Chapter5-Excretory System

What is excretion in the context of human biology?

Excretion is the elimination of metabolic wastes such as CO2 and urea.

Define egestion.

Egestion is the elimination of non-digested food, which primarily makes up feces.

What role does the kidney play in excretion?

The kidney acts as the major excretory organ, eliminating excess water, salts, glucose, and major metabolic wastes.

What are the nitrogenous byproducts formed by the breakdown of proteins?

They include ammonia, urea, and uric acid.

How is ammonia converted in the body?

Ammonia, which is highly toxic, is converted by the liver into urea.

What are the main structures of the urinary system?

Renal artery, renal vein, kidney, cortex, medulla, renal pelvis, ureter, urinary bladder, prostate, urethra.

What is the function of the nephron?

The nephron is the functional unit of the kidney that filters blood and forms urine.

Describe the filtration process in Bowman's Capsule.

Water and small molecules like glucose, salt, and urea are filtered into Bowman's Capsule, creating a dilute urine.

What governs the concentration of urine in the Loop of Henle?

The concentration of urine in the Loop of Henle is controlled by specialized transport mechanisms and the hormone ADH.

What is the typical volume of urine formed daily?

The typical volume of urine formed daily is about 1500 ml (1.5 L).

What occurs during micturition?

Micturition is the process of urine being expelled from the bladder; it involves stretch receptors activating bladder muscles.

What are the causes of kidney stones?

Kidney stones have various causes and can be treated through methods like dissolution, ultrasonic shock, or surgery.

What is hemodialysis?

Hemodialysis is a dialysis method that typically lasts 3-5 hours, performed 3 times a week.

What is the typical water budget for an adult?

The typical water budget includes an income of about 2600 ml and an expenditure that balances it, totaling around 2600 ml.

In what ways can ADH affect urine concentration?

ADH can lead to concentrated urine (0.5 ml/min) or dilute urine (16 ml/min) depending on hydration levels.