Term
| What is the function of the Urinary System? |
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Definition
| Maintain the volume and composition of the body fluid within normal limits. |
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Term
| What are the components of the Urinary System? |
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Definition
Two Kidneys Two Ureters One Urinary Bladder One Urethra |
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Term
| What are the steps in Renal Function? |
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Definition
Filtration Reabsorption Secretion Excretion |
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Term
| Trace the Artery flow of the Renal Vascular System. |
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Definition
| Renal Artery, Interlobar Artery, Arcuate Artery, Interlobular Artery, Afferent Arterioles, Glomerular Capillaries, Efferent Arterioles, Peritubular Capillaries (renal cortex), Vasa Rects (renal medulla), Venous System |
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Term
| What % of blood perfuses Superficial Glomeruli? Juxtamedullary Glomeruli? |
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Definition
| 90% superficial, 10% juxtamedullary |
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Term
| Where are Lymph Vessels located in the Kidney? What do they do? |
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Definition
The Cortex. They drain intersitial fluid. Can contain high concentration of renal hormones such as renin. No lymph vessels in the Medulla. |
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Term
| What type of nerve fibers act on the Kidney? What do they do? |
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Definition
Sympathetic Nerve Fibers Regulate renal blood flow (constrict/dilate efferent and afferent arterioles), glomerular filtration and tubular reabsorption. |
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Term
| What three processes are involved in the formation of urine? |
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Definition
Glomerular Filtration Tubular Reabsorption Tubular Secretion |
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Term
| What hormones control urine volume? |
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Definition
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Term
| When are Glomerular Filtration Rate and Renal Blood Flow autoregulated? |
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Definition
| When arterial blood pressure is between 90 - 180 mmHg. |
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Term
| How can the afferent and efferent arterioles be stimulated to change Glomerular Flow Rate and Renal Blood Flow? |
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Definition
Constricting the Afferent Reduces GFR and RBF. Constricting the Efferent Increases GFR and Decreases RBF. Dilating the Afferent Increases GFR and RBF. Dilating the Efferent Decreases GFR and Increases RBF |
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Term
| For a substance to be used to measure GFR, what criteria must it fulfill? Example of such a substance? |
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Definition
Must be freely filterable in the Glomeruli Cannot be reabsorbed or secreted by renal tubules Cannot be metabolized or produced by the Kidney Cannot be toxic or affect renal funcion Inulin fulfills these requirements. |
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Term
| What substances are reabsorbed by the Proximal Convoluted Tubule? |
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Definition
| H2O (65%), Na, Cl, Glucose, Amino Acids |
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Term
| What substances are reabsorbed by the Descending Limb? |
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Definition
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Term
| What substances are reabsorbed by the Ascending Limb? |
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Definition
Cl, Na Not permeable to H2O |
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Term
| What substances are reabsorbed by the Distal Convoluted Tubule? |
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Definition
| H2O, Na (in presence of aldosterone) |
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Term
| What substances are reabsorbed by the Collecting Duct? |
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Definition
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Term
| What is the most important site for Tubular Secretion? |
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Definition
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Term
| What does tubular secretion have to do with drug concentration? |
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Definition
| The kidneys secrete many potentially harmful drugs or toxins for rapid clearance from the blood. The Kidneys can create a problem in maintaining an effective drug concentration. |
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Term
| What triggers urination reflex and when? |
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Definition
| When the bladder fills to 200-400 mL stretch receptors in the bladder wall trigger urinary reflex. Emptying the bladder is a spinal reflex process that is under concious control until volumes around 600 mL. |
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Term
| When do children develop full urination control? What causes loss of control in old age? |
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Definition
Typically around 3 years old. Lesions in nervous system or enlargement of the prostate can cause loss of control. |
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Term
| What regulates renal function? |
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Definition
Hormones: Aldosterone, Antiduiuretic Hormone (ADH), Atrial Natriuretic Hormone Renal autoregulation, sympathetic nerves |
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Term
| Describe the process of autoregulation |
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Definition
| Not dependent on nerve supply or blood-borne substances. Achieved by myogenic property of vascular smooth muscle cell of the afferent arterioles. When pressure in these increase, it stretches the vessel wall and triggers contraction of the smooth muscle.This increase in arteriolar resistance prevents an increase in systemic arterial pressure from reachign the capillaries. The opposite happens when systemic arterial pressure falls. |
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Term
| The Kidney's lack a supply of what nerve fibers? |
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Definition
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Term
| Sympathetic fibers do what to the kidneys? |
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Definition
| Vasoconstriction/Dilation of the Afferent and Efferent Arterioles. Also can increase sodium reabsorption. |
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Term
| Why does drinking alcohol or coffee cause excessive urination? |
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Definition
| Alcohol and Coffee inhibit ADH. |
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Term
| What factors affect urinary concentrating ability |
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Definition
| ADH, delivery/reabsorption of NaCl to ascending limb loop of Henle, Medullary blood flow, delivery of fluid to medullary collecting ducts, urea, length of loop of henle |
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Term
| How can renal function be tested? |
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Definition
Renal plasma clearance of PAH Inulin clearance Plasma Creatine Concentration Urinary Albumin Excretion Rate of Blood Albumin Plasma Urea Concentration |
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