URINARY SYSTEM Filtrate – the fluid that passes across the filtration
§ Consists of 2 kidneys, 2 ureters, urinary membrane
bladder, and the urethra.
Arteries and Veins
FUNCTIONS Renal arteries – branch off the abdominal aorta and
1. Excretion enter the kidneys
2. Regulation of blood volume + pressure.
3. Regulation of the concentration of solutes in Interlobar arteries – pass bet. the renal pyramids
the blood.
4. Regulation of RBC synthesis. Arcuate arteries – arch bet. the cortex and the medulla
5. Regulation of vit. D synthesis.
Interlobular arteries – branch off the arcuate arteries
ANATOMY OF THE KIDNEYS and project into the cortex
Kidneys – bean-shaped organs; size of a tightly clenched
fist Afferent arterioles – arise form branches of the
interlobular arteries and extend to the glomerular
Renal capsule – CT that surround each kidney capillaries
Hilum – where the renal artery and nerves enter Efferent arterioles – extend from the glomerular
capillaries
Renal sinus – cavity that contains blood vessels
Peritubular capillaries – surround the proximal
Cortex (outer) Medulla (inner) – surround the renal convoluted and distal convoluted tubules and the loops
sinus of Henle
Renal pyramids – located bet. the cortex & medulla Vasa recta – specialized portions of the peritubular
capillaries that extend deep into the medulla
Calyx – funnel-shaped structure that surround the tip of
each pyramid Juxtaglomerular apparatus – formed where the distal
convoluted tubule comes in contact with the afferent
Renal pelvis – formed by calyces into a larger funnel arteriole next to BC
Ureter – exits the kidney and connects to the urinary URINE FORMATION
bladder 1. FILTRATION
§ Movement of water, ions, and small molecules
Nephron – functional unit of the kidney through the FM into the BC
v Renal corpuscle
v Proximal convoluted tubule Filtration pressure – forces fluid from the glomerular
v Loop of Henle capillary across the FM into the BC
v Distal convoluted tubule
Glomerular capillary pressure – BP in the glomerular
capillary
Collecting duct – carries the fluid from the cortex
through the medulla
Capsular pressure – pressure of filtrate already inside
the BC
Papillary duct – empty their contents into a calyx
Colloid osmotic pressure – pressure of filtrate within
Juxtamedullary nephrons (15%) – have loops of Henle
the glomerular capillary
that extend deep into the medulla
Regulation of Filtration
Cortical nephrons (85%) – have loops of Henle that do
Cardiovascular shock – the filtration pressure and
not extend deep into the medulla
filtrate formation fall dramatically
Bowman’s capsule – consists of the enlarged end of the
2. TUBULAR REABSORPTION
nephron
§ Movement of substances from the filtrate across
Glomerulus – tuft of capillaries that resembles a ball of the wall of the nephrons back into the blood of
yarn; lies within the indentation of Bowman’s capsule the peritubular capillaries
Podocytes – inner layer of Bowman’s capsule that 3. TUBULAR SECRETION
consists of specialized cells § Active transport of solutes across the nephron
walls into the filtrate
Filtration membrane – formed by glomerular
capillaries, basement membrane, and podocytes of BC
A x 2 .
§ Consists of 2 kidneys, 2 ureters, urinary membrane
bladder, and the urethra.
Arteries and Veins
FUNCTIONS Renal arteries – branch off the abdominal aorta and
1. Excretion enter the kidneys
2. Regulation of blood volume + pressure.
3. Regulation of the concentration of solutes in Interlobar arteries – pass bet. the renal pyramids
the blood.
4. Regulation of RBC synthesis. Arcuate arteries – arch bet. the cortex and the medulla
5. Regulation of vit. D synthesis.
Interlobular arteries – branch off the arcuate arteries
ANATOMY OF THE KIDNEYS and project into the cortex
Kidneys – bean-shaped organs; size of a tightly clenched
fist Afferent arterioles – arise form branches of the
interlobular arteries and extend to the glomerular
Renal capsule – CT that surround each kidney capillaries
Hilum – where the renal artery and nerves enter Efferent arterioles – extend from the glomerular
capillaries
Renal sinus – cavity that contains blood vessels
Peritubular capillaries – surround the proximal
Cortex (outer) Medulla (inner) – surround the renal convoluted and distal convoluted tubules and the loops
sinus of Henle
Renal pyramids – located bet. the cortex & medulla Vasa recta – specialized portions of the peritubular
capillaries that extend deep into the medulla
Calyx – funnel-shaped structure that surround the tip of
each pyramid Juxtaglomerular apparatus – formed where the distal
convoluted tubule comes in contact with the afferent
Renal pelvis – formed by calyces into a larger funnel arteriole next to BC
Ureter – exits the kidney and connects to the urinary URINE FORMATION
bladder 1. FILTRATION
§ Movement of water, ions, and small molecules
Nephron – functional unit of the kidney through the FM into the BC
v Renal corpuscle
v Proximal convoluted tubule Filtration pressure – forces fluid from the glomerular
v Loop of Henle capillary across the FM into the BC
v Distal convoluted tubule
Glomerular capillary pressure – BP in the glomerular
capillary
Collecting duct – carries the fluid from the cortex
through the medulla
Capsular pressure – pressure of filtrate already inside
the BC
Papillary duct – empty their contents into a calyx
Colloid osmotic pressure – pressure of filtrate within
Juxtamedullary nephrons (15%) – have loops of Henle
the glomerular capillary
that extend deep into the medulla
Regulation of Filtration
Cortical nephrons (85%) – have loops of Henle that do
Cardiovascular shock – the filtration pressure and
not extend deep into the medulla
filtrate formation fall dramatically
Bowman’s capsule – consists of the enlarged end of the
2. TUBULAR REABSORPTION
nephron
§ Movement of substances from the filtrate across
Glomerulus – tuft of capillaries that resembles a ball of the wall of the nephrons back into the blood of
yarn; lies within the indentation of Bowman’s capsule the peritubular capillaries
Podocytes – inner layer of Bowman’s capsule that 3. TUBULAR SECRETION
consists of specialized cells § Active transport of solutes across the nephron
walls into the filtrate
Filtration membrane – formed by glomerular
capillaries, basement membrane, and podocytes of BC
A x 2 .
