Ch. 4 - Epithelial Tissue Flashcards Preview

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Flashcards in Ch. 4 - Epithelial Tissue Deck (73):
1

Four types of tissue

1. Epithelial
2. Muscular
3. Connective
4. Nervous

2

Connective tissue (CT) key characteristic

Abundant ECM

3

Muscle tissue key characteristic

Elongated cells specialized for contraction and movement

4

Nervous tissue key characteristic

Long, fine processes specialized to receive, generate, and transmit nerve impulses

5

Most organs can be divided into _______ and _______.

parenchyma, stroma

6

Parenchyma

The cells responsible for the organs' specialized functions

7

Stroma

The cells that have a supporting role in the organ
Always CT except in the brain and spinal cord

8

Epithelial tissue key characteristic

Tight junctions

9

Epithelial tissue

Cellular sheets that line the cavities of organs and cover the body surface

10

What are the three principal functions of epithelial tissue? Give an example of each.

1. Covering, lining, and protecting surfaces (epidermis)
2. Absorption (intestinal lining)
3. Secretion (parenchymal cells of glands)

11

Basement membrane

Amorphous, nonvascular, nonliving material secreted by the cell made up of protein, collagen, lamanin, fibronectin, and others

Connects and anchors the cell to the CT below (lamina propria) and filters material

Light microscopy term

12

Is epithelium vascular or avascular?

Avascular

13

How does epithelium obtain nutrients?

Absorption from the surrounding tissue via simple diffusion

14

Basal lamina

Same as basement membrane, but a TEM term
Divided into basal lamina and reticular lamina

15

Lamina propria

The CT beneath epithelial cells
Provides nutrients to the cells
Gives the cell a polarity

16

Cell polarity and two examples

Cells have different specializations and functions at different regions of the cell

I.e. apical specializations - microvilli
basal specializations - junctions

17

The basement membrane allows the cell to do what three things?

1. Differentiate
2. Provides movement
3. Signal transduction

18

Signal transduction

Aka cell signaling
Transmission of molecular signals from a cell's exterior to its interior

19

What are the three types of cell junctions?

1. Adhesion junctions
2. Gap junctions
3. Tight junctions

20

Adhesion junctions

Attaches cells to other cells and to membranes

21

Gap junctions

Communicating junctions
Transient
Each cell manufactures connexins

22

Tight junctions

Junctions that form a seal between two cells
I.e. zona occludens

23

Zona occludens

Tight junction found at cell apex
Cells fuse at this point
Inhibits paracellular movement

24

Zona adherens

Adhesion junctions found on the sides of cells
Involves interactions of integral proteins
Forms a band between the two cells

25

Macula adherens

Aka desmosome or "spot" junctions
Interactions of proteins
Adhesion junctions that form spot junctions, as opposed to the band junction found in zona adherens

26

Paracellular movement

Movement of material through small spaces between cells

27

What happens when someone has Celiac's disease?

When people are hyper-allergic to gluten, their intestinal cells release zonulin, a protein that breaks down the tight junctions between the intestinal cells. Gluten passes through and causes a painful response.

28

Microvilli

Apical specialization of epithelium
Very small, nonmotile extensions of the surface membrane that increase the surface area of the cell
Important for absorption
Contain actin filaments

29

Brush border

Dark band observed under the light microscope
Site of microvilli at the apex of the cell
Can't see individual microvilli

30

Cilia

Structure on the apex of the cell that aid in movement of materials across the cell surface (usually of mucous)
Have 9+2 arrangement
Shorter and more numerous than flagella
Found mainly in respiratory cells

31

9+2 arrangement

9 pairs of microtubules in a ring around a central pair
Found in cilia and flagella

32

Flagella

Structure on the cell that aids in movement
Have 9+2 arrangement
Longer and less numerous that cilia
Only cells in humans with flagella are sperm cells

33

Dynein

Motor protein that binds to ATP and causes movement via sliding filament
Found in the microtubules of cilia and flagella on side arms

34

What are the two main groups of epithelia?

1. Lining or Covering epithelia
2. Secretory epithelia and glands

35

Lining/Covering epithelia

Organized into one or more layers that cover the external surface or line the cavities of organs
Classified according to the number of cell layers and the cell morphology in the surface layer

36

Simple epithelia

One layer of cells
Simple cuboidal
Simple columnar
Simple squamous

37

Stratified epithelia

Two or more layers of cells
Stratified, squamous, or columnar (rare)
Name for the top layer of cells i.e. stratified squamous (skin)

38

Stratified squamous cells

Important for protection
I.e. skin cells are stratified squamous cells

39

The epidermis is made up of _______ cells.

keratinized stratified squamous

40

Keratin

Protein that guards against loss of water (water proof)
Found in the epidermis, hair, nails

41

Non-keratinized stratified squamous epithelium

Protects against abrasion
Not water proof
Kept moist by mucous
I.e. vagina, esophagus

42

Transitional epithelium

Aka uroepithelium or urothelium
Specialized epithelium that undergoes transition depending on what the organ is doing
I.e. bladder cells stretch when the bladder is full and contract ("dome shaped") when it is empty
Found in the bladder, ureters, and part of the urethra

43

Pseudostratified ciliated columnar epithelium

Cells unique to the respiratory tract
Nuclei are located at different planes because the cells are different heights
Looks like the cells are stratified but they are simple
All cells are anchored to the same basement membrane

44

Gland

Specialized cells or organs made up of epithelial cells that function mainly to produce and secrete various macromolecules

45

Secretory granules

Membrane-bound vesicles that store products to be secreted by glands

46

Unicellular gland

Secretory cells that function as a gland
Usually simple cuboidal, simple columnar, and pseudostratified epithelia
I.e. goblet cells (exocrine), enterochromaffin cells (endocrine)

47

Goblet cells

Cells that act as glands
Secrete mucus

48

Enterochromaffin cells

Cells that acts as endocrine glands
Secrete the hormone serotonin

49

Multicellular glands can be either _______ or _______.

endocrine; exocrine

50

Endocrine glands

Clusters of cells that secrete hormones to the blood vessels

51

Exocrine glands

Duct glands
Release produce into a duct

52

Apocrine secretion

Release from the apex of the cell
The apex ruptures and the cell dies via apoptosis
I.e. apocrine sweat glands (secrete into hair follicle)

53

Holocrine secretion

Entire cell breaks and becomes secretory product
Secrete "oil"
I.e. sebaceous glands (found in the skin)

54

The epidermis (keratinized stratified squamous epithelium) is a _______ population of cells.

renewable

55

Merocrine secretion

Exocytosis of protein of glycoprotein from membrane-bound vesicles
Most common form
Only form where the cell doesn't die

56

Simple glands

The glands have ducts and are not branched

57

Compound glands

Glands with ducts with two or more branches
Can have branching ducts and can have multiple tubular, acinar, or tubuloacinar secretory portions

58

Glands can be classified as _______ glands or as _______ glands.

simple; compound

59

Secretory portions can be _______ or _______.

tubular; acinar

60

Tubular secretory portions cons be either _______ or _______.

short; long and coiled

61

Acinar secretory portions

Rounded and saclike
Can be single or branched

62

Where are simple tubular exocrine glands found?

Mucous glands of the colon
Intestinal glands or crypts

63

Myoepithelial cells

Specialized epithelial cells that can contract due to actin and myosin
Found on the outside of the cells of exocrine glands
When they contract, they squeeze the gland
I.e. mammary and salivary glands

64

Epithelioid

Not facing the lumen

65

Axoneme

The central core of cilia and flagella
Has a 9+2 arrangement
Has side arms consisting of dynein that allow movement

66

Where can simple squamous epithelium be found?

Alveoli
Capillaries

67

Where can simple cuboidal epithelium be found?

Kidney
Nephron
Thyroid gland follicles

68

Where can simple columnar epithelium be found?

Intestine

69

Where can pseudostratified ciliated columnar epithelium be found?

Respiratory tract

70

Where can transitional epithelium be found?

Urinary bladdar
Urerters
Most of the urethra

71

Neuroepithelial cells

I.e. olfactory and gustatory cells

72

Merocrine secretion from genes to product

1. Transcription
2. Translation
3. Rough endoplasmic reticulum (RER)
4. Golgi apparatus
5. Vesicles formed
6. Exocytosis

73

Mucous vs mucus

Mucous refers to a mucous cell
Mucus is the noun form