2850 Pathophysiology Exam One Flashcards
What are the possible effects of genetic disorders?
Damage or mutation of DNA
What impact does cellular injury often have?
Synthesis of abnormal cellular proteins, which can lead to disease
What are the main causes of gene mutation?
Inheritance
Environmental influence
Germ cell mutations
Mutations on the genes of sex cells (gametes) that can be passed to future generations of offspring
Somatic mutations
Mutations on non-gamete body cells that can affect the individuals body but cannot be passed to future generations
A mutated gene can either produce what or what in terms of proteins?
Abnormal proteins or no proteins
What are some diseases that are the result of multifactorial influences?
Hypertension
Heart disease
Diabetes
Cancer
What are some predictive factors that can contribute to development of a multifactorial disease?
Inheritance of one or more predisposing genes
Environmental factors
Diet
Exercise/lack of exercise
What are some environmental factors that can contribute to disease development?
Pollution Chemicals Toxins Smoking Alcohol Drugs Sunlight Radiation
Explain the “Two Hit” hypothesis
Normally, if one allele on an allele pair becomes damaged or mutated, the corresponding normal allele will counteract the effect of the damaged one.
In order for disease to develop, something must happen to the other allele as well.
So someone could inherit one damaged allele, but not develop the disease until an environmental or lifestyle factor damaged the other allele (or disease won’t develop if that allele stays normal)
What is the exception to the “Two Hit” hypothesis?
Autosomal dominant diseases
What should be included in a genetic risk assessment?
Family health history
Ethnicity and culture
Social practices
Why is it important to include ethnicity in a genetic assessment?
Because certain illness patterns are more common in certain ethnic groups
What are the physical responses that occur with any type of stress?
Heart rate goes up and myocardial contractility increases
Bronchodilation
Chemical mediators provoke stress hormone release, increasing alertness
Strength and agility increase
What happens when the stressful situation ends?
Hormones end the stress response and the body returns to normal
What are the effects of frequent or long term stressors?
Stress hormones are always in the tissues and bloodstream, leading to diminished immunity, increased risk of autoimmune disease, cancer, heart disease, and depression
Which theory discusses adaptive ability and coping mechanisms?
Selye’s stress response theory
Adaptive ability
How an individual manages stress and reduces the effects of stress
Coping mechanisms
Emotional and behavioral responses used to manage threats to physical and mental homeostasis (can be healthy or unhealthy)
What are some conditioning factors when it comes to coping with stress?
Support systems Age Gender Genetic predisposition Developmental and educational level Life experiences Pre-existing conditions
How do conditioning factors affect how a person reacts to stress?
A person’s perspective on a stressful situation, their past experiences, and other listed factors will determine whether they can adapt or not in times of stress
What hormone is released in the alarm stage of the general adaptation syndrome?
Norepinephrine
What happens physiologically in response to norepinephrine release in the alarm stage?
Vasoconstriction (increased blood to heart/lungs/muscles)
Increased alertness
Increased cardiovascular and respiratory response
A survival oriented, involuntary, neuroendocrine physiological change in response to a severe, acute stressor
Fight or flight response
What are the physiological effects of cortisol?
Mobilization of glucose, amino acids, and fat for energy production
Increased WBC production and decreased inflammation (for the first 3-5 days of stress response)
What does cortisol cause after sustained presence in the body after 3-5 days?
Immunosuppressive
What are the effects of increased WBC production?
Less inflammation and increased immunity
What does aldosterone and ADH do during the alarm stage?
Increase sodium and water retention to increase blood pressure
How does the body attempt to stave off stress effects during the resistance stage?
Continued hormone and catecholamine (norepinephrine) secretion
What does the parasympathetic nervous system do when stress subsides?
Counteracts SNS actions, so HR goes down, pupil dilation decreases, digestion/urinary functions return to relaxed state, all normal parasympathetic responses resume
What are symptoms of the exhaustion stage?
Feeling run down Inability to cope Depression Anxiety Illness
What are the effects of chronic stress?
effect is cumulative, causing Immunosuppression leading to illness and infection
Also has a negative mental and emotional effect
What are some consequences of long term cortisol secretion?
Decreased immunity
Less efficient WBC response
Who theorized about allostasis in terms of stress?
McEwen (McEwen’s stress response theory)
Allostasis
A dynamic state of balance that changes with exposure to stressors
Allostatic load
Wear and tear on body systems caused by stress reactions
What are the four mechanisms that cause accumulation of allostatic load?
Repeated stressful experiences
Inability to adapt
Prolonged stress reaction
Inadequate response to stressor
What are some factors that influence adaptive ability?
Genetics Cognitive ability Developmental level SES Lifestyle Diet Exercise Past experiences Support system
Allostatic overload
Stress exceeds the body’s ability to adapt, initiating pathophysiological disorders
Allostatic overload corresponds with which stage of the GAS?
Exhaustion stage
What are some examples of stress related disorders?
Asthma Autoimmune diseases IBS Migraines Peptic ulcer disease
Why do elderly individuals have less resiliency against stress?
Body takes longer to recover from a stressful event as it ages
What are some symptoms of stress?
Nervousness Irritability Headaches Inability to concentrate Insomnia Appetite changes Depression Panic attacks
Biological, intrinsic phenomena of aging and the gradual loss of function of body systems
Senescence
How does senescence relate to gerontology and geriatrics
It describes how the cells lose their ability to replicate and repair over time, leading to the loss of function that comes with aging
What is meant by loss of physiologic reserve?
Decreased ability to repair damage and adapt to physiologic stressors
What is meant by the multicausality theory of aging?
Combination of Internal processes and environmental factors that cause cell changes and aging of the body
What is the single largest cause of death in the United States?
Cardiopathologies
Atherosclerosis
Development of cholesterol-laden plaques in the endothelial lining of arteries, and increased connective tissues in the walls of the vessels
Arteriosclerosis
Thickening of the inner and central walls of arteries
What does free radical damage do to cardiac cells? What does this cause?
It causes inappropriate cross linking of the proteins and DNA that accumulates over time. This causes decreased elasticity of the muscle fibers and decreased ability for arteries to vasodilate
How does maximum achievable heart rate change over time?
It decreases in a linear fashion over time
What are some changes to the respiratory system as a result of aging?
Responding more slowly to hypoxia and hypercapnia
Decrease in aerobic capacity (10% per decade)
Weaker cough reflex
Decrease in diameter of bronchioles and smaller airways
How does exposure to atmospheric air cause respiratory changes?
Damaging pollutants and free radical damage cause alveolar surface area loss and narrowing of bronchioles
Weaker cough reflex makes older adults more susceptible to..
Pneumonia
What can cause an older adult to NOT exhibit early warning signs of hypoxia?
Serious respiratory illness
What causes decreased kidney function in older adults?
Loss of nephrons and decreased activity of nephron tubules
How does aging change when the kidneys excrete fluid and electrolytes?
Older kidneys excrete more fluid and electrolytes at nighttime as compared to younger kidneys
Before administering a medication, a nurse checks serum creatinine to determine what?
Kidney function (and subsequent ability to eliminate medications)
What are some age related changes in the GI system?
Decreased strength in lower esophageal sphincter
Decreased production of hydrochloric acid and intrinsic factor
Changes in normal bacterial flora of the GI system
Presbyesophagus and its consequences
Age related changes in the esophagus, including weaker lower esophageal sphincter. This allows more acid reflux into the esophagus, leading to esophagitis and GERD
Why are older adults at greater risk for iron deficient anemia?
Decreased HCl production in the stomach leads to less iron and calcium absorption
Why are older adults at higher risk for pernicious anemia?
Decreased intrinsic factor causes decreased absorption of vitamin B12
Pernicious anemia causes..
Decreased red blood cell production in the bone marrow
What predisposes older adults to GI infections?
Changes in GI flora, leading to decreased GI immunity
Why does BMR decrease with age?
Less thyroid action/secretion of thyroid hormones
What causes thin skin in older adults?
Slower replacement of epidermal cells
Why do older adults have difficulty with thermoregulation?
Decrease in subdermal fat, sweat glands, hair follicles, and sensory end organs
What are the most common areas of bone loss in older adults?
Trabecular bones of vertebrae, hips, and wrists
Why are women at greater risk for bone loss than men?
Decreased estrogen levels after menopause (estrogen helps keep osteoblasts viable)
What are the neurological consequences of vitamin B12 deficiency?
Demyelination of dorsal columns of spinal cord, which can cause gait issues, tremors, and confusion
What are some possible outcomes of the higher pain threshold of older adults?
Mechanical and thermal injury due to less protective actions being taken
How does aging change hearing and vision?
Both decline, especially hearing high pitched noises and seeing things close to the face
What is meant by frailty in older adults/How does it manifest?
Fatigue Cognitive impairment Weakness Weight loss Decreased balance and activity Slowness Social withdrawal
What are some factors that contribute to frailty?
Normal aging changes Common diseases Musculoskeletal changes Neurological changes Immune system changes
Atrophy
Cells reverting to smaller size in response to metabolic or environmental changes
What are some causes of cellular atrophy?
Paralysis Loss of hormone stimulation to cells Aging Malnutrition Disuse Ischemia
Hypertrophy
Cellular adaptation in which individual cell size and functional tissue mass increases, stimulating angiogenesis
Describe the difference between physiologic hypertrophy and pathological hypertrophy
Physiologic: enlarged muscles have adequate blood supply, oxygen, and nutrients
Pathologic: increase in cellular size without an increase in necessary supportive structures for increased metabolic needs
Example of physiologic hypertrophy
Muscles of athletes
Example of pathologic hypertrophy
Left ventricular hypertrophy
Hyperplasia
Cellular adaptation in which number of cells in a tissue or organ increase
What is an example of hyperplasia?
Benign prostatic hyperplasia
What are two conditions of hyperplasia that are caused by hormone stimulation?
Breast gland cells in pregnancy and keloid development in wound healing
Metaplasia
Cellular adaptation in which cells of one type are replaced by cells of another type
What is metaplasia normally caused by?
Chronic inflammation
Give an example of metaplasia
Acid reflux causing the squamous cells of the esophagus to change to columnar cells that are more similar to stomach cells
Dysplasia
Cellular adaptation that is deranged cellular growth within a specific tissue, often due to chronic inflammation or a precancerous condition
Give an example of dysplasia
Cervical dysplasia (detected by Pap test)
How do dysplastic cells differ from healthy cells?
They vary in size, shape, and architectural arrangement compared to healthy cells
What alteration occurs when the active transport system (sodium potassium pump) is not occuring?
Osmotic balance altered, leading the cellular swelling
What effect does a defective sodium potassium pump have on calcium?
Calcium pump also becomes deficient, leading to calcium accumulation in the cell and altered biochemical processes
What factors contribute to accumulation of substances inside cells?
Abnormal metabolic function
Aging
Exposure to high amounts of environmental materials
What are the consequences of intracellular accumulation?
Cell injury
Give two examples of conditions associated with continual accumulation of substances within cells
Alcoholism causing hepatocyte accumulation, leading to fatty liver Familial hypercholesterolemia (defective cholesterol metabolism)
What is the most common cause of hypoxia?
Diminished circulation (ischemia)
What are some additional causes of ischemia?
Anemia Low environmental oxygen Inadequate diffusion at alveoli Suffocation injury Airway obstruction
Describe ischemic reperfusion injury
When a tissue experiences transient ischemia and then circulation resumes, leading to oxidative stress and activation of damaging forces by free radicals, causing death to cells that might have otherwise recovered
Free radicals
Reactive oxygen molecules caused as a byproduct of cellular energy production
A potential consequence of free radicals is
Oxidative stress
Oxidative stress
A form of cell injury in which free radical removal mechanisms are overwhelmed
What is a disease that involves ischemic-reperfusion injury?
Heart disease
What is the difference between endogenous and exogenous substances?
Endogenous: biological substances
Exogenous: synthetic substances
How does hypernatremia cause cellular injury?
It causes cell dehydration and shrinkage
What are some symptoms of hypernatremia?
Lethargy
Weakness
Irritability
Confusion
How does hyperglycemia cause cellular injury?
High blood glucose reacts with endothelial membrane to produce advanced glycation end products that can damage arteries, kidneys, nerves, and retina of eyes
What is VEGF?
Vascular endothelial growth factor
What does VEGF do?
Stimulates the synthesis of collateral blood vessel branches
What will endothelial damage do to blood flow?
Decrease it, because there will be less VEGF to stimulate blood vessel formation
What does endothelial cell injury initiate?
Arteriosclerosis leading to cardiovascular disease
Apoptosis
Genetically programmed degenerative changes leading to cell death
Physiologic apoptosis example
Development of individual fingers from web-like structure in embryos
Dysfunctional apoptosis example
Cells no longer doing apoptosis, giving rise to certain cancers
What are the benefits of normal apoptosis?
Elimination of damaged or unwanted cells without inflammation or injury to surrounding tissue
Cell necrosis
Cell death due to stressors that overwhelm the cells survival ability
Infarction
Ischemic necrosis (death due to prolonged ischemia)
Osteoblasts
Bone building cells that secrete osteoid to form bone matrix
Osteocytes
Mature osteoblasts trapped in bony matrix. Help maintain metabolism and nutrient and waste exchange
Osteoclasts
Bone breakdown cells. reabsorption and degradation of existing bones
Bone modeling
Period in which osteoblast activity dominates and bone mass increases
Bone remodeling
Mature bone breaking down and being renewed by osteoclasts activity
What leads to hypertrophy of skeletal muscle?
Working it against high resistance
Causes of atrophy
Long periods of immobility
Function of tendons
Attach muscles to bones and transmit load from muscle to bone. Causes joint motion
Example of well-known tendon
Achilles’ tendon
Function of ligaments
Attaching bone to bone and creating joint stability
Example of well-known ligament
ACL
What is the impact of injury to tendons?
Inflammation Tendon weakening Tendon rupture (prolonged healing process)
Impact of injury to ligaments
Inability to return to normal shape —> rupture
Healing process replaces ligament with hypertrophic mass which provides less joint stability
Muscular dystrophy
Progressively degenerative non-inflammatory muscle disorder
Etiology of dúchenne muscular dystrophy
X-linked recessive genetic disorder
Half of cases arise from hereditary mutation, the other half arise from sporadic mutation
Pathophysiology of muscular dystrophy
Defects in the genetic code for dystrophin (which is found in all muscle as well as brain tissue) causes T cells to attack the muscles. The dead muscle is then replaced with a fibrous fatty infiltrate
The changes that occur due to muscle being replaced with fatty fibrous infiltrate in muscular dystrophy is called
Pseudo hypertrophy
What are the initial clinical manifestations of muscular dystrophy?
Progressive muscle weakness without obvious cause
What are additional clinical findings with muscular dystrophy?
Waddling, wide based gait Children not walking until 18 months or after Hyperlordosis of spine Toe walking Growers sign Weakness Poor posture Pain and pseudohypertrophy in calves
Describe multiple sclerosis
Progressive, demyelinating autoimmune disorder that causes inflammation and damage to nerve cells in the CNS and peripheral nerves
Etiology of multiple sclerosis
Unknown, but is thought to be autoimmune and inflammatory
What is the role of T cells in the development of MS?
It is theorized that they become abnormally sensitized to attack myelin, but exact role is unknown
What are some risk factors for MS development?
Being a woman Heavy metal exposure Genetics Virus/infection Trauma
Describe what happens in MS remission
Inflammation periodically resolves, allowing the demyelination to heal
What happens when MS fails to go into remission?
There is no time for damage to heal, so demyelinated areas turn into fibrotic scar tissue, permanently disrupting/altering nerve impulse conduction
What are common symptoms of MS?
Weakness Numbness Tingling Balance problems Blurred vision Fatigue
Describe how to remitting-relapsing form of MS works
Brief episodes that can last for a couple weeks to three months and occur every 1-3 years. Each episode is followed by a near complete return to normal
What causes the vision problems that occur with MS?
Optic nerves are highly myelinated, so them being attacked can cause vision issues
What kind of vision issues can be caused by MS?
Vision loss
Changed color perception
Pain with eye movement
What are some symptoms of motor nerve damage with MS?
Hemiparesis Paraparesis Quadriparesis Problems with walking and coordination Incontinence and sexual dysfunction
Why are MS patients in late stages at higher risk for aspiration pneumonia?
Weakened esophageal muscles
What are some risk factors for osteoarthritis?
Aging Obesity Team sports participation Joint trauma and overuse Heavy occupational work
Describe the etiology of osteoarthritis
Stress on the joints leads to degenerative alteration of articular cartilage, which leads to breakdown of chondrocytes and subchondral bone
What is the impact of excessive pressure on a joint?
It wears away cartilage and exposes subchondral bone, leading to inflammation and swelling
What is the role of proteoglycans in the progression of osteoarthritis?
Fluid substance secreted by chondrocytes to try to repair cartilage, but levels decrease as OA progresses, causing cartilage to lose elasticity and crack
What are the consequences of damaged cartilage in osteoarthritis?
Bone is exposed, and the increasing stress on the bone exceeds the strength of the bone, increasing inflammation. The joint then thickens
What are some presenting symptoms of osteoarthritis?
Deep and aching joint pain Swelling Pain in cold or after activity Limited ROM Fluid buildup Does not have to be symmetrical
What are herberden’s nodes and Bouchards nodes?
Swelling at interphalangeal joints in the hands
Describe rheumatoid arthritis
Systemic, inflammatory autoimmune disorder affecting joints and other organs as well (heart, lungs, etc)
What are factors that may play a significant role in development of RA?
Age Genetics Being female Past infections Immunological factors
What is the pathophysiology of RA?
The immune system attacks synovial tissues
What are the consequences of the inflammatory process of RA?
Destruction of cartilage, bones, tendons, and ligaments
Damage to heart, lungs, etc
What is the role of activated T cells in the progression of RA?
They secrete cytokines, which bring white blood cells to the area, which escalates inflammation
What is the result of continual inflammation of the synovial membrane?
Hypertrophy in pannus of the joint and loss of cartilage
What are the classic symptoms of RA?
Symmetrical, tender, swollen joints
Fever
Fatigue
Malaise
What are the consequences of chronic joint inflammation associated with RA?
Permanent damage to surface of joints and mobility limitations
