CoverModule 1.0. Homeostasis, Membranes, Electrophysiology and ANS (Essay Questions)1.1. Homeostasis1.1.1. Homeostasis Defined1.1.2. Homeostatic Control Systems1.1.3. Feedback Response Loop1.2. Cell Transport; Water & Solutes1.2.1. Fluid Compartments1.2.2. Osmosis1.2.3. Diffusion of Solutes1.2.4. Active Transport1.2.5. Bulk Transport1.3. Electrophysiology1.3.1. Ions and Cell Membranes1.3.2. Membrane Potentials1.3.3. Graded Potential1.3.4. Action Potentials1.3.5. Refractory Periods1.3.6. Propagation of an Action Potential1.4. THE SYNAPSE1.5. THE AUTONOMIC NERVOUS SYSTEM1.5.1. Organization of the Nervous System1.5.2. Structural Organization of the ANS1.5.3. The SNS and the PNS1.5.4. The Enteric Nervous System1.5.5. Physiology of the ANS1.5.6. Neurotransmitters of the ANS1.5.7. Receptors of the ANS1.5.8. Actions of the Autonomic Nervous System1.5.9. Table of Actions for the SNS and PNS and Some Common DrugsModule 2.0. Skeletal Muscle and Special Senses2.1. Structural Organization of Skeletal Muscle2.2.1. Neuromuscular Junction, Excitation-Contraction Coupling2.2.2. Muscle Contractures and Cramps2.3. Whole Muscle Contraction, Fiber Type, Fatigue and Muscle Pharmacology2.3.1. Motor Units2.3.2. Factors that Influence the Force of Contraction2.3.3. Energy Source for Muscle Contraction2.3.4. Skeletal Muscle Fiber Types2.3.5. Fatigue2.3.6. Muscle Pharmacology2.4. Smooth Muscle2.4.1. Smooth Muscle Contraction2.5. Control of Body Movement2.5.1. Voluntary Control of Muscle2.5.2. Reflexes2.6. Taste and Smell2.6.1. Taste2.6.2. The Sense of Smell2.7. Vision2.7.1. Structure of the Eye2.7.2. Focusing Light on the Retina2.7.3. Converting Light to Action Potentials2.7.4. The Retina2.7.5. Phototransduction2.7.6. Receptive Fields2.8. Hearing and Equilibrium2.8.1. The Nature of Sound2.8.2. The Hearing Apparatus2.8.3. Sound Vibrations to Action Potentials2.8.4. The Sense of Balance and EquilibriumModule 3.0. Cardiovascular System3.1. Structure of the Heart3.1.1. Chambers and Circulation3.2. Cardiac Cell Action Potentials3.2.1. Action Potentials in Cardiac Muscle Cells3.2.2. Action Potentials in Cardiac Autorhythmic cells3.2.3. Cellular Mechanisms of Inotropy and Chronotropy3.3. Electrophysiology of Heart Muscle3.3.1. Heart Conduction System3.3.2. Electrocardiogram (ECG)3.3.3. Abnormal ECG - Current of Injury3.4. The Cardiac Cycle3.4.1. Cardiac cycle3.4.2. Cardiac Measurements and Pressure Volume Loops3.5. Blood vessels and Blood Pressure3.5.1. Arteries and Veins3.5.2. Capillaries3.5.3. Blood Pressure Regulation and Shock3.5.4. Capillary Exchange3.5.5. Myogenic and Paracrine Regulation of Vasoconstriction and Vasodilation3.6. Blood3.6.1. Composition of Blood3.6.2. Hematopoeisis3.6.3. Breaking Down Red Blood Cells3.6.4. HemostasisModule 4.0. Urinary and Respiratory Systems4.1. Function and Structure of the Kidney4.1.1. Urinary System Function4.1.2. Functional Anatomy of the Urinary System4.1.3. The Nephron: Functional Unit of the Kidney4.1.4. The Renal Corpuscle: Bowman's Capsule4.2. Physiology of Urine Production4.2.1. Filtration4.2.2. Renal Clearance4.2.3. Tubular Reabsorption4.2.4. Urine Concentration and Dilution4.2.5. Hormonal Regulation of Urine Production4.3. Acid/Base Balance4.3.1. Buffers4.3.2. Acid/Base Disturbances4.4. The Respiratory System4.4.1. Respiratory System Structure and Function4.4.2. Respiratory Membrane4.4.3. Respiratory pressures and Inspriation/Expiration4.4.4. Alveoli and Surfactant4.4.5. Pneumothorax4.5. Gas Exchange and Transport4.5.1. Gas Laws4.5.2. Partial Pressure Gradients in the Lung4.5.3. Alveolar Gas Equation4.5.4. Oxygen and Carbon Dioxide Transport in the Blood4.5.5. Alveolar Ventilation4.5.6. Ventilation/Perfusion Ratio4.6. Chronic Bronchitis and Emphysema4.6.1. Respiratory Control by the Medulla Oblongata4.6.2. Chemicals that Regulate VentilationModule 5.0. Digestive, Endocrine and Reproductive Systems5.1. Functional Anatomy of the Digestive System5.1.1. Layers of the Digestive Tract5.1.2. Enteric Nervous System5.1.3. Organs of the Digestive System5.2. Digestion5.2.1. Carbohydrates5.2.2. Proteins5.2.3. Lipids5.2.4. Lipoproteins5.3. Regulation of Digestive Secretions5.4. Endocrine System5.4.1. Overview of the Endocrine System5.4.2. Hormone Receptors5.4.3. Hormones of the Body5.4.4. Other Hormones: Melatonin and Pheromones5.5. The Hypothalamus and Pituitary Gland5.5.1. Structure and Function of the Hypothalamus and Pituitary Gland5.5.2. The Posterior Pituitary5.5.3. The Anterior Pituitary5.5.4. Growth Hormone5.5.5. Prolactin5.5.6. Thyroid Hormones5.5.7. Adrenal Hormones5.6. Pancreas5.6.1. Insulin and Glucagon5.6.2. Diabetes Mellitus5.7. Reproductive System Anatomy5.7.1. Female Reproductive Anatomy5.7.2. Male Reproductive Anatomy5.7.3. Sexual Development at Puberty5.7.4. Male Reproductive Endocrine Axis5.7.5. Spermatogenesis5.7.6. Female Reproductive System: Oogenesis5.7.7. Ovulation and Fertilization5.7.8. The Ovarian Cycle5.7.9. The Uterine Cycle5.7.10. PregnancyAppendix A. GenderAppendix B. The Placebo EffectB.2.1. The Placebo EffectB.2.2. Examples of the Placebo EffectB.2.3. How do Placebos Work?B.2.4. Are Placebos Ethical?B.2.5. How do we validate actual effectiveness of placebosB.2.6. Tips for evaluating scientific evidenceB.2.7. What about Faith Healings
4.1.2

Functional Anatomy of the Urinary System

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Urinary system
https://commons.wikimedia.org/wiki/File:Urinary_system.svg; License: Creative Commons Attribution-Share Alike 3.0 Unported license.

Urinary System:  1. Human urinary system: 2. Kidney, 3. Renal pelvis, 4. Ureter, 5. Urinary bladder, 6. Urethra (Left side with frontal section) 7. Adrenal gland, 8. Renal artery and vein, 9. Inferior vena cava, 10. Abdominal aorta, 11. Common iliac artery and vein. With transparency: 12. Liver, 13. Large Intestine, 14. Pelvis

Imagine stepping aboard the magic school bus and entering the urinary system through the exit, or the urethral orifice. Perhaps going backward through the direction of urine flow of the kidneys will help us see the design of the system. Moving through the urethral orifice will lead to the urinary bladder. The urinary bladder is designed to expand and fill with urine to a maximum capacity of approximately 500ml. Despite rumors of more frequent female urination, there is probably no inherent difference between male and female bladders, except for in pregnancy as the baby sits right on top of the bladder. The habit of urination (micturition) has a direct bearing on the discomfort felt with bladder stretching. If the individual has the habit of urinating frequently, he (or she) may be "uncomfortable" retaining the average amount and therefore will need to urinate more frequently. Of course, there is also the possibility that the bladder of the individual has a smaller capacity. There is, however, a difference between men and women in the length of the urethra. The shorter length of the female urethra and the proximity of the urethral orifice to the anus makes women more susceptible to developing bacterial infections of the bladder (urinary tract infections or UTIs).

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Anatomy of the Bladder
File: 2605 The Bladder.jpg; Author: OpenStax College; Site: Wikimedia commons: http://commons.wikimedia.org/wiki/File:2605_The_Bladder.jpg; License: This file is licensed under the Creative Commons Attribution 3.0 Unported license.

There are three semi-sealed openings in the bladder; the urethral opening, and two ureteral openings (notice the subtle spelling between urethral and ureteral). At the bottom of the bladder is the opening to the urethra which is sealed by the internal urinary sphincter, a reflexively controlled muscle. On the posterior side, also near the bottom of the bladder are two ureteral openings, each is associated with a hollow tube called a ureter that leads to each kidney. The smooth muscle walls of the ureters propel the urine along to the bladder. The smooth muscle contracts in a series of wavelike contractions known as peristalsis to move the urine through the ureters in only one direction. Let's take the magic school bus through the ureteral opening on the right. Entering the ureter will lead us through a tube (ureter; 10 - 12 inches long) towards the right kidney. The ureter is about 3-4mm in diameter and is composed of transitional epithelium, smooth muscle and pain fibers. Fortunately, the magic school bus is only 2mm in diameter, imagine trying to squeeze a 6mm crystalized (meaning sharp pointing edges) kidney stone down the ureter….yeeouziee! (Click Here to see Kidney Stone Pictures)

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The Kidney
Title: 2610_The_Kidney.jpg; Author: OpenStax; Site: http://cnx.org/contents/14fb4ad7-39a1-4eee-ab6e-3ef2482e3e22@6.17:173/Anatomy_&_Physiology; License: licensed under a Creative Commons Attribution 4.0 License.

As we enter the kidney, the ureter will widen and form a structure called the renal pelvis which will branch into 5-6 different extensions called major calyces (Calyx is singular). The point that we entered the kidney into the renal pelvis is known as the hilum, represented by a concave structure of the kidney (think of a kidney bean). The hilum is also the entry point of the renal artery and nerves and the exit point for the renal vein, lymphatics and the ureter. If we continue to move, the major calyces branch into the minor calyces that end at a wall with thousands of small holes. Each of the small holes dumps urine into the minor calyx. Shrinking the bus down further we could enter one of the holes to try and trace the source of the urine. Entering one of these small holes we enter a collecting duct which will eventually take us to the functional unit of the kidney, the nephron.

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