Flashcards
Excretion
Cards in this deck (39)
- 1Define Excretion.The eliminating of waste products of metabolism
- 2what is Urea made from and where is it made?the combination of ammonia and carbon dioxide
Made in the liver - 3What are the sides effects of having to much protein which leads to too much Urea?1. Tiredness
2. Nausea and vomiting
3. Headaches
4. Bad taste in the mouth
5. Bad breath
6. Poor memory and concentration - 4what blood vessels are present in the Liver?1. Hepatic artery
2. Hepatic portal vein
3. hepatic vein - 5what are the features of the Hepatic artery?Carries oxygenated blood into the liver
- 6what are the features of the Hepatic portal vein?carries nutrient rich blood - de-oxygenated high concentration of glucose and amino acids.
comes from the small intestine - 7what are the features of the Hepatic vein?carries de-oxygenated blood away from the liver to the Vena Cava and back to the heart.
- 8what is the liver tissue made up of?Lobules
- 9What are the lobules made up of?hepatocytes
- 10what is the function of the sinusoids?carry blood to the central vein from the hepatic portal vein and hepatic artery
- 11What is the function of Bile Canaliculi?Carry bile to bile duct in portal canal.
- 12What is the function of the Kupffer Cells?contain phagocytic macrophages that engulf bacteria present in blood.
- 13What is deamination?the removal of the amine group from an amino acid
- 14what happens during deamination?The amino acid group is removed and from ammonia and a keto acid.
- 15why is ammonia very toxic?It is very soluble and froms an alkaline solution
- 16How is Urea formed?The ammonia is combined with CO2 using ATP
- 17Where does the detoxification of alcohol happen?In the smooth endoplasmic reticulum of hepatocytes.
- 18what is the process of deamination?1. Ethanol dehydrogenase converts the ethanol to ethanal.
2.Aldehyde dehydrogenase then converts the ethanal to ethanoate - 19What is needed during deamination?Oxidised NAD
- 20What substances (other than alcohol) are removed in the kidneys and why?1. Hormones- prevent long lasting effects
2. Medicinal drugs - 21what could an excess amount of alcohol cause in the liver.Fatty liver, which may develop into Cirrhosis.
- 22What does Cirrhosis cause?The ammonia to build up- can lead to damage to the CNS and can cause coma/death.
- 23why is it important to remove metabolic waste ( CO2)?1. It may denature enzymes due to the change in pH.
2. Transport proteins are affected. - 24What is the gross structure of the kidney?cortex, medulla, pelvis
- 25What are the two stages of forming urine?1. Ultrafiltration
2. Selective reabsorption - 26where does ultrafiltration occur?In the Bowman's capsule- all in the cortex of the kidney
- 27How is the blood pressure maintained during Ultrafiltration?The afferent arteriole leading to the glomerulus is wider than the efferent arteriole leading out
- 28What is the process of Ultrafiltration?The process when blood plasma is forced out from blood vessels in bowman's capsule.
Only small molecules will pass through the blood vessel such as sodium ion, potassium ion, urea. - 29What size are the molecules that are not able to pass through the basement membrane?molecules with a relative molecular mass of over 69,000
- 30Why can the water in the filtrate not move back into the capillaries?Because of the high hydrostatic pressure generated in the carpillaries
- 31What are Podocyte cells?Cells i the Bowman's capsule that have finger like projections
- 32Where does Selective reabsorption take place?In the Proximal Convoluted Tubule.
- 33What is the process of Selective reabsorption?It is the process by which certain substances that are required by the body (such as glucose, amino acids, vitamins and water) that have been filtered out of the blood during ultrafiltration, are reabsorbed.
- 34What happens during selective reabsorption?The Na+ is actively pumped out of the inner membrane of the PCT.
This causes the conc. of Na+ in those cells to drop and the Na+ passively enters the epithelial cells.
The Na+ ions are co-transporters- bring in other substances (glucose).
Water is reabsorbed by osmosis down the water potential gradient. - 35What is the role of the Loop of Henle?To create a very low water potential in the Medulla.
- 36What are the stages of reabsorption in the loop of Henle?1. fluid passes down loop- becomes more concentrated (salt diffuses out)
2. Fluid moves up loop- becomes more dilute.
3. This passes salts from ascending limb to descending limb = increasingly concentrated,
4. creates concentration gradient in medulla.
5. water potential is v. low
6. fluid passes along collecting duct- water is withdrawn by osmosis into tissue fluid.
7 results in urine- conserves water - 37What does the Distal Convoluted Tubule do?Actively absorbs sodium ions
- 38What is the name given to the hormone that alters the permeability of the collecting duct?Anti- diuretic Hormone (ADH)
- 39How does ADH alter the permeability of the collecting duct?1. Cells in the wall of the collecting duct have membrane receptors for ADH.
2. ADH binds to the receptors and cause a series of enzyme-controlled reaction inside the cell.
3. The end result id to insert aquaporins in the walls of the collecting duct.
Information
- Description
- A Levels Biology (F214) Flashcards on Excretion, created by megan.radcliffe16 on 28/11/2014.
- Created by
- megan.radcliffe16
- Views
- 185
- Tags
- Rating