Epithelial Tissue Glandular

Question 1

What are Secretory Epithelial Cells?

Answer 1

1. Arranged in specialized organs called Glands
2. Form Parenchyma

Question 2

What is Invagination?

Answer 2

1. Retain their connection with the epithelium surface
   * Forming Exocrine Glands
2. Loose their connection with the epithelium surface

• Close contact with capillary blood vessels
• Form Endocrine Glands

Question 3

What is Endocrine Glands?

Answer 3

1. Ductless Glands
2. Release secretion into blood stream
3. Ex

• Adrenal Gland
• Parathyroid Gland
• Anterior lobe of the pituitary gland
• Thyroid Gland

4. Secretion

• Release basally
• Go through Basal Lamina
• Move under CT and Capillary network

Question 4

What are Exocrine Glands?

Answer 4

1. Composed

• Secretory Portions
  
  • Tubular
    
    • Tube-shaped lumen
  • Acinar
    
    • Grape-like, small lumen
  • Tubuloacinar
    
    • Lumen has both shapes (tubular and acinar)
• Duct System
  
  • Transport secretory cells
    
    • Unicellular glands
    • Multicellular glands

2. Mechanism of Secretion

• Merocrine (eccrine)
• Holocrine
• Apocrine

3. Type of Secretion

• Serous
• Mucous
• Mixed

Question 5

What are Unicellular Glands?

Answer 5

1. Single secretory cells (exocrine glands)
2. Ex: In Humans Only

• Goblet Cells
  
  • Mucus-secreting cells
  • Empty appearance in H and E stain
    
    • Mucus doesn’t stain
  • Periodic Acid Schiff (PAS) stain
    
    • Stained Purple

Question 6

What are Multicellular Exocrine Glands?

Answer 6

1. Enclosed by capsule of CT

• Provide Support
• Septa divides gland
  
  • Lobes- Large
  • Lobules- Small

Question 7

What are the different types of Secretory ducts?

Answer 7

1. Simple Tubular

• Mucous glands of colon
• Crypts of Lieberkuhn (intestinal glands)

2. Simple Coiled Tubular
   * Sweat glands of the Skin
3. Simple Branched Tubular

• Gastric Glands
• Glands in Uterus

4. Simple Alveolar (Acinar)
   * Small mucous glands along urethra
5. Simple Branched Alveolar
   * Sebaceous glands of the Skin
6. Compound Tubular
   * Submucosal mucous glands (of Brunner) in Duodenum
7. Compound Alveolar (Acinar)

• Exocrine
• Pancreas

8. Compound Tubuloalveolar
   * Salivary Glands

Question 8

What is Merocrine (Eccrine) Secretion?

Answer 8

1. Exocrine and Protein Secretion
2. Migrate to apical surface and leaves cell
3. Contents

• Proteins and Glycoproteins
  
  • Release by exocytosis
  • NO loss of Cytoplasm

4. Example

• Exocrine Pancreas
• Mucous and Serous cells
  
  • Salivary Glands
• Sweat Glands
  
  • Abundant on Palms of hands and Soles of feet

Question 9

What is Apocrine Secretion?

Answer 9

1. Dependent on Sex Hormones
2. Granules form secretory vesicles as it leaves the cell
3. Apocrine glands
   * Become functional at puberty
4. Ex

• Ceruminous gland of external auditory canal
• Ciliary (Moll’s) glands on the eyelids
• Sweat Glands
  
  • Odor due to Skin Flora

*Released portion contains Lipid Droplets

Question 10

What is Holocrine Secretion?

Answer 10

1. Granules fill the cell
2. Cell becomes “bloated” with secretory (lipid-rich) products
3. Inside lumen

• Cell degenerates and dies
• Secretory products released

4. Ex

• Sebaceous Glands
  
  • Abundant on Scalp and Face
• Tarsal (Meibomian) glands of the eyelids

Question 11

What are Serous Glands?

Answer 11

1. Serous Cells

• Nonglycosylated protein-rich secretion
  
  • Digestive enzymes
• Basal Region
  
  • Well-developed rER (Typical)
• Apical Region
  
  • Filled with Protein-rich Secretory granules
• Prominent Golgi complex

2. Found

• Partoid and Lacrimal Glands
• Exocrine Pancreas
• Gastric chief cells

3. ZYMOGEN GRANULES

• Enzymes for digestion (Pancreatic acinar cells)
• Precursor for enzyme (Inactive form)

Question 12

What is Mucous Glands?

Answer 12

1. Multicellular Exocrine Gland
2. Produce Goblet Cells
   * For respiratory and digestive tract
3. In Duodenum (Brunner’s)
4. Mucous cells

• Glycosylated Proteins called MUCINS
• Basal Region
  
  • Flatten
  • Stains purple
• Apical Region
  
  • Filled with secretory granules containing Glycoproteins called Mucin
• Mucin
  
  • After exocytosis
  • Absorb water
  • Form Mucus

5. Stains with Periodic Acid Sheiff (PAS)

Question 13

What is Seromucous (Mixed) Glands?

Answer 13

1. Contains

• Mucous cells
• Serous cells

2. Demilunes
   * Small half-moon or crescent-shaped structures
3. Secretion
   * Watery mucin and a digestive enzyme (salivary amylase)
4. Ex
   * Submandibular Salivary Gland