Urinary System Flashcards
What is the location of the kidneys?
lie against the posterior abdominal wall in a retroperitoneal position.
They extend from T12-L3 and are protected by the ribcage
Why is the right kidney lower?
pushed down due to the liver
What surrounds each kidney?
firbrous renal capsule which holds them in place against the dorsal body wall.
Purpose of the kidneys?
excrete nitrogen waste, maintain water, electrolyte and PH balance of blood.
cleanse blood and adjust its composition
What 3 regions are visible in the frontal section of the kidney?
renal pelvis, medulla, cortex
What is the renal cortex?
granular appearance and light in color
outer region of kidney
What is the renal medulla?
has cone shaped masses called renal pyramids
brown in color
what is renal pelvis?
continuous with ureters and collects urine
branches into calyces
What is a calyce?
Collects urine which flows to the renal pelvis, ureter, bladder
Which parts contain smooth muscle?
wall of calyce, pelvis and ureter
contract rhythmically to push urine to bladder
Where does blood enter the kidneys?
renal arteries
Composition of blood in renal veins is ________, while that of urine is _______
most constant, most variable
Where is most blood that enters the kidney directed to?
cortex where the nephrons are located
Each nephron consists of what?
a glomerulus
What is a glomerulus?
contains capillaries associated with renal tubule
The end of the renal tubule is known as what?
glomerular capsule (bowman’s capsule)
What do efferent arterioles do?
move blood away from glomerulus
What do afferent arterioles do?
move blood to glomerulus
What is special about the glomerulus endothelium?
has pores which allow small substances to pass from blind into the glomerular capsule EXCEPT blood cells and plasma protein
Glomerulus does what?
filters out all material from urine especially blood and protein
Having RBC or protein in urine is an indication of what?
the glomerulus is not functioning
The proximal and distal convoluted tubules are made of what type of tissue?
cuboidal epithelium lined with microvilli.
this increases the surface area for processing the filtrate.
What is the glomerular filtration rate?
120ml/min
decreases with age
increases with body size
Excretion formula?
excretion= filtration-reabsorption +secretion
What electrolytes are reabsorbed by active transport?
water, sodium, potassium (most excreted), chlorine
glucose (100%), amino acids (100%) [except in diabetes mellitus]
What is usually secreted?
urea and uric acid
What causes diabetes insipidus?
lack of ADH (antidiuretic hormone) from posterior pituitary for water retention
what is diabetes mellitus?
high blood sugar levels
What does ADH do?
prevents excess water loss
What should urine look like?
clear or light coloured
What causes urochrome pigment in urine?
hemoglobin breakdown which gives it a yellow color
Purpose of nephrons?
forms urine
