Exam #1: Epithelial Tissue I & II Flashcards Preview

Cell & Tissue Biology > Exam #1: Epithelial Tissue I & II > Flashcards

Flashcards in Exam #1: Epithelial Tissue I & II Deck (70):
1

What are the three cell domains of the epithelium?

- Apical
- Lateral
- Basal

2

What is the epithelial sheet anchored to?

Basal Lamina

3

What is the only type of epithelium that is vascular?

- Stria Vascularis
- Located in the cochlear duct
- Produces endolymph

4

Simple Epithelia

One layer w/ all the cells residing on the basement membrane

5

Stratified Epithelia

- 2 or more strata (layers)
- Only the deepest cells reside on the basement membrane

6

Pseudostratified Epithelia

- All cells reside on the basement membrane
- Nuclei are located at various levels giving a stratified appearance

7

Transitional Epithelia

- Urothelium
- Transitions from cuboidal (relaxed) to sqamous when bladder is distended

8

Keratinized

Outer layer of cells is dead

9

What are the functions of simple squamous epithelia?

1) BBB
2) Filtration
3) Exchange

10

Where is simple squamous epithelia found?

- Blood vessels (lining, called endothelium)
- Mesothelium (abdominal cavity)
- Alveolus

11

What are the functions of simple cuboidal epithelia?

1) Absorption
2) Secretion
3) Barrier
4) Conduit

12

Where is simple cuboidal epithelia located?

- Thyroid Follicles
- Renal Tubules
- Ducts of glands

13

What are the functions of simple columnar epithelia?

1) Absorption
2) Secretion
3) Barrier

14

Where is non-ciliated simple columnar epithelia located?

- Stomach
- Intestines

15

Where is ciliated simple columnar epithelia located?

Uterine Tubes (helps transport ovulated oocyte)

16

What are the functions of ciliated pseudostratified columnar epithelia?

1) Secretion
2) Absorption
3) Barrier
4) Transport

17

Where is ciliated pseudostratified columnar epithelia located?

- Trachea (will have very thick basement membrane)
- Bronchi
- Ducts of male reproductive system (steriocilia)

18

What are the functions of stratified squamous epithelia?

1) Barrier
2) Protection

19

Where is nonkeratinzed stratified squamous epithelia located?

- Esophagus
- Distal anal canal
- Vagina

20

Where is keratinized stratified squamous epithelia located?

Epidermis

21

Keratin pearls

- Hallmark of a squamous cell carcinoma
- Whirls of keratin deep in the tissue involved

22

Stratified Cuboidal Epithelium

- Not common
- Present in ducts that are in transition from one epithelial type to another
-

23

Where is transitional epithelium located?

- Ureters
- Bladder
- Urethra

24

What is the function of transitional epithelium?

1) Barrier
2) Protection
3) Distension

25

Transitional Cell Carcinoma

- Stages 0-IV
- Penetrates into the outer layers of the bladder wall
- The deeper the penetration the higher the grade

26

Metaplasia

- Epithelium changes from one type to a type that is not normally present (can revert back)
- E.g. Trachea & smoking
- Pseudostratified columnar epithelium turns into stratified squamous, which is more protective
- Simultaneous loss of mucous clearance
- Can go back when one stops smoking

27

Barett's Esophagus

- GERD
- Constant reflux causes a metaplasia in the distal esophagus
- Stratified squamous turns into protective intestinal type cell with mucous production
- Pre-cancerous
- V. Difficult to reverse

28

What are the different types of Cilia?

1) Motile
2) Primary (Non-motile)
3) Nodal

29

Microvilli

- Extensions of the plasma membrane
- Actin microfilaments insert into terminal web
- Cross-linked by actin binding proteins & myosin
- Myosin II present in terminal web, which is motile & causes microvilli to change direction

30

Stereocilia

- DO NOT RESEMBLE CILIA
- Rather, resemble microvilli-- called stereovilli

31

Motile Cilium

- 9+2 array of MTs
- Contain Dynein ATPase
- Two individual MTs in center

32

Basal Body

- Base of Motile Cilium
- 9x3 of MTs (like centrioles) NOT 9+2

33

Primary Monocilium

- Different MT array 9 doublet WITHOUT 2 in center
- Chemosensors, osmoreceptors, & mechanoreceptors
- E.g. kidney & fibroblast

34

Primary cilium & polycystic kidney disease

- Polycystin 1&2 are involved in Ca++ signaling
- Mutation disrupts signaling and changes orientation of mitotic spindle
- Results in cyst formation

35

Nodal cilia

- Motile, but MT array is similar to non-motile (9 doublets without two central)
- Direct fluid flow in primitive node from right to left, establishing left/right axis in body

36

Situs Inversus

- Caused by defect in nodal cilia
- Flipping of internal organ orientation

37

Microvilli fed state

Spread apart by the action of myosin II in the terminal web

38

Microvilli in starvation state

Close together by the action of myosin II in terminal web

39

Brush Border

- Well developed microvilli
- Contains a carbohydrate coat that is Pas + (glycocalyx)

40

Stereocilia/ stereovilli

- Elongated microvilli
- Actin microfilaments
- Actin binding proteins
- Terminal web

41

Where are stereocilia located?

- Male reproductive ducts
- Hair cells in the inner ears (sensory epithelium)

42

Kartagener's Triad

1) Chronic sinusitis
2) Bronchiectasis
3) Situs inversus

- Caused by defective cilia

43

Zonulae Occludens

- Tight Junctions
- Most apical junctional complexes
- Go around the circumference of the cell

44

Zonulae Adherens

- Just basal to the zonulae occludentes or tight junctions
- Go around the circumference of the cell

45

Maculae Adherens

- "Spot connection" known as desmosome
- Basal to the Zonula Adherens

46

Gap Junctions

- Also called nexus
- Communicating junctions
- Pores when open

47

Hemidesmosomes

- Base of the cell
- Connect the cell to the underlying basal lamina

48

General Structure of a Junctional Complex

1) Cytoskeletal Elements
2) Intracellular Anchor Proteins
3) Cell Adhesion Molecule (CAM)

49

Intracellular Anchor Proteins

Link between cytoskeletal element & CAM

50

Structure of the Zonulae Occludens

1) Cytoskeletal Element= Actin
2) Intracellular Anchor Proteins= ZO proteins (1, 2, &3)
3) Cell Adhesion Molecule (CAM, transmembrane)= Occludin & Claudin, form a tight connection between cell membranes

51

H. Pylori & Tight Junctions

- Disrupt tight junctions in stomach
- Epithelial cells more susceptible to injury

52

What are the different disease states that can be caused by claudin mutations?

- Loss of Mg++ in urine
- Brain Cancer
- Deafness

53

What part of the tight junction does the Cholera toxin disrupt?

ZO protein, intracellular anchor protein

54

Occludin/ Claudin Ratio

- High Occludin= non-permeable (E.g. BBB)
- High Claudin= permeable

55

How do tight junctions form functional polarity?

- Restrict the movement of membrane domains
- E.g. Na+/ GLUT transporter

56

Zonula Adherens Structure

1) Cytoskeletal Elements= Actin
2) Intracellular Anchor Proteins= Catenin & Vinculin
3) Cell Adhesion Molecule (CAM)= E-Cadherin

57

Macula Adherens Structure

Desmosome

1) Cytoskeletal Elements= Intermediate Filament
2) Intracellular Anchor Proteins
3) Cell Adhesion Molecule (CAM)= Desmocollin & Desmoglein

58

Stratum Spinosum

- Pink spinous like projects
- Acidophilic
- Points of contact between cells

59

Pemphigus

- Blistering skin disorder
- Caused by autoantibodies against desmoglein (CAM of desmosome)

60

Focal Adhesions Structure

1) Cytoskeletal Elements= Actin
2) Intracellular Anchor Proteins= Vinculin, Paxillin, & Talin
3) Cell Adhesion Molecule (CAM)= Integrin

61

Integrin

CAM that makes focal contacts with ECM (Fibronectin)

62

Hemidesmosome Structure

1) Cytoskeletal Elements= Intermediate Filaments
2) Intracellular Anchor Proteins
3) Cell Adhesion Molecule (CAM)= Integrin, Type XVII

63

Bullous Pemphigoid

- Blistering Skin Disorder
- Caused by autoantibodies against Type XVII collagen (CAM of Hemidesmosome)

64

Gap Junction Structure

- 6x Connexins (transmembrane) form a Connexon
- Connexons oppose each other

65

Where are gap junctions found?

- Cardiac muscle cells

66

What are the consequences of mutations in connexons?

- Female infertility
- Neuropathy
- Deafness
- Congenital Cataracts
- Cardiac Arrhythmias

67

Stippled Epithelial Cells from Vagina

Bacterial Vaginal Infection

68

What is the first step in malignant transformation & metastasis?

Invasion of basement membrane

69

What does invasion of basement membrane require in malignancy?

Loosening of junctional complexes

70

Loosening of junctional complexes

- Cadherin (CAM) loss is most common
- Catenin mutation
- Integrin mutation