Epithelial Tissue

Question 1

Define histology.

Answer 1

Microscopic study of tissues.

Question 2

What is a biopsy?

Answer 2

Removal of tissues for diagnostic purposes.

Question 3

What is the primary characteristic of epithelial tissue?

Answer 3

Cellularity (consists almost entirely of cells).

Question 4

Name three surfaces of epithelial cells.

Answer 4

Apical, basal, lateral.

Question 5

What is the function of the basement membrane?

Answer 5

Supports epithelium and acts as a selective filter.

Question 6

Why is epithelial tissue avascular?

Answer 6

It lacks blood vessels; nutrients diffuse from underlying connective tissue.

Question 7

How does epithelial tissue regenerate?

Answer 7

Replaces lost cells via cell division.

Question 8

List three functions of epithelia.

Answer 8

Protection, absorption, secretion.

Question 9

Where is simple squamous epithelium found?

Answer 9

Kidney glomeruli, air sacs of lungs, lining of blood vessels.

Question 10

What is the function of simple cuboidal epithelium?

Answer 10

Secretion and absorption (e.g., kidney tubules).

Question 11

What distinguishes pseudostratified epithelium?

Answer 11

Appears stratified but all cells contact the basement membrane.

Question 12

Where is ciliated pseudostratified columnar epithelium found?

Answer 12

Trachea and upper respiratory tract.

Question 13

What is the role of goblet cells?

Answer 13

Secrete mucus.

Question 14

How does stratified squamous epithelium protect the body?

Answer 14

Multiple layers resist abrasion (e.g., skin, esophagus).

Question 15

What is the difference between keratinized and non-keratinized stratified squamous epithelium?

Answer 15

Keratinized has dead surface cells filled with keratin (e.g., skin); non-keratinized is moist (e.g., mouth).

Question 16

Where is transitional epithelium found?

Answer 16

Bladder, ureters, urethra.

Question 17

What is unique about transitional epithelium?

Answer 17

Stretches to accommodate urine volume (dome-shaped when relaxed, flattened when stretched).

Question 18

What are the two types of glands?

Answer 18

Endocrine (ductless) and exocrine (with ducts).

Question 19

What are the two types of glands mentioned?

Answer 19

Thyroid, pituitary.

Question 20

Give an example of an endocrine gland.

Answer 20

Thyroid gland.

Question 21

What is a unicellular exocrine gland?

Answer 21

Goblet cells.

Question 22

How are multicellular exocrine glands classified?

Answer 22

By duct structure (simple/compound) and secretory unit shape (acini/alveoli).

Question 23

Name three types of cell junctions.

Answer 23

Tight junctions, desmosomes, gap junctions.

Question 24

What is the function of tight junctions?

Answer 24

Form impermeable barriers (e.g., near apical surfaces).

Question 25

How do desmosomes provide strength?

Answer 25

Cadherin proteins link plaques; intermediate filaments anchor cells.

Question 26

Where are gap junctions important?

Answer 26

In electrically excitable tissues (e.g., heart, smooth muscle).

Question 27

What is the function of microvilli?

Answer 27

Increase surface area for absorption (e.g., small intestine).

Question 28

Where are cilia found and what do they do?

Answer 28

Respiratory tract; move mucus in coordinated waves.

Question 29

What are the four main classes of connective tissue?

Answer 29

Connective tissue proper, cartilage, bone, blood.

Question 30

What is the embryonic origin of connective tissue?

Answer 30

Mesenchyme (derived from mesoderm).

Question 31

What are the three components of extracellular matrix (ECM)?

Answer 31

Protein fibers, ground substance, fluid.

Question 32

Name the three types of protein fibers in ECM.

Answer 32

Collagen, elastic, reticular.

Question 33

What is the function of collagen fibers?

Answer 33

Provide tensile strength (e.g., tendons).

Question 34

Where are elastic fibers found?

Answer 34

Lungs, large blood vessels (recoil after stretching).

Question 35

What is the role of reticular fibers?

Answer 35

Form branching networks (stroma) in lymphoid organs.

Question 36

What do fibroblasts secrete?

Answer 36

Proteins for fibers and ECM

Question 37

What is the function of mast cells?

Answer 37

Release heparin, histamine, and enzymes in response to injury.

Question 38

What is the origin of macrophages?

Answer 38

Derived from monocytes (WBCs).

Question 39

What do chondroblasts form?

Answer 39

Cartilage.

Question 40

What is the role of hematopoietic stem cells?

Answer 40

Form blood cells.

Question 41

What are the three types of loose connective tissue?

Answer 41

Areolar, adipose, reticular.

Question 42

What is the role of hematopoietic stem cells?

Answer 42

Form blood cells.

Question 43

Where is areolar connective tissue found?

Answer 43

Under epithelia (e.g., lamina propria).

Question 44

What is the function of adipose tissue?

Answer 44

Energy storage, insulation, organ protection.

Question 45

Where is reticular connective tissue located?

Answer 45

Lymphoid organs (spleen, lymph nodes).

Question 46

What is the primary fiber type in dense irregular connective tissue?

Answer 46

Collagen fibers (irregularly arranged).

Question 47

Where is dense regular connective tissue found?

Answer 47

Tendons, ligaments.

Question 48

What is the function of elastic connective tissue?

Answer 48

Allows recoil (e.g., aorta, lungs).

Question 49

What are cartilage cells called?

Answer 49

Chondrocytes (located in lacunae).

Question 50

Why is cartilage slow to heal?

Answer 50

Avascular and lacks nerve supply.

Question 51

What is the perichondrium?

Answer 51

Dense irregular connective tissue surrounding cartilage.

Question 52

What are the three types of cartilage?

Answer 52

Hyaline, elastic, fibrocartilage.

Question 53

Where is hyaline cartilage found?

Answer 53

Trachea, nose, costal cartilages, embryonic skeleton.

Question 54

What is the function of elastic cartilage?

Answer 54

Maintains shape while flexible (e.g., ear, epiglottis).

Question 55

Where is fibrocartilage located?

Answer 55

Intervertebral discs, knee joints.

Question 56

What is the matrix of bone made of?

Answer 56

Calcified collagen fibers.

Question 57

What are intercalated discs?

Answer 57

Specialized junctions in cardiac muscle.

Question 58

Where is smooth muscle located?

Answer 58

Walls of hollow organs (e.g., stomach, bladder).

Question 59

What is the function of nervous tissue?

Answer 59

Transmit electrical signals.

Question 60

What are the two cell types in nervous tissue?

Answer 60

Neurons and supporting cells.

Question 61

How does aging affect collagen fibers?

Answer 61

Become irregular; tendons/ligaments less flexible.

Question 62

What is metaplasia?

Answer 62

Transformation of one epithelial type to another (e.g., in smokers).

Question 63

What is adenocarcinoma?

Answer 63

Malignant tumor from glandular tissue.

Question 64

What are intercalated discs?

Answer 64

Specialized junctions in cardiac muscle.

Question 65

Where is smooth muscle located?

Answer 65

Walls of hollow organs (e.g., stomach, bladder).

Question 66

What is the function of nervous tissue?

Answer 66

Transmit electrical signals.

Question 67

What are the two cell types in nervous tissue?

Answer 67

Neurons and supporting cells.

Question 68

How does aging affect collagen fibers?

Answer 68

Become irregular; tendons/ligaments less flexible.

Question 69

What is metaplasia?

Answer 69

Transformation of one epithelial type to another (e.g., in smokers).

Question 70

What is adenocarcinoma?

Answer 70

Malignant tumor from glandular tissue.