Podcast
Questions and Answers
Which structure is located posterior to the renal artery?
Which structure is located posterior to the renal artery?
What structure primarily supports the kidney and its associated organs?
What structure primarily supports the kidney and its associated organs?
Which layer is directly surrounding the kidney and lies just outside the fibrous capsule?
Which layer is directly surrounding the kidney and lies just outside the fibrous capsule?
At which level of the vertebrae is the kidney primarily located?
At which level of the vertebrae is the kidney primarily located?
Signup and view all the answers
What is the anatomical position of the aorta in relation to the inferior vena cava?
What is the anatomical position of the aorta in relation to the inferior vena cava?
Signup and view all the answers
Which structure collects urine produced by the kidneys before it moves to theureter?
Which structure collects urine produced by the kidneys before it moves to theureter?
Signup and view all the answers
What is the primary function of the renal artery?
What is the primary function of the renal artery?
Signup and view all the answers
Which type of artery branches into smaller arteries within the kidneys?
Which type of artery branches into smaller arteries within the kidneys?
Signup and view all the answers
Which vein drains blood from the kidneys and returns it to the heart?
Which vein drains blood from the kidneys and returns it to the heart?
Signup and view all the answers
Which component is NOT part of the kidney's blood supply system?
Which component is NOT part of the kidney's blood supply system?
Signup and view all the answers
What is the function of the macula densa in the juxtaglomerular complex?
What is the function of the macula densa in the juxtaglomerular complex?
Signup and view all the answers
What is the main function of the kidneys in relation to blood?
What is the main function of the kidneys in relation to blood?
Signup and view all the answers
What is the primary function of the filtration membrane in the renal corpuscle?
What is the primary function of the filtration membrane in the renal corpuscle?
Signup and view all the answers
Which cells in the juxtaglomerular complex are responsible for sensing blood pressure?
Which cells in the juxtaglomerular complex are responsible for sensing blood pressure?
Signup and view all the answers
Which cell types create the visceral layer of the glomerular capsule?
Which cell types create the visceral layer of the glomerular capsule?
Signup and view all the answers
Which artery delivers blood directly to the kidneys?
Which artery delivers blood directly to the kidneys?
Signup and view all the answers
What role do extraglomerular mesangial cells serve in the juxtaglomerular complex?
What role do extraglomerular mesangial cells serve in the juxtaglomerular complex?
Signup and view all the answers
What substance is stored in the secretory granules of granular cells?
What substance is stored in the secretory granules of granular cells?
Signup and view all the answers
In relation to the glomerular filtration process, what does 'big stuff' refer to?
In relation to the glomerular filtration process, what does 'big stuff' refer to?
Signup and view all the answers
What is the order of arterial flow to the kidneys starting from the renal artery?
What is the order of arterial flow to the kidneys starting from the renal artery?
Signup and view all the answers
What structures are primarily involved in regulating blood flow into the glomerulus?
What structures are primarily involved in regulating blood flow into the glomerulus?
Signup and view all the answers
In terms of blood supply, which statement about the renal veins is accurate?
In terms of blood supply, which statement about the renal veins is accurate?
Signup and view all the answers
What is the primary role of the juxtaglomerular complex in nephron function?
What is the primary role of the juxtaglomerular complex in nephron function?
Signup and view all the answers
What role do podocytes play in the filtration membrane?
What role do podocytes play in the filtration membrane?
Signup and view all the answers
Which part of the kidney is responsible for the collection of urine before it moves to the ureter?
Which part of the kidney is responsible for the collection of urine before it moves to the ureter?
Signup and view all the answers
What is the primary nerve supply of the kidneys?
What is the primary nerve supply of the kidneys?
Signup and view all the answers
Which structure of the kidney is primarily involved in urine formation?
Which structure of the kidney is primarily involved in urine formation?
Signup and view all the answers
What is true about the fibrous capsule surrounding the kidney?
What is true about the fibrous capsule surrounding the kidney?
Signup and view all the answers
What is the primary function of the glomerulus?
What is the primary function of the glomerulus?
Signup and view all the answers
Which structure is primarily involved in the reabsorption of nutrients and water?
Which structure is primarily involved in the reabsorption of nutrients and water?
Signup and view all the answers
What type of epithelium is found in the renal corpuscle?
What type of epithelium is found in the renal corpuscle?
Signup and view all the answers
What feature is characteristic of proximal convoluted tubule cells?
What feature is characteristic of proximal convoluted tubule cells?
Signup and view all the answers
Which layer of the glomerular capsule is composed of podocytes?
Which layer of the glomerular capsule is composed of podocytes?
Signup and view all the answers
How do substances pass from the blood into the glomerular capsule?
How do substances pass from the blood into the glomerular capsule?
Signup and view all the answers
Which part of the nephron loop is impermeable to water?
Which part of the nephron loop is impermeable to water?
Signup and view all the answers
What role do intercalated cells in the collecting duct serve?
What role do intercalated cells in the collecting duct serve?
Signup and view all the answers
What is the primary structural difference between the renal cortex and the renal medulla?
What is the primary structural difference between the renal cortex and the renal medulla?
Signup and view all the answers
In which part of the nephron would you find thick and thin segments?
In which part of the nephron would you find thick and thin segments?
Signup and view all the answers
Study Notes
Urinary System Overview
- The urinary system is a major excretory organ
- It maintains the body's internal environment by regulating water volume, solute concentration, ion concentrations in extracellular fluid, acid-base balance, and excreting metabolic wastes, toxins, and drugs
- It produces renin, regulating blood pressure and erythropoietin for red blood cell production
- It also activates vitamin D, and performs gluconeogenesis if needed
Kidney Function
- Kidneys filter blood plasma, removing waste products and excess water
- They produce urine
- They cleanse and adjust blood composition
- They deliver about 1/4(1200 ml) of cardiac output per minute
- Blood flow: renal → segmental → interlobar → arcuate → cortical radiate (interlobular)
- Venous flow: cortical radiate → arcuate → interlobar → renal veins
- There are no segmental veins
- Nerve supply: via sympathetic fibers from renal plexus
Kidney Anatomy
- Kidneys are positioned against the posterior body wall, behind the parietal peritoneum
- They lie retroperitoneal, between the twelfth rib and the iliac crest.
- The internal anatomy includes the renal cortex, medulla, major calyx, papilla of pyramid, renal pelvis, minor calyx, ureter, renal pyramid, and renal column.
- The fibrous capsule surrounds the kidney. There are supportive tissue layers called renal fascia, and perirenal fat capsule
Nephrons
- Nephrons are the structural and functional units that form urine in each kidney.
- There are greater than 1 million nephrons per kidney
- Two main parts:
- Renal corpuscle (where filtration occurs)
- Renal tubule (where reabsorption and secretion happen)
Filtration Membrane
- Composed of three layers, the capillary endothelium, basement membrane, podocyte foot processes
- It acts as a filter, allowing smaller substances like water, glucose, amino acids, salts, and some ions to pass into the tubule. Larger molecules, like proteins remain in the blood vessels.
Glomerular Filtration Rate (GFR)
- GFR is the volume of filtrate formed by both kidneys per minute (normal = 120-125 ml/min)
- GFR is directly proportional to the net filtration pressure (NFP), total surface area for filtration, and filtration membrane's permeability
- NFP is determined by hydrostatic pressure within the capillaries, and capsular hydrostatic pressure, and colloid osmotic pressure.
Kidney Function Regulation (intrinsic)
- Intrinsic controls (autoregulation)maintain nearly constant glomerular filtration rate (GFR) when mean arterial pressure is between 80-180 mm Hg.
- Two types of autoregulation:
- Myogenic mechanism- The afferent arterioles constrict when stretched, decreasing blood flow into the glomerulus.
- Tubuloglomerular feedback mechanism- The macula densa cells detect changes in NaCl content of filtrate and signal to the afferent arterioles.
Kidney Function Regulation (extrinsic)
- Extrinsic mechanisms regulate GFR by adjusting the systemic blood pressure, thus adjusting GFR
- Two types of extrinsic control are the sympathetic nervous system, and hormones, like renin - angiotensin-II—aldosterone system (RAAS).
Tubular Reabsorption
- Most of the filtrate is reabsorbed back in to the bloodstream through the tubular membranes
- Key substances are reabsorbed by primary active transport (Na+) which provides the energy for secondary active transport for other nutrients: water, glucose, amino acids, salts.
Tubular Reabsorption of Water
- Water's reabsorption depends on ADH released from the posterior pituitary; with higher ADH levels, more water is reabsorbed into the bloodstream.
Tubular Secretion
- This is opposite of reabsorption
- Substances like drugs, metabolites, H+, NH4, creatinine and organic acids enter the filtrate through the tubular cells; thus, it's important for eliminating unwanted substances, regulating blood pH, or for eliminating excess K+
Urine Characteristics
- Physical characteristics: Color, transparency, odor, pH, and specific gravity
- Variations in these characteristics can indicate various conditions or diseases
Urine Concentration and Volume
- Two countercurrent mechanisms: the countercurrent multiplier and countercurrent exchanger in the juxtamedullary nephrons
- The gradient causes the collecting ducts to concentrate or dilute the urine as needed
Urinary Bladder
- Urine storage; collapses when empty, rugae appear; expands and rises superiorsly during filling without significant rise in internal pressure
- Holds 500 ml (1 pint)
- Capacity can double if necessary
- Can burst if excessively distended
Urethra
- Carries urine out of the body
- Males have a longer urethra
- Three named regions:
- Prostatic urethra, Intermediate, Spongy urethra
- Sphincters help control urination
- Internal urethral sphincter (smooth muscle): involuntary, Contracts to open
Renal Clearance Rate
- Measures the volume of plasma cleared of a substance by the kidneys per minute
- Renal clearance of inulin is approximately equal to the GFR.
- If the renal clearance rate is less than the estimated GFR, then the substance is reabsorbed or not filtered.
- If the renal clearance rate is greater than the estimated GFR, then the substance is actively secreted.
Other
- Other substances like electrolytes are also found in blood such as -Na+, K+, PO₄³¯, and SO42-, Ca2+, Mg2+, and HCO3−; abnormally high concentration or abnormal components could indicate pathology.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the essential functions and anatomy of the urinary system and kidneys. Explore how the kidneys filter blood, regulate bodily functions, and produce urine. Test your knowledge on the systemic role of the urinary system in maintaining homeostasis.
