Excretion (Ch 41) Flashcards
What is diffusion?
The random motion of individual molecules, with net movement occurring where there are areas of higher and lower concentration of the molecules.
What is osmoregulation?
The regulation of osmotic pressure inside cells and organisms.
What is a hypotonic solution?
Solutions with low concentration solutes, high water
What is a hypertonic solution?
Solutions with high concentration solutes, low water
What is an isotonic solution?
Equal concentrations of solutes and water
What by-product is produced when proteins and nucleic acids are broken down by metabolism?
Ammonia
Since ammonia contains nitrogen and is toxic to organisms, it is a form of what?
Nitrogenous waste
What are the three major forms of nitrogenous waste excreted by animals?
Urea, Uric acid, and Ammonia
What are the three processes of waste elimination?
1) Filtration - which produces a filtrate of the blood.
2) Reabsorption - an active process that removes useful solutes from the filtrate and returns them to the blood
3) Secretion - when solutes are added to the filtrate
Define Renal Cortex.
Outer tissue layer of the kidney; where the circulatory system connects with the nephrons; where filtration occurs.
Define Renal Medulla.
Inner tissue layer of the kidney.
Define Renal Pelvis.
The chamber that collects the urine and sends it on the ureter.
Define Cortical.
Nephrons that are confined to the cortex.
Define Juxtamedullary.
an extension of nephrons into the medulla.
Define Glomerulus.
a cluster of capillaries around the end of a kidney tubule, where waste products are filtered from the blood.
What happens in the proximal tube of the kidneys?
Filtration, secretion, and absorption occurs.
What happens in the descending loop of henle?
Water leaves, salt stays.
What important role does the loop of Henle play?
They create a concentration gradient in the interstitial fluid from the cortex to the medulla, with the interstitial fluid of the cortex being less concentrated and the interstitial fluid of the medulla being more concentrated.
What happens in the ascending loop of Henle?
Salt leaves; water stays.
What happens in the distal tube of the kidneys?
Absorption and secretion takes place
What happens in the collection duct?
Water is removed and some salt regulation action occurs
What are the concentrations of each section in the filtrate?
- Low concentrations of solutes in the cortex
- medium concentrations of solutes in the outer medulla
- high concentrations of solutes in the inner medulla.
Explain what happens in the Vasa Recta.
The blood in the vasa recta moves in a countercurrent fashion, just like the filtrate in the loop of Henle, to maintain the concentration gradient from the cortex to the medulla.
Each kidney collects urine in the ____ ____. This drains via the _____ to the _____
Renal Pelvis; ureter; bladder.
How are kidney stones accumulated?
The are accumulated as a result from a build up of crystals in the urine.
What are the four types of kidney stones?
Calcium stones
Uric acid stones
Infection stones
Crystine stones
How do you get calcium stones?
When you acquire too much calcium or oxalate such as in cola, tea, coffee, dairy, vitamin D, or overactive parathyroid
How do you get uric acid stones?
By having excess meat in diet
How do you get infection stones?
By having too much ammonia from urinary tract infection
How do you get crystine stones?
By hereditary, crystals form from the amino acid Crystine.
Define osmosis.
The net movement of water molecules from regions of HIGH water concentrations to LOW water concentrations.
What is a nephron?
The functional unit of the kidney.
Define the Bowman’s Capsule?
A membranous sac where tufts of capillaries are encased.
