Pdbio305 Unit 3 Body Fluid

Front 1

How much water comprises the total body weight of the average adult?
What is this water reffered to as?

Back 1

50-60%

The water is referred to as total body water (TBW).

Front 2

What are the two categories into which TBW falls?

Back 2

Intracellular fluid (ICF) - comprises the water within cells in the body.

Extracellular fluid (ECF) - everything else, comprises the water in plasma and interstitial fluid (within tissue spaces).

Front 3

What is the percentage breakdown of categories of TBW?

Back 3

ECF:
6% plasma
27% Interstitial fluid

ICF: 67%

Front 4

What are three factors that effect an individual's TBW% of total body weight?

Back 4

Age - infants and young children have up to 80% TBW.

Gender - women, because of relatively more fatty tissues that have little water, have lower TBW%'s than men.

Body weight: more obese==>more fat==>lower TBW% due to relative amount of fat to the rest of the body.

Front 5

What are the major purposes of body fluids in the body?

(Hint: 4, dealing with metabolism, energy, and structure/function)

Back 5

1. Bring 02 and nutrients to cells.
2. Take up discharged metabolic waste from cells.
3. Provides moving water and electrolytes essential for cells to maintain a normally functioning internal environment.
4. Add structure, lubrication/cushion, transport, and an incubator of chemical reactions in the body.

Front 6

What is the daily amount of liquids ingested by the average person? What is the daily urinary output?

Back 6

Water ingested: 1450 mL
Water urinated: 1550 mL

Front 7

What is hypertonicity? What usually causes ECF to take on this quality?

Back 7

Hypertonicity is an excessive concentration of solutes in ECF fluids.

Hypertonicity of ECF is usually the result of dehydration, aka hypovolemia.

Front 8

What are the three major causes of dehydration/hypovolemia?

Back 8

1. Insufficient water intake.
2. Excessive water loss via vomiting, heavy sweating, and diarrhea.
3. Diabetes insipidus, an ADH deficiency.

Front 9

How does the ADH negative feedback mechanism work?

Back 9

When hypertonicity of body fluid is detected, the hypothalamus responds by making ADH, which is secreted into the bloodstream via the posterior pituitary gland, reaching the kidneys.

Front 10

What does ADH/vasopressin do to the kidneys?

Back 10

Increases permeability of the distal and collecting tubules of the nephron loops, allowing the body to reabsorb water rather than excreting it as urine.

Front 11

What is diabetes insipidus? What is the result of this condition?

Back 11

Diabetes insipidus is the lack of the ability of the hypothalamus to produce ADH/vasopressin.

The result is that affected persons are not able to retain body fluid, and may urinate up to 20L of dilute urine/day.

Front 12

What is a diuretic/"water pill"? What is the result of taking it?

Back 12

Diuretics are hormones/drugs that induce the formation of urine. Those taking it produce more urine. It works in a manner opposite of ADH/vasopressin.

Front 13

What does ADH stand for? What is another name for this hormone?

Back 13

It stands for anti-diuretic hormone.

Another name for ADH is vasopressin.

Front 14

Where is ADH produced? What secretes it into the bloodstream? What part of which organ does ADH effect?

Back 14

ADH is produced in the neurosecretory cells of the hypothalamus.

The posterior pituitary gland secretes ADH into the bloodstream.

It effects the distal and collecting tubules of the kidney's nephrons.

Front 15

What is hypovolemia? What causes it?

Back 15

Hypovolemia is dehydration.

It is caused by decreased water intake or water output due to:
vomiting, diarrhea, loss of blood, and excess drainage from burns.

Front 16

What are some neurological symptoms of hypovolemia?
(Hint: CDCC)

Back 16

Mental symptoms:
Confusion
Delirium
Convulsions
Coma

Front 17

What are the neurological symptoms of hypovolemia?
Hint: 4, CDCC

Back 17

Confusion
Delirium
Convulsions
Coma

Front 18

What are the circulatory symptoms of hypovolemia?
(Circulatory symptoms are usually due to a reduction in plasma volume.)
HInt: 5

Back 18

Weight loss
Decreased blood pressure/volume
Increased heart rate/cardiac output
Sunken eyeballs
Decreased urinary output

Front 19

What is the body's response to hypovolemia?
Hint: due to decrease in salivary secretion and due to drying of the mouth and pharynx, which is interpreted by thirst centers of hypothalamus.

Back 19

Drinking and thirst are stimulated.
Hypothalamus also released more ADH and aldosterone leading to an increased retention of body fluids.

Front 20

What is hypervolemia?

Back 20

Over-hydration

Front 21

When are cells hypertonic to the environment? Hypotonic? Isotonic?

Hint: Consider the hypo- and hyper- as "too little/too much solute in ECF, not ICF"

Back 21

Hypertonic: ICF solute concentration < ECF solute concentraiton
Hypotonic: ICF solute concentration > ECF solute concentration
Isotonic: ICF solute concentration = ECF solute concentration

Front 22

What are some common causes of hypervolemia?

Back 22

Excessive IV administration
Psychotic drinking episodes
Kidney failure resulting in decreased urinary output

Front 23

What are some neurological symptoms of hypervolemia?
(Caused by enlarged neurons due to extra fluid in the neuron)

Back 23

Confusion
Irritability
Lethargy
Dizziness
Vomiting
Drowsiness
Convulsions
Coma
Death

Front 24

What are some circulatory symptoms of hypervolemia?

Back 24

Muscle weakness
Decreased body temperature
Increased blood pressure
Edema (large amounts of fluid in the interstitial space)

Front 25

What are acids?

Back 25

Acids are molecules that easily protons to a given solution, increasing its acidity (hydrogen ion concentration).

Front 26

What is the difference between weak acids and strong acids?

Back 26

Weak acids do not completely dissociate into hydrogen ions and the conjugate base, whereas strong acids dissociate much more.

Front 27

What is Ka? What is pH?
(The formulas)

Back 27

Ka = [product1][product 2]/[reactant1]

pH = -log([H+])

Front 28

How does the pH scale work?
What is Kw?

Back 28

HIgher pH ==> more basic
pH scale goes from 1 to 14, due to the fact that Kw=[H+][OH-]=10^-14 M^2, which is constant (also known as the autoionization of water).

Front 29

What is a chemical buffer system?

Back 29

A mixture in a solution of a weak acid and its salt that minimizes pH changes when either a strong acid or strong base is added to or removed from the solution.

Front 30

What is the main buffer system in body fluid that we studied in class?

Back 30

The "bicarbonate" buffer system:

H20+C02<==>H2C03<==>H+ + HC03-

Front 31

What is the advantage of using a weak acid as the buffer against strong pH changes when a strong acid is added to the solution?

Back 31

A weak acid is able to absorb many of the hydrogen ions that the strong acid gives off as it dissociates in the solution.

Front 32

What is the Henderson-Hasselbach equation?

Back 32

pH=6.1 + log[HC03-]/[C02]
Under normal conditions, pH=7.4 in the blood, which is calculated by the Henderson-Hasselbach equation.

Front 33

How does the respiratory system regulate the Acid-Base balance of the blood when pH is too high? Too low? What is this category of regulation called?

Back 33

If blood pH becomes too high, the respiratory system can decrease the rate of C02 output, increasing the concentration of C02 in the blood. The result shifts the reaction to the right and increases [H+], lowering pH.

If pH becomes too low, the respiratory system can also increase the rate and depth of respiration, causing C02 to leave the blood. This raises pH.

This type of regulation is known as respiratory regulation of the acid-base balance.

Front 34

How does the kidney regulate pH? What is this known as?

Back 34

The kidney can regulate acid-base balance of the blood by regulating the concentration of [H+] that leaves in the urine, as well as the rate of reabsorption of bicarbonate back into the bloodstream.

If HC03- increases, alkalosis is experienced; if HC03- decreases, metabolic acidosis is experienced.

This regulation (among others not respiratory) is known as metabolic acid-base regulation.

Front 35

What are some causes of respiratory acidosis? (3 of them)

Back 35

Lung diseases
Asthma (decreased ventilation, leading to C02 not leaving the body via respiration, increasing the levels of C02 and H+ in the blood)
Nerve or muscle disorders that reduce respiratory muscle ability.

Front 36

How does the body compensate for respiratory acidosis?

Back 36

When the respiratory system can't function to deal with acidosis, the kidneys must act by conserving filtered bicarbonate, causing H+ to be excreted into the urine.

Front 37

When the lungs work more slowly than normal, does acidosis or alkalosis result?

Back 37

Acidosis results, because not enough C02 can leave the system as ought to leave.

Alkalosis conversely occurs because the respiratory system released too much C02.

Front 38

What is the upper pH limit of the blood around which death can occur? What is the lower limit? What other symptoms are experienced?

Back 38

Lower limit of the blood: pH=6.8-7.0
Disorientation
Coma
Death

Upper limit of the blood: pH=7.8-8.0
Overexcitability of the nervous system
Tetany
Death

Front 39

What are some causes of metabolic acidosis?

Back 39

Severe diarrhea (causes loss of bicarbonate)
Diabetes mellitus
High intensity exercise (causes an increase in lactic acid)
Kidney failure (inability to excrete hydrogen ions from the body fluids)

Front 40

How is metabolic acidosis compensated?

Back 40

It is compensated by both respiratory and kidney mechanisms (respiratory acidosis/alkalosis can only be compensated by the kidneys).

Front 41

What are some causes of respiratory alkalosis?
Hint: all are a result of excessive stimulation of ventilation without regard to oxygen, carbon dioxide, and hydrogen ion concentrations in the body,

Back 41

Fever
Aspirin poisoning
High altitude

Front 42

What are the two ways that respiratory alkalosis is compensated?

Back 42

1. Chemical buffer systems liberate hydrogen ions to decrease the severity of the alkalosis.
2. Kidneys compensate by conserving hydrogen ions and excreting more bicarbonate.

Front 43

What are two causes of metabolic alkalosis?

Back 43

1. Vomiting, which causes abnormal loss of hydrogen ions.
2. Excessive bicarbonate ingestion, which would push the bicarbonate buffer reaction toward a more basic state.

Front 44

What are some compensations for metabolic alkalosis?

Back 44

Chemical buffer systems liberate hydrogen ions.
Ventilation is reduced in order to retain carbon dioxide, thereby increasing acidity of the bloodstream.
If the condition persists for several days, the kidneys conserve hydrogen ions and excretes excess bicarbonate into the urine.