What is the function of the urinary system?
detoxification, blood pressure regulation, maintenance of correct balance of pH, minerals, iron and salt levels in the blood
What organs make up the urinary system?
kidneys, ureters, bladder, urethra
Which organs make up the upper urinary tract?
kidneys and ureters
Which organs make up the lower urinary tract?
urinary bladder and urethra
What is the normal size of an adult kidney?
9-11cm in length, 2.5-4cm depth, 4-6cm diameter.
In adults, the normal cortex measurement is approximately ____.
What is the normal size of a neonatal kidney?
3.5-5cm in length, 1.5-2.5cm depth, 2-3cm diameter.
How do we know if a kidney is enlarged or smaller than normal?
Compare to other kidney; should not be more than 2-3cm in difference.
Hydration state may increase/decrease the size of the kidneys
If only one kidney is present (congenital agenesis), the other kidney may _______.
Age, circulatory insufficiency or renal disease may enlarge/shrink the kidneys
Normal location for a donated kidney is _______ and is attached where _______?
Pelvis; iliacs and distal portion of the ureter.
The kidneys are bordered posteriorly by?
Diaphragm, psoas muscle, transversus muscle and quadratus lumborum muscle.
The kidney has a lateral _______ border and a medial ______ border.
What are the anterior structures that cover the right kidney?
right adrenal, right lobe of liver, second part of duodenum, hepatic flexure of colon and jejunum or ileum of small bowel
Why is the right kidney lower than the left?
The liver displaces the right kidney inferiorly.
What separates the right kidney from the liver?
Morison's pouch (aka hepatorenal recess or subhepatic recess)
The right kidney has a slightly longer/shorter ureter
What are the anterior structures that cover the left kidney?
tail of pancreas, left adrenal gland, spleen, jejunum, stomach, and the splenic flexure of the colon
The renal artery may divide into as many as ___ branches before entering the hilum.
The hilum of the kidney is located in the _____.
What is the normal sonographic order of the vessels and ureter of the kidney from anterior to posterior?
Vein, Artery, Ureter
What is the function of the kidneys?
Detoxify blood and regulate blood pressure with hormones.
How do the kidneys maintain homeostasis?
Countercurrent Multiplier System
Describe the countercurrent multiplier system.
Blood from the efferent arteriole supplies the peritubular capillaries, which in turn supply the proximal and distal convulated tubules, and the vasa recta. Through osmotic pressure, the vasa recta trap salt and urea in the medulla and move water back into the blood.
What are the vasa recta?
A series of intertwining capillary loops that surround the juxtamedullary nephron.
What is the first protective layer of the kidney made up of?
Fibrous tissue that doesn't connect to the renal parenchyma.
What is the second protective layer of the kidney made up of?
Perirenal fat (AKA perinephric fat, adipose capsule, packing fat of Zukerkandl). It is a layer of fat that surrounds the encapsulated kidney and is continuous with the fat in the renal sinus. Accommodates kidney movement during respiration.
What is the third protective layer of the kidney made up of?
Gerota's fascia (AKA renal fascia, perirenal fascia, perinephric fascia). It surrounds the kidney and perirenal fat.
What surrounds all the layers of the kidney?
Pararenal fat (AKA pararenal body). It is especially thick posterior to Gerota's fascia. Accommodates kidney movement during respiration.
What are the two sonographic areas of the kidney?
Renal parenchyma and renal sinus.
Hypoechoic area of kidney where filtration begins
The renal parenchyma is composed of what?
Cortex (outer portion) and medulla (inner portion)
What is the renal sinus composed of?
Medullary pyramids and major and minor calyces
There are _____ major calyces and each one will branch into several minor calyces.
What is the sonographic appearance of the renal capsule?
thin, continuous, highly reflective line visualized along the periphery of the kidney; hyper echoic relative to adjacent renal cortex
What is the sonographic appearance of the renal cortex?
mid-gray or medium- to low-level homogeneous echoes that are less than or equal to the density of the liver or spleen.
What is the sonographic appearance of the renal medulla?
consists of the medullary pyramids, which appear as triangular, round, or blunted anechoic areas when urine-filled and are otherwise not visible.
What is the sonographic appearance of the renal sinus?
Irregular, echogenic due to fibrous tissue and fat.
What is the sonographic appearance of the renal vasculature?
Anechoic lumens surrounded by bright walls which can be followed to their origin.
Name the branches of the renal arteries that enter the kidney
Renal artery, segmental, interlobar, arcuate, interlobular.
Renal arteries branch ______ from the abdominal aorta.
Segmental arteries are formed before/after the renal arteries enter the kidney.
Interlobar arteries course ____ the pyramids.
Arcuate arteries are formed at the ____ of the renal pyramids.
Interlobular arteries are formed and travel into the ________ and appear as finger-like projections.
What is the order of renal vasculature starting with the aorta and ending with the IVC?
Aorta --> renal artery --> segmental artery --> interlobar artery --> arcuate artery --> interlobular artery -->afferent arterioles --> glomerulus --> efferent arteriole --> peritubular capillaries --> interlobular vein --> arcuate vein --> interlobar vein --> renal vein --> IVC
What is the functional unit of the kidney?
There are how many microscopic nephrons in each kidney?
over a million
Basic function of the nephron
Move metabolic products from areas of high concentration to areas of low concentration via osmosis (passive transport) and active transport.
What are the two types of nephrons?
Juxtamedullary and cortical (named for their location in the kidney and the length of their loops)
Juxtamedullary nephrons originate in the ______ of the renal cortex and have shorter/longer loops of Henle than cortical nephrons.
inner third; longer
Cortical nephrons are located in the _______ of the renal cortex.
Where does the nephron receive blood from?
interlobular arteries via the afferent arteriole which carries it to the glomerulus, the first site of filtration.
After being filtered by osmosis, the blood leaves the glomerulus through the _______ to travel to the ________, then back to the _________, ________, etc.
efferent arteriole, peritubular capillaries, interlobular vein, arcuate vein
Ultrafiltrate from the _______ capillary bed passes through the ________ where substances that are useful to the body are reabsorbed.
Salt and urea are filtered by the vasa recta and are carried to the ______
distal convulated tubule
Everything that has not be reabsorbed or is a waste product becomes _______.
Where are the renal corpuscle, the proximal and distal convolated tubules located?
What does the renal corpuscle consist of?
Bowman's capsule and glomerulus
What does the renal tubule consist of?
Proximal convulated tubule, loop of Henle, distal convulated tubule and collecting duct.
What occurs in the Loops of Henle?
Reabsorption of fluid, sodium and chloride
The medulla contains:
loop of Henle and collecting duct
The renal cortex contains:
glomerulus, Bowman's capsule and the proximal and distal convulated tubules
Renal pyramids are separated from each other by _____________?
Cortical tissue called columns of Bertin.
What is the first site of filtration?
Osmosis occurs in the?
What is tubular reabsorption?
The process by which substances in the plasma solute that are useful to the body are reabsorbed into the bloodstream.
Reabsorption takes place in:
proximal convulated tubule and the descending and ascending loop of Henle.
What is tubular secretion?
The process whereby waste substances, including ammonia, drugs, hydrogen, and potassium, are secreted into the distal convulated tubule into the collecting tubule or duct.
What are the 4 renal hormones?
Antidiuretic hormone, aldosterone, renin, erythropoietin.
Aldosterone is stimulated by _______, and is released by the _______. What does it do?
decrease in blood volume, adrenal cortex; increases salt and water reabsorption in the distal collecting tubules.
Antidiuretic hormone (ADH) is stimulated by_________________, and is released by___________. What does it do?
decrease in blood volume, posterior pituitary gland; increases water reabsorption in distal collecting tubules.
Renin hormone is stimulated by __________, and is released by the ___________. What does it do?
decrease in blood volume, granular cells in the afferent arteriole; Acts on angiotensinogen in the blood to increase systemic pressure.
Erythropoitin is stimulated by ____________, and is released by the ________. What does it do?
decrease in oxygen, kidneys; increases RBC production.
What are the normal measurements of the ureters?
28-34 cm in length, 6 mm in diameter
Urine is carried from the distal convulated tubule to a __________ where it will carry it to the _________, then into _________.
collecting duct; renal pyramids; minor calyx
Several minor calyces will carry urine into a _________, then to the renal ________ and through a ________ into the ___________. Urine will then exit the bladder and body via the _______.
major calyx; pelvis; ureter; urinary bladder; urethra
The kidneys produce on average how much urine daily?
The kidneys filter approximately how much blood per minute?
Excreted urine is __% water and __% nitrogenous waste and inorganic salts.
Ureters connect the _______ to the _________.
Renal pelvis; urinary bladder
The ureters connect _______ at the base of the bladder called the _______.
Where are the three constrictions along the ureters?
where it leaves the renal pelvis, at the pelvic brim, and where it enters the bladder
What is the approximate length of a ureter?
What are ureteral jets?
squirts of urine seen entering the posterior portion of the bladder through the ureteral orifices in the trigone area
Describe the urinary bladder.
large, muscular bag with smooth walls
What is the normal thickness of a distended urinary bladder wall?
The urethra attaches to the _______ portion of the bladder.
What are the two sphincters that control the flow of urine in the urethra?
internal and external
What is the normal length of a female urethra?
What is the normal length of a male urethra?
Is it easier to see the adrenal glands sonographically in adults or young children?
young children, because their adrenals are proportionately larger than the adult adrenals.
What are the three zones of the adrenal cortex and what do they collectively produce?
zona glomerulosa (outermost), zona fasciculata (middle), zona reticularis (innermost); steroid hormones (corticoids)
What does the zona glomerulosa produce?
mineralocorticoids (aldosterone-regulates sodium and potassium levels)
What does the zona fasciculata produce?
glucocorticoids (cortical-regulates glucose metabolism)
What does the zona reticularis do?
supplements the sex hormones produced by the reproductive organs (ovaries and testes)