excretion in humans (topic 13) Flashcards
excretion
the removal of toxic materials and substances in excess of requirements from organisms.
name 3 excretory products
carbon dioxide, urine, sweat
describe excretion of carbon dioxide
co2 is one of the products of aerobic respiration, excreted via lungs after being transported there by its dissolved self in blood plasma
what is the urinary system
Organ system involved in excretion of urea, and excess salts and water. It includes the kidneys, ureters and urethra.
ureter
carries urine to the bladder
urethra
carries urine to the outside
bladder
temporarily stores urine
what does the kidney do
excrete urea, excess water and ions as urine
passageway of urine in body
kidney- ureter- bladder- urethra
function of liver
assisting the body in taking up amino acids for cellular use
breaking down excess amino acids (deamination)- to produce urea
deamination
The removal of the nitrogen-containing part of amino acids to form urea.
what is the role of the liver in assimilation
converts amino acids into proteins
where is urea formed
in liver, by excess amino acids
renal artery vs renal vein
renal artery- carries blood to the kidney
renal vein- carries blood away from kidney
what are the structures in the kidney
cortex, medula, ureter
cortex
outer part where blood is filtered and some selective reabsorption happens
medulla
inner part where some selective reabsorption happens, and fluid is collected to form urine
what are neprhons
structure, in which millions are present in the kidney positioned between the cortex and the medulla
what is the role of the nephron
to filter the blood, separating waste and returning substances that are needed back to the bloodstream
what is the glomerolous
unit of filtration in the nephron, consists of a network of capillaries
-water, glucose, urea, ions enter tubule (go through glomerolous
-proteins are too big of molecules to pass
what is the tubule
Part of a kidney nephron in which selective reabsorption of substances occurs.
what substances are reabsorbed in the tubule
all of the glucose
most of the water
some ions.
composition of urine
urea, excess water and excess ions
what is the importance of excreting urea
it is toxic
