Chapter 25 Flashcards
what are the major functions of the urinary system
removal of waste
acid base homeostasis
electrolyte balance
controlling blood volume and maintaining BP
briefly describe the major functions of the kidneys
- the main processing centre of our excretory system.
- waste elimination: nitrogenous wastes, bilirubin, CO2, bacterial toxins and inorganic salts
- regulates blood composition: selective reabsorption or secretion, sodium, chloride, potassium, calcium, phosphate,
- regulates BP: secretes enzyme renin that activates a pathway to increase blood volume and pressure
- regulates blood pH: long term: eliminates excess hydrogen ions, and reabsorbs bicarbonate ions.
- Metabolism:
- release hormones: RBC production, and calcium uptake
- maintenance of blood osmolality: regulate water volume and composition of solutes in blood.
List the pathway of filtrate/urine follow form the renal corpuscle to the urethral opening:
afferent arteriole > glomerulus > proximal convoluted tubule > descending loop of henle > ascending loop of henle> distal convoluted tubule > collecting duct > renal pyramid > minor/major calyx> renal pelvis > ureter > bladder > urethra
what is the main function of the cortical nephron versus the juxtameduallary nephron
1) the cortical nephron, contains shorter loops of henle, and are situated in the outer cortex, their main function is reabsorption and secretion.
2) the juxtameduallary nephron has long loops of henle, and are situated close to the cortex - medulla, their main function is regulating urine concentration.
what does vas recta mean
concentration of urine
what is the descending loop of henle permeable to and what is the ascending loop of henle permeable to
1) descending: H2O
2) ascending: Na+, K+, Cl-,
explain the net pressure system of the glomerulus
afferent –> 55mmGh (net = 10 mmGh)
efferent
why can some filtrate pass though the globular capsule and others can’t
due to the fenestrations, size polarity of ions, 3nm easy, >5nm is hard to pass through
What are the main hormones that lay a roll in fine tuning reabsorbing in the DCT (distal convoluted tubule) and collecting duct
- aldosterone: causes reabsorption of Na+ by principle cells, water follows, result=increases blood volume and pressure.
- ADH: increases waste products, principle cells more permeable to water, water reabsorbed = concentrated urine = why coffee dehydrates you,
explain the differences in the formation of dilute versus concentrated urine
ADH: makes the wall of the collecting duct more permeable to water. in the presence of ADH more water is reabsorbed and less is excreted = concentrated urine.