Physiology PDF - Study of Body Systems

Physiology is an integrative science focusing on “how” our body works. Anatomy is the study of structure and terminology of the body Aristotle was the first one to use the Physiology Term. Comparative physiology is the study of Animals. Levels of organization: Atom →Molecules → Cells →Tissue →Organ→...

Physiology is an integrative science focusing on “how” our body works. Anatomy is the study of structure and terminology of the body Aristotle was the first one to use the Physiology Term. Comparative physiology is the study of Animals. Levels of organization: Atom →Molecules → Cells →Tissue →Organ→Organ system→Organism→Population of one Species Ecology is the study of how organisms interact with one another and with their physical environment. The Human Body is organized across multiple layers : 1. Chemical level (C , H , O , N , Ca2+ , Na+ , K+ ) 2. Molecular level (carbohydrates, lipids, proteins, nucleic acid, water) 3. Cellular level (unit of life , 200 different types of cells , 40 trillion cells in our body!) 4. Tissue level (four types we will discuss: epithelial, connective, muscle, neural) 5. Organ level (heart, brain, stomach, liver, bones, etc.) 6. Organ System level Compartmentation is a way to look at things that are made up in compartments (sum of the parts). The key properties of life you learned in general biology (growth, reproduction, movement, and homeostasis) all require energy to occur. Energy is in the form of a molecule called ATP. Flow of Information coordinates body function: 1. DNA-The set of instructions for the protein your cell wants to make is in Gene X. 2. DNA to RNA-Gene X will be transcribed into RNA. 3. DNA to RNA to protein, RNA will be translated into a protein. Homeostasis means the body’s internal environment is stable (balancing act/edge of the cliff). Homeostasis is really two big ideas: 1) One’s body’s internal environment needs to be stable. 2) If one’s body’s internal environment is unstable, then the body does everything it can to be stable. If one’s body's internal environment is back to being stable, then that body is in a healthy state. If not, then the body is in a diseased state. What usually kept homeostasis in our body ? Blood pH, Body temperature, Nutrient Levels, water levels, sodium levels, calcium levels, hormone levels. Physiology is not static. There is always change, but we want the “change” to be stable. Homeostasis occurs in the body through a negative feedback loop. Negative feedback loop: Initial stimulus, response, stimulus, response loop shuts off. Negative Feedback Example: if your body temperature is too high, a negative feedback loop will act to bring it back down towards the set point, or target value, of 98.6 ∘ F ‍/ 37.0 ∘ C ‍. Positive feedback: is the disruption of homeostasis- the response reinforces the stimulus, sending the variable farther from set point. A good example of positive feedback involves the amplification of labor contractions. The contractions are initiated as the baby moves into position, stretching the cervix beyond its normal position. The feedback increases the strength and frequency of the contractions until the baby is born. (POSITIVE FEEDBACK is NOT HOMEOSTASIS ***Concepts from this physiology course comes from carefully designed scientific experiment Scientific method : The scientific method has five basic steps, plus one feedback step: 1.-Observation. (Something you have seen or notices and you are interested in) 2.-Question.(When you observe something , you wonder and ask a question. You really want to find and answer) 3.-Hypothesis(an explanation that you come up with to try to answer your question) 4.-Prediction. (This statement is something you expect to see if you believe your hypothesis is true) 5.-Experiment. (testing your predictions in a controlled environment) 6.-Results (see if your hypothesis was supported or contradicted) Concepts from this physiology course comes from carefully designed scientific experiment How to make a well-designed experiment? Independent variable : The type of thing that will be changed in the experiment. Dependent variable: the thing that will be measured at the end of the experiment. Hypothesis: the independent variable will change the dependent variable. Control Variables: three specific things that will be held constant always across all groups. Experimental group: One specific way the independent variable gets changed. Control group: Setup a condition where the independent variable is NOT changed. (For a drug trial, a control group would be patients getting a placebo (sugar pill) as opposed to an actual drug pill.