Exam 1: Cellular injury, stress, & genetics Flashcards
(41 cards)
Atrophy
Cellular adaptation in which cells revert to the smaller size. It
is the shrinking of skeletal muscle seen in paralysis or even
inactivity from bed rest.
Acts to decrease energy requirements
Conditions it occurs:
1. disuse
2. denervation
3. loss of endocrine stimulation
4. inadequate nutrition
5. ischemia or decreased blood flow
Hypertrophy
An increase in the individual cell size and often mass where there is an enlargement of functioning tissue. It increases the cell’s functional components which leads to greater metabolic demand and energy needs
Physiologic hypertrophy
Enlarged muscle that is adequately perfused and supplied with
blood flow. There is proportional increase in cell size and
enhancement of coronary blood supply. (Working out and muscles larger)
Pathological hypertrophy
An increase in cellular size without an increase in the supportive structures necessary for the enlarged cells increase in metabolic demand. Seen in hypertension or heart failure. LV hypertrophy
Hyperplasia
Increase in the number of cells in the tissue or gland, generally stimulated by hormonal or compensatory cellular mechanism.
normal: increase in breast gland cells when a
woman is pregnant
maladaptive: a keloid
Metaplasia
Replacement of one cell type by another cell type generally due to environmental conditions
chronic inflammation
(Gastroesophageal reflux is a good example of this and can lead to cancer)
Dysplasia
Chronic inflammation or precancerous condition dysplastic cells vary in size, shape and architectural organization compared to healthy cells. (Cervical dysplasia example)
Classic precursor to cancer.
Neoplasia
Uncoordinated, uncontrolled proliferative cell growth that is cancerous like a tumor
Ischemia
Inadequate blood flow
Hypoxia
Oxygen deprivation, blood cannot deliver oxygen to cells this
can be body or region
-emia: low ox content in blood
-ia: low ox supply in body
↓oxygen →anaerobic metabolism →use up glycogen stores →↑lactic acid →alter cell member → failure Na+/K+ pump → ↓intracellular K+ →↑Na+ and H20→cell swells→ ↓mitochondrial function
Infarction
Also known as ischemic necrosis, it is the death of tissue due to prolonged ischemia
oxidative stress
Cell injury induced by free radicals
Causes changes in gene and protein expression
Reactive oxygen species exceeds the ability of the body to neutralize and eliminate
plays role in development of cancer and other disease processes
free radicals
Have a single unpaired electron in an outer orbit that creates instability and reactivity with adjacent molecules they react with constituents of the cell’s plasma causing oxidative degradation
generated from: excessive UV light, radiation, chemicals/drugs, reperfusion
antioxidants
block free radicals and prevent or delay cell damage
vitamins A, C, E, and zinc
Apoptosis
Genetically programmed degenerative change that causes cell death no adverse effects on the body a reduction in cell size, intact plasma membrane but an altered structure, no adjacent inflammation
Necrosis
Cellular death due to stressors of insults that overwhelm the cell’s ability to survive, it is irreversible an enlarged cell size, disrupted plasma membrane, cellular contents leak out of cell and frequent adjacent inflammation
Gangrene
Occurs when a considerable mass of tissue undergoes necrosis
Seyle’s stress response theory
Explains the body’s response to acute, intermittent stressors. Stressors can be positive or negative. The adaptive ability is the way in which individuals manage the stress and reduce the stressor’s effect on their life.
Homeostasis is the equilibrium between various physiologic parameters, adaptive ability depends on coping mechanisms, reaction to a stress is individual
3 stages:
1. alarm - fight or flight response
2. resistance - recovering from illness
3. exhaustion - chronic exposure increases risk for disease
McEwen’s Stress response theory
Stress is a routine part of daily life not episodic or a crisis
Frequent stressors change the body’s physiologic balance and create new set points, allostasis load accumulates because of four mechanisms:
repeated stressful experiences
inability of the individual to adapt to stress
prolonged reaction to a stressor
inadequate response to a stressor
Allostasis
The dynamic state of balance that changes to exposure to stressors
Allostatic load
The wear and tear on the body systems caused by stress reactions
Gene
Specific group of nucleotides of the DNA helix that carry a code for protein
Segment of DNA on chromosome
gene locus refers to location of a gene on a chromosome
Karyotype
Picture of the chromosomes that are contained within the DNA of a species, human karyotype as 23 pairs of chromosomes
Mendelian genetics
Inherited traits are passed from parents to offspring. The Punnett square is a predictable pattern in transmission of a single gene, not used for multifactorial inheritance. Used with autosomal dominant, autosomal recessive, and sex linked.
