1. Bio 348 Human Anatomy & Physiology
Janice Lapsansky
BI 305
Phone: x7337

2. Levels of Organization
Chemical
Cellular
Tissue
Organs
Organ System
Organism

3. Overarching Themes (How do we know something is alive?)
Living things are …
composed of a single cell or a group of cells
AT LEAST physical and chemical machines
respond to short term changes in their environment
grow and reproduce
adapt to long term changes in their environment through natural selection
For a review of the chemistry of life, and cell structure and function, study the slide sets posted on the course web page.

4. The Boundary Organ Concept

5. Homeostasis of Body Fluids
Separation of fluid compartments
intracellular fluid (ICF) = within cells
extracellular fluid (ECF) = outside cells
intercellular fluid = tissue fluid = interstitial fluid
plasma = fluid portion of blood, part of ECF
Composition of fluids change as substances move between compartments
nutrients, oxygen, ions and wastes move in both directions across capillary walls
Practice these terms! Always confusing!

6. Differential Distribution of Solutes in the ICF and ECF
An estimated ___ % of cytoplasmic ATP is used to run the Na-K pump in most human cells.

7. How is this (homeostasis) controlled?

8. Components of Feedback Loop
Receptor
monitors a controlled condition
Control center
determines next action
Effector
receives directions from the control center
produces a response that changes the controlled condition

9. Eg. Homeostasis of Blood Pressure
Pressure receptors in walls of certain arteries detect an increase in BP
Blood Pressure = hydrostatic pressure; the force of blood on walls of vessels
Brain receives input and signals heart and blood vessels
Heart rate slows and arterioles dilate (increase in diameter)
BP returns to normal

10. Eg.Positive Feedback during Childbirth
Stretch receptors in walls of uterus send signals to the brain
Brain releases hormone (oxytocin) into bloodstream
Uterine smooth muscle contracts more forcefully
More stretch, more hormone, more contraction etc.
Cycle ends with birth of the baby & decrease in stretch