Excretory System
What is the primary function of the excretory system?
The primary function of the excretory system is to remove waste products and excess substances from the body to maintain internal balance.
What is a nephron?
A nephron is the functional unit of the kidney, responsible for filtering blood and forming urine.
What is the function of antidiuretic hormone (ADH)?
ADH increases water reabsorption in the kidneys, reducing urine output and helping to maintain blood pressure.
What are the main structural parts of a kidney?
The main structural parts include the renal cortex, renal medulla, renal pelvis, and nephrons.
Name a common disorder of the excretory system.
A common disorder is urinary tract infection (UTI).
Name the main organs involved in the excretory system. Put them in order!
The main organs involved are the kidneys, ureters, bladder, and urethra.
Describe the filtration process in the nephron.
Blood is filtered in the glomerulus, where water, ions, and small molecules pass into the Bowman's capsule, forming filtrate.
How does aldosterone affect sodium ion reabsorption?
Aldosterone promotes the reabsorption of sodium ions in the distal convoluted tubule and collecting duct, which helps regulate blood volume and pressure.
What is the role of the renal cortex?
The renal cortex contains the glomeruli and proximal tubules, where filtration and reabsorption occur.
What are kidney stones and how do they form?
Kidney stones are hard deposits made of minerals and salts that form in the kidneys when urine becomes concentrated.
Describe the role of urine in waste elimination.
Urine is a liquid by-product of metabolism that contains waste products, toxins, and excess substances, which are excreted from the body.
Explain the reabsorption process in the nephron.
Reabsorption occurs mainly in the proximal convoluted tubule where essential nutrients and water are reabsorbed back into the bloodstream.
What triggers the release of ADH from the pituitary gland?
High blood osmolarity or low blood volume triggers the release of ADH.
Explain the function of the renal medulla.
The renal medulla contains the loops of Henle and collecting ducts, playing a key role in concentrating urine.
Describe the effects of diabetes insipidus on ADH levels.
In diabetes insipidus, there is a deficiency of ADH, leading to excessive urination and thirst due to the inability to concentrate urine.
What are metabolic wastes? Provide examples.
Metabolic wastes are substances produced from metabolic processes that are toxic or in excess, such as urea, creatinine, and uric acid.
What role does the loop of Henle play in urine concentration?
The loop of Henle creates a concentration gradient in the medulla, allowing for the reabsorption of water and concentrating urine.
Describe the relationship between ADH and blood pressure.
ADH increases water reabsorption, leading to increased blood volume, which in turn raises blood pressure.
What structures make up the renal pelvis?
The renal pelvis is formed by the convergence of the major and minor calyces, which collect urine from the nephrons.
What is chronic kidney disease?
Chronic kidney disease is a long-term condition where the kidneys gradually lose function, affecting waste excretion and fluid balance.
Explain the concept of homeostasis in relation to excretion.
Homeostasis is the body's ability to maintain a stable internal environment; the excretory system helps achieve this by regulating fluid balance and eliminating waste.
What is the significance of secretion in nephron function?
Secretion allows for the removal of additional wastes and excess ions from the blood into the filtrate, aiding in the regulation of blood composition.
How do both ADH and aldosterone work together?
ADH and aldosterone work together to regulate water and sodium reabsorption, respectively, thus maintaining blood pressure and fluid balance.
How does blood flow through the kidney?
Blood flows into the kidney via the renal artery, enters the glomeruli for filtration, and exits through the renal vein after waste processing.
How does hypertension affect kidney function?
Hypertension can damage blood vessels in the kidneys, impairing their ability to filter blood and excrete waste effectively.