Epithelium & Glands

Question 1

Basic Tissue Types

Answer 1

• Connective
• Epithelial
• Muscle
• Nervous

Question 2

Origins of Epithelia

Answer 2

Ectoderm: skin, sweat glands, oral cavity, vagina, anus
Mesoderm: Endothelium, mesothelium (lining of body cavities; genital/Urinary systems
Endoderm: Esophogus, GI tract, liver, pancreas

Question 3

Functions of Epithelia

Answer 3

• provide boundary layer through which movement of substances can be regulated
• line passages
• Protection, lining, absorption, secretion sensation, cantractability

Question 4

Epithelia Junctions

Answer 4

• Zonula Occludens (barrier)
• Zonula Adherans (adhesion)
• Desmosomes (adhesions)
• Gap Junctions (communication)

Question 5

Basal Lamina

Answer 5

-Can only be seen by EM
-Extracellular structure that underlies epithelia
-composed of
Lamina Densa: Electron Dense
Lamina Lucida:
Surrounds Lamina Densa

Question 6

Basement Membrane

Answer 6

Visible in LM

-PAS layer that underlies epithelia

Question 7

Basal Lamina

Answer 7

Visible only at TEM

-made of Type IV collagen, glycoproteins laminin & entactin, and heparin sulfate

Question 8

Basolateral Surface Functions

Answer 8

• Receive signals from chemical messangers (hormones)
• ATP-dependent Na+ export
• ATP dependent nutrient uptake

Question 9

Microvilli

Answer 9

• Actin Filaments cause protrusion of plasma membrane- increasing surface area
• Anchored in terminal web
• found in small intestines, proximal renal tubule
• microvilli + glycocalyx= brush border

Question 10

Sterocillia

Answer 10

• Misnomer: NOT cillia, not motile
• Elongated microvilli
• Incease surface are to facilitate absorption

Question 11

Cilia

Answer 11

Found in trachea, bronchi, oviduct

• consist of microtubules in 9+2 pattern that form membrane protrusions
• contain dynein arms with ATPase activity

Question 12

Flagella

Answer 12

• Esentially a long cillium
• 1 per cell
• only on sperm

Question 13

Microplicae

Answer 13

• small ridge like elevations
• help hold layer of protective mucus
• found on wet epithehelia (oral cavity/esophagus)

Question 14

Metaplasia

Answer 14

reversible changes epithelia can undergo that change from one type to another in response to environmental stimuli

Question 15

Merocrine

Answer 15

Secretory granules extruded by exocytosis with no loss of cellular material (paratid, salivary gland, pancreas)

Question 16

Holocrine

Answer 16

Secretory extruded along with entire cell content (sebaceous gland)

Question 17

Apocrine

Answer 17

Secretion discharged with small amount of apical cytoplasm (mammary gland)

Question 18

Secretory Unit Structure

Answer 18

• Tubular (simple, Compound)
• Coiled Tubular (simple)
• Branched Tubular (simple)
• Acinar(simple, compound)
• Tubuloacinar(compound)

Question 19

Types of Secretion

Answer 19

• Serous: secretion has low level of hydrophillic carbohydrates (pancreatic acinar cells)
• Mucous: Viscous secretion with high level of hydrophillic carbohydrates (Goblet Cells)
• Mixed: Both serous and mucus cells (sublingual and submandibular glands)