Week 13: Interdependence Osmoregulation Control Of Blood Pressure Flashcards
What is osmosis?
The diffusion of water across a membrane in response to osmotic pressure caused by an imbalance of molecules on either side of the membrane
What’s osmoregulation?
The process of maintaining salt and water balance (osmotic balance) across membranes within the body’s fluids
Why are osmoregulation and osmotic balance important?
Without these, toxic waste and water can accumulate in the body.
What is osmolarity and the units used?
Total number of particles in a solution (Osmoles/L)
What is molarity and the units used?
Number of particles of a solute in a given volume of solvent (Moles/L)
What is osmolality and the units used?
Total numer of particles in a given mass of solvent (Osmoles/kg)
What is molality and the units used?
Number of particles of a solute in a given mass of solvent (Moles/kg)
What’s the afferent arteriole? Does it contain blood or filtrate?
The capillary network that supplies the nephron with blood to be filtered (Enters glomerulus)
Has blood
What’s the Bowmans’ capsule or glomerular capsule? Does it contain blood or filtrate?
A capsule-shaped membranous structure surrounding the glomerulus of each nephron
Extracts wastes, excess salts, and water from the blood
Has blood
What’s the collecting duct? Does it contain blood or filtrate?
Collects filtrate coming from the nephrons
Has filtrate
What’s the distal convoluted tubule? Does it contain blood or filtrate?
The last part of the nephron that connects and empties its contents into collecting ducts
Has filtrate
What’s the efferent arteriole? Does it contain blood or filtrate?
The capillary network that supplies the nephron with blood that needs to be filtered (Exits glomerulus)
Has blood
What’s the glomerulus? Does it contain blood or filtrate?
The network of capillaries that makes up the renal corpuscle
Has blood
What’s the loop on henle? Does it contain blood or filtrate?
The looop between the descending and ascending limbs that goes through the renal medulla
Has filtrate
What’s the peritubular capillaries? Does it contain blood or filtrate?
Formed when the efferent arteriole exists the glomerulus
Surrounds the renal tubule
Has blood
What’s the proximal convoluted tubule? Does it contain blood or filtrate?
The first part of the renal tubule; close to glomerulus
Has filtrate
What’s the vasa recta? Does it contain blood or filtrate?
Where the peritubular capillary network forms a network around the loop of henle
Has blood
Describe glomeruluar filtration.
All solutes (except for proteins) are filtered out into the glomerulus using the capillary network. They pass via passive diffusion.
Describe secretion.
Solutes and waste enter kidney tubules via active or secondary active transport
Describe reabsorption.
Involves most parts of the nephron via passive or active transport
Almost all nutrients are reabsorbed. Water and some key nutrients are regulated.
What are osmoconformers? Give some examples.
They do not regulate their body fluid osmolarity; it matches the environmental osmolarity.
Ex. Sponges, some marine invertebrates
What are osmoregulators? Give some examples.
They do regulate their body fluid osmolarity.
Ex. Birds, fish
What are ionoregulators? Give some examples.
They regulate the concentration of at least some ions.
Ex. Sharks, amphibians, birds, mammals, arthropods
What are ionoconformers? Give some examples.
They don’t regulate the concentration of ions.
Ex. Sponges, some marine invertebrates
What are euryhalines? Give some examples.
They tolerate a wide environmental osmolarity range.
Ex. Octopus
What are stenohalines? Give some examples.
They tolerate a narrow environmental osmolarity range.
Ex. Eel
Describe the osmoregulatory mechanisms of freshwater fish.
They drink little water, passively absorb water through their skin, actively take up ions through their gills, and excrete dilute urine.
Describe the osmoregulatory mechanisms of saltwater fish.
They drink lots of water, passively lose water through their skin, excrete ions through their gills, and excrete concentrated urine.
How do contractile vacuoles help regulate osmolarity?
They use endocytosis to allow nutrients and water to move into the cell.
How does nephridia help regulate osmolarity?
It’s coated with cilia and helps get water into the pores.
How do malphigian tubules help regulate osmolarity?
It’s lined with microvilli and aids with reabsorption.
What occurs in the baroreceptor system when blood pressure increases? Decreases?
When blood pressure increases, the baroreceptors are stretched more tightly, initiating action potentials at a higher rate.
When blood pressure decreases, the degree of stretch is lower, so the firing rate is slower.
