Urinary System Flashcards
What are the functions of kidneys?
Maintain blood/body water homeostasis via production of urine
Monitor acid/base balance
Raises blood pressure
What happens when the kidneys secrete renin?
Raises blood pressure
What happens when the kidneys secrete erythropoietin?
Accelerates red blood cell production
What do ureters do?
Conduct urine to the bladder
What is the urethra for?
Passage of urine out of the body
Where is the anatomical position of the kidneys?
Lie on each side on the posterior abdominal wall
What are kidneys encapsulated in?
A retroperitoneal bag and protected by layers of fascia and renal fat
Where are nephrons stored?
In renal pyramids
What do renal pyramids/papilla feed into?
The minor calcyx
What tissue lies between each papilla?
The cortex
What are the 5 different structure in the nephron?
Renal corpuscle (glomerulus)
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct
What are the two types of nephrons?
Juxtamedullary and superficial
Describe the juxtamedullary nephron
Receives around 10% of renal supply
Concentrates urine
Glomeruli in inner cortical regions
Associated with vascular structure
Describe a superficial nephron
Receives around 90% of renal supply
Reabsorbs large percentages of fluid that filters from vasculature
Glomeruli in outer cortical regions
What type of waves propel urine down the ureter?
Peristaltic waves
How does the bladder fill?
By relaxing its muscular wall (detrusor muscle)
What type of epithelial structure lines this system?
Transitional epithelium (urothelium) which is urine proof
Which muscle is the only voluntary muscle in the urinary system?
The external sphincter
What filters blood?
Glomerulus which sits in the Bowman capsule
What forces the plasma through the filtration barrier?
The hydrostatic pressure generated by the blood flowing in and out of the golmerular capillaries
What are the two ways solutes can pass through the apical membrane?
Paracellular or transcellular reabsorption
What allows for a greater and sodium reabsorption?
The countercurrent multiplication mechanism
What part of the kidney has the greatest osmoality?
The papilla then decreases outwards
What part of the nephron recovers most of the reabsorption?
The proximal tubule
How is reabosrbed fluid returned to the vasculature?
Via the peritubular networks
How are different ions reabsorped?
Glucose- via Na cotransport
Na by Pt, driven by basolateral NA/KATPase
Cl-, late PT, paracellular route by a chlorine base exchanger
Water- osmosis
What is micturition?
The action of urinating
Where is there no modification of urine?
Between kidneys and bladder
What happens when the bladder is filled?
The parasympathetic motor efferents to stimulate bladder contraction
Emptying is prevented by the CNS until the outer sphincter is relaxed voluntarily
What carries urine to the bladder?
Channeled by renal calcyes and the renal sinus into ureters
