NU 545 UNIT #1 EXAM STUDY GUIDE
QUESTIONS AND ANSWERS
What are free radicals in relation to cell damage? Progression of diseases? - Answer-A
free radical is any molecular species capable of independent existence that contains a
single unpaired electron in an outer orbit. Having one unpaired electron makes the
molecule unstable; The molecule becomes stabilized either by donating or by accepting
an electron from another molecule. When the attacked molecule loses its electron, it
becomes a free radical. Therefore, it is capable of injurious chemical bond formation
with DNA, RNA, proteins, lipids, and carbohydrates- many other key molecules in
membranes and nucleic acids. Free radicals are difficult to control and initiate chain
reactions. With low chemical specificity and high reactivity, free radicals can react with
most molecules in their proximity.
An important mechanism of membrane damage is injury induced by free radicals,
especially by a disturbance in the balance between the production of ROS and
antioxidant defenses called oxidative stress. Oxidative stress can be caused by an
increase of different reactive species or depletion of antioxidant defense, or both, and
result in detrimental oxidation of different molecules including proteins, lipids, nucleic
acids, and others. Oxidative stress can activate several intracellular signaling pathways
because ROS can modulate enzymes and transcription factors. This process is an
important mechanism of cell damage and many conditions, including cell injury, cancer,
certain degenerative diseases (Alzheimer's disease), and aging (p. 54).
Know all about lead poisoning. How does it cause damage within the cell? - Answer-
Lead is a toxic heavy metal. Developing fetuses and young children absorb lead more
easily, susceptibility to brain damage. Organ systems affected: nervous, hematopoietic,
reproductive, gastrointestinal, cardiovascular, musculoskeletal, as well as kidneys.
Exposure occurs via inhalation, ingestion and skin contact. Lead exposure damages or
destroys the plasma membrane, alters cellular ion status (disruption of divalent cations,
ion transport mechanism and protein function). Lead then disrupts the movement and
storage of calcium inside cells, increasing cell stress, which can lead to the death of
neurons and other brain cells. Lead causes abnormal conformational changes in the
protein structure, altered protein functions. Pg 66
Know about the effects of fetal alcohol syndrome on infants. - Answer-Diagnosis of FAS
requires all three facial abnormalities: short palpebral fissure lengths, smooth philtrum
and thin upper lip. FAS may have abnormal facial features, growth problems, CNS
problems, issues with learning, memory, attention, vision, hearing. Pg 70
How does alcohol affect the nervous system? - Answer-Alcohol causes CNS
depression. sedation, drowsiness, loss of motor, altered mental status. Can possibly
cause respiratory arrest because of medullary center depression. Pg 68
,Where do lipids accumulate? - Answer-Although lipids sometimes accumulate in heart
and kidney cells, the most common site of intracellular lipid accumulation, or fatty
change, is liver cells. Pg 84
What is hemosiderosis? - Answer-Hemosiderosis is a condition which excess iron is
stored as hemosiderin (a yellow-brown pigment derived from hemoglobin) in the cells of
many organs and tissues. Common in people that get multiple blood transfusions. pg 86
What causes free calcium in the cytosol? - Answer-Influx of extracellular calcium in
injured mitochondria. Calcium stores in mitochondria and endoplasmic reticulum
pumped into the extracellular space bound to calcium-binding proteins -> released after
cell damage -> free Ca++ (see table on pg 86)
What happens to sodium and water during cell injury? - Answer-A process known as
oncosis hypoxia that leads to ATP production decreases which leads to sodium and
water moving into the cell and potassium moving out of the cell, osmotic pressure
increases more water moves into the cell cisternae of endoplasmic reticulum distend
rupture and form vacuoles causing hydropic degeneration pg 84
During cell injury caused by hypoxia, what happens to osmotic pressure? - Answer-The
increase of intracellular sodium concentration increases osmotic pressure which draws
more water into the cell pg 84
What causes mammary glands to enlarge in pregnancy? - Answer-Prolactin and GH
secreted from anterior pituitary cause glands and ducts to grow
After ovulation what happens to uterine endometrial cells? - Answer-Estrogen
stimulates the endometrium to grow and thicken for reception of the fertilized ovum
What happens to liver cells when a portion of the liver is removed? - Answer-When liver
cells are compromised, new cells can regenerate from intrahepatic stem cells.
Compensatory hyperplasia is this adaptive mechanism that enables certain organs to
regenerate. If part of the liver is removed it leads to hyperplasia of the remaining
cells(hepatocytes) to compensate for the loss. Even if 70% of the liver is removed it only
takes 2 weeks for complete regeneration. Hepatocytes usually live approximately a year
or more, and through a very slow rate of cell division they renew themselves. If large
number of hepatocytes are lost due to surgery or injury; a burst of rapid cell division
occurs from the surviving hepatocytes to replace the lost tissue. (p49)
Understand necrosis in relation to pulmonary TB and gangrene. - Answer-TB- Caseous
necrosis commonly results from tuberculosis pulmonary infection (mycobacterium
tuberculosis). This is a combination of coagulative and liquefactive necrosis. the dead
cells disintegrate but the debris is not digested completely by hydrolysis. Remaining
tissues appear soft and granular, resembling clumped cheese. A granulomatous
inflammatory wall encloses areas of caseous necrosis. (p88)
, Gangrene- gangrenous necrosis is a term commonly used in surgical clinical practice
referring to death of tissue and results from severe hypoxic injury, commonly occurring
because of arteriosclerosis and blockage of major arteries, especially in the lower leg.
With hypoxia and subsequent bacterial invasion, the tissues undergo necrosis.
Dry gangrene is a result of coagulative necrosis. The skin becomes very dry and
shrinks, resulting in wrinkles and a dark brown/black color change.
Wet gangrene develops when neutrophils invade the site, causing liquefactive necrosis.
This usually occurs in internal organs, causing the site to become cold, swollen, and
black. A foul odor is present and produced by pus, and if systemic symptoms persist
and become severe, it can result in death.
Gas Gangrene is a special type of gangrene caused by infection of injured tissue by one
of many species of clostridium. These anerobic bacteria produce hydrolytic enzymes
and toxins that destroy connective tissue, cellular membranes, and cause bubbles of
gas to form in the muscle cells. It can be fatal if enzymes lyse the membranes of red
blood cells, destroying their oxygen carrying capacity. death is a result of shock, and the
condition is treated with antitoxins and supplemental oxygen delivered in a
hyperbaric(pressurized) chamber. (p88-89)
Infants are susceptible to significant total body water loss, why? - Answer-In a newborn
infant total body water (TBW) is about 70 to 80% of body weight because infants store
less fat. In the immediate postnatal period, a physiologic loss of body water occurs,
equivalent to about 5% of body weight as the infant adjust to a new environment. Infants
are particularly susceptible to significant changes in TBW because of their high
metabolic rate and potential for evaporative fluid loss attributable to their greater body
surface area in proportion to total body size. Loss of fluids from diarrhea can represent
a significant proportion of body weight in infants. Renal mechanisms that regulate fluid
and electrolytes conservation may not mature enough to counter the losses so
dehydration can develop rapidly. (p105)
Why are obese people at greater risk for dehydration? - Answer-Exchange of solutes
and water occurs between compartments to maintain their unique compositions. The
percentage of TBW varies with the amount of body fat and age. Because fat is water
repelling (hydrophobic), very little water is contained in adipose cells. Individuals with
more body fat have proportionately less total body water and tend to be more
susceptible to fluid imbalances that cause dehydration. (p105)
With low plasma albumin you have edema, why? - Answer-Decrease plasma oncotic
pressure results from losses or diminished production of plasma albumin. Decreased
oncotic attraction of fluid within capillaries causes fluid to move into the interstitial
space, resulting in edema. Decreased synthesis of plasma protein and decreased
oncotic pressure may occur with liver disease or protein malnutrition. Losses of plasma
proteins occur with glomerular disease of the kidney (nephrotic syndrome), hemorrhage,
and serous drainage from open wounds or burns. (p106)
QUESTIONS AND ANSWERS
What are free radicals in relation to cell damage? Progression of diseases? - Answer-A
free radical is any molecular species capable of independent existence that contains a
single unpaired electron in an outer orbit. Having one unpaired electron makes the
molecule unstable; The molecule becomes stabilized either by donating or by accepting
an electron from another molecule. When the attacked molecule loses its electron, it
becomes a free radical. Therefore, it is capable of injurious chemical bond formation
with DNA, RNA, proteins, lipids, and carbohydrates- many other key molecules in
membranes and nucleic acids. Free radicals are difficult to control and initiate chain
reactions. With low chemical specificity and high reactivity, free radicals can react with
most molecules in their proximity.
An important mechanism of membrane damage is injury induced by free radicals,
especially by a disturbance in the balance between the production of ROS and
antioxidant defenses called oxidative stress. Oxidative stress can be caused by an
increase of different reactive species or depletion of antioxidant defense, or both, and
result in detrimental oxidation of different molecules including proteins, lipids, nucleic
acids, and others. Oxidative stress can activate several intracellular signaling pathways
because ROS can modulate enzymes and transcription factors. This process is an
important mechanism of cell damage and many conditions, including cell injury, cancer,
certain degenerative diseases (Alzheimer's disease), and aging (p. 54).
Know all about lead poisoning. How does it cause damage within the cell? - Answer-
Lead is a toxic heavy metal. Developing fetuses and young children absorb lead more
easily, susceptibility to brain damage. Organ systems affected: nervous, hematopoietic,
reproductive, gastrointestinal, cardiovascular, musculoskeletal, as well as kidneys.
Exposure occurs via inhalation, ingestion and skin contact. Lead exposure damages or
destroys the plasma membrane, alters cellular ion status (disruption of divalent cations,
ion transport mechanism and protein function). Lead then disrupts the movement and
storage of calcium inside cells, increasing cell stress, which can lead to the death of
neurons and other brain cells. Lead causes abnormal conformational changes in the
protein structure, altered protein functions. Pg 66
Know about the effects of fetal alcohol syndrome on infants. - Answer-Diagnosis of FAS
requires all three facial abnormalities: short palpebral fissure lengths, smooth philtrum
and thin upper lip. FAS may have abnormal facial features, growth problems, CNS
problems, issues with learning, memory, attention, vision, hearing. Pg 70
How does alcohol affect the nervous system? - Answer-Alcohol causes CNS
depression. sedation, drowsiness, loss of motor, altered mental status. Can possibly
cause respiratory arrest because of medullary center depression. Pg 68
,Where do lipids accumulate? - Answer-Although lipids sometimes accumulate in heart
and kidney cells, the most common site of intracellular lipid accumulation, or fatty
change, is liver cells. Pg 84
What is hemosiderosis? - Answer-Hemosiderosis is a condition which excess iron is
stored as hemosiderin (a yellow-brown pigment derived from hemoglobin) in the cells of
many organs and tissues. Common in people that get multiple blood transfusions. pg 86
What causes free calcium in the cytosol? - Answer-Influx of extracellular calcium in
injured mitochondria. Calcium stores in mitochondria and endoplasmic reticulum
pumped into the extracellular space bound to calcium-binding proteins -> released after
cell damage -> free Ca++ (see table on pg 86)
What happens to sodium and water during cell injury? - Answer-A process known as
oncosis hypoxia that leads to ATP production decreases which leads to sodium and
water moving into the cell and potassium moving out of the cell, osmotic pressure
increases more water moves into the cell cisternae of endoplasmic reticulum distend
rupture and form vacuoles causing hydropic degeneration pg 84
During cell injury caused by hypoxia, what happens to osmotic pressure? - Answer-The
increase of intracellular sodium concentration increases osmotic pressure which draws
more water into the cell pg 84
What causes mammary glands to enlarge in pregnancy? - Answer-Prolactin and GH
secreted from anterior pituitary cause glands and ducts to grow
After ovulation what happens to uterine endometrial cells? - Answer-Estrogen
stimulates the endometrium to grow and thicken for reception of the fertilized ovum
What happens to liver cells when a portion of the liver is removed? - Answer-When liver
cells are compromised, new cells can regenerate from intrahepatic stem cells.
Compensatory hyperplasia is this adaptive mechanism that enables certain organs to
regenerate. If part of the liver is removed it leads to hyperplasia of the remaining
cells(hepatocytes) to compensate for the loss. Even if 70% of the liver is removed it only
takes 2 weeks for complete regeneration. Hepatocytes usually live approximately a year
or more, and through a very slow rate of cell division they renew themselves. If large
number of hepatocytes are lost due to surgery or injury; a burst of rapid cell division
occurs from the surviving hepatocytes to replace the lost tissue. (p49)
Understand necrosis in relation to pulmonary TB and gangrene. - Answer-TB- Caseous
necrosis commonly results from tuberculosis pulmonary infection (mycobacterium
tuberculosis). This is a combination of coagulative and liquefactive necrosis. the dead
cells disintegrate but the debris is not digested completely by hydrolysis. Remaining
tissues appear soft and granular, resembling clumped cheese. A granulomatous
inflammatory wall encloses areas of caseous necrosis. (p88)
, Gangrene- gangrenous necrosis is a term commonly used in surgical clinical practice
referring to death of tissue and results from severe hypoxic injury, commonly occurring
because of arteriosclerosis and blockage of major arteries, especially in the lower leg.
With hypoxia and subsequent bacterial invasion, the tissues undergo necrosis.
Dry gangrene is a result of coagulative necrosis. The skin becomes very dry and
shrinks, resulting in wrinkles and a dark brown/black color change.
Wet gangrene develops when neutrophils invade the site, causing liquefactive necrosis.
This usually occurs in internal organs, causing the site to become cold, swollen, and
black. A foul odor is present and produced by pus, and if systemic symptoms persist
and become severe, it can result in death.
Gas Gangrene is a special type of gangrene caused by infection of injured tissue by one
of many species of clostridium. These anerobic bacteria produce hydrolytic enzymes
and toxins that destroy connective tissue, cellular membranes, and cause bubbles of
gas to form in the muscle cells. It can be fatal if enzymes lyse the membranes of red
blood cells, destroying their oxygen carrying capacity. death is a result of shock, and the
condition is treated with antitoxins and supplemental oxygen delivered in a
hyperbaric(pressurized) chamber. (p88-89)
Infants are susceptible to significant total body water loss, why? - Answer-In a newborn
infant total body water (TBW) is about 70 to 80% of body weight because infants store
less fat. In the immediate postnatal period, a physiologic loss of body water occurs,
equivalent to about 5% of body weight as the infant adjust to a new environment. Infants
are particularly susceptible to significant changes in TBW because of their high
metabolic rate and potential for evaporative fluid loss attributable to their greater body
surface area in proportion to total body size. Loss of fluids from diarrhea can represent
a significant proportion of body weight in infants. Renal mechanisms that regulate fluid
and electrolytes conservation may not mature enough to counter the losses so
dehydration can develop rapidly. (p105)
Why are obese people at greater risk for dehydration? - Answer-Exchange of solutes
and water occurs between compartments to maintain their unique compositions. The
percentage of TBW varies with the amount of body fat and age. Because fat is water
repelling (hydrophobic), very little water is contained in adipose cells. Individuals with
more body fat have proportionately less total body water and tend to be more
susceptible to fluid imbalances that cause dehydration. (p105)
With low plasma albumin you have edema, why? - Answer-Decrease plasma oncotic
pressure results from losses or diminished production of plasma albumin. Decreased
oncotic attraction of fluid within capillaries causes fluid to move into the interstitial
space, resulting in edema. Decreased synthesis of plasma protein and decreased
oncotic pressure may occur with liver disease or protein malnutrition. Losses of plasma
proteins occur with glomerular disease of the kidney (nephrotic syndrome), hemorrhage,
and serous drainage from open wounds or burns. (p106)
