Packet 2 (page 1-8, Quiz 1) Flashcards
What is pathology?
-the study of structural and functional abnormalities that are expressed as diseases of organs and systems; causes of disease and associated changes of cells, tissues, organs, and the presenting signs and symptoms of a patient
-the study of cell injury and the expression of a cells preexisting capacity to adapt to such injury
(a living cell must maintain the ability to produce energy, therefore it is vital that cells establish a structural and functional membrane between the internal and external environment)
What are the 5 main adaptive responses for cells?
1) hypertrophy
2) hyperplasia
3) atrophy
4) metaplasia
5) dysplasia
cells which cannot adapt appropriately or if the stress is inherently harmful to the cell= cell injury
Some levels of cell injury are reversible and the cell will be able to return to stable baseline
if the stress is persistent, severe, or rapid onset, the cell will undergo irreversible injury which leads to cell death
What are the 2 types of triggers for adaptation?
1) physiological stresses (usually normal, ex: increase in exercise will increase size of cell and result in bigger muscles)
2) pathological stresses (abnormal, ex: hypertension will cause the heart to pump harder and cause enlargement)
T/F: an adapted cell is NOT NORMAL or is NOT INJURED
true
What is cellular atrophy?
cells shrink, literally means without growth
What is hyperplasia?
increase in the number of cells
ex: pregnant mom or kid going through puberty
What is hypertrophy?
increase in size of cells
ex: exercise or high BP will cause heart to work overtime and enlarge
What is metaplasia?
change in shape, but all the cells change uniformly
this can be normal or abnormal
What is dysplasia?
abnormal change in shape, cells change into different shapes (not uniform)
this is known as the pre-cancer stage
Is atrophy reversible?
usually
What is a characteristic feature of atrophy?
autophagic vacuoles
-membrane bound vacuoles that contain fragments of cell components (mitochondria, ER) that are destined for destruction and into which lysosomes discharge the hydrolytic contents (autophagy). The cellular components are then digested
What are the most common organs to atrophy?
-skeletal muscle
-heart
-brain
-sex organs (breast, penis, ovaries)
What are the 5 causes of atrophy?
1) decreased work load (ex: weight lifter stops lifting, decrease in uterus postpartum, thymus gland due to stress)
2) disuse (decreased muscle workload, most often seen in muscles of paralyzed limbs and muscles attached to immobilized joints (usually seen in type II fibers))
3) ischemia (decreased blood supply to a tissue or organ that is caused by constriction or obstruction of local blood vessels, resulting in inadequate oxygen which is necessary for cellular function and metabolism (decreased nutrients and elimination of metabolic wastes), generally due to obstruction of the blood vessels caused by vasoconstriction, embolism, or thrombosis)
4) malnutrition/starvation
5) pressure/compression (persistent pressure will cause atrophy of a compressed cell, tissue or organ by interfering with blood flow and therefore, nutrition and metabolic activity of the affected area, cells in a local area like the liver atrophy from pressure of materials such as amyloid deposited around them, other examples include aneurysms of the aorta or brain, hernias, and hypertensive changes in the eye (nicking))
What is the most common cause of ischemia?
arteriosclerosis (overtime, arteries narrow and harden which slows the blood flow (old age))
Besides arteriosclerosis, what are the other causes of ischemia?
-heart attack/ MI
-stroke/ CVA
-peripheral artery disease (PAD), most common in the legs
-mesenteric ischemia (intestines)