Exam 1 Review Flashcards
Prepare for Exam 1 (175 cards)
1
Q
What is the primary function of the nucleus?
A
cell division and control of genetic information
2
Q
Which organelle protects vital genetic information and is in charge of replication and repair of DNA?
A
Nucleus
3
Q
Which organelle is a small, dense structure composed largely of DNA and contains the nucleolus?
A
Nucleus
4
Q
What is the term that describes RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore complexes (NPCs)?
A
Ribosomes
5
Q
What is the chief function of ribosomes?
A
Provide sites for cellular protein synthesis
6
Q
Which organelle signals cellular adaptation and maintenance of metabolic homeostasis? P.S. the signaling functions have far-reaching implications for metabolic regulation in health and in disease.
A
Lysosome(s)
7
Q
Lysosomes maintain cellular health through which three mechanisms?
A
Efficient removal of toxic cellular components
Removal of useless organelles
Signals cellular adaptation
8
Q
Which organelle is responsible for cellular respiration?
A
Mitochondria
9
Q
Which term describes all of the chemical tasks of maintaining essential cellular functions?
A
Cellular metabolism
10
Q
True or false. Metabolism provides the cell with the energy it needs to produce cellular structures.
A
True
11
Q
True or false. ATP functions as the energy-transferring molecule.
A
True
12
Q
How do dietary proteins, fats, and carbs/starches make it to the cell to be used for vital cellular processes, including the production of ATP?
A
They are hydrolyzed into amino acids, fatty acids, and glucose in the intestinal tract. They are then absorbed, circulated, and incorporated into the cell.
13
Q
What (think molecule) drives biological reactions necessary for cells to function?
A
ATP
14
Q
What is anabolism?
A
energy-using process of metabolism
15
Q
What is catabolism?
A
energy-releasing process of metabolism
16
Q
For a cell to function, it must be able to extract and use the chemical energy in _______ _________. ___ not only stores energy but also _________ it from one molecule to another. Energy stored by carbohydrates, lipids, and proteins is ___________ and ___________ to ATP.
A
organic molecules; ATP; transfers; catabolized; transferred
17
Q
What is atrophy?
A
Decrease in size of tissue/organ; can be pathological or physiological
18
Q
Give three examples of physiologic atrophy.
A
Thymus gland undergoes physiologic atrophy during childhood.
Uterus decreases in size after childbirth.
Tonsils shrink in adolescence.
19
Q
What type of atrophy occurs from a decrease in workload, use, pressure, blood supply, nutrition, or hormonal stimulation?
A
Pathologic atrophy
20
Q
Individuals immobilized in bed for a prolonged time exhibit a type of skeletal muscle atrophy called what?
A
Disuse atrophy
21
Q
What is hypertrophy?
A
Increase in size of cell
22
Q
Give an example of physiologic hypertrophy.
A
Increase in size of myocardial cells (myocytes) seen in endurance athletes
23
Q
What causes pathologic hypertrophy?
A
Chronic hemodynamic overload from hypertension or heart valve dysfunction
24
Q
Left ventricular hypertrophy (LVH) is an example of which type of cellular adaptation?
A
Pathologic hypertrophy
25
Prolonged cardiac hypertrophy progresses to ___________ ___________, altered hemodynamics, and finally _____ _______.
contractile dysfunction; heart failure
26
In which type of hypertrophy is the myocardial matrix preserved?
Physiologic hypertrophy
27
Pathologic hypertrophy is associated with _________ interstitial fibrosis, cell death, and ________ cardiac function.
increased; abnormal
28
What is hyperplasia?
Increase in the number of cells resulting from an increased rate of cellular division
29
Hyperplasia requires that cells undergo _______, a process wherein a single cell divides into ___ identical cells. The main mechanism for hyperplasia is the production of ________or ______ _______, which stimulate the remaining cells after injury or cell loss to synthesize new cell components and ______.
mitosis; two; hormones; growth factors; divide
30
True or false. One mechanism of hyperplasia is increased output of new cells from tissue stem cells because mature cells have differing capacity for hyperplastic (mitotic) growth.
True
31
What is one example of pathologic hyperplasia?
Benign prostatic hyperplasia (BPH)
32
What is the type of cellular adaptation where cells are replaced by new cells?
Metaplasia
33
One example of metaplasia is when normal columnar, ciliated epithelial cells of the bronchial lining have been replaced by stratified squamous epithelial cells. Can this be reversed if the irritant is stopped?
Yes
34
What is the single most common cause of cellular injury?
Hypoxia
35
Hypoxia is a prominent feature of which pathological states?
bacterial infection
inflammation
wounds
cardiovascular defects
cancer
36
What is the most common cause of hypoxia?
Ischemia- a reduced supply of blood and therefore oxygen (decreased perfusion)
37
Name four circumstances that could cause hypoxia.
Reduced oxygen content in the ambient air
Loss of hemoglobin
Decreased RBC production
Respiratory and cardiovascular diseases
38
Hypoxia negatively impacts which normal physiological processes? (Think 5)
Differentiation
Angiogenesis
Proliferation
Erythropoiesis
Overall cell viability
39
Which organelle is the primary consumer of oxygen?
Mitochondria
40
Which toxic substance and known carcinogen is created from the metabolism of ethanol, and where does this metabolism occur?
Acetylaldehyde; the liver
41
Chronic alcohol consumption breaks down the gut barrier function causing leaky gut. What does this lead to?
Impaired gut motility
Delayed gastric emptying time
Chemical gastritis
Impaired absorption of nutrients (folic acid, thiamine, vitamin B6, magnesium, and phosphorus)
42
Which deficiency is problematic, in particular, in persons consuming large quantities of alcohol?
Folic acid deficiency
43
Ethanol alters folic acid (folate) homeostasis how?
Decreases intestinal absorption of folate and increases the loss of folate through urinary and fecal excretion
44
Which deficiency becomes especially serious when alcohol is consumed during pregnancy and may contribute to fetal alcohol syndrome?
Folic acid
45
_________ is the second most abundant micronutrient in the human body, and deficiency is almost universal in individuals with high levels of alcohol consumption and/or liver disease.
Magnesium
46
Urinary excretion of magnesium is increased secondary to _______ consumption, and total body stores of magnesium become ________.
alcohol; depleted
47
Ionizing radiation is emitted by x-rays, y-rays, and alpha and beta particles (which are emitted from atomic nuclei in the process of radioactive decay). A main pathologic mechanism is the subsequent ______ __ ___ (VERY BAD!). It also generates ____ ________.
Damage to DNA; free radicals
48
What term is described by an electrically uncharged atom or group of atoms having an unpaired electron? Having one unpaired electron makes the molecule unstable; thus, to stabilize, it gives up an electron to another molecule or steals one. Therefore, it is capable of injurious chemical bond formation with proteins such as fragmentation and folding, lipids, carbs--key molecules in membranes and nucleic acids.
Free radicals
49
Free radicals cause what in the body (at the cellular level)?
DNA damage and mutations
50
What substance contributes to protection against damage caused by free radicals?
Antioxidants
51
What are the two main types of cell death?
Necrosis and apoptosis
52
Which type of cell death is described here? Approximately 10 billion new cells are created every day, and the same number are destroyed. Usual physiological role. A programmed cell death that is regulated or programmed. Usually, a normal physiological process of the elimination of unwanted cells.
Apoptosis
53
Which type of cell death is described here? Usually pathologic (culmination of irreversible cell injury). Characterized by rapid loss of the plasma membrane structure, organelle swelling, and mitochondrial dysfunction.
Necrosis
54
What is the #1 cause of cellular injury leading to necrosis?
Hypoxia
55
What is one example of necrosis?
Cell death during a myocardial infarction (heart attack)
56
Every physiological process can be shown to function less efficiently as we age. Effects of aging depend on what two things?
How we take care of ourselves and genetics
57
Seen in the process of aging:
__________ causes loss of tissue-repair capacity
________ in stem cell exhaustion
__________ vascular resistance increases
_______ emptying of stomach
_________ immune response to T-dependent antigens
_________ accumulation of pro-inflammatory tissue
Senescence
Increase
Peripheral
Delayed
Decreased
Increased
58
What are the two vulnerable populations to fluid imbalances?
Infants and older adults
59
Why are infants vulnerable to fluid imbalances? (3 reasons)
75-80% TBW
High metabolic rate
Kidneys not mature enough to counter fluid losses
60
Why are geriatric adults vulnerable to fluid imbalances? (1 reason)
Thirst sensation is diminished
61
What are the 6 major players in the process of fluid balance?
Hydrostatic pressure
Oncotic pressure
Renin-angiotensin-aldosterone system (RAAS)
Aldosterone (think sodium)
Antidiuretic hormone (ADH) (think water)
Natriuretic peptides
62
Which pressure facilitates the outward movement of water from the capillary to the interstitial space and is mainly influenced by blood pressure?
Hydrostatic pressure
63
At the arterial end of capillaries, fluid moves from the _____________ space into the ____________ space because capillary ___________ pressure (blood pressure) is higher than the capillary _______ pressure.
intravascular; interstitial; hydrostatic; oncotic
64
What is oncotic pressure heavily influenced by?
Plasma proteins (albumin)
65
Low plasma albumin causes edema, especially in the lower extremities, as a result of what?
A reduction in plasma oncotic pressure
66
Renin is an enzyme secreted by what cells? Where are these cells located?
Juxtaglomerular cells; in the kidney
67
What is released in response to sympathetic nerve stimulation and decreased perfusion of the renal vasculature? This happens when circulating blood volume or blood pressure is reduced.
Renin
68
Hormonal regulation of sodium and potassium balance is influenced by what?
Aldosterone
69
Aldosterone causes resorption of what two substances/elements in order to increase blood pressure and blood volume?
Sodium and water
70
How does the resorption of sodium by aldosterone affect potassium levels?
Excretion of potassium is increased causing hypokalemia
71
Hyperaldosteronism causes what? (Specifically, what happens to potassium, sodium, and fluid volume?)
Hypokalemia
Hypernatremia
Fluid volume EXCESS
72
Hypoaldosteronism causes what? (Specifically, what happens to potassium, sodium, and fluid volume?)
Hyperkalemia
Hyponatremia
Fluid volume deficit
73
A decrease in plasma volume, an increase in serum sodium, and a decrease in blood pressure (aka decreased perfusion) stimulate what two things?
Secretion of ADH
Perception of thirst
74
The term "natriuretic peptides" refers to hormones that include which three peptides?
Atrial natriuretic peptide (ANP) produced by myocardial atria
Brain natriuretic peptide (BNP) produced by myocardial ventricles
Urodilatin in the kidney
75
What is the role of natriuretic peptides?
Decrease blood pressure and increase sodium and water excretion
COUNTERACTS/ANTAGONIST OF RAAS
76
Which electrolyte is described here?
Regulator of FLUIDS, nerve impulse conduction, acid-base balance, cellular chemical reactions, and transport of substances across the cellular membrane.
Sodium (Na+)
77
Which electrolyte deficiency is associated with hypoaldosteronism, loss of sodium, inadequate intake, and some medications?
Hyponatremia
78
Sodium depletion can have what effect on the cell?
water moves into the cells causing cells to swell to the potential of rupturing
Cellular function becomes altered
79
Clinical manifestations of hyponatremia are related to altered action potential in neurons and muscles so impaired nerve conduction and neurologic changes. What symptoms are seen with LESS severe hyponatremia?
Nausea and vomiting
80
What symptoms are seen with more severe hyponatremia?
lethargy
seizures
coma
81
Which electrolyte imbalance is a major cause of morbidity and mortality in ICU and older patients?
Hyponatremia
82
True or false. In hypernatremia, central nervous system symptoms are most serious, and some symptoms are the same as hyponatremia, such as coma and seizures.
True
83
Which electrolyte is the major determinant of the resting membrane potential necessary for transmission of nerve impulses?
Potassium
84
The ratio of potassium inside the cell to outside the cell is the major determinant of the resting membrane potential which is necessary for what three actions?
Transmission/conduction of nerve impulses
Maintenance of normal cardiac rhythms
Skeletal and smooth muscle contraction
85
Think heart/cardiac functioning for which electrolyte imbalance?
Potassium
86
Which electrolyte is a HUGE contributor to acid-base balance and why?
Potassium
An increase in hydrogen ions (acidosis) in the blood causes the body to shift hydrogen ions into the cell in exchange for potassium
87
What are two conditions that can cause hyperkalemia?
Oliguric kidney failure (little to no urine output)
Addison's disease (decreased production of aldosterone thus body holds onto K+)
88
Hyperkalemia should be investigated when there is a history of which 6 conditions/events?
Renal disease
Massive trauma
Insulin deficiency
Addison disease
Use of potassium salt substitutes
Metabolic acidosis (remember, in acidosis, hydrogen ions shift into cells in exchange for ICF potassium)
89
What are four causes of hypokalemia?
Decreased intake: starvation or anorexia nervosa, inadequate replacement
Increased renal loss: renal tubular failure, K-losing diuretics, hyperaldosteronism
Vomiting
Diarrhea
90
How does potassium shift in hypokalemia? What are examples of when you would see this?
Shifts from ECF to ICF
Seen in respiratory/metabolic alkalosis
91
How does insulin affect potassium?
Insulin promotes cellular uptake of potassium. When administering insulin to DKA patient, watch for decreased ECF potassium.
92
Which electrolyte is the major cation associated with the structure of bones and teeth?
Calcium
93
Which electrolyte serves as an enzymatic cofactor for blood clotting and is required for hormone secretion and the function of cell receptors?
Calcium
94
Which electrolyte, other than potassium, plays a role in plasma membrane stability, permeability, and repair along with the transmission of nerve impulses and the contraction of muscles?
Calcium
95
What are six causes of hypocalcemia?
Inadequate intestinal absorption
Massive blood administration
Decreases in PTH and vitamin D levels
Nutritional deficiencies
Elevated calcitonin level
Pancreatitis
96
What are seven manifestations of hypocalcemia?
Increased neuromuscular excitability (tetany, tingling, muscle spasms--esp in hands, feet, and facial muscles)
Intestinal cramping
Hyperactive bowel sounds
Osteoporosis and fractures
Severe cases show convulsions and tetany
Prolonged QT interval
Cardiac arrest
97
What are five causes of hypercalcemia?
Hyperparathyroidism
Bone metastases with calcium resorption from breast, prostate, renal, and cervical cancer
Excess vitamin D
many tumors that produce PTH
Calcium-containing antacids
98
What are manifestations for hypercalcemia? (there are several)
Many nonspecific: fatigue, weakness, lethargy, anorexia, nausea, constipation
Impaired renal function
Kidney stones
Dysrhythmias
Bradycardia
Cardiac arrest
Bone pain
99
What three things influence calcium and phosphorus balance?
Parathyroid hormone (PTH)
Calcitonin
Vitamin D
100
True or false. Phosphate has to do with energy and oxygen transport.
True
Think "energy" ATP (adenosine triPHOSPHATE) and oxygen transport 2,3 DPG (diPHOSPHOglycerate)
101
What are three causes of hypophosphatemia?
Intestinal malabsorption related to vitamin D deficiency
Long-term alcohol use disorder
Increased renal excretion of phosphate associated with hyperparathyroidism
102
Manifestation of hypophosphatemia. Conditions related to reduced capacity for ______transport by red blood cells and disturbed ______ metabolism; leukocyte and platelet ___________; deranged _____and ______function; in severe cases, irritability, confusion, numbness, coma, convulsions; possibly ___________ failure (because of muscle weakness), ________________, bone resorption (leading to rickets or osteomalacia). SAME AS HYPERCALCEMIA.
oxygen; energy; dysfunction; nerve; muscle; respiratory; cardiomyopathies
103
Which electrolyte is a cofactor in intracellular enzymatic reactions, protein synthesis, and neuromuscular excitability?
Magnesium
104
Which electrolyte improves myocardial metabolism, reduces peripheral vascular resistance, and inhibits platelet function?
Magnesium
105
What are four causes of hypomagnesemia?
Malnutrition
Malabsorption syndromes
Alcohol use disorder
Urinary losses (renal tubular dysfunction, loop diuretics)
106
What are nine manifestations of hypomagnesemia?
Behavioral changes
Irritability
Increased reflexes
Muscle cramps
Ataxia (clumsiness)
Nystagmus
Tetany
Convulsions
Tachycardia
107
What are two causes of hypermagnesemia?
Renal insufficiency or kidney failure with little to NO urine output
Excessive intake of magnesium-containing antacids
108
True or false. Magnesium is excreted by kidneys and intestines.
True
109
What are nine manifestations of hypermagnesemia?
Lethargy
Drowsiness
Loss of deep tendon reflexes
Nausea and vomiting
Muscle weakness
Bradycardia
Respiratory distress
Heart block
Cardiac arrest
110
True or false. An acid-base imbalance is not a disorder in and of itself, it is a diagnostic sign. In order to correct the imbalance, treatment is targeted at resolving the cause of the imbalance. The body will compensate at all costs to maintain a pH range of 7.35-7.45. When evaluating pH during an exacerbation of a disease entity, remember that perfect pH is 7.40, so anything less is acidotic and anything more is alkalotic.
True
111
What type of acid-base imbalance occurs with increased CO2 retention from hypoventilation?
Respiratory acidosis
112
What are four examples of poor ventilatory status (hypoventilation) that cause retention of CO2 thus making the body unable to eliminate a powerful acid via the lungs and causing respiratory acidosis?
Respiratory failure
Chronic respiratory disease (COPD)
Barbiturate or sedative overdose
Respiratory muscle weakness
113
What do the kidneys do to compensate for respiratory acidosis?
Increase HCO3 retention in the kidney--this is not immediate, so it takes some time for this mechanism to kick in. HOWEVER, with chronic respiratory conditions, the kidneys are very effective at compensating.
Secrete hydrogen ions
Regenerate bicarbonate
114
What type of acid-base imbalance is caused by increased elimination of CO2 (hyperventilation)?
Respiratory alkalosis
115
What are ten causes of hyperventilation?
Hypoxia
Anxiety
Fear
Pain
Fever
More severe causes: septicemia, stroke, meningitis, encephalitis, brain injury
116
What is the body's compensatory response to respiratory alkalosis?
Kidneys compensate by increasing HCO3 EXCRETION from the kidney.
117
How does metabolic acidosis affect the anion gap?
increased acid load = ELEVATED anion gap
118
Does a loss in bicarbonate affect the anion gap?
No, anion gap remains normal
119
Metabolic acidosis can be caused by increased acid or what?
Loss of bicarbonate
120
What are four causes of metabolic acidosis related to increased acid?
KILU
Ketoacidosis
Ingestions (ethylene glycol, salicylates)
Lactic acidosis (shock)
Uremia
121
What are causes of metabolic acidosis related to loss of bicarbonate?
Diarrhea
Renal failure
122
What is the body's compensatory response to metabolic acidosis?
increase CO2 excretion via Kussmaul breathing
Vomiting (trying to get rid of acid)
123
What are five causes of metabolic alkalosis?
Vomiting
Nasogastric suctioning
Diuretic therapy
Hypokalemia
Any condition that elevates aldosterone or mineralocorticoids (enhance sodium reabsorption and potassium and hydrogen ion excretion) which will elevate HCO3
124
What acid-base imbalance is caused by a loss of strong acid or gain of base?
Metabolic alkalosis
125
Which acid-base imbalance is caused by the gain of a fixed acid or the inability to excrete acid or loss of base?
Metabolic acidosis
126
What is the body's compensatory response to metabolic alkalosis?
Increase CO2 retention in lungs
127
Identification of a specific genetic lesion can lead to effective __________ and support early screening. The presence of a _______ component can alter the course of disease through __________ and lowering of ____ _______.
prevention; genetic; prevention; risk factors
128
True or false. A family history of disease may mean the person is more likely to develop the disease earlier in life. Give an example.
True
A person with a first-degree relative with Alzheimer disease has double the risk.
129
What term means "different forms of genes located at the same locus on the chromosome?"
Allele
130
At any given locus in a somatic cell, an individual has two genes, one from each parent. An individual may be __________ or __________ for a gene.
homozygous; heterozygous
131
A person's (genotype/phenotype) is the person's genetic makeup, and the (genotype/phenotype) reflects the interaction of the genetic makeup and the environment.
genotype
phenotype
132
Which term is described by the extent of variation in phenotype associated with a particular genotype?
Expressivity
133
If the expressivity of a disease is variable, the penetrance may be ________, but the severity of the disease can ____ _______.
complete; vary greatly
134
To serve as the basis of genetic inheritance, what must be able to provide a code for all the body's proteins?
DNA
135
True or false. DNA must be able to replicate itself accurately during cell division so that the genetic code can be preserved in subsequent cell generations.
True
136
What is a mutation?
any inherited alteration of genetic material
137
_____ are functional regions of DNA.
Genes
138
How many proteins does it take to replicate DNA?
At least three.
One to unwind the double helix
One to hold the strands apart
Others to perform different but distinct functions
139
Which enzyme is described here?
- Travels along single DNA strand
- Adds correct nucleotides to free end of new strand
- proofread the new strand by making sure the base is actually complementary to template base
- edits strand if necessary; excises incorrect nucleotide and replaces with correct one **this substantially enhances the accuracy of DNA replication
DNA polymerase
140
Cells that do not contain a multiple of 23 chromosomes are called what?
Aneuploid cells
141
Which common form of aneuploidy has only one copy of a given chromosome in a diploid cell?
Monosomy (monosomy of any chromosome is lethal)
142
____ of chromosome material has more serious consequences than ___________ of chromosome material.
Loss; duplication
143
An aneuploid cell containing three copies of one chromosome is called what?
Trisomy
144
A newborn with trisomies of which chromosomes can survive?
13, 18, or 21
145
What is the most well-known example of aneuploidy in an autosome?
Trisomy of the 21st chromosome: Down Syndrome (formerly known as mongolism--now an inappropriate term)
146
People with Down Syndrome usually have IQ in what range? What are the distinctive facial characteristics (3)?
25-70
Low nasal bridge
Protruding tongue
Flat, low-set ears
147
For a recessive allele to be expressed, they must exist in a (heterozygous, homozygous) form.
Homozygous
148
What is the most common lethal autosomal recessive disease in white children? Which gender is more common in?
Cystic fibrosis; females
149
If a male has the gene for cystic fibrosis, an _________ _________ disorder, and the female has no gene, the child may still be a carrier. Carriers do not usually show any phenotypic signs of the disease. Because most recessive alleles are maintained in normal carriers, they are able to survive in the population from one generation to the next.
autosomal recessive
150
When one allele masks those of another, they are in a ____________ form.
heterozygote
151
At a heterozygous locus, the dominant gene _____ those of a recessive gene.
masks
152
Breast cancer can be a from an autosomal dominant gene. Genes responsible for this form of breast cancer have been mapped to chromosomes 17 (_____) and 13 (_____). Women who inherit a mutation in _____ or _____ experience a 50% to 80% lifetime risk of developing breast cancer.
BRCA1; BRCA2; BRCA1; BRCA2
153
True or false. Breast cancer aggregates strongly in families. If a woman has one affected first-degree relative, her risk of developing breast cancer doubles.
True
154
Early onset Alzheimer Disease (before the age of 65) is usually associated with what type of genetic transmission?
autosomal dominant
155
True or false. Late onset Alzheimer Disease is rapidly increasing in the U.S.
True
156
Some conditions are caused by genes located on sex chromosomes. That mode of inheritance is called "sex-linked." From which chromosome (X or Y) are most sex-linked traits from? Why?
X chromosome
The Y chromosome only has a few dozen genes, so it is just a statistical thing that happens.
157
Which gender is more likely to inherit an X-linked recessive disease?
Men
A male who inherits a recessive disease allele on the X chromosome will be affected by the disease because the Y chromosome does not carry a normal allele to counteract the effects of the disease-causing allele.
158
X inactivation sex chromosome aneuploidy is the presence of a single _ chromosome and no __________ X or Y chromosome, resulting in a total of __ chromosomes. This causes a set of symptoms known as "Turner Syndrome."
X; homologous; 45
159
Why are people with Turner Syndrome always female?
Because they have no Y chromosome
160
List features of Turner Syndrome (9; think appearance, intelligence, and reproduction ability)
Sterile
Gonadal streaks rather than ovaries
Short stature
Webbing of neck (50% of cases)
Widely spaced nipples
Coarctation (narrowing) of aorta (15%-20% of cases)
Edema in feet of newborns
Sparse body hair
IQs in normal range except for some affect to intellectual abilities including spatial and mathematical reasoning
161
What are teenagers with Turner syndrome typically treated with and why?
Estrogen
Promote the development of secondary sexual characteristics
162
Which term reflects the number of new cases of a disease reported during a specific period (typically 1 year) divided by the number of individuals in the population?
For example, during COVID , this number was calculated on a weekly basis (# of new cases/week).
Incidence rate
**won't need to calculate for the exam, but know the definitions
163
Which term is reflected by a common measure of the effect of a specific risk factor? It is expressed as a ratio of the incidence rate of the disease among individuals exposed to a risk factor divided by the incidence of the disease among individuals not exposed to a risk factor.
Relative risk
164
True or false. The incidence of death from lung cancer is 1.66 in heavy smokers (>25 cigs daily), but only 0.07 in nonsmokers. The ratio of these two incidence rates is 1.66/0.07, which yields a relative risk of 23.7 deaths. Thus it is concluded that the relative risk of dying from lung cancer increased by about 24-fold in heavy smokers compared with nonsmokers.
True
165
Recurrence rate (RR) of multifactorial inheritance is affected by what four factors?
1. If expression of disease is severe, RR is higher.
2. If more than one family member is affected, RR is higher.
3. If remotely related relatives are affected, RR decreases rapidly.
4. Many genes and environmental factors contribute to multifactorial diseases.
166
What kind of changes are modifications to DNA that regulate whether genes are turned on or off? Do these changes alter the sequence of DNA?
Epigenetic changes
These modifications are attached to DNA and no not change the sequence of DNA building blocks.
167
True or false. Epigenetics modifies gene expression without altering the DNA sequence. "Epi-" means on or above in Greek, and "epigenetic" describes factors beyond the genetic code.
True
168
What causes individuals with the same DNA (IDENTICAL TWINS) to have different disease profiles? For example, why would asthma occur in only one of a pair of identical twins?
Epigenetic modification
169
As twins age, they demonstrate increasing differences in ___________ patterns of their DNA sequences, causing increasing numbers of phenotypic differences.
methylation
170
What are two environmental factors that may cause epigenetic modification?
diet
exposure to certain chemicals
171
Epigenetic factors are behaviors and environmental factors that can change how genes work, turning them "on" or "off." These factors can include:
Exposure to toxins
Substances
Lifestyle
172
What are toxins that could cause epigenetic modifications?
air pollution
diesel exhaust
cigarette smoke
plastics
BPA
heavy metals (lead or cadmium)
173
What are substances that could cause epigenetic modifications?
alcohol
tobacco
recreational drugs
certain prescription medications
174
What are lifestyle factors that could cause epigenetic modifications?
food
physical activity
stress levels
relationships
social interactions
community support
access to healthcare
175
Epigenetic changes can occur throughout life, both as a part of normal development and aging, and due to exposure to environmental factors. These changes can affect health in different _____.
ways
