Patho - Term Test I Flashcards
How much body weight is water?
60% of total body weight
What are the two components of body fluids?
ICF (2/3 of TBW) and ECF (1/3 of TBW)
What consistitutes ECF (i.e. what are the components of ECF)
blood plasma (intravascular fluid), interstitial fluid, transcellular fluids (CSF, synovial fluid)
What is intersitital fluid?
Fluid that is found in spaces between cells but not within blood vessels
When is anaerobic glycolysis used?
When there is no oxygen present, cells use this method to breakdown glucose (pyruvate and lactic acid as byproducts)
- not a very efficient process (makes little ATP)
Define intravascular fluid
fluid found within blood vessels (aka blood plasma)
Define transcellular fluid and provide an example.
Fluid contained within epithelial-lined cavities of the body (smallest component of ECF)
ex. CSF, synovial fluid, urine, GI fluids, pleural fluids, pericardial fluids, peritonial fluids)
What are two methods in which you would inevitably lose fluids?
sweat and lung ventilation
Rank from greatest to least: water loss from these following methods
1) ventilation
2) stool
3) perspiration
4) renal excretion
renal > ventilation > perspiration > stool
What are the major cations and anions in ECF?
sodium (Na+)
chloride (Cl-)
What are the major cations and anions in ICF?
K+, phosphates and Mg2+
What forces move water between ICF and ECF
osmotic forces
Define Starling Forces. What are the 4 forces?
Forces that determine whether net effect is filtration or reabsorption
1) capillary hydrostatic pressure
2) capillary oncotic pressure
3) interstitial hydrostatic pressure
4) interstitial oncotic pressure
What does capillary hydrostatic pressure do?
facilitates water movement from capillary to interstitial space
What does capillary oncotic pressure do?
osmotically attracts water from interstitial spaces to capillary
What does interstitial oncotic pressure do?
osmotically attracts water from capillary to interstitial spaces
What does interstitial hydrostatic pressure do?
facilitates water movement from interstitial space to capillary
Which of the 4 starling forces promote fluid and proteins into lymphatics
interstitial hydrostatic pressure
True or false: Water, sodium and glucose move readily across capillary membrane
TRUE
True of False: albumin and other proteins move across capillary membrane to facilitate hydrostatic/oncotic pressures
False. They do not cross the membrane. Proteins stay in the capillary and generate oncotic pressures within plasma
Define filtration
movement of fluid out of capillaries and into interstitial space
Define reabsorption
fluid movement into capillaries from intersitial space
At the arterial end of capillary, is hydrostatic or oncotic pressure higher?
hydrostatic
At venous end of capillary, is hydrostatic or oncotic pressure higher?
oncotic
True or False: Typically intracellular and extracellular fluid osmotic pressures are equal, and water is equally distributed between interstitial and intracellular components
True
Which cation is responsible for osmotic balance of ECF?
Na+
Which cation is responsible for osmotic balance of ICF?
K+
What is edema?
excessive accumulation of fluid within interstitial spaces (fluid shifts from capillaries or lymphatic vessels –> interstitial spaces
What are the 4 causes of edema?
1) increased capillary hydrostatic pressure
2) decreased plasma oncotic pressure
3) increased capillary membrane permeability
4) lymphatic channel obstruction
How does increased capillary hydrostatic pressure cause edema? provide 2 explanations
1) venous obstruction (increased hydrostatic pressure behind the obstruction and fluid is pushed into interstitial spaces)
2) salt/water retention - causes volume overload leading to increased capillary hydrostatic pressure and edema
Provide two conditions that causes edema due to increased capillary hydrostatic pressure secondary to venous obstruction.
Any two:
- thrombophlebitis
- hepatic obstruction
- tight clothing around extremities
- prolonged standing
Provide a condition that causes edema due to increased capillary hydrostatic pressure secondary to salt/water retention
CHF, renal failure, liver cirrhosis
How does decreased plasma oncotic pressure cause edema?
due to decreased or loss of protein production (albumin) that typically holds onto water in blood vessels (so fluid remains in interstitial spaces)
Provide two conditions that causes edema due to decreased plasma oncotic pressure.
Any of these:
- protein malnutrition
- liver disease (reduced albumin production)
- glomerular diseases of the kidney
- serous damage from open wounds
- hemorrhage
- burns
- liver cirrhosis
How does increased capillary membrane permeability lead to edema?
proteins escape from within blood and into interstitial spaces which decreases capillary oncotic pressure so fluids are not pulled back into capillaries and protein buildup in interstitial fluid - typical in inflammatory responses
Provide two conditions that cause edema due to increased capillary membrane permeability
- trauma (burns/crush injuries)
- allergic reactions
- neoplastic diseases (conditions that cause abnormal cell growth)
How does lymphatic channel obstruction lead to edema?
if the channels are blocked it will lead to protein and fluid accumulation within interstitial space (cannot be drained) aka lymphedema (firm and non-compressible)
Provide two conditions that cause edema due to lymphatic channel obstruction.
any of the following:
- surgical removal of lymph nodes in arm/leg
- radiation therapy (can cause scar tissue formation that presses on the lymphatic channels)
- obstruction from malignant tumours
- infection
True or false: fluid accumulation does not affect nutrients and waste travelling through the capillaries and tissues
False. fluid accumulation increases distance they have to travel
Define pitting edema
When an indentation (pit) is left on the skin after being pressed
Define effusion
fluid accumulation within a body cavity or space
Severe generalized edema is also known as
anasarca
Dependent edema occurs when ______
fluid accumulates in gravity-dependent areas of the body (ex. legs and feet when standing)
How do you treat edema? Provide at least two interventions.
- diuretics
- elevation of swollen limbs
- compression stockings
- restricting salt intake
- IV albumin for severe cases
What systems regulate sodium, chloride, and water?
renal and endocrine systems
Sodium balance is regulated by _________ and ________; water balance is regulated by ___________
aldosterone, renal tubular reabsroption within kidney ; ADH
What three factors influence aldosterone secretion?
1) circulating blood volume
2) BP
3) plasma concentration of Na+ and K+
Describe how the renin-angiotensin-aldosterone system (RAAS) works when there is a decrease in blood pressure.
1) Decrease in blood volume or pressure causes renin to be secreted from juxtaglomerular cells in kidney
2) renin stimulates formation of angiotensin I
3) Angiotensin I converted to Angiotensin II by ACE
4) Angiotensin II is a vasoconstrictor so it increases BP by constricting blood vessels and renal perfusion is restored
5) Angiotensin II also stimulates aldosterone and ADH release to Na+ and water reabsorption, and K+ excretion –> blood volume increased
What are natriuretic peptides?
Hormones primarily produced by myocardium, natural antagonists of RAAS
What is the function of natriuretic peptides?
When increase BP is detected, natriuretic peptides cause vasodliation and increase Na+ and water secretion to decrease BP
ex. in CHF
True or false: changes in chloride concentration are proportionate to changes in sodium concentration
True
How does ADH (vasopressin) regulate water balance when plasma osmolality increases?
1) Increased plasma osmolality and circulating blood volume decreases (drop in BP) stimulate hypothalamus osmoreceptors that induce thirst sensation and ADH release
2) Increased fluid intake and water reabsorption in the distal tubules occurs
3) TBW increases
4) plasma osmolality decreases to normal
What are three common causes of dehydration?
excessive sweating, vomiting, inadequate intake
Where are volume-sensitive receptors found?
right and left atria; thoracic vessels
Where are baroreceptors found?
Aorta; pulmonary arteries, carotid sinus
Define isotonic fluid alterations
Changes in total body water with PROPORTIONAL changes of electrolytes
isotonic fluid loss causes (hypervolemia/hypovolemia)
hypovolemia
Four common causes of hypovolemia?
- hemorrhage
- severe wound drainage
- excessive sweating
- inadequate fluid intake
Which of the following is not a symptom of hypovolemia?
1) flat neck veins
2) increased HR, decreased BP
3) weight loss
4) increased urine output
5) dry skin and mucous membranes
increased urine output (output would actually decrease in hypovolemia)
What is the general treatment for hypovolemia?
Fluid replacement with isotonic solutions
- 0.9% normal saline
- 5% dextrose (D5NS)
- Ringer’s Lactate
- Pediatric oral replacement solution
- sports beverages
Isotonic fluid excess causes (hypervolemia/hypovolemia) as well as weight (gain/loss) and (increased/decreased) hematocrit and plasma protein concentration.
hypervolemia; gain; decreased
Common causes of hypervolemia?
- excess administration of IV fluids
- hypersecretion of aldosterone
- effect of drugs (i.e. cortisone)
Which of the following is a sign/symptom of hypervolemia?
1) neck vein distension
2) increased BP
3) edema
4) development of pulmonary edema and heart failure
5) all of the above
all of the above
Treatment for isotonic fluid excess (hypervolemia) includes:
diuretics
Define isovolemic hypernatremia.
When there is a deficit of free water accompanied by normal/near normal body sodium concentration
*the most common presentation of hypernatremia
Common causes of isovolemic hypernatremia:
inadequate water intake vomiting diarrhea excessive sweating burns resp. tract infections and fever (increased breathing leading to water loss)
*less common: diabetes insipidus (due to lack of ADH or inadequate response to ADH)
Define hypovolemic hypernatremia
When there is a loss of Na+ accompanied by a greater loss of water
Provide an example of a common cause of hypovolemic hypernatremia.
Any of the following:
- loop diuretics (increase water loss but inhibit sodium reabsorption)
- renal failure (can’t concentrate urine so loss of large volumes)
- diabetes-induced hyperglycemia (excess urinary solute that is non-reabsorable so water goes with it)
- osmotic diuretics (impairs renal concentrating capacity, ex. mannitol)
Define hypervolemic hypernatremia
When there is an increase in TBW with an even greater increase in Na+ level
All of the following cause hypervolemic hypernatremia except:
1) oversecretion of aldosterone or adrenoorticotropic hormone (ACTH)
2) vomiting
3) infusion of hypertonic saline solution in cases of salt depletion
4) Cushing syndrome
5) all of them cause hypervolemic hypernatremai
2) vomiting (does not cause hypervolemic hypernatremia)
Describe isovolemic hyponatremia
loss of Na+ without significant loss of water (purely just missing Na+)
Provide an example of a common cause of isovolemic hyponatremia.
- hypothyroidism
- pneumonia
- glucocorticoid deficiency (due to impaired renal free water clearance = diluted [Na+])
- water retention secondary to inappropriate ADH (SIADH)
- in those who are on low sodium diets + take diuretics
Treatment for isovolemic hyponatremia
vaptans (ADH receptor antagonists)
Describe hypovolemic hyponatremia
occurs when there is a loss of TBW but an even greater loss of Na+
Which of the following is not a common cause of hypovolemic hyponatremia?
1) prolonged vomiting
2) renal losses from diuretics
3) severe diarrhea
4) excess IV fluid administration
5) adrenal insufficiency (inadequate secretion of aldosterone)
excess IV fluid administration
Describe hypervolemic hyponatremia
An increase in Na+ levels but and even greater increase in TBW (dilution of Na+)
Provide a condition that causes hypervolemic hyponatremia
think fluid overload - edema usually occurs
- CHF
- liver cirrhosis
- nephrotic syndrome
Treatment for hypervolemic hyponatremia includes:
vaptans (ADH receptor antagonists)
Describe dilutional hyponatremia
- aka water intoxication
when large amounts of free water are taken in or if IV fluids (without salt so like dextrose in water) is given causing dilution in sodium
Which of the following is a common causes of dilutional hyponatremia?
1) tap water enemas
2) endurance sports (drinking lots of water, no eletrolytes)
3) compulsive water drinking
4) near drowning in fresh water
5) use of SSRIs
6) all of the above
all of the above
Treatment for dilutional hyponatremia includes
water restriction
True or false: hypokalemia is prevalent in elderly, those with alcoholism, and anorexia nervosa
True
Treatment of hypokalemia includes what?
Eaching potassium rich foods, replacement therapy to replace lost K+ and then treating underlying mechanism
Common causes of hyperkalemia include:
- increased intake of K+
- trauma to cell that causes shift of K+ from ICF to ECF
- decreased renal excretion/compromised renal function
- drugs that decrease renal K+ excretion (ACE inhibitors, angiotensin receptor blockers, aldosterone antagonists)
- burns & crush injuries (in response to severe burn/injuries, extra K+ is released in the blood)
- extensive surgeries (cells release extra K+ or from blood transfusions)
- insulin deficit (cannot faciliate uptake of K+ into cells)
- Digitalis toxicity (blocks Na-K ATPase pump so K+ can’t go into cells)
Treatment for hyperkalemia includes which of the following:
1) calcium gluconate (for cardiac membrane potential)
2) glucose administration
3) administration of K-binding agents
4) dialysis
5) all of the above
all of the above
- calcium gluconate helps stabilize cardiac membrane potential and therefore restores neuromuscular irritability)
- Glucose administration: stimulates insulin secretion to facilitate K+ uptake into cells
- administration of K-binding agents (and lower K+ levels)
- dialysis to remove excess K+ in cases of renal failure
Causes for hypophosphatemia
- malabsorption syndromes (long term alcohol use, vitamin D deficiency, use of Mg or aluminum containing antacids)
- respiratory alkalosis (increased pH causes increased cellular demands for phsophate so a fall in levels extracellularly)
- increased renal excretion of phosphate (associated with hyperparathyroidism)
Causes for hyperphosphatemia
- hypoparathyroidism (cannot inhibit phosphate reabsorption in the kidney)
- acute/chronic renal failure (cannot filter it out)
- treatment of metastatic tumours (chemotherapy because it releases large amounts of phosphate into serum)
- long term use of laxatives and enemas with phosphates
Which of the following are potential causes of hypomagnesemia?
1) malnutrition
2) malabsorption syndromes
3) alcoholism
4) urinary losses (loop diuretics, renal tubular dysfunction)
5) 1 and 3
6) all of the above
all of the above
Provide an example of a cause for hypermagnesemia.
- renal failure or insufficiency
- excessive intake of Mg-containing antacids
- adrenal insufficiency
What are volatile acids?
substances that can be eliminated through CO2 through lungs (ex. carbonic acid)
What are non-volatile acids?
substances that can be eliminated only by kidneys
Does the respiratory rate go up or down during acidosis?
up - trying to breathe off CO2
What is the definition of pathophysiology?
Study of underlying changes in body physiology resulting from disease or injury
What leads to metabolic acidosis?
increase in acid concentration or lost of bicarbonate in ECF (ratio is less than 20:1)
How does the body compensate in metabolic acidosis?
hyperventilate (Kussmaul’s respirations) and excrete H+
What leads to metabolic alkalosis
elevated HCO3- usually caused by excessive loss of metabolic acids (from vomiting or diuretics where you’re losing a bunch of ions specifically Cl-)
How does the body compensate for metabolic alkalosis
- suppress breathing
- kidneys try to excrete excess HCO3-
What leads to respiratory acidosis?
increased partial pressure of CO2 (hypercapnia) resulting from hypoventilation
How does the body compensate for respiratory acidosis
increase breathing to blow off CO2 and renal compensation by eliminating H+ and retention of HCO3-
What leads to respiratory alkalosis?
hyperventilation causes decrease in partial pressure of CO2 (co2 in blood)
How does the body compensate for respiratory alkalosis?
Slow down breathing, kidneys compensate by decreasing H+ excretion and bicarbonate reabsorption
True or False: Newborns are more susceptible to changes in TBW due to high metabolic rate and greater surface area
True
True or false: adaptation is a reversible response involving structural or functional modifications to accommodate both physiologic (normal) and pathologic (adverse) demands/conditions
true
sublethal cellular injuries are (reversible/irreversible) while lethal cellular injuries are (reversible/irreversible)
reversible; irreversible
What are the 8 common sources of cell injuries?
1) ischemic-hypoxic
2) ischemia
3) free radicals
4) reperfusion
5) immunologic
6) infectious
7) intentional/unintentional
8) inflammatory
What are the two main cell death types?
necrosis, apoptosis (and a third process - autophagy but not really cell death type)
Atrophy
shrinking in cell size
Common organs that are affected by atrophy?
heart, skeletal muscle, secondary sex organs, brain
Hypertrophy
increase in cell size (in response to mechanical load/stress)
Hypertrophy is common in which organs?
heart, kidney
Hyperplasia
increase in cell number (resulting from increased rate of cellular division, growth factors or increased output of new cells from tissue stem cells)
Metaplasia
reversible replacement of one mature cell type (epithelial or mesenchymal) by another cell type, frequently one less differentiated.
Lung cells being replaced in a long term smoker to cells that do not secrete mucus/have cilia is an example of what type of cellular adaptation?
Metaplasia
Dysplasia
- aka atypical hyperplasia
- abnormal/deranged cellular growth (changes in size, shape, and organization of mature cells)
- can be described as high grade or low grade
- Dysplasias that do not involve the entire thickness of epithelium may be completely reversible
Where is dysplasia commonly found?
in epithelial tissue of: uterine cervix, endometrium, GI and respiratory tract mucosa, also often found next to cancer cells (not indicative of cancer though)
When does cellular injury occur?
When cell is unable to maintain homeostasis
Which of the following in not a general mechanism of cellular injury?
1) ATP depletion
2) increased ROS
3) Ca2+ entry
4) mitochondrial/membrane damage
5) K+ entry
6) protein misfolding
K+ entry
How does reperfusion cause cellular injury?
1) increases oxidative stress (damages membrane and Ca+2 buildup)
2) calcium buildup (from damaged cell membrane + ROS-mediated injury lead to enhanced mito permeability leading to minimal to no ATP production)
3) inflammation (dead cells stimulate immune cells)
4) complement activation (exacerbates damage)
What is oxidative stress?
When there is a buildup of reactive oxygen species that exceeds antioxidant’s ability to detoxify
How does free radicals cause cellular injury?
the unpaired electrons are unstable so they try to stabilize self by forming bonds with proteins, lipids, and carbs and change a bunch of shit in the cells
leads to:
- lipid peroxidation (destroying lipids = damage to membrane)
- protein alterations
- DNA damage (mutations)
- mitochondrial dysfunction
What are xenobiotics?
compounds that have toxic, carcinogenic, or mutagenic properties that are found in an organism but not naturally produced within said organism
Signs and symptoms of lead poisoning include what? Treatment?
- GI symptoms (abdominal cramping, nausea, loss of appetite, weight loss)
- glucose, amino acids, and phosphates in urine
Treatment:
- removal of exposure source, chelation therapy (removes heavy metals from the body), correcting mineral deficiencies in the body
Lead poisoning in children can cause:
- cognitive deficits
- behavioural changes (antisocial behaviour, attention deficits)
- hyperpigmentation in gums
- children are most susceptible due to increased hand-mouth behaviour, blood brain barrier not mature yet, and infants absorb lead more than adults do
- also lead paint chips off the wall have sweet taste
Signs and symptoms of CO poisoning include:
tinnitus, nausea, vomiting, weakness, dizziness
Signs of FASD
microcephaly low birth weight cardiovascular defects growth retardation facial anomalies cognitive impairment ocular malformations
What substance causes the colour of periorbital ecchymosis?
hemosiderin
Mercury poisoning can negatively impact:
fetal brain development (if exposed during pregnancy)