E1 - Organs Flashcards
What is the function of the kidneys?
Remove metabolic wastes (ammonia, urea, uric acid), maintain water balance.
How much water does an average adult lose daily?
About 2 L through sweat, urine, and exhalation.
What happens with a 1%, 5%, and 10% drop in body fluid levels?
1% - thirst; 5% - extreme pain & collapse; 10% - death.
What is deamination and where does it occur?
The removal of nitrogen-containing amino groups from excess amino acids in the liver.
What are the toxic and less toxic forms of nitrogen waste?
Ammonia is highly toxic; it is converted into less toxic urea in the liver.
How do fish, birds/reptiles, and mammals excrete nitrogen waste?
Fish: ammonia
Birds/reptiles: uric acid
Mammals: urea
What organs make up the urinary system?
Kidneys, ureters, urinary bladder, urethra.
Describe the structure and location of kidneys.
Two fist-sized organs near the spine in the lower back; produce urine.
What is the function of the ureters?
Transport urine from kidneys to bladder via peristalsis.
What is the function of the urinary bladder?
Temporarily stores urine.
How does the urethra differ between males and females?
Males: ~20 cm (merges with vas deferens)
Females: ~4 cm
What are the main parts of the kidney?
- Renal cortex - outer section, contains Bowman’s capsule.
- Renal medulla - inner section, contains collecting ducts.
- Renal pelvis - funnel like area that collects urine into the ureter.
What is a nephron?
The main functional unit of the kidney that filters blood and generates urine.
How many nephrons are in each kidney?
Approximately 1 million.
What are the four main functions of a nephron?
- Filtration - removal of water/solutes from blood.
- Reabsorption - reabsorption of water/essential solutes.
- Secretion - active removal of other wastes.
- Excretion - final release of urine.
Describe the blood pathway through the kidney.
Renal artery → arterioles → glomerulus → efferent arteriole → peritubular capillaries → renal vein.
What does the glomerulus do?
A high-pressure capillary bed that filters blood.
What are the parts of the nephron?
Bowman’s capsule, proximal tubule, loop of Henle, distal tubule, collecting duct.
What is the function of Bowman’s capsule?
Encapsulates the glomerulus and begins the filtration process.
Where is urine collected before moving to the renal pelvis?
In the collecting duct.
What is the function of the Afferent arteriole?
Carries blood into glomerulus.
What is the function of the Efferent arteriole?
Carries blood away from glomerulus.
What is the function of the Peritubular Capillaries?
Surround the nephron to reabsorb water & essential solutes.
What is Homeostasis?
