Epithelial tissue

Question 1

Urothelium

Answer 1

• nuclei seen in 3-6 layers
• umbrella cells ⇒ binucleated, cytoplasmic processes to basement membrane
• pear shaped cells
• basal layer composed of cuboidal/columnar cells

Question 2

Stratified squamous non-keratinized epithelium layers

Answer 2

1. STRATUM BASALE ⇒ columnar/cuboidal cells supported by basal membrane, assure renewal of surface cells
2. STRATUM SPINOSUM ⇒ many layers of large polygonal cells
3. STRATUM PLANOCELLULARE ⇒ superficial layer of flattened cells, signs of progressive degeneration

Question 3

Stratified squamous keratinized epithelium layers

Answer 3

1. STRATUM BASALE ⇒cuboidal/columnar cells, mitotic figures
2. STRATUM SPINOSUM ⇒ several cells thick, spiny appearance due to desmosomes
3. STRATUM GRANULOSUM ⇒ dense basophilic granules in cytoplasm of flattened cells, contain keratohyalin. 1-5 layers of granular cells
4. STRATUM LUCIDUM ⇒ highly flattened cells loose their nuclei, homogenous eosinophilic layer
5. STRATUM CORNEUM: desquamation of keratinized cells

Question 4

Goblet cells

Answer 4

• mucus secreting modified epithelial cells

- apical part contain mucoid granules

Question 5

Serous cells

Answer 5

• protein secreting cells
• aerous acini + minute central lumina
• triangular in shape
• basophilia due to accumulation of rER
• zymogen granules in luminal part

Question 6

Mucous cells

Answer 6

• glycoprotein containing granules ⇒ mucigen granules

- demilune of Gianuzzi

Question 7

Merocrine secretion

Answer 7

secretory granules released without loss of cytoplasm and cell membrane
e.g. mucous and serous glands

Question 8

Apocrine secretion

Answer 8

detachment of apical cytoplasm with its cell membrane

e.g. apocrine sweat glands

Question 9

Holocrine secretion

Answer 9

degeneration, disintegration of whole epithelial cells

e.g. sebaceous gland

Question 10

Sebaseous gland

Answer 10

• holocrine secretion
• dermis of skin
• associated with hair follicles
• simple branched acinar type
• acini open into short duct that enters pilosebaceous canal
• their cytoplasm enlarges, lipid droplets fill it, nuclei pyknotic

Question 11

Apocrine sweat gland

Answer 11

• deep part of dermis
• narrow lumen, lined by stratified cuboidal epithelium
• straight course toward hair follicle
• wide secretory portions lined by cuboidal/columnar cells
• numerous granules fill apical cytoplasm and cell membrane