54 terms

Chapter 26- Urinary System

Seeley's Anatomy Nineth Edition
Urine formation involves
filtration of the plasma, reabsorption from the filtrate, and the secretion into the filtrate.
Formation of filtrate depends on a
pressure gradient
The active transport of substances into the filtrate is called
tubular secretion.
The part of the cardiac output through the kidneys
is the renal fraction
The amount of filtrate produced per minute is called
the glomerular filtration rate
At the rate of 125 ml of filtrate/minute, estimate the amount of filtrate formed in 24 hours.
180 liters.
What percent of filtrate becomes urine?
less than 1 %
Decreased blood colloid osmotic pressure affects renal function by
increasing net filtration pressure.
The movement of fluid into Bowman's capsule is opposed by
capsular pressure
What pressure tends to force fluid from the glomerulus through the filtration membrane into Bowman's capsule
glomerular capillary pressure
What event would increase filtration pressure
constriction of the efferent arteriole
Substances that are cotransported into proximal convoluted tubule cells include
glucose molecules with sodium ions
Most water is reabsorbed from the filtrate in the
proximal convoluted tubule
the proximal convoluted tuble
the site of glucose and amino acid reabsorption
Glucose is usually completely reabsorbed from the filtrate by the time the filtrate has reached
the end of the proximal convoluted tubule
The collecting ducts and distal convoluted tubles
vary in their permeability to water relative to the amounts of ADH present.
The collecting duct becomes more permeable to water when
ADH production increases
As ADH production declines
the urine volume increase
When ADH binds to receptor sites on distal tubule cells
the distal tubule is more permeable to water
Urea is
diffuse out of the collecting duct into the interstitial fluid of the medulla and then diffuse into the descending loop of Henle
Hydrogen ions are secreted into filtrate by both the
proximal and distal tubules
Tubular secretion occurs where
in the distal convoluted tubule
Tubular reabsorption and tubular secretion differ
that tubular secretion adds materials to the filtrate ; tubular reabsorption removes materials from the filtrate.
the vasa recta
collects excess water and solutes from the medullary interstitial fluid
the kidney dialysis machine is an example of
a mechanical counter current system
By the time filtrate reaches the tip of the loop of Henle,
80 % of the filtrate volume has been reabsorbed
Urine concentration and volume depend on water reabsorption in what
distal convoluted tubule and collecting ducts
Decreased ADH levels results in a urine high in
water content
Diabetes inspididus is the result of
decreased ADH production
the juxtaglomerular apparatus secretes
Renin converts
angiotensinogen to angiotensin I
The kidneys produce renin when
the blood pressure is the afferent arteriole decreases
Angiotensin II
stimulates aldosterone secretion
Aldosterone targets cells
in the distal convoluted tuble
Aldosterone exerts its effect on the kidney tubules by
increasing the synthesis of the transport molecules for sodium
consumption of alcohol increases urine production by
inhibiting the release of ADH from the posterior pituitary
Atrial natriuretic hormone
is secreted when atrial blood pressure increases
autoregulation in the kidney involves changes in the degree of
constriction of afferent aterioles
When macula densa cells experience increased NA+ concentration in the filtrate, they respond by
decreasing renin secretion.
Decreased blood pressure in the afferent arterioles results in
increased renin secretion.
Increased secretion of atrial natriuretic hormone results in
increased urine output.
Urine flows through the ureters to the bladder as the result of
peristaltic contractions
removal of the posterior pituitary will immediately cause
an increase in urine volume
the proximal convoluted tubule is
the site of glucose and amino acid reabsorption.
Most water is reabsorbed from the filtrate
in the proximal convoluted tubule
Urine is carried from the kidneys to the urinary bladder by the
Arrange the following structures in correct sequence
1) ureter
2) renal pelvis
3) calyx
4) urinary bladder
5) urethra
Blood vessels, nerves, and the ureter enter and leave the kidney at the
the structural and functional units of the kidneys are called
the juxtamedullary nephrons
have long loops of Henle
the visceral layer of Bowman's capsule
is part of the filtration membrane and contains podocytes
an obstruction in the afferent arteriole would reduce the flow of blood into the
The filtration membrane consists of the
podocytes, capillary endothelium, and basement membrane
One feature of renal blood circulation that makes it unique is that
each nephron has at lease two capillary networks.