1. Cells Come in all Shapes and Sizes
Cells come in all shapes and sizes. In this diagram we have examples of the different types of cells in your arm. Notice that the cells are shaped differently, packed differently and carry out different functions. How did this variety of cells arise since you started as a single cell? It’s in the genes. Different genes are turned on and off in different types of cells. All cells have certain genes that are active – like the ones that code for the enzymes in cellular respiration and the ones that build the enzyme responsible for making membrane phospholipids. But the different cell types seen here also have different combinations of proteins.

2. From 1 to MANY

3. Differentiation Go
Undifferentiated
Cell aka “Stem Cell”

4. How do Cells Differentiate aka Specialize?
Cells get signals from:
their own genes
chemical signals from neighbors
neighbor contact
chemicals in their microenvironment
Cells become specialize in a series of steps

5. Tissues, and Their Cell Types
The four types of tissues are found in all organ

6. Epithelium Stratified Squamous Sweat Gland – stratified cuboidal
These are the general shapes that epithelial cells take on . Our skin is an organ made up of layers of epithelium. The outermost layer is squamous and our inner most layer is columnar.
Sweat Gland – stratified cuboidal
Uterine Gland - Simple Columnar

7. Muscle (skeletal)
Bar = 30 Microns

8. Nervous Tissue Types
Nerve cells are divided into three regions: the cell body, the dendrite and the axon. The nerve cell receives signals through its dendrites and then sends the signal along the cell membrane to the axon where secretory granules release the neurotransmitters into the gap or between its axon and the neighboring cell’s dendrites.

9. Cell Potency Early Embryonic Cells Stem Cells Later Embryonic cells
All cells in an individual contain the same DNA. In the early embryo, all the cells are “totipotent” i.e. every cell can make all the cell types in the adult form. As the embryo continues to grow and develop, its cells lose their totipotency but still retain the ability to make a variety of related cell types. i.e. they can make any kind of muscle or any kind of epithelium or any kind of nerve cell. These cells are called pluripotent i.e. they can make a limited variety of different cell types.
Specialized Cells

10. Growing Tissues and Organs

11. Breast Cancer
Cells Dividing

12. Are Stem Cells and Cancer Related?