1/16
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
What systems are involved in maintaining fluid and electrolyte homeostasis?
Cardiovascular system, respiratory system, urinary system, behavioral responses, and endocrine pathways.
How does extracellular fluid (ECF) osmolarity affect cells?
It affects cell volume due to osmosis.
What is the relationship between water gain and water loss?
Water gain equals water loss.
How can water gain occur?
Water gain can occur via intravenous (IV) injection.
What are some additional causes of water loss?
Excessive sweating and diarrhea.
Describe the process of fluid concentration in the kidneys.
Isosmotic fluid leaving the proximal tubule becomes more concentrated in the descending limb; solute removal in the thick ascending limb creates hyperosmotic fluid.
What regulates permeability to water and solutes in the distal tubule and collecting duct?
Hormones regulate permeability.
What determines final urine osmolarity?
Final urine osmolarity depends on reabsorption in the collecting duct.
What is the countercurrent multiplier?
It creates high osmolarity of medulla ECF through osmosis of water out of the descending limb and solute transport out of the ascending limb.
How does the countercurrent multiplier affect filtrate and interstitial fluid (ISF)?
It creates dilute filtrate and concentrated ISF.
What happens to water and solutes in the vasa recta?
They move into the vasa recta if an osmotic/concentration gradient exists.
What is the significance of blood flow in relation to filtrate flow in the tubules?
Blood flow is opposite to filtrate flow, helping to prevent dilution of concentrated ISF.
What is the role of Antidiuretic Hormone (ADH)?
ADH causes aquaporins to be added to the apical membrane of collecting duct tubule cells.
How does ADH function at the cellular level?
Vasopressin binds to a membrane receptor, activating a cAMP second messenger system that inserts AQP2 water pores into the apical membrane.
What triggers the release of ADH?
Decreases in blood pressure, decrease in atrial stretch due to low blood volume, and osmolarity greater than 280 mOsM.
What is AVP and where is it produced?
AVP (arginine vasopressin) is made and packaged in the cell body of a neuron.
How is AVP transported and released?
Vesicles containing AVP are transported down the cell and stored in the posterior pituitary, then released into the blood.