The kidney

• Excretion is the removal of toxic material, the waste products of metabolism and excess materials
• How is undigested food removed from the body?

  it is egested
• Metabolism means the chemical processes going on in the body
• The main product of excretion is urea
• Excess proteins or amino acids are broken down to produce a nitrogen waste called urea
• Heat, water and carbon dioxide are made from respiration
• The excretory system removes waste products from the body and Regulates the volume and composition of body fluids
• Kidneys are important for homeostasis and excretion
• If you eat too much protein it is broken down into amino acids, these are then broken down by the liver and make urea
• True or false,Urea is toxic at high enough quantities so your body needs to remove it. true
• Urea passes into the blood and the kidneys will filter it out, when it mixes with water it makes urine which then passes to the bladder for storage via the ureter
• If the concentration of fluids change in your body, it can cause water to move in or out by osmosis which could destroy your cells
• When ADH levels increase, more water reabsorbs back into the bloodstream making the urine less dilute.
• Water levels can change by:

  • breathing out water
  • eating and drinking
  • If you sweat or not
• You have two kidneys, each receives blood from the renal artery. Kidneys act like filters removing urea
• Once the bladder fills the urine passes out the urethra
• Any sugar that enters the kidneys is reabsorbed as are some salts
• The amount of water in the urine is adjusted to suit the body’s needs
• The renal vein carries filtrated blood from the kidney to heart after urea and other substances have been removed from the blood
• The renal artery carries blood containing urea and other substances from the heart to kidney
• Each kidney has four parts: ureter, renal cortex, renal medulla, and renal pelvis
• The cortex is the outer layer of the kidney jammed full of filters called nephrons which filter the blood
• The medulla is the middle layer of the kidney which has the tubes carrying filtered wastes to the Center of the kidney. contains the loop of henle
• The pelvis is the area where all collecting ducts come together and connect with the ureter
• The ureter transports urine to the bladder
• The nephron carries out filtering and reabsorbtion
• Nephron consists of glomerulus (filter), proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct.
• Your kidneys filter your blood then transient everything you need
• Glucose, amino acids, mineral salts and urea all move out of the blood into the kidneys by diffusion
• During selective reabsorbtion all of the sugar is then reabsorbed back into the blood by active transport
• The amount of water and mineral ions reabsorbed varies depending on what your body needs
• Kidneys have a rich blood supply so they constantly produce urine
• Excretion is the process of eliminating or expelling metabolic waste
• Homeostasis is the control of internal environments
• Osmoregulation is a homeostatic mechanism that regulates the optimum temperature of water and salts in the tissues and body fluids
• The urinary system are the organs that make urine and remove it from the body
• The proximal convoluted tubule is a long winding part of the nephron where selective reabsorbtion occurs
• The glomerulus is a cluster of nerve endings around the end of the tubule, it filters the blood and removes water, glucose, salts and waste urea from the blood. It’s a barrier for large molecules
• the loop of henle is the long curved region of the nephron which is where water and iron is adjusted
• The collecting duct is the region in the nephron where the final composition of the urine is decided on