packet 23 Flashcards
Kidneys, ureters, urinary bladder & urethra are all part of the
urinary system
Urine flows from each kidney, down its ureter to the bladder and to the outside via
the urethra
Urine flows from each kidney, down its ureter to the bladder and to the outside via the urethra
Filter the blood and return most of water and solutes to the bloodstream
urinary system
Regulation of blood ionic composition
Na+, K+, Ca+2, Cl- and phosphate ions
Regulation of blood pH, osmolarity & glucose
Regulation of blood volume
conserving or eliminating water
Regulation of blood pressure
secreting the enzyme renin
adjusting renal resistance
Release of erythropoietin & calcitriol
Excretion of wastes & foreign substances
overview of kidney function
Micro essay
functions of kidneys
- Regulation of blood ionic composition
- Regulation of blood pH, osmolarity & glucose
- Regulation of blood volume
- Regulation of blood pressure
- Release of erythropoietin & calcitriol
- Excretion of wastes & foreign substances
4-5 in long, 2-3 in wide,1 in thick
Found just above the waist between the peritoneum & posterior wall of abdomen
retroperitoneal along with adrenal glands & ureters
Protected by 11th & 12th ribs with right kidney lower
kidney bean shaped
external anatomy of kidney
Blood vessels & ureter enter hilus of kidney
Renal capsule = transparent membrane maintains organ shape
Adipose capsule that helps protect from trauma
Renal fascia = dense, irregular connective tissue that holds against back body wall
external anatomy of kidney
transparent membrane maintains organ shape
renal capsule
helps protect from trauma
adipose capsule
dense, irregular connective tissue that holds against back body wall
renal fascia
parenchyma of kidney and drainage system fills renal sinus cavity
internal anatomy of the kidneys
renal cortex = superficial layer of kidney
renal medulla
inner portion consisting of 8-18 cone-shaped renal pyramids separated by renal columns
renal papilla point toward center of kidney
parenchyma of kidney
superficial layer of kidney
renal cortex
fills renal sinus cavity
cuplike structure (minor calyces) collect urine from the papillary ducts of the papilla
minor & major calyces empty into the renal pelvis which empties into the ureter
drainage system
collect urine from the papillary ducts of the papilla
calyces
Outline a major calyx & the border between cortex & medulla.
internal anatomy of kidney
Abundantly supplied with blood vessels
receive 25% of resting cardiac output via renal arteries
Functions of different capillary beds
glomerular capillaries where filtration of blood occurs
vasoconstriction & vasodilation of afferent & efferent arterioles produce large changes in renal filtration
peritubular capillaries that carry away reabsorbed substances from filtrate
vasa recta supplies nutrients to medulla without disrupting its osmolarity form
Sympathetic vasomotor nerves regulate blood flow & renal resistance by altering arterioles
blood and nerve supply of kidney
filtration of blood occurs
vasoconstriction & vasodilation of afferent & efferent arterioles produce large changes in renal filtration
glomerular capillaries
afferent=
efferent=
arrive
leave
carry away reabsorbed substances from filtrate
peritubular capillaries
supplies nutrients to medulla without disrupting its osmolarity form
vasa recta
Functions of different capillary beds
- glomerular capillaries where filtration of blood occurs
- peritubular capillaries that carry away reabsorbed substances from filtrate
- vasa recta supplies nutrients to medulla without disrupting its osmolarity form
Glomerular capillaries are formed between the afferent & efferent arterioles
Efferent arterioles give rise to the peritubular capillaries and vasa recta
blood vessel around nephron
Kidney has over 1 million composed of a corpuscle and tubule
Renal corpuscle
renal tubule
collecting ducts and papillary ducts
nephron
site of plasma filtration
- -glomerulus is capillaries where filtration occurs
- -glomerular (Bowman’s) capsule is double-walled epithelial cup that collects filtrate
renal corpuscle
- proximal convoluted tubule
- loop of Henle dips down into medulla
- distal convoluted tubule
renal tubule
drain urine to the renal pelvis and ureter
collecting ducts and papillary ducts
80-85% of nephrons are cortical nephrons
Renal corpuscles are in outer cortex and loops of Henle lie mainly in cortex
cortical nephron
15-20% of nephrons are juxtamedullary nephrons
Renal corpuscles close to medulla and long loops of Henle extend into deepest medulla: excretion of dilute or concentrated urine
juxtamedullary nephron
Single layer of epithelial cells forms walls of entire tube
Distinctive features due to function of each region
–microvilli
–cuboidal versus simple
–hormone receptors
histology of the nephron and collecting duct
surrounds capsular space
- podocytes cover capillaries to form visceral layer
- simple squamous cells form parietal layer of capsule
bowman’s capsule
arise from afferent arteriole & form a ball before emptying into efferent arteriole
glomerular capillaries
Bowman’s capsule surrounds capsular space
–podocytes cover capillaries to form visceral layer
–simple squamous cells form parietal layer of capsule
Glomerular capillaries arise from afferent arteriole & form a ball before emptying into efferent arteriole
structure of renal corpuscle
Remains constant from birth
any increase in size of kidney is size increase of individual nephrons
If injured, no replacement occurs
Dysfunction is not evident until function declines by 25% of normal (other nephrons handle the extra work)
Removal of one kidney causes enlargement of the remaining until it can filter at 80% of normal rate of 2 kidneys
number of nephrons
