Kidney

Question 1

renal capsule

Answer 1

connective tissue surrounding the kidney

Question 2

renal cortex

Answer 2

area immediately beneath the capsule, which contains the glomeruli and portions of tubules- receives most of the blood flow- mostly concerned with reabsorbing filtered material

Question 3

Renal Medulla

Answer 3

the innermost part of the kidney

Question 4

Renal artery

Answer 4

supplies each kidney with blood

Question 5

Renal sinus

Answer 5

cavity within the kidney which is occupied by the renal pelvis

Question 6

Calyces

Answer 6

tubes through which urine drains into the renal pelvis

Question 7

Glomerulus

Answer 7

clusters of capillaries-plasma is filtered from capillaries into the Bowman’s capsule

Question 8

Bowman’s capsule

Answer 8

double membrane that surrounds the glomerulus

Question 9

PCT

Answer 9

reabsorbs most of the filtered load

Question 10

Loop of Henle

Answer 10

Urine concentration

Question 11

DCT

Answer 11

reabsorbs Na and H2O

Question 12

Collecting Duct

Answer 12

collects urine from excretion

Question 13

Ureters

Answer 13

transports urine from the calyces to the bladder

Question 14

Urethra

Answer 14

transports urine from bladder to urinary meatus

Question 15

How many nephrons are in each kidney?

Answer 15

Approximately 1 million nephrons i

Question 16

How much blood flow does the kidney receive?

Answer 16

~22% of cardiac output

Question 17

What are the functions of the kidney?

Answer 17

• Excretion of metabolic waste products
• Excretion of foreign chemicals
• Hormone synthesis, metabolism, and excretion
• Regulation of acid base balance
• Regulation of arterial pressure
• Regulation of water and electrolyte balance
• Gluconeogenesis

Question 18

What is involved in urine formation?

Answer 18

Glomerular Filtration
Tubular Reabsorption
Tubular Secretion

Question 19

What is involved in filtration?

Answer 19

Non selective; averages 20% of renal plasma flow

Question 20

what is involved in reabsorption?

Answer 20

highly variable and selective; most electrolytes and nutritional substances are almost completely reabsorbed

Question 21

what is involved in secretion?

Answer 21

highly variable; important for rapidly excreting some waste products, foreign substances, and toxins

Question 22

Glomerular Filtration

Answer 22

• Urine formation begins with filtration of large amounts of fluid through the glomerular capillaries into Bowman’s capsule
• the glomerular capillaries are relatively impermeable to proteins

Question 23

Constituents of glomerular filtrate

Answer 23

most salts, organic molecules (similar to the concentrations in the plasma)

Question 24

The 3 layers of glomerular filtration barrier

Answer 24

1. The endothelium of the capillary
2. A basement membrane
3. A layer of epithelial cells

Question 25

Constant GFR

Answer 25

80-180 mmHg

Question 26

The Net Filtration Pressure

Answer 26

The sum of the hydrostatic and colloid osmotic forces that either favor or oppose filtration across the glomerular capillaries

Question 27

How much water is excreted each day?

Answer 27

1 liter

Question 28

How much sodium is excreted each day?

Answer 28

150 mmol

Question 29

How much glucose is excreted each day?

Answer 29

0

Question 30

How much creatinine is excreted each day?

Answer 30

1.8 gm

Question 31

Autoregulation

Answer 31

feedback mechanism intrinsic to the kidneys normally to keep renal blood flow and GFR relatively constant, despite marked changes in arterial blood pressure (80-180 mmHg)

Question 32

What is the Juxtaglomerular Complex equation

Answer 32

Juxtaglomerular Complex = Macula Densa + Juxtaglomerular Cells

Question 33

Clearance of insulin (Cin)

Answer 33

if CxCin: indicates secretion of X

Question 34

Formation of a Dilute Urine

Answer 34

- Continue electrolyte reabsorption - Decrease water reabsorption - Mechanism: decreased ADH release and reduced water permeability in distal and collecting tubules

Question 35

Formation of a Concentrated Urine

Answer 35

- Continued electrolyte reabsorption - Increase water reabsorption - Mechanism: - increased ADH release which increases water permeability in distal and collecting tubule - high osmolarity of renal medulla - countercurrent flow of tubular fluid

Question 36

Characteristics of normal urine

Answer 36

``` No protein No RBC No Heme No cellular casts No fat No sugar ```