Urinary System (Ch. 27) Flashcards
What does the urinary system include?
Kidneys
Ureters
Bladder
Urethra
What are the fxns of the urinary system?
Elimination of nitrogenous wastes and excess ions (storage and excretion of urine)
Maintain ion balance, acid-base (pH balance), regulates blood volume
Where are the kidneys located?
Retroperitoneal position (behind vertebrae T12-L 1, 2, or 3)
*Remember, the kidneys are not parallel to each other.
What protects the kidneys?
The floating ribs
Kidney anatomy
Study kidney drawings. Familiarize yourself with these structures and their locations: Hilum Major calyx Renal cortex Papilla of pyramid Renal medulla Renal pyramid [in renal medulla] Renal pelvis Minor calyx Renal column Fibrous capsule Ureter
Starting from the outer region, the kidney is surrounded by a ____ ____.
Fibrous capsule
In this saggital section, the outer part of the kidney is the ____ and the inner part is the ____.
Cortex; Medulla
Beyond the medulla is the ____ ____, which is really just an expansion of the ureter.
Renal Pelvis
The ureter will carry the ____ to the bladder.
Filtrate
Looking more closely, the medulla has a series of segments called the ____ ____.
Renal Pyramids
Each pyramid is separated by a ____ ____ (extension of the cortex).
Renal Column
The papilla of the pyramid contain many ____ ____, which drain urine into the ____ ____ located in the renal pelvis.
Urine Tubules; Minor Calices
Minor calices drain into larger, ____ ____, which then drain into the ____.
Major Calices; Ureter
The ____ is the region where blood vessels and the ureter enter/exit.
Hilum
Kidney Blood Supply
Renal arteries branch several times, travel through renal columns to afferent arterioles. The afferent arterioles form a capillary network called the glomerulus. Once blood is filtered, it exits via efferent arterioles.
Efferent arterioles branch into peritubular capillaries surrounding nephron structures.
–termed peritubular capillaries if they surround tubules in cortex
Peritubular capillaries around Loop of Henle are the vasa recta
Drain into interlobar vessels eventually
The Nephron
A nephron is the smallest functional unit of the kidney. It’s the actual site of filtration of all of the blood passing through the body. Each renal pyramid contains millions of nephrons.
How many quarts blood can a healthy kidney process per hour?
about 8-9 quarts of blood/hour
Glomerulus
Capillary bed fed by the afferent arteriole. The walls of the glomerular capillaries are fenestrated - they have slits or pores - and small molecules and water (not RBCs!) are pushed out of the capillaries and into Bowman’s capsule. The fluid is termed filtrate and will be the urine
Filtrate vs Blood
Always keep track of whether you’re talking about filtrate or blood. The filtrate is in the tubules. The blood is in vessels.