Lecture #33 - The nephron

Question 1

The nephron:

1. ____ ____ unit of the kidney
2. Approximately how many per kidney?
3. Responsible for what formation?

Answer 1

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Question 2

Types of nephron:

1. ____ nephrons
   - how much percentage of all nephrons are these?
   - Lie mainly in what?
2. Juxtamedullary nephrons
   - extend deep into what?
   - Important for formation of what?
   - Do they have longer or short loops of Henle than the cortical nephrons?

Answer 2

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Question 3

The nephron and associated structures

Function:

1. Selectively ____ blood
2. ____ to blood anything to be ____
3. Carry ____ away for storage and _____

Each nephron comprises of what three things?

Each nephron is associated with what capillaires

Answer 3

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Question 4

Glomerular capillaries:

1. Specialised for ____
2. Thick/thin walled single layer of _____ endothelial cells
3. Fed and drained by what?
4. High/low pressure and ____ regulated

Peritubular capillaires:

1. Specialised for ____
2. Arise from ____ arterioles draining glomeruli
3. After filtration the blood is ___ and _____/____ rich
4. Therefore, ____ pressure and p____

Answer 4

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Question 5

Vasa recta:

1. Long straight ____
2. Associated with the loop of Henle in the ____ ____

Answer 5

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Question 6

The renal corpuscle:

1. What two things is this made of?
2. Site og filtration - blood/___ barrier
3. It’s where blood and ___ meet
4. Site of ____ _____

Answer 6

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Question 7

Bowman’s capsule:

1. Two layers: Outer ____ layer of what kind of cells? (why thin?)
2. Two layers: inner layer ____ layer of ____
3. Between these two layers is the ____ ___ (aka what two other names?)
4. What other cells exist?
   - regulate ____ ____
   - produce _ _ _

Answer 7

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Question 8

Podocytes (the visceral epithelium of the Bowman’s capsule)

1. Surround what?
2. Very ____ and very specialised epithelium
3. Branches form intertwining foot processes called what?
4. ____ ___ form between pedicels
5. Filtered blood (filtrate) goes through these slits and passes into _____ ____
6. How do they limit what comes into the Bowman’s space?

Answer 8

6. Only small ish can get through

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Question 9

Filtration barrier (blood-urine barrier/glomerular capsular membrane)

1. Lies between ____ and ____ ____
2. Allows free passage of what?
3. Restricts passage of most ____ (why?)
4. RBCs aren’t filtered into nephron - why?
5. Three layers:
   - what are they?

Answer 9

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Question 10

Components of the nephron:

1. B____’s c____
2. T_____ system (
proximal,
 Loop
 of
 Henle, 
distal
)
   - selectively reabs what?
   - actively secrete what?
3. Collecting duct

Answer 10

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Question 11

Proximal convoluted tubule:

1. Closest to ____ ___
2. Bulk _____
3. Structure:
   - _____ epithelial cells
   - Dense microvilli (____ ____) on ____ surface
   - Highly folded ______ _____
   - Many ____ for active transport

Why so folded?

Answer 11

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Question 12

Loop of Henle:

1. Only part of the tubule to penetrate the ____
2. Thick descending limb:
   - similar to ____ structure
3. Thin descending limb:
   - What epithelium?
   - permeable to ___ and impermeable to ____
4. Thin ascending limb:
   - what epithelium?
   - impermeable to ___ and permeable to ____
5. Thick ascending limb:
   - similar to ____ structure
6. Length is important in production of very ____ or very _____ urine

Answer 12

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Question 13

DCT:

1. Located between what two things?
2. What epithelium? compared to PCT
3. About about the brush border?
4. What about the mitochondria?
5. And reabsorption is influenced by what? What about the bulk reabs in PCT?

Answer 13

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Question 14

Collecting duct:

1. Filtrate from several DCTs drains into one ____ ___ which empty at ____
2. What epithelium is the wall made of?
3. What two types of cells are there and what do they do/look like?
4. Reabs influenced by __ through the use of aquaporins
5. Which cells are the aquaporins inserted in?

Answer 14

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Question 15

JGA (juxtaglomerular apparatus):

1. Specialised zone in every nephron
2. Located where ___ lies against ____ ____
3. Both vessels have ___ cells
4. Controls ____ ____ ___, ensuring system is working at full capacity
5. Stabilises ____ ____ (help controls BP through controlling filtration through nephron)

Afferent arteriole:

• what’s the name of the cells?
• what kind of receptors
• release ____ in repossess to ____
• renin ______ angiotensin II formation

Distal convoluted tubule:

• name of cells?
• what kind of receptors
• sense ____ concentrations

So basically, juxtaglomerular cells detect the blood pressure as blood passes past them. Macular dense senses the NaCl concentrations. These two communicate between each other to help control the glomerular filtration rate and how much H2O we are keeping etc so control BP. Because low level of Na+ = lots of filtering (vice versa). H20 follows Na+ and this affects the H20 in the blood so affects BP.

Answer 15

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