urinary system Flashcards
functions ?
Excretion:formation of urine to remove
Regulation:Modifying the volume and solute balance in plasma
where does excretion of urine occur in body?
through the kidneys to the Urethra
where does regulation occur in body?
mammalian kidney
position of the kidneys in the body?
near top of abdominal cavity, imbedded in adipose tissue, anchored by renal fascia, covered by renal capsule
Kidney internal structure?
an outer cortex, a medulla in the middle, and the renal pelvis in the region called the hilum
nephron?
produces urine in the process of removing waste and excess substances from the blood.
cortical nephron
-type of nephron(85%)
-tubular system penetrating into the medulla(short loop of Henle)
-function is excretion®ulation
blood flow into and around a
nephron?
Renal artery -> Afferent arterioles -> Glomerulus -> Arterioles(carries out of kidney)
functional role renal corpuscle?
-Blood is filtered by the glomerulus
-filtered fluid (glomerular filtrate) is collected in the Bowman’s capsule
round part of nephron, before the proximal tubular
functional role of proximal convoluted tubule?
-absorption of H2O, organic molecules(glucose amino acids), vitmines & ions
-secretion of materials, drugs
-facilitated diffusion&cotransport.
-osmosis through aquaporins
functional role of loop of Henle?
-absorption of H2O, Na+,Cl-
-reabsorbs 25% H2O, Na+,Cl-
functional role of distal convoluted tubule?
-absorption of Na+, Ca2+, H2O
-Secretion of ions, acids, drugs&toxins
regulating extracellular fluid volume and electrolyte homeostasis
functional role of collecting duct?
-final adjustments to osmolarity of filtrate(by collecting duct)
-Papillary duct receives filtrate from several medullary collecting ducts
processes in urine formation and know where they occur?
-Glomerular filtration:filtered to remove excess fluid and waste
-Tubular reabsorption:back into the bloodstream
-Tubular secretion: removed from the renal tubular cells -> collecting duct. final step in urine formation
how is glomerular filtration rate controlled?
-Local autoregulation
-Hormonal regulation
-Autonomic regulation (involuntary)
how do hormones influence absorption in the tubules?
The hormone also promotes sodium retention and loss of potassium and hydrogen ions by the kidney