Vanders Renal Ch1 Flashcards
What are the seven major functions of the kidneys?
- Regulation of Water and Electrolyte Balance
- Regulation of Systemic Blood Pressure and Extracellular Fluid Volume
- Excretion of Metabolic Waste and Foreign Substances
- Regulation of Red Blood Cell Production
- Regulation of Acid-Base Balance
- Regulation of Vitamin D Production and Regulation of Calcium and Phosphate Balance
- Gluconeogenesis
These functions highlight the kidneys’ multifaceted role in maintaining homeostasis.
Define the balance concept in renal function.
Balance refers to matching output to input to keep a constant amount of substances in the body, such as water and electrolytes.
List the gross structures of the kidneys and their interrelationships.
- Renal pelvis
- Calyces
- Renal pyramids
- Renal medulla (inner and outer zones)
- Renal cortex
- Papilla
These structures work together to facilitate urine formation and drainage.
What are the components of the nephron-collecting duct system?
- Renal corpuscle
- Glomerulus
- Tubule
- Collecting-duct system
These components are essential for the filtration and reabsorption processes in the kidneys.
Draw the relationship between glomerulus, Bowman’s capsule, and the proximal tubule.
The glomerulus is enclosed by Bowman’s capsule, and the proximal tubule extends from Bowman’s capsule.
What is the juxtaglomerular apparatus?
A structure that regulates blood pressure and glomerular filtration rate, consisting of three cell types: granular cells, macula densa, and mesangial cells.
What are the three cell types found in the juxtaglomerular apparatus?
- Granular cells
- Macula densa
- Mesangial cells
What is the function of the granular cells in the juxtaglomerular apparatus?
To secrete renin, which helps regulate blood pressure.
List the individual tubular segments of the nephron in order.
- Proximal tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
Each segment plays a specific role in renal function.
Define principal cells and intercalated cells.
- Principal cells: Involved in sodium and water reabsorption
- Intercalated cells: Involved in acid-base balance
What are the basic renal processes?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
- Tubular production
These processes are essential for maintaining homeostasis in the body.
What is renal metabolism of a substance?
The process by which the kidneys metabolize substances, such as the conversion of vitamin D to its active form.
True or False: The kidneys only excrete waste products from the body.
False
The kidneys also regulate water, electrolytes, blood pressure, and produce hormones.
What is the role of the kidneys in regulating systemic blood pressure?
They determine blood volume and produce hormones that regulate vascular resistance.
What are uremic retention solutes?
Waste products that must be excreted by the kidneys, including urea, uric acid, and creatinine.
What stimulates red blood cell production?
Erythropoietin, produced primarily by the kidneys.
What is the major source of erythropoietin in adults?
The kidneys.
Fill in the blank: The kidneys help regulate __________ and phosphate balance.
calcium
What is gluconeogenesis?
The synthesis of glucose from non-carbohydrate sources, occurring in the liver and kidneys.
Describe the anatomy of the kidneys.
The kidneys are bean-shaped organs located under the rib cage, consisting of a cortex and medulla, with pyramids and calyces.
What is the function of the calyces in the kidneys?
They act as collecting cups for urine formed in the renal pyramids.
True or False: The renal corpuscles are found in the medulla.
False
Renal corpuscles are located in the cortex.
What are the two zones of each pyramid in the medulla?
Outer zone and inner zone
The outer zone borders the cortex and the inner zone continues to the papilla.
What structures are primarily found in the cortex of the kidney?
Renal corpuscles, coiled blood vessels, and coiled tubules
The medulla contains straight blood vessels and straight tubules.
How many nephrons are approximately present in each kidney?
About 1 million nephrons
What is the primary function of a nephron?
To modify filtered fluid to form the final urine
What is the renal corpuscle composed of?
Bowman’s capsule and glomerulus
What are the two arterioles associated with the renal corpuscle?
Afferent arteriole and efferent arteriole
What is the role of glomerular mesangial cells?
Act as phagocytes, removing trapped material from the basement membrane
What is the space within Bowman’s capsule that is not occupied by capillaries called?
Urinary space or Bowman’s space
What is the filtration barrier’s significance?
Permits filtration of large volumes of fluid but restricts plasma proteins
What are the segments of the renal tubule?
Proximal convoluted tubule, proximal straight tubule, descending thin limb, ascending thin limb, thick ascending limb, distal convoluted tubule, connecting tubule, cortical collecting duct, outer medullary collecting duct, inner medullary collecting duct
What is the first segment of the renal tubule?
Proximal tubule
What marks the end of the thick ascending limb?
Macula densa
What is the juxtaglomerular apparatus (JGA) composed of?
Granular cells, extraglomerular mesangial cells, and macula densa cells
True or False: The granular cells in the JGA contain renin.
True
What is glomerular filtration?
The bulk flow of fluid from the glomerular capillaries into Bowman’s capsule
What is the glomerular filtration rate (GFR) in a healthy young adult male?
180 L/day (125 mL/min)
Fill in the blank: The process of moving substances from the tubular lumen into the blood is called _______.
[Reabsorption]
What is the definition of excretion in the context of renal function?
Exit of the substance from the body via urine
What is the primary difference between glomerular filtrate and blood plasma?
Glomerular filtrate contains very little total protein
What substances are freely filtered in the glomerulus?
- Sodium
- Potassium
- Chloride
- Bicarbonate
- Glucose
- Urea
- Amino acids
- Peptides like insulin and antidiuretic hormone
What happens to the composition of urine compared to glomerular filtrate?
It is quite different; almost all filtered volume must be reabsorbed
What is the primary function of the kidneys in relation to plasma?
To filter plasma approximately 60 times a day and excrete waste products while regulating the internal environment
This process includes the precise regulation of substances in the body.
What happens to the volume of urine if tubular reabsorption did not occur?
We would urinate ourselves into dehydration very quickly
This is due to the filtration rate of 180 L/day.
What are the two main processes that alter the composition of glomerular filtrate in the tubules?
Tubular reabsorption and tubular secretion
What is the typical daily glomerular filtration rate (GFR) for a healthy young adult?
150 to 180 L/day
What is the significance of tubular reabsorption compared to tubular secretion?
Most tubular transport consists of reabsorption rather than secretion
What are the three important generalizations regarding tubular reabsorption?
- Large quantities are filtered daily
- Reabsorption of waste products is partial
- Reabsorption of useful plasma components is nearly complete
Fill in the blank: The body of a 70 kg person contains about _____ of water.
42 L
What triggers the regulation of renal excretion?
Changes in the rates of filtration, reabsorption, or secretion based on body content of a substance
What role does arginine vasopressin (AVP) play in renal function?
Regulates water and urea excretion, and contributes to sodium excretion
True or False: Excretion of major substances is regulated by overlapping, redundant controls.
True
What is the primary function of the glomerulus in the nephron?
Filtration of blood
What percentage of filtered water, sodium, and chloride is reabsorbed by the proximal tubule?
About two-thirds
What does the loop of Henle primarily reabsorb?
About 20% of filtered sodium and chloride, and 10% of filtered water
What is the role of the macula densa in the nephron?
Senses sodium and chloride content and influences renal function through signals
What hormones regulate sodium and water reabsorption in the distal tubule and collecting duct?
ADH, angiotensin II, and aldosterone
What is the function of the medullary collecting duct?
Continues salt and water reabsorption and plays a major role in excretion of acids and bases
Key concept: The kidneys regulate excretion of substances to maintain _______.
Appropriate body content
What is a major function of the kidneys in terms of extracellular fluid?
Regulate the volume and osmolality
What are the two main components of each functional renal unit?
Filtering component (glomerulus) and transporting tubular component (nephron and collecting duct)
Basic renal mechanisms consist of filtering a large volume, reabsorbing most of it, and adding substances by _______.
Secretion
