Urinary System Practice Questions PDF

Practice questions: urinary, fluid and electrolyte balance, acid-base, digestion and nutrition Urinary System 1. What is the function of the urinary system? Which structures are included? - The function of the urinary system is to regulate and maintain the balance of fluids, electrolytes, and pH in...

Practice questions: urinary, fluid and electrolyte balance, acid-base, digestion and nutrition Urinary System 1. What is the function of the urinary system? Which structures are included? - The function of the urinary system is to regulate and maintain the balance of fluids, electrolytes, and pH in the body. - It filters blood to remove waste products, toxins, and excess water from the bloodstream. - The urinary system helps control blood pressure by regulating fluid volume and releasing hormones involved in blood pressure regulation. - It plays a crucial role in maintaining acid-base balance by excreting hydrogen ions and reabsorbing bicarbonate ions. - The urinary system also produces urine, which contains waste products such as urea, uric acid, and creatinine that need to be eliminated from the body. Structures included in the urinary system: - Kidneys: Two bean-shaped organs responsible for filtering blood, producing urine, and maintaining fluid balance. - Ureters: Tubes that transport urine from the kidneys to the bladder. - Bladder: A muscular sac that stores urine until it is expelled from the body during urination. - Urethra: A tube that carries urine from the bladder to outside of the body. 2. Describe the general location, structure, and function of the kidneys - Location: The kidneys are located in the abdominal cavity, on either side of the spine. They are positioned towards the back, just below the ribcage. - Structure: Each kidney is bean-shaped and about the size of a fist. They have an outer layer called the cortex and an inner region called the medulla. The renal pelvis connects to the ureter, which carries urine from the kidneys to the bladder. - Function: The primary function of the kidneys is to filter waste products and excess fluid from the blood to form urine. They regulate water and electrolyte balance, maintain proper pH levels in the body, produce hormones like erythropoietin (stimulates red blood cell production) and renin (regulates blood pressure), and help in vitamin D activation for bone health. 3. Describe the general location, structure, and function of the ureters. - General location: The ureters are long, slender tubes that connect the kidneys to the urinary bladder. - Structure: Each ureter is approximately 25-30 cm in length and about 3-4 mm in diameter. They have a muscular wall composed of smooth muscle fibers that allow for peristaltic contractions to propel urine from the kidneys to the bladder. The inner lining is lined with epithelial cells that help prevent urine reflux. - Function: The primary function of the ureters is to transport urine from the kidneys to the urinary bladder. As urine is produced in the kidneys, it flows into the renal pelvis and then enters the ureters. Peristaltic waves generated by smooth muscles in the walls of the ureters help push urine towards the bladder through a process called peristalsis. This movement prevents backflow of urine and ensures proper elimination of waste products from the body. 4. Describe the general location, structure, and function of the urinary bladder. - Location: The urinary bladder is located in the pelvic cavity, posterior to the pubic symphysis and anterior to the rectum (in males) or uterus (in females). - Structure: The urinary bladder is a hollow, muscular organ that is roughly pear-shaped when empty. It is composed of three layers: the inner mucosa, middle muscular layer, and outer adventitia/serosa. - Function: The main function of the urinary bladder is to store urine produced by the kidneys until it can be voluntarily expelled from the body through urination. When the bladder fills with urine, its walls stretch to accommodate the increasing volume without a significant increase in pressure. Once filled to capacity, nerve signals trigger a reflex urge to urinate. 5. Describe the general location, structure, and function of the urethra. - The urethra is a tube-like structure that serves as a passageway for urine to exit the body. - It is located in both males and females, but its length and structure differ between the two sexes. - In males, the urethra runs through the penis and serves a dual function of eliminating urine from the bladder and transporting semen during ejaculation. It can be divided into three parts: prostatic urethra, membranous urethra, and spongy (penile) urethra. - In females, the urethra is shorter and opens just above the vaginal opening. Its primary function is to eliminate urine from the bladder. - The structure of the urethra consists of three layers: mucosa (innermost layer), muscularis (middle layer), and adventitia or serosa (outermost layer). These layers help with maintaining the integrity of the urethral wall and facilitating urine flow. - The function of the urethra is to transport urine from the bladder to outside the body. It does so by contracting its muscular walls, which propels urine out through an external opening called the urinary meatus. 6. Compare the course, length, and functions of the male urethra with those of the female - The male urethra is longer than the female urethra. It extends from the bladder to the tip of the penis, measuring about 8 inches in length. - The female urethra, on the other hand, is shorter and measures about 1.5 to 2 inches in length. It runs from the bladder to the external opening called the urinary meatus, located between the clitoris and vaginal opening. - The course of the male urethra includes three distinct parts: prostatic urethra, membranous urethra, and spongy (penile) urethra. These parts pass through various structures such as the prostate gland, pelvic floor muscles, and corpus spongiosum of the penis. - In females, there is no division or distinct parts in the urethra. It is a straight tube that runs parallel to and below the vagina. - The main function of both male and female urethras is to transport urine from the bladder out of the body during urination. However, in males, it also has a reproductive function as it serves as a passage for semen during ejaculation. 7. Describe the gross anatomy of the urinary system. - The urinary system consists of several organs, including the kidneys, ureters, bladder, and urethra. - The kidneys are bean-shaped organs located on either side of the spine in the upper abdominal cavity. They are responsible for filtering waste products from the blood to produce urine. - Each kidney is composed of an outer cortex and an inner medulla. Within these regions are millions of tiny functional units called nephrons, which filter blood and help regulate water and electrolyte balance. - The ureters are long, muscular tubes that connect each kidney to the bladder. They transport urine from the kidneys to the bladder through peristaltic contractions. - The bladder is a hollow organ located in the lower abdomen. It functions as a reservoir for urine storage before elimination. The walls of the bladder are made up of smooth muscle tissue that can expand to accommodate varying amounts of urine. - The urethra is a narrow tube that connects the bladder to the external opening called the urinary meatus. In males, it also serves as a passageway for semen during ejaculation. - The urinary system comprises two kidneys situated in retroperitoneal position on either side of vertebral column.- "Each kidney has an outer renal cortex and an inner renal medulla." (Tortora & Derrickson, 2017) - Ureters extend from each kidney's hilum downward behind parietal peritoneum. - Bladder is a hollow muscular organ situated posterior to pubic symphysis and anterior to rectum or vagina. - The male urethra commences at internal urethral orifice within floor of urinary bladder and ends at external urethral orifice on glans penis 8. Describe the gross anatomy of the kidney. What happens in the cortex, medulla, calyx, and pelvis? Cortex: - Outer region of the kidney - Contains glomeruli, renal tubules, and blood vessels - Responsible for filtration and reabsorption of substances from the blood Medulla: - Inner region of the kidney - Composed of renal pyramids - Contains collecting ducts that carry urine to the calyx - Involved in concentrating and transporting urine Calyx: - Cup-like structures that collect urine from the medulla - Divided into minor calyces which merge to form major calyces Pelvis: - Expanded upper part of the ureter within the kidney - Collects urine from major calyces and transports it to the bladder via the ureter 9. Trace the blood supply through the kidney. Be sure to include the arterioles and capillaries. Renal artery segmental arteries interlobar arteries arcuate arteries interlobular arteries afferent arterioles glomerulus efferent arterioles peritubular capillaries/vasa recta interlobular veins arcuate veins interlobar veins renal vein 10. What is the glomerulus? Distinguish between renal corpuscle and capsule. - The glomerulus is a tiny network of blood vessels found in the kidney. - It is part of the renal corpuscle, which also includes the Bowman's capsule. - The renal corpuscle filters blood and forms urine. - The glomerulus is responsible for filtering waste products from the blood. - The Bowman's capsule surrounds the glomerulus and collects filtered materials to form urine. - In summary, the glomerulus is a component of the renal corpuscle, while the capsule is its surrounding structure. 11. Describe the anatomy of a nephron. Be sure to name each part and its function. What are the 2 types? The nephron is the functional unit of the kidney responsible for filtering blood and producing urine. - It consists of several distinct parts, including the renal corpuscle, proximal convoluted tubule (PCT), loop of Henle, distal convoluted tubule (DCT), and collecting duct. - The renal corpuscle includes the glomerulus and Bowman's capsule. The glomerulus filters blood under high pressure, allowing small molecules like water, ions, and waste products to pass through while retaining larger molecules like proteins. - Bowman's capsule surrounds the glomerulus and collects the filtrate produced by the glomerulus. - The PCT reabsorbs most of the filtered water, glucose, amino acids, and necessary ions back into the bloodstream. - The loop of Henle consists of a descending limb and an ascending limb. It creates a concentration gradient in the medulla that helps concentrate urine. - The DCT further regulates ion concentrations by selectively reabsorbing or secreting specific ions based on hormonal signals. - The collecting duct receives urine from multiple nephrons and carries it towards the renal pelvis for elimination from the body. The two types of nephrons are: 1. Cortical nephrons: These make up about 85% of all nephrons and have their loops of Henle located mainly in the outer cortex region of the kidney. They play a crucial role in maintaining electrolyte balance and water absorption. 2. Juxtamedullary nephrons: These account for approximately 15% of all nephrons and have longer loops of Henle that extend deep into the medulla. They are involved in creating concentrated urine through countercurrent multiplication mechanisms. Overall, these components work together to filter blood, regulate fluid balance, maintain electrolyte concentrations, and produce urine as a waste product. 12. Describe the forces (pressures) that promote or counteract glomerular filtration. - Hydrostatic pressure in the glomerular capillaries: This is the primary force that promotes filtration. It is created by the pressure exerted by blood flow in the glomerular capillaries. - Glomerular filtration rate (GFR): GFR refers to the amount of filtrate formed per minute. An increase in GFR promotes glomerular filtration. Forces that counteract glomerular filtration: - Oncotic pressure in the glomerular capillaries: This is the osmotic pressure exerted by proteins in the blood plasma. It opposes filtration by drawing water back into the capillary. - Capsular hydrostatic pressure: Pressure exerted by fluid already present in Bowman's capsule, which opposes filtration by pushing fluid back into the capillary. - Renal autoregulation: The kidneys have mechanisms to maintain a relatively constant GFR despite changes in systemic blood pressure. Autoregulation can counteract excessive increases or decreases in glomerular filtration. - Renin-angiotensin-aldosterone system (RAAS): Activation of this hormonal system can result in vasoconstriction of afferent arterioles, reducing blood flow and subsequently decreasing glomerular filtration rate. 13. Compare plasma to filtrate to urine. - Plasma is the liquid component of blood and contains various substances like water, electrolytes, proteins, hormones, and waste products. - Filtrate is formed when plasma passes through the glomerulus in the kidneys. It consists of water, electrolytes, glucose, amino acids, and small molecules. - Urine is the final product that is excreted from the body. It is formed when filtrate undergoes reabsorption and secretion processes in the renal tubules. Urine mainly contains water, urea, electrolytes, creatinine, and other waste products. 14. What are the 3 steps needed to make urine? Describe them and where they occur. 1. Filtration: Occurs in the glomerulus of the kidney, where blood is filtered to remove waste products and excess water. 2. Reabsorption: Takes place primarily in the renal tubules, where essential substances such as glucose, amino acids, and water are reabsorbed back into the bloodstream. 3. Secretion: Occurs in the distal convoluted tubule and collecting ducts of the nephron, where additional waste products such as urea and certain drugs are actively transported into the urine. 15. What is GFR? - GFR stands for glomerular filtration rate - It is a measure of how well the kidneys are functioning - GFR is used to estimate kidney function and determine the stage of chronic kidney disease (CKD) - GFR is calculated based on blood creatinine levels, age, gender, and other factors - A normal GFR is typically around 90 mL/min/1.73m² or higher - Decreased GFR indicates reduced kidney function and can be a sign of kidney damage or disease 16. Compare the intrinsic and extrinsic controls of the glomerular filtration rate. How do they help with BP control? - Intrinsic controls of glomerular filtration rate (GFR) involve mechanisms within the kidneys that regulate GFR based on local factors. - Extrinsic controls of GFR involve neural and hormonal mechanisms that regulate GFR based on systemic factors. - Intrinsic controls include the myogenic mechanism, tubuloglomerular feedback, and the mesangial cell contraction. - The myogenic mechanism involves the constriction or dilation of afferent arterioles in response to changes in blood pressure to maintain a constant GFR. - Tubuloglomerular feedback is mediated by macula densa cells in the distal convoluted tubules, which detect changes in sodium chloride levels and send signals to constrict or dilate afferent arterioles accordingly. - Mesangial cell contraction helps regulate GFR by altering the surface area available for filtration through changes in capillary diameter. - Extrinsic controls involve sympathetic nervous system activation and the release of hormones like angiotensin II and atrial natriuretic peptide. - Sympathetic nervous system activation causes vasoconstriction of afferent arterioles, reducing GFR to help maintain blood pressure during times of low blood volume or hypotension. - Angiotensin II constricts both afferent and efferent arterioles, reducing GFR as part of the renin-angiotensin-aldosterone system's role in regulating blood pressure. - Atrial natriuretic peptide promotes vasodilation of afferent arterioles and inhibits sodium reabsorption, increasing GFR to help reduce blood volume and lower blood pressure. 17. How do GFR and blood pressure correlate? - GFR (glomerular filtration rate) and blood pressure are closely related and can influence each other. - Changes in blood pressure can affect GFR, while changes in GFR can also impact blood pressure. - Increased blood pressure can lead to increased glomerular capillary pressure, which may result in an increase in GFR. - Conversely, decreased blood pressure can cause a decrease in glomerular capillary pressure, leading to a decrease in GFR. - Maintaining normal blood pressure is crucial for optimal kidney function and proper regulation of GFR. - The renin-angiotensin-aldosterone system plays a significant role in regulating both blood pressure and GFR. - Disturbances in this system, such as excessive activation or inhibition, can disrupt the balance between GFR and blood pressure. - Chronic conditions like hypertension can have long-term effects on both GFR and blood pressure regulation. 18. What is the JGA? How does it work? What is the role of the macula densa and granular cells? The JGA (juxtaglomerular apparatus) is a specialized structure located in the kidney, specifically at the junction of the distal convoluted tubule and afferent arteriole. - It functions to regulate blood pressure and filtration rate in the kidney. - The macula densa is a group of cells in the distal convoluted tubule that monitor sodium chloride levels in the filtrate. - Granular cells are also known as juxtaglomerular cells and they are located in the walls of the afferent arteriole. - The main role of granular cells is to secrete renin, an enzyme that plays a key role in regulating blood pressure. - Together, the macula densa and granular cells work to maintain homeostasis by sensing changes in sodium chloride levels and releasing renin accordingly. 19. Describe which substances are reabsorbed or secreted and in which part of the nephron. - Glucose, amino acids, and ions such as sodium, chloride, and potassium are reabsorbed in the proximal convoluted tubule. - Water is primarily reabsorbed in the descending limb of the loop of Henle and the collecting ducts. - Urea is both reabsorbed and secreted throughout different parts of the nephron. It is reabsorbed in the proximal convoluted tubule and secreted into the thin descending limb of the loop of Henle. - Hydrogen ions (H+) are actively secreted in the distal convoluted tubule and collecting ducts to regulate blood pH. - Creatinine, a waste product from muscle metabolism, is not significantly reabsorbed or secreted and therefore can be used to estimate kidney function. 20. Describe how sodium and water reabsorption are regulated in the distal tubule and collecting duct. - The reabsorption of sodium in the distal tubule and collecting duct is regulated by hormones such as aldosterone. - Aldosterone increases the reabsorption of sodium by upregulating the expression of sodium channels (ENaC) on the luminal membrane of epithelial cells in these segments. - Water reabsorption in the distal tubule and collecting duct is regulated by antidiuretic hormone (ADH), also known as vasopressin. - ADH promotes water reabsorption by increasing the insertion of aquaporin-2 channels into the luminal membrane, allowing water to move out of the tubular fluid and into the interstitium. - The regulation of sodium and water reabsorption in these segments helps maintain overall fluid balance and blood pressure regulation. 21. Describe the importance of tubular secretion and list several substances that are secreted. - Tubular secretion is an essential process in the kidneys that helps maintain electrolyte balance, regulate pH levels, and remove waste products from the blood. - It plays a crucial role in eliminating substances that were not filtered by the glomerulus, ensuring their removal from the body. - Some substances that are secreted through tubular secretion include: - Hydrogen ions (H+): Regulation of acid-base balance. - Potassium ions (K+): Maintenance of normal potassium levels. - Creatinine: A waste product of muscle metabolism. - Uric acid: Waste product resulting from nucleic acid breakdown. - Penicillin and other drugs: Excretion of foreign substances from the body. Tubular secretion also contributes to the reabsorption and conservation of certain molecules, such as organic acids and bases, which are necessary for various physiological processes. 22. What is the counter current mechanism and why is it important? - The counter current mechanism is a physiological process in which fluid flows in opposite directions across adjacent segments of a tubular structure. - It plays a crucial role in the kidneys, specifically in the loop of Henle, which helps to concentrate urine and maintain water balance in the body. - In this mechanism, the descending limb of the loop of Henle allows for passive reabsorption of water, while the ascending limb actively transports ions out of the tubule. - This creates an osmotic gradient that enables efficient reabsorption of water from the filtrate back into circulation and concentration of urine. - The counter current mechanism is important because it allows the kidneys to conserve water when necessary and excrete concentrated urine, helping to regulate body fluid volume and osmolarity. 23. Describe the mechanisms responsible for the medullary osmotic gradient. The medullary osmotic gradient is created by the counter-current multiplication mechanism in the kidney. - It involves the interaction between the descending and ascending limbs of the loop of Henle. - The descending limb allows water to passively leave, resulting in an increase in solute concentration as it descends deeper into the medulla. - The ascending limb actively transports sodium and other solutes out of the tubule, creating a dilute filtrate. This process further increases the osmolarity of the surrounding interstitial fluid. - The vasa recta, specialized capillaries running alongside the loop of Henle, also contribute to maintaining the osmotic gradient by removing excess water and solutes from the medulla while preserving its high osmolarity. - Hormones such as antidiuretic hormone (ADH) can regulate the permeability of collecting ducts to water, allowing for reabsorption and preservation of water within urine. 24. Explain formation of dilute versus concentrated urine. - Dilute urine is formed when the body needs to excrete excess water and maintain fluid balance. - The formation of dilute urine involves decreased reabsorption of water from the renal tubules back into the bloodstream. - This can happen due to a high intake of fluids, low levels of antidiuretic hormone (ADH), or certain medications like diuretics. - In dilute urine, the concentration of solutes is lower compared to the concentration in the blood plasma. - Concentrated urine is formed when the body needs to conserve water and prevent dehydration. - The formation of concentrated urine involves increased reabsorption of water from the renal tubules back into the bloodstream. - This occurs due to higher levels of ADH, which increases the permeability of the collecting ducts to water. - In concentrated urine, the concentration of solutes is higher compared to the concentration in the blood plasma. 25. Review the importance of renin, angiotensin II, ADH, aldosterone, PTH, ANP. - Renin is an enzyme produced by the kidneys that plays a crucial role in regulating blood pressure and fluid balance. - Angiotensin II is a hormone that is formed from angiotensin I by the action of renin. It constricts blood vessels, increases blood pressure, and stimulates the release of aldosterone. - ADH (antidiuretic hormone), also known as vasopressin, regulates water reabsorption in the kidneys, helping to maintain proper hydration levels. - Aldosterone is a hormone secreted by the adrenal glands that promotes sodium reabsorption and potassium excretion in the kidneys, thereby regulating electrolyte balance and blood pressure. - PTH (parathyroid hormone) is released by the parathyroid glands and helps regulate calcium and phosphate levels in the blood by promoting bone resorption and increasing renal tubular reabsorption of calcium. - ANP (atrial natriuretic peptide) is released by cells in the heart when there is increased volume or pressure in the atria. It acts as a natural diuretic to promote sodium excretion and decrease blood volume and pressure 26. What is a diuretic? A diuretic is a medication or substance that promotes diuresis, which is the increased production of urine. Diuretics work by increasing the excretion of water and electrolytes from the body through the kidneys. These drugs are commonly used to treat conditions such as high blood pressure, edema (fluid retention), and certain kidney disorders. 27. Define renal clearance and explain how this value summarizes the way a substance is handled by the kidney. How does this relate to GFR and overall kidney function? - Renal clearance is the measurement of how effectively the kidneys can remove a substance from the blood and excrete it in urine. - It is calculated by dividing the rate at which a substance is excreted in urine by its concentration in plasma. - This value represents the efficiency of renal filtration, reabsorption, and secretion processes involved in handling that particular substance. - The renal clearance value indicates whether a substance is filtered through glomerulus, completely reabsorbed, partially reabsorbed or actively secreted into the tubules. - A high renal clearance value suggests efficient filtration and excretion of the substance by the kidneys, while a low value implies poor elimination. - Renal clearance is closely related to glomerular filtration rate (GFR), as both measures reflect kidney function. - GFR is the volume of fluid filtered from the glomeruli into Bowman's capsule per unit time. - GFR indirectly influences renal clearance because substances with higher GFR are more likely to be filtered and have greater chances of being cleared from the body efficiently. - Overall kidney function can be assessed using renal clearance measurements as they provide an indication of how well different substances are processed by the kidneys. 28. Describe the normal physical and chemical properties of urine. Yellow color: Urine is typically pale to dark yellow in color, which is due to the presence of urobilin, a pigment formed from the breakdown of bilirubin. - Clear appearance: Normal urine is usually clear or slightly cloudy. Cloudiness can indicate the presence of mucus, crystals, or bacteria. - Mild odor: Urine has a characteristic smell that is often described as slightly ammonia-like. - pH level: The normal pH range of urine is slightly acidic, ranging from 4.5 to 8.0, with an average around 6.0. - Chemical composition: Urine contains various substances including urea, creatinine, uric acid, electrolytes (sodium, potassium), organic acids, hormones, enzymes, and trace amounts of drugs/metabolites depending on individual factors such as diet and health. 29. List several abnormal urine components, and name the condition characterized by the presence of detectable amounts of each. - Hematuria: presence of blood in urine - Condition: Hematuria can be a sign of various conditions such as urinary tract infections, kidney stones, bladder or kidney cancer, and trauma to the urinary tract. - Proteinuria: presence of excess protein in urine - Condition: Proteinuria can be indicative of kidney damage or dysfunction, such as glomerulonephritis, nephrotic syndrome, and diabetic nephropathy. - Glycosuria: presence of glucose in urine - Condition: Glycosuria is commonly seen in uncontrolled diabetes mellitus. It can also occur during pregnancy or due to certain medications. - Pyuria: presence of white blood cells (pus) in urine - Condition: Pyuria is often associated with urinary tract infections, but it can also indicate inflammation or infection in the kidneys or bladder. - Bilirubinuria: presence of bilirubin in urine - Condition: Bilirubinuria indicates liver dysfunction or obstruction of the bile ducts. It is commonly seen in conditions like hepatitis, cirrhosis, and gallstones. - Ketones: presence of ketone bodies in urine - Condition: Ketones are usually present in the urine when the body breaks down fat for energy instead of glucose. This can occur during fasting/starvation, uncontrolled diabetes mellitus (diabetic ketoacidosis), or low carbohydrate diets. 30. Define micturition and describe its neural control. - Micturition is the process of emptying urine from the bladder through the urethra. - It is controlled by a complex neural circuitry known as the micturition reflex. - The micturition reflex involves both voluntary and involuntary components. - The primary control center for micturition is located in the brainstem, specifically in the pontine micturition center (PMC). - Sensory information from stretch receptors in the bladder wall is transmitted to the PMC via afferent nerves. - The PMC integrates this sensory information with input from higher brain centers to initiate or inhibit urination. - Parasympathetic neurons are responsible for stimulating contraction of the detrusor muscle in the bladder, which leads to increased pressure and expulsion of urine. - Somatic motor neurons control the relaxation of the external urethral sphincter, allowing urine to flow out of the body. - Inhibition of micturition occurs through activation of sympathetic pathways, which maintain continence by contracting the smooth muscles of the bladder neck and relaxing the detrusor muscle. 31. Homeostatic imbalances: diabetes (both), kidney stone, bed wetting, incontinence, urinary retention - Diabetes (both types): - Insufficient insulin production or insulin resistance leads to elevated blood sugar levels. - Symptoms include frequent urination, increased thirst, unexplained weight loss, and fatigue. - Long-term complications can include kidney damage, nerve damage, and cardiovascular issues. - Kidney stones: - Formed from the buildup of minerals and salts in the kidneys. - Can cause severe pain in the back or side, blood in urine, and difficulty urinating. - Risk factors include dehydration, certain medical conditions, and a diet high in oxalates. Bed wetting (enuresis): - Involuntary release of urine during sleep, typically seen in children. - Often resolves on its own as a child grows older. - May be caused by genetics, bladder immaturity, or psychological factors. Incontinence: - Loss of bladder control resulting in involuntary leakage of urine. - Can occur due to weakened pelvic floor muscles, nerve damage, or urinary tract infections. - Treatment options include lifestyle changes, pelvic floor exercises, medications, or surgery. Urinary retention: - Inability to empty the bladder completely or at all. - Causes can range from obstruction due to an enlarged prostate or kidney stones to nerve damage. - Symptoms may include a weak urine stream, frequent urination attempts, and discomfort or pain. Water, Electrolyte and Acid/Base Balance: 1. What is the normal pH of blood? 7.35-745 2. Define acidosis and alkalosis. - Acidosis is a condition characterized by an excess of acid in the body, leading to a decrease in blood pH below the normal range of 7.35-7.45. - Alkalosis is a condition characterized by an excess of alkaline substances or a depletion of acid in the body, resulting in an increase in blood pH above the normal range. - Acidosis can be caused by factors such as excessive production of acids, impaired elimination of acids, or loss of bicarbonate ions. - Alkalosis can be caused by factors such as excessive loss of acids, increased intake of alkaline substances, or conditions that stimulate excessive release of bicarbonate ions. - Acidosis and alkalosis can have various symptoms depending on their severity and underlying cause. - Both acidosis and alkalosis can disrupt normal bodily functions and require prompt medical attention for proper diagnosis and treatment. 3. Describe the controls of your body’s acid/base balance. - The kidneys play a significant role in maintaining the body's acid/base balance by regulating the levels of bicarbonate (HCO3-) and hydrogen ions (H+). They can reabsorb or excrete these ions as needed. - The respiratory system also helps to regulate acid/base balance through the control of carbon dioxide (CO2) levels. Increased CO2 leads to higher acidity, so the lungs can adjust breathing rate and depth to expel excess CO2 and decrease acidity. - Buffers in the blood, such as bicarbonate, proteins, and phosphate, help to prevent drastic changes in pH by accepting or donating hydrogen ions to maintain balance. - The body has various feedback mechanisms that monitor pH levels, including chemoreceptors in the brain that detect changes in CO2 concentration and sensors in the kidney that measure HCO3levels. These signals trigger appropriate responses to restore balance. - Hormones like aldosterone and angiotensin II can also influence acid/base balance by regulating kidney function and controlling sodium and potassium levels, which indirectly impact pH regulation. 4. Describe the difference between respiratory and metabolic pH issues. - Respiratory pH issues are caused by problems with the lungs and the ability to properly eliminate carbon dioxide from the body, leading to an imbalance in pH levels. - Metabolic pH issues are caused by problems with the kidneys and their ability to regulate acid-base balance through the excretion of hydrogen ions or bicarbonate. - Respiratory acidosis occurs when there is an increase in carbon dioxide levels due to inadequate ventilation, leading to a decrease in pH. - Respiratory alkalosis occurs when there is a decrease in carbon dioxide levels due to hyperventilation, leading to an increase in pH. - Metabolic acidosis occurs when there is an excess production or accumulation of acids, such as lactic acid or ketones, resulting in a decrease in pH. It can also occur due to loss of bicarbonate ions. - Metabolic alkalosis occurs when there is excessive loss of acids or increased retention of bicarbonate ions, leading to an increase in pH. 5. What do compensated and uncompensated mean? Compensated: When the body successfully adjusts its pH levels through respiratory or renal mechanisms to counteract an acid-base imbalance, it is considered compensated. This helps to maintain a relatively normal blood pH. Uncompensated: If the body fails to fully compensate for an acid-base disturbance, resulting in an abnormal blood pH that remains outside of the normal range, it is called uncompensated. 6. Practice how to work acid/base problems and how CO2 and HCO3 work oppositely to balance pH. See Acid- Base Practice Sheet 7. Describe the different fluid compartments and electrolyte compositions of each. - Intracellular fluid (ICF): Fluid inside the cells; contains high concentrations of potassium, magnesium, phosphate, and proteins. - Extracellular fluid (ECF): Fluid outside the cells; includes interstitial fluid and plasma. - Interstitial fluid: Found between cells in tissues; has similar composition to plasma but with lower protein concentration. - Plasma: Liquid component of blood; contains high concentrations of sodium, chloride, bicarbonate, and proteins. 8. Describe the regulation of Na, K, Cl, Ca, Mg and water. - Regulation of Na: Sodium (Na) is regulated primarily through the renin-angiotensin-aldosterone system (RAAS). When blood pressure drops, renin is released, which leads to the production of angiotensin II. Angiotensin II stimulates aldosterone release from the adrenal glands, promoting reabsorption of Na in the kidneys. - Regulation of K: Potassium (K) levels are regulated mainly by aldosterone as well. Aldosterone promotes K excretion in exchange for Na reabsorption in the distal tubules of the kidneys. Insulin also plays a role in stimulating cellular uptake of K. - Regulation of Cl: Chloride (Cl) levels are regulated indirectly through its association with sodium. As Na is reabsorbed in the kidneys, Cl follows passively due to electrical charge balance. The RAAS system and aldosterone also influence chloride reabsorption. - Regulation of Ca: Calcium (Ca) homeostasis is maintained by parathyroid hormone (PTH), calcitonin, and vitamin D. PTH increases calcium reabsorption in the kidneys and stimulates bone resorption to release calcium into the bloodstream. Calcitonin inhibits bone resorption and enhances renal calcium excretion. - Regulation of Mg: Magnesium (Mg) levels are controlled by intestinal absorption, renal excretion, and bone storage. The hormone parathyroid hormone plays a role in regulating magnesium metabolism by influencing renal excretion. - Regulation of water: Water balance is regulated by antidiuretic hormone (ADH), also known as vasopressin. ADH acts on the kidneys to increase water reabsorption, preventing excessive water loss in urine when there is dehydration or high osmolality. 9. Describe how fluid moves between compartments. - Fluid moves between compartments through a process called fluid balance. - Fluid can move through the body's compartments, such as intracellular and extracellular spaces, through osmosis and filtration. - Osmosis is the movement of water from an area of lower solute concentration to an area of higher solute concentration. This helps maintain proper electrolyte balance in cells. - Filtration occurs when hydrostatic pressure forces fluid out of blood vessels into the surrounding tissues. This helps deliver nutrients and remove waste products from cells. - The movement of fluid between compartments is regulated by various mechanisms, including hormones (such as antidiuretic hormone), and the function of organs like the kidneys, which play a crucial role in maintaining fluid balance. 10. How are input and output of fluids and electrolytes regulated? - Fluid and electrolyte balance is regulated through various mechanisms in the body. - The kidneys play a crucial role in regulating fluid and electrolyte levels by filtering waste products, reabsorbing necessary substances, and excreting excess fluids and electrolytes through urine. - Hormones such as antidiuretic hormone (ADH), aldosterone, and atrial natriuretic peptide (ANP) help regulate fluid balance by altering the reabsorption or excretion of water and electrolytes in the kidneys. - Thirst mechanism prompts individuals to drink fluids when their body needs hydration, helping to regulate fluid input. - Sweat production, respiration, and gastrointestinal processes also contribute to fluid and electrolyte regulation. - Fluid intake is controlled primarily by thirst. When blood volume decreases or osmolality increases, sensory receptors stimulate the hypothalamus to produce thirst. - The kidney regulates extracellular fluid volume by adjusting urinary output to match fluid intake Digestive System 1. What organs comprise the GI tract? Explain the function of each. 1. Mouth: Begins the process of digestion by breaking down food through chewing and mixing it with saliva. 2. Esophagus: Transports food from the mouth to the stomach via peristalsis, a wave-like muscle contraction. 3. Stomach: Secretes enzymes and acids to further break down food into a semi-liquid mixture called chyme. 4. Small intestine: Absorbs nutrients from chyme into the bloodstream, facilitated by specialized cells and villi. 5. Large intestine (colon): Absorbs water and electrolytes from undigested food, forming solid waste (feces). 6. Rectum: Stores feces before elimination. 7. Anus: Allows for the expulsion of feces during defecation. 2. Which organs are accessory digestive organs? Explain the function of each. - Liver: Produces bile, which helps in the digestion and absorption of fats. - Gallbladder: Stores and concentrates bile produced by the liver. It releases bile into the small intestine to aid in fat digestion. - Pancreas: Produces digestive enzymes (lipase, amylase, and proteases) that break down fats, carbohydrates, and proteins. It also produces insulin and glucagon for regulating blood sugar levels. 3. The steps in processing food thru the GI tract. Where does each step occur? - Ingestion: The process of taking food into the mouth and beginning to chew it. This step occurs in the mouth. - Mechanical Digestion: Chewing breaks down food into smaller pieces, increasing its surface area for further digestion. It also mixes food with saliva, which contains enzymes that initiate the breakdown of carbohydrates. Mechanical digestion primarily takes place in the mouth. - Chemical Digestion: Enzymes from saliva continue to break down carbohydrates in the mouth. Stomach acid and digestive enzymes from the pancreas and small intestine further break down proteins, fats, and carbohydrates. Chemical digestion primarily occurs in the stomach and small intestine. - Absorption: Nutrients from digested food are absorbed through the walls of the small intestine into the bloodstream. Some water and electrolytes are absorbed in the large intestine as well. - Elimination: Undigested waste material, along with some water and electrolytes, is eliminated from the body as feces. This occurs in the rectum and anus. 4. What is mastication? Mastication, also known as chewing, is the process of breaking down food into smaller pieces using the teeth and jaw muscles. This mechanical action prepares the food for swallowing and digestion in the stomach. 5. Name the structures involved in mastication. - Temporomandibular joint (TMJ) - Mandible (lower jawbone) - Maxilla (upper jawbone) - Teeth - Masseter muscle - Temporalis muscle - Medial pterygoid muscle - Lateral pterygoid muscle 6. What digestive processes begin in the mouth? - Mechanical digestion: Chewing breaks down food into smaller pieces. - Chemical digestion: Salivary amylase begins to break down carbohydrates. - Mixing with saliva: Food is moistened and formed into a bolus for easier swallowing. 7. Identify the salivary glands and their secretions. - Parotid glands: located near the ears, they secrete serous saliva that contains enzymes like amylase to help break down carbohydrates. - Submandibular glands: situated beneath the lower jaw, they produce a mixture of both serous and mucous saliva. - Sublingual glands: found under the tongue, they secrete mainly mucous saliva that aids in lubricating food for swallowing. 8. Identify teeth structure, types and how many of each type. Teeth are hard, mineralized structures found in the mouth. The primary function of teeth is to aid in the mechanical breakdown of food during digestion. - There are four main types of teeth: incisors, canines, premolars, and molars. - Incisors: These are the eight teeth located at the front of the mouth (four on top and four on bottom). They have a sharp edge for biting and cutting food. - Canines: There are four canines, two on each side of the incisors. Canines have a pointed tip and are used for tearing and grasping food. - Premolars: Also known as bicuspids, there are eight premolars in total (four on top and four on bottom). They have a flat chewing surface and assist in grinding food. - Molars: The largest teeth in the mouth, there are usually twelve molars (six on top and six on bottom). They have multiple cusps and ridges for crushing and grinding food. An adult typically has 32 permanent teeth: - 8 incisors - 4 canines - 8 premolars - 12 molars (including four third molars or "wisdom teeth") - Children start with primary or baby teeth before their permanent teeth erupt. - Primary dentition consists of 20 teeth: - 8 incisors - 4 canines - 8 molars (including four second molars) 9. What can cause heartburn? Name treatments. - Eating large meals or lying down after eating - Consuming certain foods and beverages, such as spicy or fatty foods, citrus fruits, tomatoes, chocolate, coffee, alcohol - Obesity or being overweight - Pregnancy - Smoking - Common treatments for heartburn: - Antacids: Over-the-counter medications that neutralize stomach acid. - Proton Pump Inhibitors (PPIs): Prescription drugs that reduce the production of stomach acid. - H2 blockers: Medications that decrease the amount of acid produced by the stomach. - Lifestyle changes: Avoiding trigger foods, eating smaller meals, elevating the head while sleeping, quitting smoking. 10. Name the cells that secrete digestive enzymes. List each enzyme and its function. - Salivary glands secrete amylase, which breaks down starch into smaller sugar molecules. - Stomach cells secrete pepsinogen, which is converted to pepsin and helps break down proteins into peptides. - Pancreatic cells secrete pancreatic amylase, lipase, and proteases. Amylase further breaks down starch into sugars, lipase digests fats into fatty acids and glycerol, and proteases help break down proteins into amino acids. - Intestinal cells secrete various enzymes including maltase, sucrase, lactase, and peptidases. Maltase breaks down maltose into glucose molecules, sucrase digests sucrose into glucose and fructose, lactase breaks down lactose into glucose and galactose, and peptidases further break down peptides into individual amino acids. 11. Name the cells or organs that secrete digestive hormones and the function of each hormone. Stomach: - Gastrin: stimulates the release of gastric acid and promotes stomach contractions for digestion. Small Intestine: - Secretin: stimulates the release of pancreatic enzymes and bicarbonate, which aid in neutralizing stomach acid and promoting digestion. - Cholecystokinin (CCK): stimulates the secretion of digestive enzymes from the pancreas and bile from the gallbladder, aiding in fat digestion. It also helps regulate appetite by signaling satiety to the brain. (Source: https://pubmed.ncbi.nlm.nih.gov/25064596/) Pancreas: - Amylin: regulates blood sugar levels by slowing down gastric emptying and suppressing glucagon secretion. (Source: https://pubmed.ncbi.nlm.nih.gov/12175764/) - Insulin: lowers blood sugar levels by facilitating glucose uptake into cells and promoting its storage as glycogen. (Source: https://pubmed.ncbi.nlm.nih.gov/28867113/) - Glucagon: increases blood sugar levels by stimulating the breakdown of glycogen into glucose in the liver. (Source: https://pubmed.ncbi.nlm.nih.gov/27557774/) Duodenum: - Enterogastrone hormones, such as duodenal lipase inhibitor, inhibit gastric motility and secretion to slow down digestion when there is a high concentration of nutrients in the small intestine. 12. What is the importance of the mucosal barrier in the stomach? - The mucosal barrier in the stomach plays a vital role in protecting the underlying tissue from the harsh environment of stomach acid and digestive enzymes. - It prevents damage to the stomach lining, reducing the risk of ulcers and other gastrointestinal disorders. - The mucosal barrier helps maintain proper pH balance in the stomach, which is crucial for optimal digestion and absorption of nutrients. - It acts as a physical barrier, preventing harmful bacteria, toxins, and pathogens from entering the bloodstream through the stomach lining. - The mucosal barrier also contains mucus-producing cells that secrete a protective layer of mucus, further enhancing its defense mechanism. 13. What is chyme? How it is moved to the duodenum. - Chyme is a semi-fluid mixture of partially digested food and gastric juices in the stomach. - It is moved to the duodenum (first part of the small intestine) through a process called gastric emptying. - Gastric emptying involves the contraction of muscles in the stomach walls, which propel the chyme into the duodenum. - The movement of chyme from the stomach to the duodenum is regulated by various factors, including hormonal signals and nerve impulses. - One important hormone involved in this process is gastrin, which stimulates gastric emptying. 14. Define peristalsis and segmentation. Peristalsis: - Peristalsis is a rhythmic muscular contraction that propels food through the digestive tract. - It involves sequential waves of muscle contractions and relaxations in the smooth muscles of the gastrointestinal (GI) system. - The purpose of peristalsis is to push food forward, allowing for digestion and absorption to occur. Segmentation: - Segmentation is a mixing movement that occurs in the small intestine. - It involves the contraction and relaxation of segments of circular muscles in the intestinal wall. - The purpose of segmentation is to mix food with digestive enzymes and absorb nutrients more effectively. 15. Identify villi, microvilli and lacteals. Villi: Finger-like projections found in the small intestine. Microvilli: Tiny hair-like structures on the surface of cells, including those lining the villi. Lacteals: Specialized lymphatic capillaries located within the villi. 16. Identify the ducts from the gallbladder, liver and pancreas. Gallbladder duct: The main duct from the gallbladder is called the cystic duct. It connects the gallbladder to the common bile duct. Liver ducts: The liver has multiple ducts that drain bile. The two main ones are the left and right hepatic ducts, which join together to form the common hepatic duct. Pancreas duct: The main pancreatic duct, also known as the Wirsung's duct, runs through the center of the pancreas and carries digestive enzymes to the small intestine. 17. What are the causes of constipation and diarrhea? Causes of constipation: - Lack of fiber in the diet - Inadequate fluid intake - Sedentary lifestyle and lack of physical activity - Certain medications (e.g., opioids, antacids) - Hormonal changes during pregnancy or menstrual cycle - Bowel obstruction or blockage - Neurological disorders affecting bowel movements (e.g., Parkinson's disease) - Certain medical conditions (e.g., hypothyroidism, diabetes) Causes of diarrhea: - Viral or bacterial infections (e.g., norovirus, salmonella) - Food poisoning from contaminated food or water - Side effects of certain medications (e.g., antibiotics) - Intolerances to certain foods (e.g., lactose intolerance) - Inflammatory bowel diseases (e.g., Crohn's disease, ulcerative colitis) - Irritable bowel syndrome (IBS) - Stress and anxiety - Certain digestive disorders (e.g., celiac disease) 18. What is the importance of bacteria in the large intestine? - Bacteria in the large intestine play a crucial role in digestion and nutrient absorption. - They help break down complex carbohydrates, fiber, and other components that our bodies cannot digest on their own. - Bacteria produce essential vitamins, such as vitamin K and some B vitamins, which are absorbed by the body. - They aid in the fermentation of undigested food, producing short-chain fatty acids that provide energy for colon cells. - Bacteria help maintain a healthy balance in the gut microbiome, which is important for immune function and overall health. 19. Explain the process of defecation. - Defecation is the process of eliminating waste material from the body through the rectum and anus. - It begins with the relaxation of the internal anal sphincter, which allows feces to enter the rectum. - The rectum then stretches, triggering a sensory signal that indicates the need to defecate. - At this point, voluntary control comes into play as a person decides whether to release or hold back their bowel movement. - If they choose to proceed, they relax the external anal sphincter voluntarily, facilitating the passage of feces. - The abdominal muscles contract, providing additional force for elimination by increasing intra-abdominal pressure. - The rectum continues to empty its contents through rhythmic contractions called peristalsis. - Finally, the feces pass through the anus and are expelled from the body. Nutrition 1. What are nutrients? Nutrients are substances that are essential for the growth, development, and maintenance of our body. They are obtained from the food we eat and play a crucial role in supporting various bodily functions such as energy production, metabolism, immune response, and overall well-being. 2. Define macronutrients and micronutrients and examples of each. Macronutrients refer to nutrients that are needed in larger quantities as they provide energy to the body. They include carbohydrates, proteins, and fats. 1. Carbohydrates: These are the primary source of energy for the body. Examples of carbohydrates include grains (rice, wheat), fruits, vegetables, legumes (beans, lentils), and sugars (sucrose, fructose). 2. Proteins: Proteins are essential for growth, repair, and maintenance of tissues in the body. Good sources of protein include meat, poultry, fish, dairy products, eggs, soybeans, nuts/seeds, and legumes. 3. Fats: Fats serve as a concentrated source of energy and help transport fat-soluble vitamins in the body. Examples include olive oil, avocadoes, nuts/seeds, fatty fish (salmon), butter/margarine. Micronutrients are nutrients that are needed in smaller quantities but play crucial roles in various physiological processes. They include vitamins and minerals. 1. Vitamins: These organic compounds are necessary for normal cell function and metabolism. Examples include vitamin C (citrus fruits), vitamin A (carrots), vitamin D (sunlight exposure), B-vitamins (meat/fish/dairy/legumes/grains). 2. Minerals: These inorganic substances are involved in numerous bodily functions such as bone formation, nerve transmission, and enzyme activity. Examples include calcium (dairy products), iron (red meat/spinach), potassium (bananas/potatoes), magnesium (nuts/seeds/whole grains). 3. Define essential and nonessential nutrients and examples of each. Essential nutrients are substances that the body needs for normal functioning but cannot produce on its own, so they must be obtained from food. They are necessary for growth, development, and overall health. - Examples of essential nutrients include vitamins (such as vitamin C and vitamin D), minerals (such as calcium and iron), essential fatty acids, and essential amino acids. Nonessential nutrients are substances that the body can produce on its own or can obtain from other sources besides food. While they may still provide certain health benefits, they are not considered crucial for survival. - Examples of nonessential nutrients include certain amino acids (which the body can synthesize), some types of dietary fiber, and certain compounds found in plants called phytonutrients. 4. Define RDA. RDA stands for Recommended Dietary Allowance. - It is a set of guidelines developed by the Food and Nutrition Board of the National Academy of Medicine in the United States. - RDA represents the average daily intake level of a nutrient that meets the nutritional needs of most healthy individuals within a specific age and gender group. - The purpose of RDA is to prevent nutrient deficiencies and maintain optimal health. 5. Describe the MyPlate for balanced nutrition. - MyPlate is a visual representation of the five food groups that should be included in a balanced diet. - It was designed by the United States Department of Agriculture (USDA) to provide guidance for healthy eating. - The five food groups depicted on MyPlate are fruits, vegetables, grains, protein foods, and dairy products. - Each section on MyPlate represents the relative portion sizes of these food groups that should be consumed. 6. What information is contained on nutrition labels? Serving size: The recommended portion size for consumption. - Calories: The amount of energy provided by the food or beverage. - Macronutrients: The amounts of carbohydrates, fats, and proteins present in the product. - Sugar: The quantity of added sugars and naturally occurring sugars. - Fiber: The amount of dietary fiber present in the food. - Sodium: The quantity of salt found in the product. - Vitamins and minerals: Some labels may include information on specific vitamins and minerals present in significant amounts. - % Daily Value (% DV): A reference to the percentage of a nutrient that one serving provides based on a 2,000-calorie diet. 7. What are carbohydrates, proteins and lipids? How do we use them? What are good dietary sources? Carbohydrates: - Carbohydrates are one of the three macronutrients found in food, along with proteins and lipids. - They are composed of carbon, hydrogen, and oxygen atoms. - Our body breaks down carbohydrates into glucose, which is then used as a primary source of energy. - Good dietary sources of carbohydrates include fruits, vegetables, whole grains, legumes, and dairy products. Proteins: - Proteins are essential macronutrients made up of amino acids. - They play a crucial role in building and repairing tissues, producing enzymes and hormones, and supporting immune function. - Our body uses proteins for various functions such as growth, maintenance, and repair of cells. - Dietary sources rich in protein include meat, poultry, fish, eggs, dairy products, legumes, nuts, and seeds. Lipids: - Lipids (commonly known as fats) are another type of macronutrient that provide energy for our body. - They consist of carbon, hydrogen, and oxygen atoms. - Our body uses lipids to store energy for future use, cushion vital organs, insulate the body against temperature changes, and aid in the absorption of fat-soluble vitamins. - Good dietary sources of healthy fats include avocados, olive oil, nuts/seeds (such as almonds or flaxseeds), fatty fish (like salmon or sardines), and plant-based oils. 8. What happens if energy in does not equal energy out? - If energy in (calories consumed) does not equal energy out (calories burned), it can lead to weight gain or weight loss, depending on the imbalance. - Consuming more calories than expended leads to a positive energy balance and can result in weight gain, as excess calories are stored as fat. - Conversely, expending more calories than consumed creates a negative energy balance and can lead to weight loss, as the body taps into stored fat for fuel. - Consistently having an energy imbalance can contribute to long-term changes in body weight and composition. 9. Name all molecules that can be used to generate ATP. - Adenosine triphosphate (ATP) itself is the primary molecule used to generate ATP. - Glucose can be broken down through glycolysis, the Krebs cycle, and oxidative phosphorylation to produce ATP. - Fatty acids can undergo beta-oxidation in mitochondria to generate ATP. - Amino acids can also be converted into intermediates of metabolism, such as pyruvate or acetyl-CoA, which can enter pathways that lead to ATP production.