Chapter 7 - Kidneys Flashcards
Why are fluctuations in homoeostasis dangerous?
They can disrupt biochemical activities and large fluctuations can kill the cells
What is homoeostasis?
The maintenance of a constant internal environment
What four internal features must be kept constant?
Chemical composition – blood pH ranging from 7.35 to 7. 45 – osmotic pressure, Osmo regulation – temperature
What are effectors?
Things that change in response to stimuli in order to correct and achieve homoeostasis
Name some of the response mechanisms that change in the body to correct temperature?
Blood vessels constrict or dilate – sweat produced – piloerection – shepherding thermogenesis
What does it mean if one solution is hyperosmotic to another?
Hyper osmotic – means the solution contains more solutes than other solution it therefore contains less water
What does it mean if one solution is hypoosmotic to another?
It means it contains less solutes than the other solution therefore contains more water
Define osmolarity
The number of osmoles solute per litre of solution
Name the three important regulatory functions of the kidney
Removal of nitrogenous waste –
regulation of water content of the body – regulation of salt balance, sodium, potassium, chlorine, magnesium, calcium this is known as ionic regulation
What three ways can ammonia be excreted?
As ammonium, urea and you uric acid
Describe the toxicity levels from high to low for ammonia, Urea and uric acid
Ammonia high - urea low - uric acid very low
Describe the solubility for ammonia, urea, Uric acid
Ammonia has high solubility levels, urea has a low solubility levels, uric acid is almost not soluble
Describe the metabolic cost for ammonia, urea, uric acid – from high to low
Ammonia has no metabolic cost
Urea has some metabolic cost
Eurich acid has a high metabolic cost
What animals would have ammonia in the form of nitrogenous waste?
Fish or aquatic animals
What animals with have urea in the form of nitrogenous waste?
Mammals, adult terrestrial amphibians
What animals would have uric acid in the form of the nitrogenous waste,
birds and insects
What percentage of the bodyweight are the kidneys?
1%
What did juxtamedullary nephrons mean
Urine is very concentrated
What are the two types of nephrons?
Cortical and juxtamedullary
What does cortical nephrons mean?
Less concentrated urine
What percentage of nephrons are cortical and juxtamedullary and humans?
85% are cortical and 15% of juxtamedullary
What animals have both juxtamedullary and cortical nephrons?
Birds and mammals