BIO 12 Lecture Notes - Lecture 2: Reflex Arc, Cell Membrane, Extracellular Fluid
Document Summary
Reflex arc: stimulus (internal or external, receptor (tissue/organ) - afferent pathway, integrating control center - set point, effector (tissue/organ) - efferent pathway response. Response brings variable in opposite direction original change then stops: thermoregulation (ex) Accelerates a process: ex childbirth (oxytocin produced , uterus, starts contracting and gets everything out the uterus. snowball effect) Anticipates changes for efficient responses: ex- digestion (mouth watering to smell of food when hungry, starts digestion process. Cellular communication to maintain homeostasis via chemicals: hormones, glands, act thru bloodstream, paracrine, ecf, local cells, neurotransmitters, neurons, ecf (extracellular fluid released and acts on other cell, autocrine, local self-regulatory (releases on itself) ex prostaglandin. Plasma membrane: cells are surrounded by a limiting barrier, the plasma membrane (also. Called the cell membrane), which covers the cell surface. Regulate the passage of substances into and out of cells and between cell organelles and cytosol. Detect chemical messengers arriving at the cell surface.
