Excretion - humans Flashcards
(27 cards)
What is excretion
Excretion is the removal of the waste substances of metabolic reactions, toxic materials and substances in excess of requirements
What are the organs of excretion
lungs kidneys and skin are the organs responsible for excreting waste products
What is the kidney’s role in excretion and osmoregulation
kidneys filter waste from the blood and regulate water and salt balance in the body
What is the structure of the urinary system
the urinary system includes kidneys ureters bladder and urethra
What is the structure of a nephron
a nephron consists of Bowman’s capsule and glomerulus, convoluted tubules, loop of Henlé, and collecting duct
What is ultrafiltration in the Bowman’s capsule
ultrafiltration is the process where blood pressure forces small molecules like water and urea into the Bowman’s capsule forming glomerular filtrate
What is the composition of the glomerular filtrate
the glomerular filtrate contains water glucose salts and urea but not proteins or blood cells
What is water reabsorption in the collecting duct
water is reabsorbed from the collecting duct back into the blood to help maintain water balance
What is selective reabsorption of glucose
glucose is selectively reabsorbed in the proximal convoluted tubule to prevent its loss in urine
What is the role of ADH in water regulation
ADH regulates water balance by increasing the amount of water reabsorbed by the kidneys when the body is dehydrated
What is in urine
urine contains water urea and salts
What is the function of the kidneys
kidneys filter blood to remove waste products and excess substances
What is the role of the ureters
the ureters carry urine from the kidneys to the bladder
What is the function of the bladder
the bladder stores urine until it is excreted from the body
What is the role of the urethra
the urethra carries urine from the bladder out of the body during urination
What is Ultrafiltration in the kidneys
ultrafiltration occurs in the glomerulus where blood pressure forces small substances like water urea and glucose into the Bowman’s capsule
What is reabsorption in the nephron
reabsorption is the process of taking back useful substances like glucose water and salts from the filtrate back into the blood
What is secretion in the nephron
secretion is when additional waste products are added to the filtrate from the blood in the distal convoluted tubule
What is the loop of Henlé’s role
the loop of Henlé helps concentrate urine and conserve water by creating a concentration gradient in the kidney medulla
What is ADH
ADH (antidiuretic hormone) is a hormone that helps regulate water balance by controlling water reabsorption in the kidneys
What does ADH do when the body is dehydrated
ADH increases water reabsorption in the kidneys to conserve water and produce concentrated urine
What happens if ADH levels are low
More water in urine
What is osmoregulation
osmoregulation is the control of water and salt balance in the body to ensure cells function properly
What are the main waste products excreted by the body
the main waste products are urea (from protein metabolism) salts and excess water
