Urinary System Flashcards
components of the urinary system
kidneys, ureters, urinary bladder and urethra
blood supply to the kidneys
25% of total blood pumped by the heart goes to the kidneys at rest
- need such a large blood supply because the kidneys filter the plasma, returning most water and solutes to the bloodstream
functions of the kidneys
excretion regulation of blood volume and pressure regulation of solute concentration in blood regulation of pH regulation of RBC synthesis vitamin D synthesis
excretion as a function of the kidneys
urea
urobillin (a waste product from the heme group of RBC)
toxins
drugs and waste products
regulation of blood volume and pressure as a function of the kidneys
flow=pressure/resistance
so if you have a greater volume of blood, BP increases and causes flow to increase.
thus, when you decrease blood volume (by removing fluids) you also decrease BP
regulation of solute concentration in the blood as a function of the kidneys
regulates solute concentration of ions such as Na+, K+, Cl-
regulation of pH as a function of the kidneys
H+ ion balance is regulated in the kidneys
they work with the bicarbonate system to regulate blood pH
regulation of RBC synthesis as a function of the kidneys
erythropoietin, the hormone responsible for RBC synthesis, is produced in the kidney
vitamin D synthesis as a function of the kidneys
active form of vitamin D is created by kidneys and aids in calcium absorption from the gut into the blood
where are the kidneys found in the body
- they are positioned above the wait
- are retroperitoneal, protected by 11th and 12th floating ribs
- right kidney is slightly lower than the left because the liver is located predominantly on the right side
3 layers of CT that surround the kidney
(superficial to deep)
- peritoneum on anterior and lateral sides of kidney
1. renal fascia
2. adipose capsule
3. renal capsule
renal fascia
- most superficial layer around the kidney
dense irregular CT layer that connects the kidney to abdominal cavity and other organs on the abdominal wall
adipose capsule (CT layer around kidney)
middle layer of protection
- might be thicker in obese people
- surrounds entire kidney, cushions with essential fat
renal capsule
innermost layer of protection around the kidney
- surrounding dense irregular CT that gives strength in many directions
- maintains and gives kidney its bean shape and holds everything together
renal hilum
medial curved part of kidney where blood vessels and ureters enter/exit the kidney
renal cortex
the part of the kidney close to the outside
- some dips down towards hilum called the renal column
renal column
parts of renal cortex that dip down between pyramids
renal medulla
highly organized into pyramids that are cone shaped structures on the inside of the kidney (deep to cortex)
- a person has 8-18 pyramids
- larger portion is the base of the pyramid, apex is called the renal papilla
nephron
functional portion of the kidney where filtration happens
- highly supplied with blood
- long tube, most of it located in cortex, loop runs into medullary region
- most filtrate produced in 1st portion of the nephron
path of urine drainage in the kidney
collecting duct > papillary duct > minor calyx > major calyx > renal pelvis > ureter > urinary bladder