Physiology 1021 Study Guide - Comprehensive Final Exam Guide - Neuron, Homeostasis, Ganglion

• School: Western University
• Department: Physiology
• Course: Physiology 1021
• Professor: Dr. Ciriello

Document Summary

The cells in a multicellular organism play a critical role in the homeostasis of the organism as a whole. External environments= continuous with outside world: respiratory system, digestive system, urinary system, reproductive system. Pathological conditions arise when the body fails to maintain homeostasis. So, to help maintain homeostasis, the body uses negative feedback loops which monitor and respond to changes in the internal environment. The larger the concentration gradient, the faster the diffusion rate. Once molecules reach equilibrium (concentrations are equal), the diffusion and movement of molecules stop. The diffusion rate of a molecule is affected by its lipid solubility. The hydrophobic core of the cell membrane prevents water soluble molecules from passing through. The larger the membrane"s surface area, the less molecules can diffuse through. The thicker the membrane, the harder for the molecules to diffuse through. Osmosis= the net movement of water down its concentration gradient.