Excretion Flashcards
Excretion
The elimination of waste products of metabolism
Function of renal artery
Carries blood high in waste products from aorta to kidney
What is urea made from and where?
Amino acids, liver
Function of renal vein
Carry purified blood from kidney back to vena cava
Function of ureters
Carry urine formed in kidneys to bladder
What is urine made up of
Water, urea (nitrogenous waste) salts
Function of bladder
Stores urine
Function of urethra
Carries urine out of body
What are the pyramids in the kidney
Cone shaped areas in the medulla projecting into the pelvis of the kidney
Name the three parts of the kidney
Cortex, medulla, pelvis
What is the pelvis
Hollow chamber, expanded head of the ureter
Where are the kidneys located
Back of the abdominal cavity, left kidney slightly higher than right
Give three functions of the kidneys
Blood and tissue pH is regulated
Osmoregulation: control of water and salt concentration in body fluids
Elimination of waste
Give a feature of the kidney that indicates that it is an exocrine gland
It has ducts
From what blood vessel does the renal artery arise
Aorta
Name the three processes that take place in the kidneys and in which part
Filtration: outer cortex
Reabsorption: cortex and medulla
Secretion of substances such as potassium and hydrogen ions: cortex
What does ADH stand for
Antidiuretic hormone
What does ADH do
Changes the permeability of the collecting duct and the distal tubule
When is ADH released
High salt or low water levels
Where is ADH secreted from
Pituitary gland
What effect does ADH have on urine volume
Decreases it
Why should urine not contain protein
Protein molecules are too big to pass into the glomerular filtrate
Why should urine not contain glucose
Glucose should be reabsorbed from the filtrate
How does filtration take place in the nephron
Small molecules forced out of plasma through glomerulus and into bowmans capsule. Form the glomerular filtrate which contains more water and useful substances compared to urine. Large molecules do not enter the filtrate
How does reabsorption take place in the nephron and by what processes
Prox. Convoluted tubule Most of water: osmosis. glucose, amino acids and vitamins: diffusion and active transport. Loop of Henle Water and minerals:descending limb Salts:ascending loop: active transport. Distal con. Tubule Water and salts
What and where is secreted into the blood from the nephron
Prox. Tubule: hydrogen ions due to changes in blood pH
Distal tubule: potassium and hydrogen ions
Name three ways that the glomerulus is adapted to filter blood
High pressure
Large surface area of capillaries
Bowmans capsule only 1 cell thick
Three Adaptations of proximal tubule to aid reabsorption
Thin walled
Long
Lots of mitochondria for active transport
Give three causes of kidney failure
Infections
Tumours
Kidney stones
Two treatments for kidney failure
Dialysis
Transplant
What are two excretory products of plants
Carbon dioxide and oxygen
Where do plants store some wastes
Vacuoles
Falls off as dead structures
What controls the opening and closing of stomata
Guard cells controlled by carbon dioxide concentration
What are lenticels
Small pores in the stem that carry out gaseous exchange
