What is homeostasis?
The maintenance of a relatively constant (range of) environment w/i the body.
What is stress?
A non-specific response of the body to any damage placed on it.
What is a stressor?
Anyagent responsible for producing stress.
What is distress?
Harmful or unpleasant stress.
What is eustress?
Positive events that stimulate growth.
What are some general responses to stress?
- Specific homeostatic adjustments
- - General Adaptation Syndrome (response to sudden
What are the 3 phases of General Adaptation Syndrome?
- 1) Alarm phase
- 2) Resistance phase
- 3) Exhaustion phase
What branch of the nervous system directs the Alarm Phase and what is the dominant hormone?
The sympathetic nervous system; epinephrine.
When does the Resistance Phase occur and what is the dominant hormone?
Occurs when stress last longer than a few hours; glucocoritcoids.
What are the goals and problems of the Resistance Phase?
- Mobilize lipid/protein reserves
- Retain water
- Glucocorticoids are an immunosuppresant
- Proteins begins breakind down once lipid stores are used
What are the causes of the Exhaustion Phase?
Collapse of vital systems. May include: exhausted lipid reserves, can't produce glucocoritcoids, electrolyte imbalance.
May prove fatal.
What are some examples of stress related disorders?
Hypertension, ulcers, skin disorders, CVD, migraines, easting disorders, anxiety, arrythmias, asthma, cancer, alcoholism, drug abuse, endocrine disorders, GI disorders, muscular tension, sleep difficulty.
What is disease?
Failure to maintain homesostatic conditions.
What is etiology?
Cause of disease.
What is pathogenesis?
Sequence of evens in the development of disease.
What is pathophysiology?
Study of funtional and structural changes caused by disease.
What are the 6 different etiologies?
- - Inherited: due to genetic defect
- - Congenital: present at birth
- - Acquired: developed during lifetime
- - Multifactorial: more than 1 factor
- - Idiopathic: no understood cause
- - Iatrogenic: treatment-induced
What are the 5 intrinsic (from w/i the body) etiologies?
- Degenerative: progressive loss of normal structure and function
- Innunologic: abnormal immune response (allergies)
- Metabolic: abnormal body chemistry
- Nutritional: abnormal dietary intake or nutrient use
- Psychogenic: related to psychological state
What are the 4 extrinsic etiologies?
- Infectious: due to a microorganism (bacterial, viral, fungal) or parasite
- Hypoxia: insufficient oxygen
- Chemical, drugs, toxins
-Environmental agents: temp/atm pressure, radiation, electrical)
What are the 3 different altered states of cells and tissues?
- Cellular adaptations: niether normal or abnormal
- Cellular injury: reversible or irreversible
- Cell death: necrosis, apoptosis
What is atrophy?
Shrinkage in cell size by loss of cell substance (diminished function).
What are some causes of cellular atrophy?
Decreased workload, loss of innervation, diminished blood supply, inadequate nutrition, loss of endocrine stimulation, aging.
What is hypertrophy?
Increase in the size of individual cells.
How do cells hypertrophy?
By increased synthesis of structural proteins and organelles.
What is hypertophy caused by?
- Increased funtional demand
- Specific hormone stimulation
What is hyperplasia?
An increase in the number of individual cells in an organ or tissue.
What are 3 types of physiologic hyperplasia?
What are 3 cell types that do not undergo hyperplasia?
- Cardiac m.
- Skeletal m.
What is metaplasia?
- The reversible replacement of one cell type by another in response to paticular stress/stimuli.
- An orderly arrangement of the new cell type is found.
What is an example of metaplasia?
Cigarette smoker; new tracheal arrangement of cells.
What is dysplasia?
An abnormal change in the size, shape, and arrangement of mature cells in response to a stimulus. May be reversible of stimulus removed.
(Not an adaptation)
What 3 factors influence cellular injury?
What are the general mechanisms of cell injury?
- Hypoxic injury
- Free radicals and reactive oxygen species
- Chemical injury
- Tissue trauma
What are Free Radicals?
Unstable/paired electrons that come from UV light, x rays, and normal metabolism.
How do Free Radicals cause injury?
- Lipid peroxidation
- Fragmentation of polypeptide chains
- Alteration of DNA
What can decrease damage from free radicals?
What agents can cause chemical injury?
- Carbon tetrachloride (dry cleaning)
- Carbon monoxide
What are some examples of traumatic tissue injury?
Blunt force, contusion, hematoma, abrasion, laceration (stab, incision), avulsion, gunshot, asphyxiation (suffocating, strangulation, drowning)
What are 3 types of hypoxic injury?
- Anoxia: complete lack of oxygen
- Hypoxia: a lack of sufficient oxygen supply to the tissues
- Ischemia: inadequate blood flow in the tissues
What can hypoxia result from?
Decreased oxygen in the air, CVD/resp. disease, lack of RBCs/anemia, inadequate hemoglobin, ischemia.
What are 3 effects of hypoxia?
- Sodium pump failure
- Increased glycolysis
- Release of enzymes
Hypoxia causes ATP depletion which leads to...?
Failure of the sodium potassium pump
- - Sodium (Na) in the cell
- - Potassium (K) out
- - Osmotic gain of water (
What does acute cellular swelling cause?
- Dilation of the endoplasmic reticulum
- Leakage of lysosomes
What results from failure of the sodium potassium pump?
Acute cellular swelling.
When is a cell injury considered reversible and when is it restored?
- If the injury is mild or short-lived
- Restored when ATP production is working
- Cell pumps out water (requires ATP)
When is cellular injury irreversible?
When damage to mitochondrial membrane occurs.
When does damage to the cell membrane (such as with irreversible injury) cause?
- Increased permeability of membrane
- Loss of volume regulation
- Massive calcium influx
- Loss of proteins
What are 3 types of cell death?
- Necrosis: changes that follow cell death of living tissue
- Apoptosis: programmed cell death that occurs normally in developing and adult tissues
- Autolysis: postemortem dissolution of cells/tissues by enzymes present in those tissues
What are 4 types of necrosis?
What are the 3 classifications of gangrene?
What are the 2 types of pathologic calcification?
- Dystrophic calcification: depositin of calcium in dead or dying tissues.
- Metastatic calcification: occurs in normal tissues whenever there is hypercalcemia.