Chapter 21 Flashcards
What ion is relatively high in extracellular fluids.
Sodium
Because of selective membrane permeability, the concentrations of ions such as K+ are higher inside cells cells than Na+
Name 4 transcellular fliud
Vitreous humor, peritoneal fluid , mucus and serous fluid
What is the main force that causes water to move among the various fluid compartments
Osmosis
The concentration differences between cells and extracellular compartments create osmotic pressure differences
What is the main force that causes fluid to leave the plasma compartment
Hydrostatic pressure
Since the hydrostatic pressure component of blood pressure is always slightly higher than the plasma osmotic pressure, some water is constantly lost from the capillaries
What favors the development of edema
Decreased venous pressure
A drop in blood protein can result in a reduction of the osmotic pressure necessary to move fluids into the capillaries
Name 3 causes of hypoproteinemia
Glomerulonephritis, poor diet and liver disease
Name a direct cause of ascites
Hepatic disease
What causes the edema seen in inflammations
Histamine
Name 3 characteristics of Addison’s disease
Sodium decreases, adrenal cortex failure, and low aldosterone
When a strong base reacts with the bicarbonate buffer system, ? Is formed from the base
Water
If one were to trace the OH- base in NaOH, it would end up as HOH or water and therefore, now as water, cannot effect pH alteration
When an acid reacts with the bicarbonate buffer system ? Is formed as an end product
Carbonic acid
What happens to HCl in the phosphate buffer reaction?
Forms a weak acid and salt
What reacts with excess acids in protein buffers?
NH3+
What buffers the addition of hydrogen in blood cells following the uptake of carbon dioxide
Hemoglobin
What Ions account for nearly 90% of the positively charged ions found in extracellular fliud?
Sodium
How is the excess tissue fluid returned to the blood?
Lymphatic vessels
About ?% of the total daily intake of water is derived from internal cell metabolism
10%
10% of daily water is an end product of cellular respiration as metabolic water; about 60% is obtained from drinking
As total body water decreases, the ? Of the extracellular fluid increases
Osmotic pressure
As fluid is lost, the concentration of particles increases, raising the osmotic pressure
The main factor that causes the kidney to conserve water is
ADH
Anti diuretic hormone increases the permeability and absorption of water at the distal convoluted tubules of the nephrons
ADH is secreted from the
Posterior pituitary
Although produced by the hypothalamus, ADH is stored and secreted into the blood from the posterior lobe of the pituitary
What has a diuretic affect
Drinking alcohol
Name 3 things ADH has a direct effect on
Blood pressure, water reabsorption, and blood concentration
Excessive vomiting usually results in the disorder of
Dehydration
The symptoms of dehydration result from the loss of ? Water
Intracellular
Although the loss may be caused by extracellular changes, the alteration in CNS activity such as confusion and coma, result from direct changes in the intra cellular compartment
The effects of water intoxication are usually related to
Low sodium
Water intoxication effects are related to ion concentrations
Where are most electrolytes normally lost
Urine
What is the most abundant extracellular cation
Sodium
What factor accounts for the ability of the body to conserve high levels of sodium?
Aldosterone
What ion is usually exchanged for sodium absorption
K+
What cells are most sensitive to electrolyte changes
Neurons
Nerve and muscle cells are most sensitive to ion changes and must be maintained at stable levels for normal conductivity or contraction
Name 3 effects of parathyroid hormone
Osteoclast stimulation, increase in blood Ca2+, and increase in intestinal absorption
PTH causes the kidneys to retain Ca2+; the net effect is to raise blood calcium levels
What ion is directly related to calcium homeostatis
Phosphate
Hyperparathyroidism usually causes an increase in
Calcium
Name 3 things that become involved with maintaining blood calcium balance
Bone, kidneys and intestine
Name 3 characteristics of hypocalcemia
Vitamin C deficiency, tetany, and cardiac arrhymia
What is the most important ion, which affects all of the functions of the others
H+
The H+ ion or acidity is the most important ion that has the capability of interacting with the other ions, pH balance is essential for proper enzyme functioning
Name 3 things that produce H+ ions?
Respiration of glucose, oxidation of fatty acids and oxidation of sulfur amino acids
The synthesis of proteins or other substances may not produce H+
Name 3 things associated with acidity
H3PO4, lactic, ketone
Glucose will not produce an acidic solution, but lactic acid, some ketones and phosphoric acids will produce H+
What is the likely cause of hypernatremia
Diabetes insipidus
The normal concentration of sodium in the blood plasma is 136-145 mM. Hypernatremia is defined as a serum sodium level over 145 mM.
Hypokalemia could result from what 3 things?
Vomiting, crushing’s disease and renal failure
Hypokalemia is a lower-than-normal amount of potassium in the blood
Name a base in bodily fluids
NCO3-
Name 3 things that play a significant role in maintaining acid-base balance.
Blood buffers, kidneys, and respiration
Although the acidic pH of the stomach has a significant effect on blood pH, the stomach cannot maintain blood balance
What can act by itself as a buffer
Albumin
The purpose of a buffer system is to
Stabilize pH
What factor greatly increases the reaction between carbon dioxide and water
Carbonic anhydrase
Carbonic anhydrase is the enzyme found in the erythrocyte membrane which increases the reaction more than 100,000 times
Name an effect of acidosis
Mental confusion
Alkalosis tends to make neurons more excitable tending towards seizures while acidosis causes CNS depression leading to coma
What blood parameter is directly affected by breathing
Carbon dioxide
Breathing directly alters blood levels of carbon dioxide which then leads to changes in pH
During acidosis, the kidneys will secrete ? Into the urine
H2PO4
In an attempt to remove acid from the blood, the kidneys will secrete ? Into the urine compartment
NH4+
Ammonium (NH4+) were formed from a combination of ammonia and H+
What mechanism requires the most time to regulate pH
Renal function
The blood chemical buffers operate instantly while respiration may require several minutes to adjust pH; the kidneys require 12-24 hours to completely adjust pH
What condition is a generalized accumulation of body edematous tissues?
Anasarca
What is the normal pH of the blood
7.35-7.45
What is the pH range compatible with life?
6.8-8.0
Persons cannot survive long with pH values under6.8 or over 8.0
Hyperventilation from anxiety usually causes
Respiratory alkalosis
Name 3 things that can cause edema
Obstruction of lymphatic vessels
Increased capillary permeability because of inflammation
Increased venous pressure
The imbalance known as ? Can be caused by certain diuretic medications
Hypokalemia
Some diuretics conserve sodium ions at the expense of potassium
Name 3 things that occur as a result of a shift in the acid-base balance of the body
An alteration in the rate of enzyme-controlled metabolic reactions
A shift in the distribution of other ions
A modification in hormone actions
Name 3 factors that are major metabolic sources of hydrogen ions in the body
Aerobic and anaerobic respiration of glucose
Oxidation of amino acids that contain sulfur
Hydrolysis of phosphoprotiens
How is it possible for the rate and depth of breathing to affect hydrogen ion concentrations in body fluids?
During increased air exchange, more carbon dioxide is given off, returning hydrogen ion concentrations to normal
What is considered a secondary defense against changes in pH
Renal excretion of hydrogen ions
Physiologic mechanisms are secondary mechanisms
Of the following: metabolic water, water output , water in food or water in drinks, what value is the smallest?
Metabolic water
What condition leads to a severe, life threatening water loss?
Diabetes insipidus
Diabetes insipidus is a condition where ADH is ignored
An abnormal accumulation of interstitial fluid is termed
Edema
Edema or swelling is excess fluid in the interstitium
The most serious consequence of potassium imbalance is
Cardiac abnormalities
Cardiac muscle is very sensitive to potassium imbalance
What is the normal pH of blood
7.35-7.45
What is the most significant inorganic plasma buffer
Bicarbonate
Bicarbonate is very abundant in extracellular fluid
What is the most effective intra cellular inorganic buffer
Phosphate
Phosphate is in high intracellular concentration
Diabetic ketoacidosis is an example of which imbalance
Metabolic acidosis
Improper metabolism causes a pH less than 7.35
During drinking of water, the stretching of the stomach causes a hypothalamic reflex to send impulse to the nervous system causing the person to stop
T or F
True
The stretch receptors in the stomach often initiate a reflex that inhibits drinking, even before the absorption into the blood is complete
The osmoreceptors in the hypothalamus cannot detect the change in body fluids until e loss is decreased to around 20% of body water
T or F
False
The hypothalamus osmoreceptors are extremely sensitive to tonicity changes and will respond when the body loss is around 1%
The ability to sweat is the major method of regulating body water and concentration
T or F
False
Sweating is a major method of controlling body temperature; the usual loss of 6% is greatly outweighed by the regulatory capability of the kidneys
Loss of blood from trauma will usually reduce the amount do urine that is produced
T or F
True
One of the methods of conserving water, electrolytes and raising blood pressure is the inhibition of urine output from the increase in ADH secretion caused by a reduction in water and increase in tonicity sensed by the hypothalamus
Diuretics can have an effect of reducing blood pressure
T or F
True
Blood pressure is the main force governing the rate of urine production; high blood pressure can cause an increase in urine output, and diuretics can be used to reduce blood pressure
Drinking water can cause intoxication with symptoms similar to alcohol
T or F
True
Water intoxication results when the blood becomes hypotonic and results in the CNS delirium and muscle craps similar to alcohol intoxication
Edema caused by surgical procedures or inflammation is always serious and must be treated
T or F
False
Edema is not a disease but a symptom, and it only becomes a problem when it occurs in critical areas such as the lungs or brain (pulmonary or cerebral edema)
Diuretics could be used to reduce the edema seen in the legs or sacral regions
T or F
True
Diuretics cause the increase in urine output which will draw fliud from the blood and then the tissue spaces because they are in equilibrium with each other
Surgical removal of the breast can cause edema in the arm
T or F
True
Since lymphatic vessels drain ares, the loss of thoracic or pectoral tissue could prevent the return of water from distal areas
Most of the requirement for electrolytes can be adequately met by water drinking
T or F
False
Most drinking water is hypotonic and will not contain sufficient electrolytes to meet body demands
Cells attempt to maintain electrical charge stability by transporting ions such as sodium inward as soon as they are lost from a cell
T or F
False
Cells must maintain ionic balance which is usually achieved by causing the movement of ions that counterbalance the loss such as K+ for Na+
Breast, lung or bone cancers can cause hypercalcemia
T or F
True
Cancer cells can produce hormones similar to PTH or bone cancers can destroy bone tissue, either event causes rises in blood Ca 2+ levels
Increases in carbon dioxide production usually result in a decrease in acidity
T or F
False
Carbon dioxide from any source such as metabolism, readily combines with water to yield carbonic acid which ionizes to release H+
The oxidation of fatty or amino acids always must cause a decrease in pH
T or F
False
Some fatty acids produce acidic ketones and some amino acids result in acidic end products, but not all; most amino acids are amphoteric which means they have acidic and basic properties together in the same molecule
Factors that decrease the pH of a solution must always increase the acidity
T or F
True
The pH scale is a measurement of acidity and is inversely related to acid; the higher pH numbers means lower acidity
Diuretics have a higher probability of causing a sodium than a potassium depletion
T or F
False
The normal function of the kidney is to conserve sodium and excrete potassium, under the influence of aldosterone; factors which increase the rate of urination formation usually exaggerate this effect and cause a potassium depletion
Either hyperkalemia or hypokalemia could be associated with muscle paralysis or cardiac arrhythmias.
T or F
True
Either high or low levels of K+ are associated with nerve and muscle excitability disturbances; since the causative factors are complex, the resultant symptoms are also not directly related to either condition
Carbonated beverages usually have a higher pH than stomach secretions
T or F
True
Carbon dioxide forms the weak acid carbonic acid while the stomach produces the strong acid HCl, making its pH lower.
Both components of the phosphate buffer system are acids, which breaks the normal buffering rules
T or F
False
Both of the components are acids, but buffer rules are not broken because in physiologic solutions, the H2PO4 acts as the relative base, therefore enabling the system to buffer acids or bases
Holding one’s breath tends to make the blood more acidic
T or F
True
Since carbon dioxide forms carbonic aci, the pH could decrease if carbon dioxide levels increase, assuming that the other buffers were not compensating
Renal secretion of phosphate acids is an example of renal compensation for respiratory acidosis
T or F
False
If the pH is restored to normal, the mechanism can be called compensation; only organs other than the one that is the cause of the imbalance can be said to compensate
A pH of 7.1 in a diabetic is caused by the production of compounds such as beta-hydroxybutyric acid
T or F
False
Ketoacidosis occurs when the production of acidic ketones exceeds the ability of all of the buffers to prevent acidosis; the production of some ketones occurs normally each day
The respiratory center in the pons and medulla are able to alter the pH of the blood
T or F
True
The respiratory centers react to the levels of H+ by altering breathing rate and depth; the effect is to facilitate the actions of the chemical bicarbonate blood buffers
A Person’s blood may be alkaline at the same time they are considered to be in acidosis
T or F
True
The normal range is considered neutral physiologically but is chemically alkaline; a pH of 7.2 is alkaline but considered physiologically to be an indication of acidosis because it is less than 7.35
If blood plasma becomes more concentrated, the high osmotic pressure will cause neurons (osmoreceptors) to swell
T or F
False
High osmolarity in the blood would cause crenation.
The presence of sodium in the blood can be detected by the osmoreceptors of the hypothalamus
T or F
False
Osmoreceptors are not specific to one solute
The phosphate buffer system is more important in extracellular fluids
T or F
False
Phosphate is an intracellular buffer
