
* **Location (t):** Kidney tubules, ducts of small glands, and ovary surface.
* **Function (u):** Secretion and absorption.

Step 8: Identify Diagrams in Question 2

* **Diagram (a):** A single layer of cube-shaped cells with central, spherical nuclei. This is **simple cuboidal epithelium**.
* **Diagram (b):** Multiple layers of cells, with flat, scale-like cells at the apical surface. This is **stratified squamous epithelium**.
* **Diagram (c):** A single layer of cells of differing heights with nuclei at different levels, bearing cilia at the apical surface. This is **pseudostratified ciliated columnar epithelium**.
* **Diagram (d):** Multiple layers of cells where the surface cells are rounded/dome-shaped. This is **transitional epithelium**.
* **Diagram (e):** A single layer of tall, column-like cells with oval nuclei located near the base. This is **simple columnar epithelium**.
* **Diagram (f):** A single layer of highly flattened, scale-like cells viewed from the surface. This is **simple squamous epithelium**.

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Answer:

1. Complete the following table:

Letter	Answer
b.	Air sacs of lungs (alveoli) / Lining of blood vessels
c.	Diffusion, filtration, and secretion
d.	Pseudostratified ciliated columnar
e.	Single layer of cells of differing heights, nuclei at different levels, ciliated
f.	Secretion and propulsion of mucus
g.	Stratified squamous (non-keratinized)
h.	Multiple layers of cells; apical cells are flat
i.	Lining of the esophagus, mouth, and vagina
j.	Simple columnar
k.	Lining of the digestive tract (stomach to rectum)
l.	Absorption and secretion of mucus and enzymes
m.	Transitional
n.	Stratified; surface cells are dome-shaped/rounded when relaxed
o.	Stretches and permits distension of the bladder
p.	Stratified squamous (keratinized)
q.	Multiple layers of cells; apical cells are dead, flat, and keratinized
r.	Protection against abrasion, pathogens, and water loss
s.	Simple cuboidal
t.	Kidney tubules / Ducts of small glands
u.	Secretion and absorption

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2. Identify the epithelial types illustrated in the diagrams:

• a. Simple cuboidal epithelium
• b. Stratified squamous epithelium
• c. Pseudostratified ciliated columnar epithelium
• d. Transitional epithelium
• e. Simple columnar epithelium
• f. Simple squamous epithelium