Lecture 16: Body Fluids

Question 1

What are the major cations in the extracellular compartment?

Answer 1

Na+

Ca++

Question 2

What are the major anions in the extracellular compartment?

Answer 2

Cl-

HCO3-

Question 3

What are the major cations in the intracellular compartment?

Answer 3

K+

Mg++

Question 4

What are the major anions in the intracellular compartment?

Answer 4

PO4

proteins

Question 5

What is osmolarity?

Answer 5

mOsm/ L = concentration of particles per liter of solution

Question 6

What is osmolality?

Answer 6

mOsm/ kg = concentration fo particles per kg solven

Question 7

What is an effective osmoles?

Answer 7

refers to a solute that does not easily cross a membrane
creates an osmotic force for water
Proteins are effective osmoles

Question 8

Where does daily fluid intake come from?

Answer 8

ingestion: 2100 ml/ day
metabolism: 200 ml/ day

Question 9

Where does daily fluid loss come from?

Answer 9

insensible evaporation: 350 ml/day through skin and 350 ml/ day via lungs

sweat: 100 ml/day
feces: 100ml/day
urine: 1400 ml/day

Question 10

What is the total daily fluid intake? loss?

Answer 10

2300 ml/ day for both

Question 11

What is the average total body water?

Answer 11

42 liters

Question 12

What makes up the basic metabolic profile and the values for each?

Answer 12

Na+: 140 mEq/L
K+: 4 mEq/L
Cl-: 104 mEq/L
HCO3-: 24 mEq/L
BUN:. mg/dl
Cr: 1 mg/dl
Glucose: 80 mg/dl

Question 13

What is the osmolar gap?

Answer 13

difference between the measured osmolarity and the estimated osmolarity

or difference between measured and estimated osmolality

Question 14

What are common things that can elevate the osmolar gap?

Answer 14

ethanol
methanol
ethylene glycol
acetone
mannitol

Question 15

How do you calculate potential osmotic pressure?

Answer 15

osmolarity/ osmotic pressure

Question 16

Major ions that determine most of the total osmolarity of interstitial fluid

Answer 16

sodium and chloride ions

Question 17

Major ions that determine most of total osmolarity of intracellular fluid

Answer 17

potassium ions

Question 18

What happens when adding isotonic saline to extracellular fluid compartment?

Answer 18

extracellular osmolarity does not change

extracellular volume increases

Question 19

What happens when adding a hypertonic saline to extracellular fluid compartment?

Answer 19

intracellular volume decreases
extracellular volume increases
osmolarity in both compartments increases

Question 20

A solution of implement solutes having an osmolarity of 282 mOsm/L is isotonic, what does that mean?

Answer 20

water cannot enter or leave cell

Question 21

A solution of impermeant solutes having an osmolarity of > 282 mOsm/L is hypertonic, what does this mean?

Answer 21

water will diffuse out of the cell

Question 22

Addition of a hypotonic saline to extracellular fluid compartment results in….?

Answer 22

volume of both compartments increases

osmolarity in both compartments decreases

Question 23

A solution of impermeant solutes having an osmolarity <282 mOsm/L is hypotonic, what does this mean?

Answer 23

water will diffuse into the cell

Question 24

What are the causes and consequences of hyponatremia?

Answer 24

causes: serum sodium concentration <135 mmol/L or excess watering causing brain to swell
consequences: seizures, coma, permanent brain damage, death

Question 25

What are the causes and consequences of hypernatremia?

Answer 25

cause: deficit in total body water in relation to total body sodium
consequence: cognitive effects, other illnesses

Question 26

Causes of extracellular edema

Answer 26

(1) abnormal leakage of fluid from the plasma to the interstitial spaces across the capillaries
(2) failure of the lymphatics to return fluid from the interstitium back into the blood, often called lymphedema

Question 27

What is the anatomical organization of the kidney?

Answer 27

• capsule
• renal cortex: bowman’s capsules and proximal and distal convoluted tubules
• renal medulla: renal pyramids
• penal pelvis: minor and major calyces

Question 28

Describe cortical nephrons

Answer 28

have glomeruli located in outer cortex and have short loops of Henle

Question 29

Describe juxtamedullary nephrons

Answer 29

have glomeruli deep in renal cortex near medulla and have long loops of Henle.

Have long efferent arterioles associated with peritubular capillaries

Question 30

Kidneys receive ____ of total cardiac output

Answer 30

22% ( 1100 ml/min)

Question 31

What does high hydrostatic pressure in glomerular capillaries causes?

Answer 31

rapid fluid filtration

Question 32

What does low hydrostatic pressure in peritubular capillaries cause?

Answer 32

permits rapid fluid reabsorption

Question 33

What is the path of blood flow to the kidneys?

Answer 33

renal artery
interloper arteries 
arcuate arteries 
interlobular arteries 
afferent arterioles 
glomerular capillaries
efferent arterioles

Question 34

What is the path of blood flow from kidneys?

Answer 34

peritubular capillaries 
interlobular veins
arcuate veins
interlobar veins
renal veins