KIN 2500 Chapter : Anatomy Chapter 2
15 Mar 2019
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Cells are the basic, living, structural, and functional units of the body. Cells perform chemical reactions to create life processes. Compartmentalization: regulate in flow and out flow (direct cell activity) Plasma membrane- outer boundary, separates internal and external, selective barrier, cellular communication, lipid bilayer, flexible yet sturdy barrier, lipids act as barriers to certain substances, proteins act as gatekeepers to certain molecules and ions. Crosses over both layers (some are ion channels) Ion channels- more substances through channel receptors- help move across. Receptors- for cellular recognition, a ligand is a molecule that binds with a receptor. Contains enzymes to help start reactions within cell. Hyperplasia: out of control cell growth due to miscommunication. The cell is either permeable or impermeable to certain substances. Simple diffusion- net movement from higher to lower concentration. Osmosis- water across selectively permeable membrane- high to low. Facilitated diffusion- concentration gradient- rate depends on filtration process re: kidneys.
