Chapter 3 - Cytology and Histology and Tissues

Question 1

What is cytology?

Answer 1

The study of cell structure and function

Question 2

What is histology?

Answer 2

The study of tissue structure and function

Question 3

What is the modern cell theory?

Answer 3

• All organisms composed of cells and cell products.
• Cell is the simplest structural and functional unit of life.
• Organism’s structure and functions are due to the activities of its cells (200 different types).
• Cells come only from preexisting cells.
• Cells of all species have many fundamental
similarities.

Question 4

What are the different types of cell junctions?

Answer 4

1. Gap Junctions
2. Tight junctions
3. Anchoring junctions

Question 5

How do tight junctions have a protective function?

Answer 5

Force bacteria to go through cells and not in between = prevent infection

Question 6

Where do tight junctions tend to be found (in regards to on the cell)?

Answer 6

On the apical side

Question 7

Where can tight junctions be found?

Answer 7

Blood-brain barrier, skin, etc.

Question 8

What proteins are used for tight junctions?

Answer 8

Claudins and occludins

Question 9

How are anchoring junctions spaced out?

Answer 9

They are like buttons, so bacteria could still squeeze through

Question 10

How do we get a blister?

Answer 10

Too much friction on the skin destroys the desmosomes, and now it gets filled with water

Question 11

What is the difference between an Adherens junction and Desmosomes?

Answer 11

Adherens junction links actin filaments between cells. Desmosomes link to intermediate filaments (and are strongest type of junction)

Question 12

What are hemidesmosomes?

Answer 12

They anchor the intermediate filaments of a cell to proteins in the matrix (strong!)

Question 13

What types of proteins are used in anchoring junctions?

Answer 13

Cadherins - make cell-cell anchoring junctions

Integrins - make cell-matrix junctions

Question 14

What are gap junctions for? What protein do they use?

Answer 14

Communication (electrical and chemical). They use connexins

Question 15

What is epithelial tissue?

Answer 15

Tissue that protects surface of the body, lines hollow organs, and produces and secretes substances

Question 16

What is the size of an average human cell?

Answer 16

10-15 um

Question 17

What are the primary tissue types?

Answer 17

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

Question 18

What is a hallmark of epithelial tissue?

Answer 18

Cells»ECM

Question 19

What is the ECM composed of?

Answer 19

Fibers and ground substance (proteoglycans, glycoproteins, sugars)

Question 20

What is the function of the different types of shapes of cells?

Answer 20

Squamous - diffusion
Cuboidal - secretion + absorption
Columnar - transport + secretion + absorption

Question 21

What is a tissue composed of?

Answer 21

Cells + ECM

Question 22

What is the majority of the ECM for epithelia?

Answer 22

the Basal lamina

Question 23

What is pseudo stratified tissue?

Answer 23

Each cell is attached to the basal lamina

Question 24

Does epithelial tissue have blood supply?

Answer 24

No. The underlying connective tissue’s job is to supply nutrients.

Question 25

What is simple squamous epithelium? Where would you find it?

Answer 25

Permits diffusion and secretes serous fluid | Found in alveoli, glomeruli, endothelium and serosa

Question 26

What is simple cuboidal epithelium? Where is it found?

Answer 26

Tend to have microvilli. Absorption and secretion. Mucous production. Liver, thyroid, mammary and salivary glands, bronchioles, and kidney tubules

Question 27

What is simple columnar epithelium? Where is it found?

Answer 27

Oval nuclei in basal half of cell. Absorption and secretion. Mucous secretion. Lining of GI tract, uterus, kidney and uterine tubes

Question 28

What is pseudo stratified epithelium and where is it found?

Answer 28

Single row of cells some not reaching cell surface. "Budding" cells will eventually replace bigger ones. Secretes and propels respiratory mucous