ANP 2 chapter 25

200 liters

How much fluid is filtered from the blood everyday?

maintaining the composition of the body’s extracellular fluids by filtering the blood

what is the kidney’s function?

Regulates total body water volume and concentration of solutes

How do the kidneys regulate osmolarity?

pressure

Blood volume controls blood _______

ions

kidneys regulate the concentration of ______ in ECF

Removed excess H+ to maintain the pH of the blood

how do the kidneys maintain acid-base balance?

toxins, metabolic wastes, and other foreign substances

Kidneys remove ______, _________ , ________

EPO and renin

Kidneys produce what hormones?

erythropoietin (EPO)

_______ stimulates red blood cell production and regulates hematocrit levels

renin

hormone that helps regulate blood pressure

parietal peritoneum, dorsal body wall

Each kidney lies between the __________ and ___________

retroperitoneal

Kidneys are __________ organs

visceral, parietal

Kidney does not have _______ layer, ONLY a ________

renal hilum

Medial portion is concave due to the _____________

• ureters, renal blood vessels, lymphatics, and renal nerve supply enter here

hilum

indent in kidney where blood supply and other things enter and leave

ureter

a tube that extends from the kidney to the urinary bladder

Adrenal gland

• ​sits right on top of each kidney

  • Don’t necessarily provide any function for the kidney

renal fascia, perirenal fat capsule, fibrous capsule

Supporting external structures of the kidney (3)

Renal fascia

• External kidney structure

• dense connective tissue

  • Anchors the kidneys to the surrounding structures to prevent sliding

perirenal fat capsule

• External kidney structure

• fat mass (adipose tissue) surrounding the kidneys

  • Cushions the kidneys from physical trauma

Fibrous capsule

• External kidney structure

• thin, transparent capsule

  • Prevents disease from spreading to the kidneys from other body parts

    • microorganisms don’t like going through tough things

renal cortex, renal medulla, renal pelvis

3 major internal regions of kidneys

Renal Cortex

• internal region of kidneys

• provides area for glomerular capillaries and blood vessel passage & EPO produced here

  • This is where blood filtering actually occurs (in glomerular capillaries)

Renal Medulla

• internal region of kindeys

• contains renal pyramids which are packed with capillaries & urine-collecting tubules

  • Allows for some water reabsorption, electrolyte balance, disposal of waste and H+ ions

Reabsorption

the process by which nephrons remove water and solutes from filtrate formed from filtration and return it to the blood

Renal Pelvis

open space in center of each kidney for urine collection from renal medulla

major calyces

Pelvis branches to form ________

minor calyces

Major calyces lead into _______ at tip of each renal pyramid

5 segmental arteries

• Renal artery branches to form __________

• Ensures blood reaches all portions of the kidney

interlobar

________  arteries 

• Travel between renal pyramids

arcuate

______ arteries

• Arc over bases of pyramids

• Branch to form cortical radiate arteries

cortical radiate

______ arteries

• Supply renal cortex

cortical radiate veins, arcuate veins, interlobar veins, renal veins

What is the order that renal veins drain into the postcava to return to the heart?

segmental vein

what type of renal vein is not present compared to the renal arteries?

Renal Plexus

where the nerve supply to the kidneys occurs

• autonomic nerve fibers & ganglia

sympathetic

renal plexus is concerned with the __________ division

• The only branch that controls blood vessel diameter

• Vasomotor fibers regulate blood supply to each kidney

Nephron

What is the functional unit of the kidney that filters blood and forms fitrate?

filtrate

raw material that is used to produce urine

renal corpuscle, renal tubule

Each nephron contains a _________ and __________

renal corpuscle

• filters blood to form filtrate

  • Located within renal cortex

Glomerulus, glomerular capsule

what are the subdivisions of renal corpuscle?

afferent, efferent

Blood enters via _______ arteriole, and leaves via ________ arteriole

arterioles

The glomerulus is fed and drained by ________, which is unique to the kidneys

higher

Arterioles hold ______ pressure than venules

Glomerular capsule

double-layered structure that completely surrounds glomerular capillaries and catches the filtrate that forms

podocytes, foot processes

Inner layer of glomerular capsule has _________ (foot cells) with __________

• Helps form a filtration membrane

  • Blood and plasma proteins can’t fit into the podocyte spaces, so they stay in the capillaries

true capsule

• Outer layer of glomerular capsule

  • Fluids are being pushed outwards, the capsule catches the filtrate so it can flow to the next portion of the nephron

renal tubule

• reabsorbs some substances from the filtrate & secretes other substances into the filtrate

  • If a substance is not reabsorbed or secreted, it will eventually be excreted in the urine and leave the body

renal cortex, renal medulla, renal cortex

the renal tubule starts in the __________, extends into the _________, then returns to _________

Proximal convoluted tubule, nephron loop, distal convoluted tubule, collecting duct

what are the subdivisions of the renal tubule?

Proximal convoluted tubule

• leads immediately off from glomerulus

  • Located in the renal cortex

  • Large cuboidal epithelial cells and dense microvilli

  • Large surface area = where reabsorption and secretion take place 

    •  reabsorption and secretion are automatic

renal cortex, large cuboidal epithelial cells, dense microvilli

Proximal convoluted tubule is

• Located in the _______

• contains _____________ and _________

• Large surface area = where reabsorption and secretion take place 

  •  reabsorption and secretion are automatic

proximal convoluted tubule

where does most of the reabsorption and secretion occur in the nephron?

 Nephron Loop

• Travel between the renal cortex and renal medulla

• Function: allows kidneys to vary concentration of urine according to how much water is reabsorbed

allows kidneys to vary concentration of urine according to how much water is reabsorbed at nephron loop

what is the nephron loop’s function?

Descending limb

• Leads off the PCT

• High permeability to H2O, impermeable to solutes

PCT, H2O, solutes

Descending limb

• Leads off the ____

• High permeability to ______, impermeable to _______

Ascending limb

• Continuous with DCT

• High permeability to solutes, impermeable to H2O

DCT, solutes, H2O

Ascending limb

• Leads off the ____

• High permeability to ______, impermeable to _______

distal convoluted tubule

• Located in the cortex, composed of small cuboidal epithelia

• Smaller diameter than PCT

• No microvilli

• Most absorption and secretion have already taken place

cortex, small cuboidal epithelia, smaller, microvilli

distal convoluted tubule is

• Located in the _______, composed of ___________

• ________ diameter than PCT

• No ________

• Most absorption and secretion have already taken place

hormones

The presence or absence of particular ________ drives reabsorption and secretion in distal convoluted tubule

distal convoluted tubule

collecting ducts are connected to the _______

principal cells, intercalated cells

what are the important cell types in collecting ducts?

principal

_______ cells: maintain Na+ balance in the body

• Can get rid of or reabsorb more Na+

• Water follows solute, so changing sodium reabsorption will change amount of water in blood, changing blood volume, changing blood pressure

maintain Na+ balance in the body

what is the function of principal cells in collecting ducts?

intercalated

• _________ cells: help maintain acid-base balance

  • Help balance H+ ions and bicarbonate ions to help maintain blood pH

maintain acid-base balance

what is the function of intercalated cells in collecting ducts?

multiple, minor calyces

• Each collecting duct receives filtrate from the tubules of _______ nephrons

  • collecting ducts in renal pyramids fuse together, dump urine into ________

cortical nephrons, juxtamedullary nephrons

types of nephrons

cortical nephron

type of nephron that is located mostly in the cortex

• Small portion of nephron loop is found in renal medulla

the cortex

cortical nephrons are mostly located where?

juxtamedullary nephron

• Very long nephron loop that deeply invade renal medulla 

• Good for water reabsorption and forming highly concentrated urine

  • Capillaries form a ladder like arrangement (vasa recta) and picks up water as it leaves descending limb

long, renal medulla, highly concentrated urine, descending

juxtamedullary nephrons are

• Very _______ nephron loop that deeply invade _________

• Good for water reabsorption and forming ___________

  • Capillaries form a ladder like arrangement (vasa recta) and picks up water as it leaves ________ limb

glomerulus, peritubular capillaries, vasa recta

capillary beds of nephrons (3)

glomerulus

capillary bed that maintains high pressure to increase filtrate production

• Pushes filtrate to glomerular capsule to flow into the kidney tubules

peritubular capillaries

• Low pressure capillaries arising from efferent arterioles

• Cling to proximal & distal tubules of cortical nephrons

  • Function: reabsorb water & solutes from tubule cells (anything that is reabsorbed or secreted is put into peritubular capillaries)

• Empty into cortical radiate veins → filtered blood returns to circulation 

low, efferent, reabsorb water & solutes from tubule cells, cortical radiate veins

peritubular capillaries are:

• ___ pressure capillaries arising from _______ arterioles

• Cling to proximal & distal tubules of cortical nephrons

  • Function: ________________

• Empty into _________ → filtered blood returns to circulation

vasa recta

capillary bed of nephron that is

• Found only on juxtamedullary nephrons

  • Run parallel to long nephron loop

  • Help form concentrated urine

    • Anytime water leaves nephron loop, this capillary bed reabsorbs it and returns it to general circulation

juxtamedullary nephrons, concentrated urine

Vasa recta

• Found only on _________________

  • Run parallel to long nephron loop

  • Help form __________

    • Anytime water leaves nephron loop, vasa recta reabsorbs it and returns it to general circulation

Juxaglomerular complex

portion of nephron where part of ascending limb lies against afferent & efferent arterioles

• Overall function: regulates blood pressure & filtration rate of the glomerulus

regulates blood pressure & filtration rate of the glomerulus

what is the function of the juxaglomerular complex?

macula densa cells, granular cells, extraglomerular mesangial cells

3 cellular modifications where ascending limb is in contact with afferent & efferent arterioles

macula densa cells

chemoreceptor cells found in ascending limb

• Function: monitor NaCl content of filtrate entering distal convoluted tubule

• Using NaCl concentration to indirectly measure the rate of filtrate formation

Macula densa, is not being reabsorbed

__________ cells are sensing high NaCl concentration in filtrate this means NaCl ______________

large volume of filtrate produced, quick, NaCl not reabsorbed

Macula densa cells are sensing high NaCl.

• what does this mean

  • for filtrate?

  • speed of filtrate through nephron

  • result?

vasoconstrict afferent arterioles

• Forming filtrate too fast indicates we’re filtering blood too fast or too much of it so we need to slow down

  • Solution?

granular cells, macula densa cells

• specialized smooth muscle cells

  • Found in arteriole walls of afferent arteriole

    • Can sense stretch of arterial walls and blood pressure in afferent arteriole

      • High pressure = large amount of blood in glomerular capillary bed

    • Stimulated by ____________

afferent, renin, efferent

Granular cells are

• Found in arteriole walls of ________ arteriole

• Contains granules that secrete ______

  • mostly affects the _______ arteriole!

afferent, efferent, constrict

When_______ arterioles release renin it causes ________ arterioles to _________

increase

• Low NaCl concentration = _______ renin release

  • _______ pressure and filtrate formation

decrease

High pressure in arteriole = _______ renin release

extraglomerular mesangial cells

cellular modification in juxtaglomerular complex packed between tubule and arterioles

• Sandwiched between granular cells and macula densa cells

• function: ???? probably a messenger

macula densa cells

responsible for sending messages and stimulating afferent arteriole to constict or dilate

Filtration membrane

allows passage of water and small solutes into the glomerular capsule

filtration slits, large-sized

• Foot processes of podocytes create ________

  • Prevent passage of _________ materials into filtrate

Diuresis

Term for urine formation

Glomerular filtration

production of a cell and protein-free filtrate that serves as the raw material for urine

high-pressure, capillary, capsule

glomerular filtration occurs under ____________ conditions, pressure forces fluid out of the glomerular _______ & into the glomerular _______