W4 - Upper Urinary System

Question 1

Unfiltered blood flows into the kidney through the ??? and filtered blood flows out via the ???

Answer 1

Renal artery, renal vein

Question 2

The capsule is made of connective tissue and is supported by underlying stromal cells ((myo)fibroblasts), what does the capsule do?

Answer 2

PReserves hydrostatic pressure for filtrations

Question 3

What can the stomal cells do within the kidney?

Answer 3

Repair it if injured

Question 4

The cortex is directly underlying the capsule, what filtration units are found in the cortex?

Answer 4

Renal corpuscle of the nephron

Question 5

What is the typical pathway of a nephron?

Answer 5

Begin in cortex, and convolute through medulla and end in papilla

Question 6

What is the functional unit of the kidney and does it have simple/stratified epithelium throughout the entirety of it?

Answer 6

Nephron, all simple epithelium

Question 7

What makes up the renal corpuscle?

Answer 7

Glomerular capillaries surrounded by Bowman’s capsule

Question 8

What process occurs in the renal corpuscle and where is it always located?

Answer 8

Ultrafiltration and located in the cortex

Question 9

What 5 structures are found in the renal tubule?

Answer 9

PCT, LoH, DCT and collecting tubule/ducts

Question 10

Where are the PCT+DCT found, where are the LoH and collecting tubules/ducts found?

Answer 10

PCT + DCT - cortex, LoH - mostly medulla, Collecting tubules/ducts - medulla

Question 11

There are different types of nephron that originate in different parts of the cortex, what are these characterised by and what are they called?

Answer 11

Length of LoH, long - juxtamedullary, short - cortical loop, intermediate - midcortical

Question 12

What is wider, the diameter of the afferent or efferent arteriole in the glomerulus?

Answer 12

Afferent is wider than efferent (therefore more pressure in efferent than afferent)

Question 13

What types of cells line the glomerulus?

Answer 13

Endothelial cells in capillaries

Question 14

The Bowman’s capsule is double walled, outer parietal and inner visceral layers, what type of epithelium/cells make these up?

Answer 14

Outer parietal - simple squamous, inner visceral - podocytes

Question 15

What is it called where afferent arterioles become efferent arterioles?

Answer 15

Vascular pole

Question 16

What is it called where the ultrafiltrate exits the Bowman’s capsule once collected in the space between the glomerulus and BC and enters the PCT?

Answer 16

Urinary pole

Question 17

What is it called where the capillaries enter and leave the corpuscle?

Answer 17

Arteriole pole

Question 18

Mesangial cells are structural and phagocytic cells that sit amongst the capillaries, how do they generally function?

Answer 18

Keep the space clear of unwanted objects and bacteria

Question 19

What type of pressure forces molecules between podocytes into the Bowman’s space?

Answer 19

High osmotic pressure

Question 20

Fenestrae are holes between the endothelial cells, what do they/do they not allow through?

Answer 20

Yes - water, ions No - RBCs and large proteins

Question 21

A glycocalyx surrounds the luminal surface of endo cells and it consists of -vely charged glycosaminoglycans, what does this therefore stop the diffusion of?

Answer 21

-vely charged molecules

Question 22

The glomerular BM has 3 layers, what are they called from internal to external and what do they prevent from crossing?

Answer 22

Lamina - rara interna, densa and rara externa, they help to limit filtration of intermediate/large solutes

Question 23

Podocytes interdigitate to form filtration slits, these slits are bridged by a slit diaphragm which contains pores, what does this prevent from crossing?

Answer 23

Large proteins

Question 24

A glycocalyx covers the podocytes, what does this restrict the filtration of?

Answer 24

LArge anions

Question 25

What is the Macula densa and lacis cells (part of juxtaglomerular apparatus)?

Answer 25

The part of the DCT that touch the glomerulus and is responsible for sensing sodium

Question 26

The main function of the LoH is to create a conc grad in the medulla, what system does this use?

Answer 26

Counter-current multiplier system by reabsorbing water, sodium and chloride ions

Question 27

The LoH has thick/thin descending limbs and thick/thin ascending limbs, but what are their epithelium types?

Answer 27

Both thick are simple cuboidal, both thin are simple squamous

Question 28

The LoH uses Na+ pumps to create a high conc of Na+ deep in the medulla near the CD, where does the water therefore move passively from and to down it’s conc grad?

Answer 28

From CD into medulla (creates conc urine)

Question 29

The DCT has less mitochondria, is shorter and less convoluted than the PCT, they are both lined with simple cuboidal epithelium but how are they different in DCT to the PCT? (3 factors)

Answer 29

DCT simple cuboidal cells are smaller and have no brush border, leading to a larger lumen

Question 30

DCT are impermeable to water, what is it’s role?

Answer 30

Absorption of NaCl and Ca2+

Question 31

Because the PCT has more mitochondria than the DCT, which one is more eosinophilic?

Answer 31

PCT

Question 32

Many CTs extend from a nephron and several join to form CDs, what do many CDs join to form and where does this structure deliver the urine to?

Answer 32

PApillae, delivers urine to minor calyx

Question 33

There are 2 cell types in the CDs, principal (predominant) and intercalated (fewer) cells, what are principal cells rich in and what do intercalated cells do?

Answer 33

Principal - lots of aquaporins, intercalated - maintain blood acid-base balance by secreting H+ or HCO3-

Question 34

What does the epithelium become in the renal papillae?

Answer 34

Transitional epithelium