A&P of the Renal System

Question 1

Kidney Functions

Answer 1

Removal of metabolic waste products and foreign chemicals
Regulation of water and electrolyte balances
Regulation of acid-base balance
Regulation of arterial BP
Secretion of hormones
Gluconeogenesis

Question 2

What hormone do the kidney secrete about 90% of?

Answer 2

Erthropoietin

Question 3

Each Kidney weighs?

Answer 3

150 grams

Question 4

Medial side of the kidney contains

Answer 4

And indented region called the hilum which passes the renal artery, vein, nerve supply and ureter

Question 5

Outer region of the kidney is called

Answer 5

Cortex

Question 6

Inner region of the kidney is called

Answer 6

Medulla

Question 7

The medulla is

Answer 7

dived into regions of cone-shaped masses called renal pyramids

Question 8

Minor and major calyx

Answer 8

Urine is formed here and sent to the pelvis and then the bladder

Question 9

Afferent arteriole

Answer 9

Supplies the glomerulus with blood

Question 10

Efferent arteriole

Answer 10

Terminates from the first capillary bed

Question 11

Glomerulus

Answer 11

First capillary bed that supplies the kidneys

Very high pressued to produce filtrate

Question 12

Peritubular capillary bed

Answer 12

Second capillary bed
Low pressure
Can receive a lot of the filtrate that is being pushed out

Question 13

Each kidney is made up of:

Answer 13

1 million nephrons

Question 14

1st segment of the kidneys is made of the

Answer 14

Bowman’s capsule where the initial filtrate is received

Question 15

The 2nd segment is th

Answer 15

Proximal tubule

Question 16

The 3rd segment is the

Answer 16

Loop of Henle which is composed on a descending thin limb, ascending thin limb and a thick ascending limb

Question 17

The 4th segment is the

Answer 17

Macular densa which is the area that passes between the afferent and efferent arterioles

Question 18

The 5th and last segment

Answer 18

Distal tubule where it is joined by 2+ nephrons to form a collecting duct

Question 19

Define Capillary endothelium

Answer 19

Contains anumber of large holes called fenestrae lending to the endothelium’s weak barrier characterisitcs

Question 20

Define Basement membrane

Answer 20

Meshwork of collagen and proteoglycans which filters a large amount of water and some solutes

Question 21

Define Epithelial cells

Answer 21

Not continuous and contain slit pores whereby the glomerular filtrate moves

Question 22

What is the primary restriction point for plasma proteins?

Answer 22

Basement membrane

Question 23

Cells of the macula densa

Answer 23

Sense changes in volume or sodium concentration

Decreased sodium or volume will cause the macula densa cells to signal the JG cells to secrete renin

Question 24

Renin does what

Answer 24

Catalyzes the formation of AngII which constrics the efferent arterioles which increases glomerular hydrostatic pressure returning GFR to normal

Question 25

Excretion =

Answer 25

Filtrate rate - Reabsorption rate + Secretion rate

Question 26

For a substance to be reabsorbed it must be

Answer 26

Transported across (1) tubular epithelial membranes into the renal interstitial fluid (2) the peritubular capillary membrane back into the blood

Question 27

Types of diffusion

Answer 27

Paracellular Transcellular Osmosis

Question 28

Define Paracellular diffusion

Answer 28

Between two cells

Question 29

Define Transcellular diffusion

Answer 29

Across cell membranes

Question 30

Define Active Transport

Answer 30

Moving a solute against an electrochemical gradient and requiring energy

Question 31

Na K ATPase

Answer 31

Primary Active Transport Basolateral side of the cell Hydrolyzes ATP and uses that energy to transport Na out of the cell and into the interstitial while K is transported inside the cell

Question 32

Na K ATPase makes what and drives what

Answer 32

A negative electrical gradient A chemical gradient bc Na wants back into the blood Drives a lot of secondary active transport

Question 33

Define Secondary Active Transport and give examples

Answer 33

Co-transport Counter transport Two or more substance interact with a specific membrane protein and are transported across the membrane

Question 34

Co-transport Example

Answer 34

``` Movement of sodium from the lumen to the cell energizes the movement of glucose and some amino acids NKCC Cotransporters (thick ascending limb) NaCl Cotransporter (distal) ```

Question 35

Counter Transporter Example

Answer 35

Inward movement of Na proves energy for outward movement of H

Question 36

Proximal Tubular Reabsorptions

Answer 36

65% of filtered load of sodium and water High metabolic capacity Extensive luminal brush border (larger surface area) Large amounts of co-transporter protein and counter transporter proteins

Question 37

Thin descending and ascending segements

Answer 37

Have thin epithelial membranes with no brush border and few mitochondria

Question 38

Descending thin limb is

Answer 38

Highly permeable to water (20%)

Question 39

Ascending thick and thin limbs are

Answer 39

Virtually impermeable to water (concentrates the urine)

Question 40

Ascending thick limb has

Answer 40

thick epithelial cells with metabolic activity that can actively reabsorb Na K Cl Bicarbonate, Ca, and Mg 25%

Question 41

Tubular fluid becomes very dilute where?

Answer 41

Thick ascending limb

Question 42

Loop Diuretics (Furosemide, Endercrin, Bumex) work where?

Answer 42

NKCC Cotransporters

Question 43

Early Distal Tubule

Answer 43

First part = juxtoglomerular complex which provides feedback control for GFR and BF [macula densa] Second part = Reabsorption of ions and impermeable to water

Question 44

Late Distal Tubule and Collecting ducts

Answer 44

Principal cells and intercalated cells | Impermeable to urea

Question 45

Principal cells

Answer 45

Reabsorb sodium and water from the lumen and secrete potassium into the lumen

Question 46

Intercalated cells

Answer 46

Reabsorbed potassium and secrete hydrogen into the lumen

Question 47

Late Distal Tubule and Collecting ducts Hormones

Answer 47

Aldosterone stimulates sodium reabsorption and potassium secretion ADH controls water permeability

Question 48

Medullary Collecting Duct

Answer 48

Reabsorbs <10% water and sodium Controlled by ADH Permeable to urea Secrete hydrogen

Question 49

Excess water =

Answer 49

50 mOsmol/L

Question 50

Deficient water =

Answer 50

1200-1400 mOsmol/L

Question 51

High levels of ADH =

Answer 51

Concentrated urine

Question 52

Low levels of ADH =

Answer 52

Dilute urine

Question 53

Dilute urine causes changes where

Answer 53

Descending loop: water reabsorption via osmosis Ascending loop: Ion reabsorptions Distal tubule and collecting ducts: Reabsorb NaCl

Question 54

Requirements for forming concentrated urine

Answer 54

High levels of ADH | High renal medullary interstitial fluid osmolarity