Kidney biology! Flashcards
(49 cards)
what are the four most important features of our internal environment that need to be kept constant
Chemical composition, Blood pH, osmotic pressure, and temperature.
In terms of temperature, catagorise the classes of fish, mammals, birds and amphibia
Mammals and birds regulate their temps (endotherms) and fish and amphibia dont regulate their temps (ectotherms)
How can ectothermic organisms help control their temperatures?
Behaviours like basking, muscle movement or conforming to their environment.
What can be named as the “control centre” for temperature regulation?
The hypothalmus.
What are some of the response mechanisms that are displayed for thermoregulation?
Blood vessels dialating or constricting, sweating, piloerection (hairs sticking up), shivering
What does it mean if one solution is said to be HYPERosmotic to another?
That that solution contains MORE solutes than the other. Therefore contains LESS water.
What does it mean if one solution is said to be HYPO-osmotic to another?
That that solution contains LESS solutes than the other. Therefore contains MORE water.
Which way will water move in relation to a hyperosmotic solution?
Hyperosmotic solutions contain less water therefore water will move into these solutions to try and balance concentrations.
How can you work out the number of osmoles solute per litre of solution?
Osmolarity/solute concentration.
Name three functions of the kidneys
Removal of nitrogenous waste, regulation of water content in the body, and regulation of salt balance.
What are the three types of substances which remove nitrogenous substances called?
Urea, Uric acid, and Ammonia
Why do the kidneys receive so much of our cardiac output?
They control the chemical composition of blood in our body.
Name the two types of kidney nephrons and their functions
Juxta-medullary which help to produce very concentrated urine. Cortical which produce less concentrated urine
What type of kidney nephron is most abundant?
Cortical (85%)
How does fluid move in Bowman’s capsule? Describe this method.
Via ultrafiltration - the blood pressure forces fluid through the glomerular capillaries into bowman’s capsule.
Why do not all substances pass into bowman’s capsule?
As molecules over a certain size are too large to fit through the podocyte split-pores.
How can you work out the glomerular ultrafiltrate?
Blood plasma minus plasma protiens.
Define hydrostatic force
The force a liquid exerts on the walls of whatever is containing it
Why is blood pressure high in glomerular capillaries?
Constriction of the arteriole, number of capillaries, low resistance input pathway.
what does Glomerular hydrostatic pressure promote?
The movement of fluid and molecules out of the plasma and into bowman’s capsule.
What does glomerular colloid osmotic preessure promote?
The movement of water back into the capillaries.
What is the glomerular filtration rate?
How much of the blood plasma is filtered into the kidney tubules per minute
True or false: Kidneys do not show selective excretion
False - kidneys do show selective excretion.
What are the two mechanisms to form urine?
Tubular REabsorption of water and solutes into the body. Substances are selectively secreted from the body into the tubule.
