BIOLOGY 151 Lecture Notes - Lecture 30: Stratified Squamous Epithelium, Connective Tissue, Loose Connective Tissue
Document Summary
Humans are the most studied organism on earth. Limit to the size of single celled organisms: surface area: volume ratio goes down as radius goes up a. i. Results in decreased efficiency: largest = centimeter b. i. Larger cells occur in colder climates where diffusion can keep up. Large organisms compensate by having organ systems that result in a huge increase in surface area: small intestine sa=baseball diamond a. i. Microvilli allow for that increase in sa a. ii. Both an excretory and absorptive organ: lung sa=tennis court, how? c. i. A tissue does not have to be made of only one kind of cell: cells of different types work together to make a tissue. Many, many, many different kinds of cells (exact # unknown) 4 main kinds of tissues: epithelial tissue a. i. Linked by tight-junctions side by side a. iv. 2. a. a. iv. 2. b. Act as glue, sealing one side off from the other. Proteins prevent waste in lumen of intestine from leaking into space between cells a. iv. 2. b. ii.
