KIN 292 1st Edition Lecture 2Outline of Last Lecture I. What is Physiology, Chapter 1.1 Organization of the Human Body Outline of Current Lecture I. Organization of the Human Body – continued from MondayII. Homeostasis: A Central Organizing Principle of PhysiologyIII. The Diabetes EpidemicCurrent LectureA simplified Body Plan- Simplified to show relationships- Wrong shape (on purpose)- Missing parts- Different cell types not shown- Try to visualize relationships- External and internal environments- Separated by a continuous epithelial membrane(barrier)- Filtration and reabsorption are specific terms forthe kidneys External Environment - External side of the epithelial body barrier- Examples of external environment:o Surroundings external to the skino Air in the lungso Food in the stomacho Urine in the bladderBody Fluids and Compartments- Body is divided into compartments- Compartments contain fluids- Compartments are separated by epithelial membranesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Membranes are semipermeable- Transport occurs between compartments- Fluid from one compartment is different from other. The epithelial compartment keeps them divided and separate. Total Body Water - Consists of water and dissolved materials- Includes solutions within cells and solutions surroundingcells- Makes up about 60% of total body weight- TBW is divided into intracellular and extracellularcompartments.- ICF = intracellular fluid; Fluid inside cells (cytoplasm)- ECF = extracellular fluid; Fluid outside cells but within body-- Is the "internal environment“- Plasma surronds the blood cells- Intersitial fluid surrounds all other cells External and Internal Exchange external ≈ plasma ≈ tissue fluid ≈ cellIn:  Nutrients and oxygenOut:  Wastes and unneeded materialHomeostasis- The maintenance of relatively constantconditions in the internal environment. –even under challenging conditions- Many different components of the internalenvironment are regulated to remainconstant under challenging conditions:o Body Temperature- 37 Celsius or 98.6 Fahrenheit. Shivering when cold, sweating when hoto Blood Glucose concentration- 90 mg/dl, 5 million mol. Constant blood glucose concentrationo ATP concentration in muscles- 5 million mol at rest or exercise. ATP in muscles- Requires organ systems integration- Disruption of homeostasis is the basis for disease and death. On a lighter note – also fatigueTBWICFECFAmount of water in the body – 10 gallonsNegative and Positive Feedback - Negative feedback- if a regulated variableincreases, the system responds by making itdecrease; if it decreases, the systemresponds by making it increase.o Most homeostatic regulatorymechanisms make adjustments onlywhen they detect a differencebetween the actual value of theregulated variable and the desiredvariable (set point). - Positive Feedback example: o Negative feedback would be if your body produced lesscortisol and in response your body produced morehypothalamus to maintain homeostasiso Positive feedback would be if your body produced morecortisol and in response, your body signaled for moreCRH to be produced because having more cortisol in thesystem is not bad for maintaining homeostasisHomeostasis- Regulated variable - That aspect which is maintained. Examples:Blood glucose concentration, blood pH, plasma levels of sodium,room temp (thermostat), body temp.- Set point – Normal “desired” value of a regulated variable- Negative feedback - If a regulated variable decreases, the system responds to make it increase back to set point, and vice versa- Error signal - Difference set point and current value of the regulated variable- Negative Feedback Terms:o Sensors – Monitors the regulated variable. Most are nerves. Ex: thermoreceptors; chemoreceptorso Integrating centers (IC) - Orchestrates an appropriate response to input signal from sensor; decide on how to respondo Effectors – body components receiving output signals from the IC on how to maintain or regain homeostasisDiabetes Epidemic- Diabetes: Greek origin, meaning "to siphon"- Mellitus: Latin origin, meaning "honey sweet"- Diabetes mellitus is a metabolic disease – disrupted glucose homeostasiso Blood glucose levels are elevatedo Urine glucose are elevatedo Plasma volumes are affected- Signs and symptoms:o Excessive thirsto Massive fluid loss - excessive urination because high glucose in urine pulls waterout of the body with it (chap 4 for explanation)- Diabetes mellitus affects every organ systemBMI- Measures weight relative to height- Used to define obesity- Overweight: BMI 25–29- Obese: BMI 30–39- BMI of 30 is ~30 lb overweight- Morbid obesity: BMI > 40 (more than100 lb overweight)Types of Diabetes - Diabetes mellitus type 1o Lack of insulino Pancreas can’t secrete insulin so they have to take dosages of it o Accounts for 5–10% of all diabetes mellitus cases- Diabetes mellitus type 2o Impaired response to normal insulin levelso Body rejects insulin- Pre-diabeteso Blood glucose 100–125 mg/dLo High blood glucose o Affects 79 million Americanso Most likely to develop DM type 2 in 10 years- Gestational diabeteso Subclass of DM type 2o Affects 4% of pregnant womeno May develop DM type 2 post pregnancy- Diabetes insipiduso Insipid urine o Unrelated to DMo Affects antidiuretic hormone (vasopressin)–aquaporin 2 system- Diagnosing Diabeteso Fasting plasma glucose test 60–100 mg/dL: Normal (70-99 is range used by many others) 100–125 mg/dL: Pre-diabetes >125 mg/dL: Diabetes – leads to eye disease, kidney disease, nerve damage, and otherso Oral glucose tolerance test – plasma glucose 2 hrs after consuming 75 grams glucose. DM slows glucose removal ≤139 mg/dL: Normal 140–199 mg/dL: Pre-diabetes ≥200 mg/dL: Diabeteso Hemoglobin A1c level - % of Hb coated with sugar Marker of blood glucose for 2–3 mo - life span of red blood cell. Glucose only enters RBC when concentrations are