Urinary System

Question 0

Define filteration

Answer 0

Water & substances moving through a membrane

Question 1

Functions

Of

Urinary System

Answer 1

1. Filters Blood plasma, not formed elements
2. Regulate blood pH, volume, pressure, and # of RBCs
3. Release erythropoietin - increase RBCs production
4. Release renin (systemic vasoconstriction) - constricts all blood vessels in the body. Increases blood pressure. Ex: may be released while in shock
5. Production of urine (waste). Urine is a representation of plasma

Question 2

Anatomy

Of

Urinary System

Answer 2

Renal artery-delivers blood to kidneys
2 kidneys-anchored by retro peritoneal
2 ureters
Bladder
Urethra

Question 3

Nephron

Answer 3

Responsible for functionality of the entire kidney

Main functional unit of the kidney

A million nephrons in each kidney

Each afferent arteriole feeds into a nephron

Question 4

Where does filtration occur?

Answer 4

Glomerulus

Question 5

Characteristics
Of
Glomerulus

Answer 5

• Fenestrated endothelium- gaps in lining
• Surrounded by podocytes (footed process that wraps outside of glomerulus capillaries)
• Plasma travels through filtration slits between the podocytes

Question 6

What does Filtration Membrane consist of?

Answer 6

Found in the glomerulus

1. Fenestrated endothelium-water & dissolved substances go through
2. Basement membrane
3. Filtration slits-formed from podocytes
   Most limiting structure of filtration membrane
   More narrow than fenestrated endothelium

Question 7

Quantity of filtrate

Produced by kidneys

Answer 7

125 ml/min

180 L/day

Filtrate is collected in the Bowman’s capillaries

Question 8

What are 2 primary functions of the kidney?

Answer 8

Excretion-H2O, waste products, & solutes in the blood

Regulation-plasma osmolarity, plasma volume, pH balance, electrolyte balance

Question 9

What are the components of the renal corpuscle?

Answer 9

Bowman’s capsule

Glomerulus capillaries

Question 10

What is filtrate?

Answer 10

Filtered plasma

Question 11

What is BHP?

Answer 11

Blood Hydrostatic Pressure

Aka: blood pressure

Question 12

What is BOP?

Answer 12

Blood Osmotic Pressure

Due to all the non-diffusable elements pulling water towards it

Question 13

What is CHP?

Answer 13

Capsular Hydrostatic Pressure

Fluids inside Bowman’s capsule (filtrate) creates a pressure

Question 14

Function & location of macula densa cells

Answer 14

In distal convoluted tubule, where DCT is between afferent arteriole & efferent arteriole

Monitor how fast or slow filtrate is moving & what is in the filtrate

Question 15

Location & Function

Of

Juxtaglomerular cells

Answer 15

In afferent & efferent arterioles

Stimulates arterioles to constrict or dilate
Effects blood pressure & net filtration rate
Adjustments to flow rate effects net filtration pressure

Question 16

Parts & function

Of

Juxtaglomerular Apparatus

Answer 16

Juxtaglomerular cells
Macula densa cells

Responsible for Renal auto-regulation
Allows for constant flow rate

Question 17

3 Methods of Regulating GFR

Answer 17

Glomerular filtration rate

1. JG Complex- renal auto-regulation system
2. Nervous System-stimulates arterioles to constrict or relax
3. Renin Angiotensin system-triggered by drop in blood pressure. Kicks in during trauma or shock

Question 18

3 organs of the body that control

Angiotensin

Answer 18

1. Hypothalamus-controls H2O balance in the body. Stimulates thirst center.
2. Cause adrenal cortex to produce aldosterone. Aldosterone causes kidneys to reabsorb Na+,then H2O follows
3. Posterior pituitary gland- release anti-diarretic hormone (ADH). Causes H2O re absorption, which influences blood pressure & volume.

Question 19

3 Major Processes of Kidneys

Answer 19

1. Filtration-filter plasma in glomerulus
2. Reabsorption-filtrate moves back into capillaries
3. Secretion-substances are moved from blood capillaries into the nephron tubule

Question 20

Steps in the renin angiotensin system

Answer 20

1. JG cells release renin
2. Renin acts on
3. Angiotensinogen (plasma protein produced by liver) converts to
4. Angiotenson I - ACE(angiotenson converting enzymes)
5. Angiotenson 2 - systemic vasoconstrictor - most powerful in the body

Question 21

Amount of filtrate throughout re absorption process

Answer 21

-125 ml/min
-Proximal convoluted tubule (PCT)
-40 ml/min
-Distal convoluted tubule (DCT)
20 ml/min
- collecting duct - 0.5 ml

Question 22

Amount of solutes reabsorbed

In

Proximal convoluted tubule

Answer 22

65%. H2O
65%. Na+
50%. K+, Cl-
All glucose & amino acids
Urea
Uric acid
90% HCO3 - bicarbonate ions - buffer
85% of filtrate is reabsorbed

Question 23

What slows down filtrate production?

Answer 23

Constriction of afferent arteriole
&
Dilation of efferent arteriole

Question 24

What increases filtration production?

Answer 24

Dilation of afferent arteriole & Constriction of efferent arteriole

Question 25

Net Filtration of Pressure amount

Answer 25

10 mm Hg

Question 26

What happens in the Juxtaglomerular Apparatus?

Answer 26

1. Macula densa cells of DCT (distal convoluted tubule) - innervates 2. Juxtaglomerular cells-innervates 3. Stimulate arterioles - either constrict or dilate

Question 27

What does aldosterone do?

Answer 27

Produced by adrenal cortex Causes kidneys to reabsorb Na+, then H2O

Question 28

What does ADH (anti-diarretic hormone) do?

Answer 28

Released by posterior pituitary gland Causes H2O reabsorption, which influences BP & volume

Question 29

What type of transport are Used in Re-absorption In Proximal convoluted tubule

Answer 29

- Active transport-Na+/K+ pump - passive transport/diffusion - Na+ - secondary active transport-co-transport-Na+ & amino acids, Na+ & glucose - osmosis

Question 30

Re-absorption Loop of henle - descending limb

Answer 30

Only H2O re-absorbed 20% of total h2O re-absorbed

Question 31

Re-absorption Loop of henle - ascending limb

Answer 31

Salts only reabsorbed K+, Na+, Cl- 20% of total salts re-absorbed

Question 32

# Define Secretion Where does it occur? What elements are secreted? 1 of the 3 processes of the kidneys

Answer 32

Substances moving from blood capillary to the renal tubule. Gives the body a back up plan because not all substances are removed with filtration. Happens mostly in DCT & CT, some in the PCT H+(to lower acidity of blood) NH3 (ammonia) Urea Uric acid

Question 33

PH of urine

Answer 33

pH 5-8

Question 34

Countercurrent mechanism

Answer 34

Blood in the vasa recta moves in the opposite direction as filtrate in the loop of henle - filtrate entering the descending limb becomes progressively more concentrated as it loses H2O - blood in the vasa recta removes H2O leaving loop of henle - ascending limb pumps out Na+, K+, & Cl-, & becomes hyposmotic

Question 35

Hormone produced in the heart

Answer 35

Natriuretic peptide Blocks ADH & aldosterone functions

Question 36

% of fluids In Extra cellular fluid

Answer 36

40% of total body fluids 300 mOsM (280 mOsM is Na+) 80% interstitial fluids 20% plasma Na+ (90% of ECF), Cl-, HCO3

Question 37

% of fluids In Intercellular fluids

Answer 37

60 % of total body fluids 300 mOsM K+, anions, PO4 (phosphorus)

Question 38

Percentage of H2O in the body

Answer 38

86% Can't live without h2O for longer than 3 days

Question 39

Input of H2O

Answer 39

Liquids. 60% Foods. 30% Metabolism 10% (electron transport chain)

Question 40

Output of H2O

Answer 40

Urine. 60% Feces. 4% Sweat. 8% Insensible. 28%. Lungs & skin (evaporation of sweat)

Question 41

Function of hypothalamus

Answer 41

Homeostatic center of the body Connected to posterior pituitary gland Controls thirst center- H2O levels Release ADH/vasopressin ADH triggered by: - Increase plasma osmolarity over 300mOsM - Low blood volume - Low blood pressure

Question 42

Causes of dehydration

Answer 42

Happens more often than too much fluid - lack of intake - heat/overheated-sweating - diarrhea - swallowing problems - exercising - bleeding

Question 43

Below 300 mOsM represents

Answer 43

Too much H2O

Question 44

Above 300 mOsM

Answer 44

Release ADH - anti diarretic hormone

Question 45

Causes of hydration (too much fluid)

Answer 45

Hypotonic hydration Renal failure Hormonal imbalances Rapid intake of H2O CHF-congested heart failure

Question 46

What is solvent drag?

Answer 46

H2O is the solvent & it drags solutes with it

Question 47

What do the renal pyramids consist of?

Answer 47

Loop of Henle & Collecting ducts

Question 48

What would happen if the Posterior pituitary gland released Too much ADH ?

Answer 48

There would be a decrease in urine Increase in osmolarity due to re absorbing H2O would cause a higher concentration of solutes.

Question 49

Structural features that can effect the filtration membrane

Answer 49

- fused filtration slits - thicker basal membrane - surface area of glomerulus - 1 kidney

Question 50

3 Systems that maintain pH

Answer 50

1) . Buffer systems- chemical response (quickest) - Bicarbonate - most common (takes just seconds) - protein buffers - phosphate 2) . Respiratory system (takes 1-3 minutes) 3) . Urinary System (takes hours/days)