unit 2

Question 1

Histology

Answer 1

the study of tissues, especially with a microscope

Question 2

Tissues definition

Answer 2

• Aggregation of similar cells, their products, and materials
  surrounding
• Have specific structure & function

Question 3

Tissue components

Answer 3

• cell
• Extracellular Matrix (ECM)

Question 4

ECM Components (varies by tissue type

Answer 4

• Extracellular fluid- mostly water
• Proteins
  -Glycoproteins attached to plasma membranes
  -Fibrous proteins- long, thin proteins like collagen
  -Proteoglycans- enormous carbohydrates with
  multiple protein-carbohydrate attachments

Question 5

ECM Functions

Answer 5

• Protection of cells
• Holds cells together
• Facilitates cellular communication

Question 6

Other names for ECM

Answer 6

• Interstitial fluid
• Tissue fluid

Question 7

types of tissues

Answer 7

Epithelial
Connective
Nervous
Muscular

Question 8

types of Epithelial tissues

Answer 8

Simple
- Simple Squamous
- Simple Cuboidal
- Simple Columnar
- Pseudostratified Columnar

Stratified
- Stratified Squamous
- Stratified Columnar
- Stratified Cuboidal
- Transitional

Question 9

types of Connective tissue

Answer 9

• Fibrous Connective
  Tissue
• cartilage
• bone
• blood

Question 10

types of Fibrous Connective
Tissue

Answer 10

Loose Fibrous
Connective Tissue (Areolar, Reticular, Adipose)

Dense Fibrous
Connective Tissue (Dense Regular, Dense Irregular, Elastic)

Question 11

types of Cartilage

Answer 11

Hyaline, Elastic, and Fibrocartilage

Question 12

types of bone

Answer 12

Spongey and Compact

Question 13

types of Muscular tissues

Answer 13

Skeletal, Smooth, and Cardiac

Question 14

how are cells in tissues joined?

Answer 14

Cells in tissues, especially epithelial tissues,
often are joined together by junctions

Question 15

Junction Functions

Answer 15

• Bind cells together
• Allow near-instant cell-cell communication

Question 16

Typical Junction Locations

Answer 16

• Lateral surface- side of cells
• Basal surface- bottom of cell

Question 17

Types of Cellular Junctions

Answer 17

• Tight Junctions
• Desmosomes
• Hemidesmosomes
• Gap Junctions

Question 18

Tight Junctions

Answer 18

• Tightly joins epithelial cells near apical surface
• Seals space between cells
  
  • Prevents fluids squeezing between cells
  • Prevents bacterial invasion
• Weak- can be broken easily

Question 19

Desmosomes

Answer 19

• Holds cells together
• Strong- Resists mechanical stress
• Loose, not continuous like tight junctions

Question 20

Hemidesmosomes

Answer 20

• Half-desmosomes
• Bind basal cells of epithelial tissue to underlying
  fibers (basement membrane)
• Prevents cells from peeling away

Question 21

Gap Junctions

Answer 21

• AKA Communicating Junction
• 6 proteins forming a large channel
• Solutes and water pass through cell-to-cell
• Allows near-instant communication
• Common in smooth muscle & cardiac muscle

Question 22

how do tissues grow

Answer 22

Tissues grow by increasing in cell number or size

Question 23

Hyperplasia

Answer 23

growth due to increase in cell number

Question 24

Hypertrophy

Answer 24

growth due to increase in cell size

Question 25

Stem cells

Answer 25

Differentiate to give rise to cell/ tissue types

Question 26

Embryonic stem cells

Answer 26

Embryonic stem cells- give rise to ALL cell types

Question 27

Totipotent

Answer 27

can become all adult cell types and placenta cells

Question 28

Pluripotent

Answer 28

can become all adult cell types

Question 29

Adult stem cells

Answer 29

give rise to 1 or a small number of cell types

Question 30

types of adult stem cells

Answer 30

* Multipotent- a few types * Unipotent- 1 type

Question 31

Atrophy

Answer 31

loss of cell size - Caused by disuse and/or aging

Question 32

Apoptosis

Answer 32

planned loss of cell number - Programmed cell death - Non-inflammatory

Question 33

Apoptosis

Answer 33

* Organ development- removing excess cells * Normal maintenance- cycling out older/damaged cells

Question 34

Necrosis

Answer 34

death of cells * Due to lack of blood supply or damage * Inflammatory * Not always reversable

Question 35

Regeneration

Answer 35

* Replacing dead cells with cells of same type * Restores organ function

Question 36

Fibrosis

Answer 36

* Replacing dead cells with scar tissue- Mostly fibrous proteins like collagen * Does not fully restore organ function * Faster, requires fewer resources

Question 37

Epithelial tissue (Epithelium)

Answer 37

* Closely adhering cells, one or more layers thick * Almost no extracellular matrix

Question 38

Epithelial tissue functions

Answer 38

* Line organs, form glands * Protection, Secretion, Absorption, Filtration and/or Sensation

Answer 39

* Cell polarity- cells are not perfectly symmetrical * Apical surface- upper * Basal surface- lower * Lateral surface- side