-
Organs that are involved in the excretion and elimination of urine compose what system?
the urinary system
-
List the organs of the urinary system.
- kidneys
- ureters
- urinary bladder
- urethra
-
List the four functions of the urinary system as discussed in class.
- Maintenance of blood volume
- Maintenance of acid-base balance
- Excretion of waste
- Maintenance of electrolyte balance
-
Within what cavity of the body do the kidneys lie?
the abdominal cavity
-
What is the position of the kidneys in respect to the peritoneum?
retroperitoneal (posterior)
-
What is the position of the kidneys with respect to the ribs?
The kidneys lie deep to the ribs. The lower pole of the kidneys extends inferior to the margin o f the 12th rib.
-
What is the position of the kidneys with respect to the vertebral column?
They lie lateral to it.
-
Which kidney lies more inferiorly?
the right kidney
-
The kidneys are flattened from front to back. What anatomical term describes this?
anteroposterior compression
-
What deep depression lies toward the center of the medial side of each kidney?
the renal sinus
-
What is the entrance into the renal sinus?
the hilum
-
What structure forms a strong, transparent, fibrous covering of the kidney?
the renal capsule
-
What is the reddish brown, granular layer that lies just deep to the renal capsule on the kidney?
the renal cortex
-
What is the darker, striped layer deep to the renal cortex within the kidney?
the renal medulla
-
What are the conical areas within the renal medulla?
renal pyramids
-
What structures separate the renal pyramids within the kidney?
renal columns
-
Within the kidney what structure does renal pyramid project into on its deep side?
a minor calyx
-
Several minor calyces join to form what structure within the kidney?
a major calyx
-
Major calyces join to form what funnel-shaped structure within the kidney?
the renal pelvis
-
What structures carry urine from the kidneys to the urinary bladder?
ureters
-
What is the position of the ureters in relation to the peritoneum?
retroperitoneal (posterior)
-
What are successive waves of involuntary contractions passing along the walls of a hollow
muscular structure and forcing the contents onward?
peristalsis
-
Smooth muscle within the ureters produces what rhythmic waves of contraction that force urine onward?
peristalsis
-
What organ stores urine?
the urinary bladder
-
What is the position of the urinary bladder in relation to the pubic symphysis?
posterior
-
What is the position of the urinary bladder in relation to the rectum?
anterior
-
What is the position of the urinary bladder in relation to uterus?
It lies inferior to the uterus
-
What is the position of the urinary bladder in relation to the vagina?
It lies anterior to it
-
What is the position of the urinary bladder in relation to peritoneum?
anteperitoneal (anterior)
-
Why do females have a higher incidence of bladder infections than males?
The urethra in females is shorter
-
What is the functional unit of the kidneys?
the nephron
-
Within the nephron, what is the tuft of capillaries that produces filtrate?
the glomerulus
-
What structure surrounds each glomerulus and collects the filtrate formed by it?
the glomerular capsule (Bowman's capsule)
-
What segment of the nephron lies relatively close to the glomerulus within the cortex and is twisted and coiled?
the proximal convoluted tubule
-
What segment of the nephron is descends into a renal pyramid within the medulla forming U-shape?
the loop of the nephron (loop of Henle)
-
What segment of the nephron is relative distance to the glomerulus and is twisted and coiled?
the distal convoluted tubule
-
What structure within the kidney is a nonsecretory tubule that receives urine from several nephrons and discharges it through the papilla of a renal pyramid into a minor calyx?
the collecting duct
-
What system of capillaries arises from the efferent arteriole leading away from the glomerulus and surrounds the tubules of the nephron?
peritubular capillaries
-
What term means having openings or pores?
fenestrated
-
What structure of the nephron consists of fenestrated capillaries?
the glomerulus
-
What factor brings about glomerular filtration?
hydrostatic pressure
-
What substance is formed by glomerular filtration?
filtrate (ultrafiltrate)
-
How much filtrate is formed 40 minutes?
the equivalent of the entire blood volume
-
How much filtrate is formed in the kidneys each day?
about 180 liters (45 gallons)
-
What factor most directly influences the glomerular filtration rate?
blood pressure as determined by the diameter of the afferent arterioles
-
What is the influence of the sympathetic nervous system on the glomerular filtration rate?
It brings about vasoconstriction of the afferent arteriole and thus reduces urine output
-
What extrinsic influence affects the glomerular filtration rate?
the sympathetic nervous system
-
What sensor is a part of the intrinsic regulation of glomerular filtration?
the juxtaglomerular apparatus
-
What is the response of the intrinsic regulatory system of the kidneys if B/P in the afferent arteriole falls below 70 mm Hg?
vasodilation of the afferent arteriole
-
What is the response of the intrinsic regulatory system of the kidneys if B/P in the afferent arteriole rises?
vasoconstriction of the afferent arteriole
-
What sensor is a part of the intrinsic regulatory system of the kidney and monitors volume of filtrate in the ascending loop of Henle?
the macula densa
-
What is the response of the instrinsic regulatory system of the kidney to an increase in the volume of filtrate?
vasoconstriction of the afferent arterioles
-
What is the obligatory water loss from the kidneys per day?
400 ml
-
What is osmalality of plasma?
300 mOsm
-
What is the osmalality of filtrate in the glomeruli of the kidneys?
300 mOsm
-
What substances are found in the renal filtrate?
- water
- electrolytes such as sodium and chloride
- glucose
- amino acids
- urea
-
What mechanisms reabsorbs glucose from the renal filtrate?
cotransport (active) of glucose and Na+ in the cells lining the proximal convoluted tubule
-
What mechanism removes Na+ from the renal filtrate in the proximal convoluted tubule?
the Na+/K+ pump in the basal and lateral sides of the epithelial cells lining
-
What process removes Cl- from the filtrate in the proximal convoluted tubule?
Cl- passively follows Na+
-
What process removes water from the proximal convoluted tubule?
osmosis (as Na+ and Cl- leave the filtrate, osmotic pressure of the filtrate drops and water is drawn into the cells)
-
What percentage of the filtrate is reabsorbed in the proximal convoluted tubule?
65%
-
The loop of Henle may be divided into what two main portions?
the descending and ascending limbs
-
What portion of the loop of Henle actively transports Na+ from the filtrate?
the thick portion of the ascending limb
-
What process removes Cl- from the filtrate in the thick portion of the ascending limb of the loop of Henle?
Cl- passively follows Na+
-
From what portion of the loop of Henle is water removed from the filtrate?
the descending limb
-
What percentage of the original volume of filtrate is removed by the loop of Henle?
20%
-
What mechanism is produced by the movement of filtrate in opposite directions in the loop of Henle and active transport of Na+ from the thick portion of the ascending limb of the same structure?
a counter-current multiplier
-
What type of mechanism is established in the vasa recta as blood descends and then ascends?
a counter-current exchange
-
What happens to the osmolality of blood as it moves through the vasa recta?
It changes with the osmolality within the renal medulla
-
What mechanism moves water into the blood within the vasa recta as it ascends toward the renal cortex?
Large plasma proteins maintain osmotic pressure of the blood and result in water being carried away and salts being left behind
-
What sensor detector a decrease in B/P within the kidneys?
the juxtaglomerular apparatus
-
What is the response of the juxtaglomerular apparatus if B/P falls?
It releases renin
-
-
What is the action of renin?
- It converts angiotensinogen to
- angiotensin I.
-
What becomes of angiotensin I?
- It is converted to angiotensin II by
- angiotensinĀ]converting enzyme (ACE) in
- the lungs.
-
What is the effect of angiotensin II?
- It causes the release of aldosterone from
- the adrenal cortex
-
What is the effect of aldosterone?
- It causes the reabsorption of Na+ in the
- distal convoluted tubule and the cortical
- portion of the collecting duct resulting in
- the reabsorption of water and decrease in
- urine production
-
What organ produces aldosterone?
the adrenal cortex
-
What portion of the heart senses an increase in blood volume?
the atria
-
What is the response of the atria of the heart to an increase in blood volume?
- They release atrial natriuretic peptide
- (ANP).
-
What is the effect of atrial natriuretic peptide?
- Less sodium is reabsorbed in the distal
- convoluted tubules of the kidneys and
- cortical portion of the collecting duct thus
- more urine is produced and blood volume
- decreases.
-
Where is antidiuretic hormone produced?
the hypothalamus
-
Where is antidiuretic hormone stored?
the posterior pituitary
-
Where are osmoreceptors for the blood located?
in the hypothalamus
-
What is the response of the osmoreceptor in the hypothalamus to an increase in the osmolality
of the blood?
- They cause the release of antidiuretic
- hormone
-
What is the effect of antidiuretic hormone?
- It increases the permeability of the
- collecting ducts to water resulting in
- water being drawn into the medulla by
- osmosis and reducing the urine output
-
Why is urine normally slightly acidic?
Normally kidneys reabsorb almost all of the bicarbonate and excrete H+, making normal urine a little acidic
-
What is the response of the kidneys to acidosis?
The distal convoluted tubules secrete more H+ into the filtrate
-
What is the response of the kidneys to alkalosis?
They reabsorb HCO3-
-
What buffers are found in the filtrate?
phosphates and ammonia
|
|