ANHB1101 Lecture Notes - Lecture 2: Epithelium, Spheroid, Skeletal Muscle
12 Jul 2018
School
Course
Professor
Document Summary
Structural and functional unit of living organisms. All human cells originate from a single fertilized egg. Development involved cell replication and specialization> cells that look different to each other express different genes. Squamous> epithelial cell, useful for material passing through> filtration in kidney (line the esophagus and surface layerer- epidermis- of skin) Polygonal> epithelial cell type, close compact, organs, lining ducts/skin> liver cells. Cuboidal> epithelial, usually in single layer, outer surface of ovary (e. g. liver cells) Columnar> epithelial, stomach lining, have villi to absorb nutrients> digestive tract. Fibrous> secrete fibrous material> collagen, need to burrow (skeletal muscle cells or axons of nerves) Stellate> neurons, protrusions to connect with each other to pass messages genes encode proteins which determine cell structure and function. Because a cells function is defined by the subset of genes it expresses (which genes are turned on) Each cells environment affects its gene expression. 1 micrometre = 1/1000 000 of a metre (10^-6 metre)
