RENAL SYSTEM ANATOMY I Flashcards
calculate body water for male and female?
- male BW = 60%
- female BW = 55%
calculate the intracellular and extracellular fluid portion in total body water?
- ECF = 1/3 BW
- ICF = 2/3 BW
calculate the portion of plasma and interstitial fluid within ECF of BW?
- plasma = 1/5 ECF
- interstitial fluid = 4/5 ECF
what is the role of urinary system and how does that work to serve the role?
- balance of water and solutes in the body
- achieve by filtering the blood
what does urinary filter from the blood?
- excess water
- excess salts
- metabolism wastes
- toxins and drugs
what is the amount of blood flow through kidney per minute and what is the amount of urine a typical person produces per day?
- 1200mL
- 800-2000mL
what does the urinary system need to make sure the role is achieved effectively? (8)
- delivery system for blood
- selective filtration system
- filtrate recovery mechanism
- system to return the recovered, filter fluid to the body
- system to remove filtrate from body
- protection
- ability to communicate with relevant parts of the body
- be adaptable
what are the major organs of the urinary system?
- 2x kidneys
- 2x ureters
- urinary bladder
- urethra
what does the structure of the kidneys allow? (4)
- blood to be brought into close proximity with the nephron for filtering
- blood that has been filtered to leave the kidney
- pathway for urine to be remove from kidney, stored and excrete
- protection
what is the location of the kidneys? how is the kidneys situated?
- location: T12 - L3, 11th and 12th ribs
- ## situated: convex side faces laterally, medial surface has concave notch called hilum
what structures go through hilum?
- renal blood vessels, lymphatics, nerves and the ureters
__________ kidney lies more inferiorly and which organ appears to push it downwards?
- right
- liver
name the structures that surround, support and protect the kidneys?
- majorily fat
- peritoneum covered on anterior side
- renal fascia
- perirenal fat capsule
- fibrous capsule
what are the major structural landmarks of the kidney?
- fibrous capsule
- renal cortex
- renal medulla
- renal pyramid
- renal column
- kidney lobe
what are the 3 regions of the kidneys from outside to inner?
- cortex
- medulla
- pelvis
what does each renal pyramid ends in?
papilla
what is the structure of the renal cortex?
- continuous layer
- renal columns
what form the kidney lobes?
- cortex (included renal columns) + 1 medullary pyramid –> functional lobes (5-11 per kidney)
what special structure made up the lobes? what does it do?
nephrons - tiny tubes that filter from blood and create urine
describe the ‘urine’ pathway of the ‘tubes’?
urine –> papilla –> minor calyx –> major calyx –> renal pelvis —–narrow as exit the hilum—–> ureter
name the 3 structures that provide external protection for the kidneys?
- 11th and 12th ribs
- fibrous capsule
- perirenal fat capsule
where does renal artery arises from?
abdominal aorta
where does filtration occurs in the kidney?
cortex
what happens to the filtered blood?
return from the cortex to renal vein, then to IVC
what is glomerulus?
a structure where blood filtration occurs and made of glomerular capillaries
which structure delivers blood from arteries to glomerulus?
afferent arteriole
which structure carries blood from glomerulus to peritubular capillaries?
efferent arterioles
what does peritubular capillaries do?
carry blood to the veins (cortical veins)
describe the pathway of blood to kidneys (cortex to be filtered) and then after that
abdominal aorta –> renal artery –> series of arterioles –> afferent arterioles –> glomerulus (glomerular capillary) –> efferent arterioles –> peritubular tubes –> series of veins –> renal veins –> inferior vena cava
what is the renal plexus?
innervation from a network of autonomic and ganglia
which type of nerves ac to adjust diameter of renal arterioles and regulate blood flow?
sympathetic
what is nephron?
a functional unit of the kidney with 1.2mil per kidney, do all the work:
- selectively filter blood at the glomerulus
- selectively reabsorbs or secretes
- produce urine and carry away for storage and expulsion
what are the 2 types of nephron, which type dominates?
- cortical and juxtamedullary
- cortical takes up 85%
which type of nephron lies where?
- cortical lies mainly in cortex
- juxtamedullary extend deep into the medulla
which type of nephron is important for the formation of concentrated urine?
juxtamedullary
which structures comprise the nephron?
- glomerular capsule
- renal tubules
- collecting duct
which are the associated structures of the nephron?
- glomerulus
- peritubular capillaries
how is the glomerular capillaries specialised for filtration?
- thin walled single layer of fenestrated endothelial cells
- fed and drained by arterioles
- blood pressure is tightly regulated
how is the peritubular capillaries specialised for absorption
- wrap around renal tubules
- non-filtered solutes that needed to be excreted can pass from here into nephron
- has vasa recta
what is vasa recta?
- extensions that follow nephron loops deep into the medulla
- only found with juxtamedullary nephrons
what do peritubular capillaries receive?
- receives filtered blood from glomerulus via efferent arterioles
- receives reabsorbed filtrate from nephron
what is glomerular capsule?
- a structure that enclose the glomerulus
- where capillary and nephron meet
- site of filtration barrier
what are the layers characteristics of the glomerular capsule?
2 layers
- outer parietal layer of simple squamous cells
- inner visceral layer of podocytes
what is podocytes?
a specialised epithelium structure that surrounds the glomerular capillaries which is very branched
what do the branches of podocytes form and what is it called?
- form intertwining foot processes called pedicels
- filtration slits form between pedicels
describe the filtration barrier
barrier lies between blood and capsular space with 3 layers from innermost to outer:
- fenestrated endothelium of glomerular capillary
- fused basement membrane
- filtration slits between the pedicels of podocytes
what is the capsular space?
a space between 2 layers of the glomerular capsule which receives filtrate
what does filtration barrier allow to pass and not allow?
- allow free passage of water and small molecules
- restrict passage of post protein and RBC
what comprise urine?
urine = filtered - reabsorbed + secreted
describe briefly the nephron pathway
renal corpuscle –> proximal convoluted tubule –> nephron loop (descending limb –> ascending limb) –> distal convoluted tubule –> collecting duct
what happen at proximal convoluted tubule?
bulk reabsorption
what structure surrounds the proximal convoluted tubule?
peritubular capillaries
what is the structure of the PCT, relate the structure to the function?
- cuboidal epithelial cells
- dense microvilli on luminal membrane
- highly folded basolateral membrane
- many mitochondria
- leaky epithelium
what structure is abundant in PCT and why?
mitochondria for active transport
describe the structure and change of structure in the lims of loop of Henle?
- thick descending limb similar to PCT
- thin descending limb: simple squamous epithelium
- thin ascending limb: simple squamous epithelium
- thick ascending limb similar to DCT
each limb has __________________________ to water and sodium
different permeabilities
what does distal convoluted tubule responsible for?
fine tuning
what is the structure of DCT?
- cuboidal epithelium but thinner than PCT
- no brush border
- fewer mitochondria
what influence the reabsorption at DCT?
aldosterone
what does collecting duct do?
- fine tuning
- filtrate from several DCTs drains into 1 collecting duct and empty at papilla
what is the structure of collecting duct?
simple cuboidal epithelium
2 cell types:
- principal cells: reabsorption
- intercalated cells: acid - base balance
what influence the reabsorption at collecting duct
aldesterone and ADH
describe the change in epithelial at the nephron
glomerular capsule with parietal and visceral layer —> PCT cuboidal epithelium with brush border —> thick part of descending limb same structure as PCT —> thin part of loop of Henle simple squamous epithelium —> thick part of ascending limb same structure as DCT —> DCT simple cuboidal epithelium —> collecting duct simple cuboidal with principal and intercalated cell
