SB7h-i Flashcards
(separated for semester 2 test 1)
What is osmoregulation?
The control of water balance and mineral salts in the body.
What does the urinary system consist of?
- Kidneys
- Ureter
- Bladder
- Renal vein
- Renal artery
What is the job of the urinary system?
Removes excess volume of water, mineral salts and toxic substances such as urea from the blood.
How is urea produced and where is it found?
Urea is produced in liver cells from the breakdown of excess amino acids. Urea passes into the blood and is carried to the kidneys.
What are the names and jobs of each part of the urinary system? (7)
Renal Veins: Carry blood with wastes removed back to the body
Renal arteries: Carry blood from the body to the kidneys
Kidneys: Remove substances from the blood and make urine
Ureters: Carry urine from the kidneys to the bladder
Bladder: Stores urine
Urethra: Allows urine to flow through to the outside of the body
Bladder muscle: Keeps the exit from the bladder closed until a person decides to urinate
Check book page 156 diagram.
What happens if a person undergoes kidney failure?
A person can survive by having just one kidney. However, if due to infection or accident both kidneys are damaged then the person will need a kidney transplant. The patient will need kidney dialysis until the transplant is found.
What is kidney dialysis and why does it happen?
Since the kidneys are not functioning waste substances will not be able to leave the body and therefore will increase in concentration in the blood. The patient is connected to a dialysis machine that will filter the blood and remove any waste substances.
What is the kidney dialysis machine made up of?
Check book page 157 diagram.
Describe the process of kidney dialysis.
- A tube is connected to the vein and another tube is connected to the same vein of the patient.
- Blood enters the dialysis machine through the vein.
- The tubes in the dialysis machine are made up of a partially permeable membrane so the osmosis and diffusion can take place.
- The dialysis fluid contains the same concentration of glucose as in the blood plasma.
- As blood enters due to concentration gradient, excess water, urea and glucose are removed from the blood
- The filtered blood returns into the patient’s vein
When does kidney transplant occur?
As a treatment for kidney failure.
How does a successful kidney transplant occur?
- A compatible kidney is donated
- All organs have antigens on them that are being recognised by the immune system as safe so they will not be attacked by their own body cells
- A compatible kidney needs to have the same antigens on its surface so that the immune system will recognise them as safe and therefore not attack them
What happens if the donor kidney is not compatible?
If the donor kidney is not compatible it means the antigens on it are different, so the immune system recognises them as foreign and attacks it to destroy it. This causes rejection of the organ.
What does the kidney consist of?
Small structures called nephrons.
What does each nephron consist of?
- Bowman’s capsule and glomerulus
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
Check book page 158 diagram.
What happens in the Bowman’s capsule and glomerulus?
Glomerulus are capillaries found in the pocket of the Bowman’s capsule, where ultrafiltration takes place.
What occurs duration ultrafiltration in the Bowman’s capsule?
Blood comes in the glomerulus with high pressure and everything is filtered in the Bowman’s capsule except large proteins, red and white blood cells.
What passes through the Bowman’s capsule?
- Urea
- Water
- Amino acids
- Hormones
- Glucose
- Plasma
What happens in the primal convoluted tubule?
Selective reabsorption occurs, where glucose and some mineral ions are absorbed back into the blood.
What happens in the Loop of Henle?
Most water and some mineral ions (NaCl) are reabsorbed into the blood.
What happens in the distal convoluted tubule?
Water and mineral ions are reabsorbed into the blood.
What happens in the collecting duct?
Reabsorption of water into the blood with the help of ADH (anti-diuretic hormone).
Where is ADH released from and what is its function?
The ADH (anti-diuretic hormone) is released from the pituitary gland. Its function is to make the walls of the collecting duct permeable to water so water can be reabsorbed into the blood and less is lost in urine.
What happens when there is too little water in the blood?
Lots of ADH is released to preserve water so you lose less in urine, thus the walls of the collecting duct become permeable so more water is reabsorbed into the blood by osmosis from high to low concentration.
What happens when there is too much water in the blood?
Little ADH is released so excess water is lost in urine, thus the walls of the collecting duct become not so permeable so less water is reabsorbed into the blood by osmosis from high to low concentration.
How and where is urea produced?
Excess amino acids need to be broken down otherwise are harmful to the body so they are converted to urea in the ornithine cycle, which occurs in the liver.
Why do desert animals have a longer Loop of Henle?
The longer the Loop of Henle, the more water is reabsorbed into the blood so less is lost in urine.
