Epithelial Tissue

Question 1

Six Basic Characteristics of Epithelium (CAPAIR)

Answer 1

Cellularity

Attachment

Polarity

Avascular

Innervation

Regeneration

Question 2

Epithelial Polarity

Differences between Basal, Apical, and Lateral Domains?

Answer 2

Basal: rests on basal lamina, anchors cell to underlying CT

Apical: directed toward exterior surface/lumen of enclosed cavity/tube

Lateral: communicates with adjacent cells (cell junctions)

Question 3

What are the chracteristics of Apical Specializations?

What are the four types?

Answer 3

Increase SA of tissue for absorption

Move substances along epithelia

May be external or lumenal

Cilia, Flagella, Microvilli, Stereocilia

Question 4

What are Microvilli and their specialized function?

Answer 4

Cytoplasmic processes containing actin core

Absorption and increase SA

Question 5

What are Stereocilia/Stereovilli?

Function?

Location?

Answer 5

Microvilli of unusual length (actin core provides rigidity)

Increase SA for absorption/secretion

Restricted to epididymis and sensory cells of inner ear (Hair Cells)

Question 6

What are Cilia?

What are Motile Cilia?

Primary Cilia?

Nodal Cilia?

Answer 6

Hair-like extension containing an axoneme, microtubule based structure

Propel substances across tissue

Immotile; chemosensors, osmosensors, mechanosensors

Embryonic; role in L/R axis determination

Question 7

What are Flagella?

Function and Location?

Answer 7

Modified, motile cilia

Forward movement for sperm

Question 8

Simple Squamous Cells

Location?

Function?

Answer 8

Lining blood and lymph vessels (endothelium)

Lining serous membranes (mesothelium)

Lining alveoli, loop of Henle

Exchange, Barrier, Lubrication

Question 9

Simple Cuboidal

What are the location and function?

Answer 9

Kidney tubules, terminal bronchioloes, covering ovary

Absorption, Barrier, Secretion

Question 10

Simple Columnar Cells

Location and Function

Answer 10

Auditory tubes, Uterus, Oviducts, Stomach, SI/LI, Gallbladder

Absorption, Secretion

Ciliated Simple Columnar Epithelium is found in Oviduct

Question 11

Pseudostratified Columnar Ciliated

Location and Function?

Answer 11

Nasal Cavity, Pharynx, Trachea, Bronchi

Absorption/Secretion, Debris & Particle movement

Question 12

Urothelium (Transitional)

Location and Function

Answer 12

Urinary Bladder, Ureters, Urethra

Barrier, Distensible Property

Question 13

Nonkeratinized Stratified Squamous

Location and Function

Unique to Apical Layer

Answer 13

Oral Cavity, Pharynx, Esophagus, Anus, Vagina, Urethra, Cornea

Barrier and Protection

Apical Layers retain Nuclei

Question 14

Keratinized Stratified Squamous Cells

Answer 14

Epidermis of Skin (Apical Layer cells do not retain nuclei)

Barrier, Protection

Question 15

Stratified Cuboidal

Location and Function

Answer 15

Sweat glands/ducts, Ovarian Follicles, Salivary Gland Ducts

Barrier & Passageway

Question 16

Mucous Membrane

Answer 16

Epithelia Tissue secreting mucus

Lines body cavities and tubular organs (Gut & Respiratory)

Question 17

Serous Membrane

Answer 17

Epithelia tissue lining specific internal cavities

Forms smooth, transparent, two-layered membrane

Mesothelium: simple squamous epithlium comprises part of serous membrane

Question 18

Merocrine Gland

Answer 18

Secretion delivered in membrane-bound vesicles to apical surface and undergo exocytosis

Question 19

Holocrine Gland

Answer 19

Secretion accumulates within cell –> apoptosis

Secretion and cell debris are released

Question 20

Apocrine Gland

Answer 20

Release of apical portion of cell, surrounded by cytoplasm within plasma membrane

Question 21

Unicellular Glands

Answer 21

Simplest in structure

Single, secretory cells distributed among non-secretory cells

Goblet Cell: Mucus-secreting cell found lining intestines and respiratory tract

Question 22

Multicellular Glands

Answer 22

Composed of more than one cell

Classified by arrangement & shape of secretory cells and ductal elements

Various combinations of duct and secretory portion are found in body

Question 23

Secretory Cells are what two?

Answer 23

Mucous (Lipid Based - Stain White/Clear)

Serous (Water Based - Stain Darker)

Question 24

Simple Tubular

Simple Coiled Tubular

Simple Branched Tubular

Simple Acinar

Simple Branched Acinar

Compound Tubular

Compound Acinar

Compound Tubuloacinar

Answer 24

Secretory cells form straight tube

Coiled tubular secretory portion deep in tissue

Branched tubular gland with wide secretory portion

Single layer of secretory cells

Secretory portion opens directly into the lumen

Coiled secretory portion located deep in tissue

Alveolar shaped secretory units, pyramid shaped secretory cell

Tubular and acinar secretory units; will have demilunes

Question 25

Occluding Junctions (Zona Occludens)

Answer 25

Impermeable, allows cells to function as barrier

Encircle cells near their most apical surface

Increased Junctions –> Decrease Permeability

Occludins and Claudins

Question 26

Anchoring Junctions

Answer 26

Lateral adhesions linking cytoskeleton to adjacent cells

Zonula Adherens: interacts with network of actin filaments inside cell

Macula Adherens (Desmosomes): interacts with intermediate filaments

Cadherins

Question 27

Gap Junctions

Answer 27

Fluid Filled channels connect apposed cells

Mediate communication

Connexins

Question 28

Focal Adhesions

Answer 28

Anchor actin filaments to basement membrane

Integrins

Question 29

Hemidesmosomes

Answer 29

Anchor Intermediate filaments to basement membrane

Integrins