Exchange Surfaces 1 Key Words

Question 1

ciliated pseudostratified columnar epithelium

Answer 1

Ciliated epithelium (single layer of cells), cell nuclei positioning give appearance of stratified epithelia (epithelia in layers)

Question 2

Goblet cells

Answer 2

Modified epithelial cells, secrete mucus on mucous membrane organ surfaces (lower digestive tract & airways)

Question 3

Alveolus

Answer 3

Gas exchange surface in lungs. Diameter 0.2mm

Question 4

Villi

Answer 4

Small, finger-like projections extend into small intestinal lumen. Length 0.5-1.6mm

Question 5

Microvilli

Answer 5

Microscopic cellular membrane protrusions, increase SA (diffusion), minimise V increase

Question 6

Enterocytes

Answer 6

Simple columnar epithelial cells line inner surface of small & large intestines. Microvilli on apical surface increase SA

Question 7

Middle lamella

Answer 7

Layer cements primary cell walls of two adjacent plant cells together

Question 8

Fick’s law of diffusion

Answer 8

Diffusion rate proportional to SA & conc diff, inversely proportional to membrane thickness

Question 9

Surface area of a sphere

Answer 9

4pir^2

Question 10

Volume of a sphere

Answer 10

4/3pir^3