Urinary System

Question 1

What is the Urinary system

Answer 1

The urinary system is vital for removing waste and maintaining the body’s internal balance

Metabolic Waste Management: After metabolism, the body produces waste that must be eliminated to prevent toxicity.​

Role of the Liver: The liver processes dead cells and chemicals, directing waste to the digestive and urinary systems.​

Urinary System’s Function: Filters toxic leftovers, especially nitrogenous waste from protein metabolism, and maintains homeostasis.

Question 2

What are the main functions of the Urinary system

Answer 2

Regulates Water Volume and Ion Concentrations: Maintains balance of water, salts, and ions like sodium and potassium.​
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Balances pH Levels: Ensures blood pH remains within a narrow, healthy range.​

Influences Red Blood Cell Production: Releases erythropoietin, stimulating red blood cell formation.​

Regulates Blood Pressure: Through mechanisms like the renin-angiotensin system.​

Filters and Eliminates Waste: Removes metabolic wastes, especially nitrogenous compounds like urea.

Question 3

Organs in the Urinary System

Answer 3

1. Kidneys
   Main organ that filters blood.

Removes urea (waste product from breaking down proteins).

Produces urine.

2. Ureters
   Tubes that carry urine from the kidneys to the bladder.
3. Urinary Bladder
   Stores urine before it is released.
4. Urethra
   Releases urine out of the body.
5. Skin
   Excretes sweat, which contains water and small amounts of urea/salt.
6. Lungs
   Excretes carbon dioxide (a waste product of respiration).
7. Liver
   Breaks down toxins (e.g., drugs, alcohol) and old blood cells.

Question 4

what is nitrogen waste

Answer 4

Comes from the breakdown of proteins.

The body converts toxic ammonia into urea (less toxic).

Urea is transported to the kidneys and excreted in urine

Question 5

The Nephron (Kidney’s Filtering Unit)

Answer 5

Each kidney has over a million nephrons, and each nephron filters small amounts of blood.

Question 6

the 3 main steps in the Nephron

Answer 6

Filtration

Happens in the glomerulus (inside Bowman’s capsule).

Filters out water, salt, glucose, amino acids, and urea from the blood.

Blood cells and large proteins stay in the blood.

Reabsorption

Happens in the proximal tubule, loop of Henle, distal tubule.

Good stuff (like water, glucose, and some salts) gets reabsorbed into the blood.

Secretion

Extra waste, hydrogen ions, and drugs are secreted into the tubule from the blood.

What’s left becomes urine

Question 7

what is the path of urine

Answer 7

Nephron → Collecting duct → Renal pelvis → Ureter → Bladder → Urethra → Out of body

Nephron: Filtrate is processed into urine.​

Collecting Duct: Transports urine to the renal pelvis.​

Ureter: Carries urine from the kidney to the urinary bladder.​

Urinary Bladder: Stores urine until excretion.​

Urethra: Conducts urine out of the body.

Question 8

Anatomy of the Kidneys

Answer 8

Location: Two bean-shaped organs located retroperitoneally (behind the peritoneum) on either side of the spine.​

Structure:

Renal Cortex: Outer layer where filtration begins.​

Renal Medulla: Inner region containing cone-shaped masses (renal pyramids) that secrete urine into tiny sac-like tubules.​

Renal Pelvis: Funnel-shaped tube that collects urine and channels it to the ureter.​

Question 9

Nephron

Answer 9

Nephrons are the microscopic structures where urine formation occurs through filtration, reabsorption, and secretion

Quantity: Each kidney contains about a million nephrons.​

Components:

Renal Corpuscle:

Glomerulus: A tangled cluster of capillaries where blood filtration starts.

Glomerular (Bowman’s) Capsule: Encases the glomerulus, collecting the filtrate.

Renal Tubule:

Proximal Convoluted Tubule (PCT): First segment where reabsorption of water, ions, and nutrients occurs.

Loop of Henle: U-shaped section that creates a concentration gradient to facilitate water reabsorption.

Distal Convoluted Tubule (DCT): Further adjusts the filtrate by secreting ions and reabsorbing water and sodium.

Collecting Duct: Receives urine from multiple nephrons, final site for water reabsorption, leading to the renal pelvis.

Question 10

Processes in Urine Formation

Answer 10

Glomerular Filtration:

Blood pressure forces water and solutes from the glomerulus into the glomerular capsule, forming filtrate.​

Large molecules like proteins and blood cells remain in the bloodstream.​

Tubular Reabsorption:

Essential substances (e.g., glucose, certain ions) and water are reabsorbed from the filtrate back into the bloodstream, primarily in the PCT.​

Tubular Secretion:

Additional wastes and excess ions are secreted from the blood into the filtrate in the DCT.​

Helps in maintaining acid-base balance and eliminating toxins.​

Urea Recycling:

Urea moves between the nephron loop and collecting duct, contributing to the concentration gradient in the medulla, aiding in water reabsorption