Podcast
Questions and Answers
In the context of cellular adaptations, which of the following scenarios best exemplifies pathologic atrophy?
In the context of cellular adaptations, which of the following scenarios best exemplifies pathologic atrophy?
- Reduced kidney size in an elderly individual as part of the normal aging process.
- The decrease in uterine size following childbirth.
- Muscle wasting in a limb immobilized in a cast. (correct)
- The shrinkage of mammary glands after lactation ceases.
Which cellular adaptation is most closely associated with an increased risk of malignancy, particularly in epithelial tissues?
Which cellular adaptation is most closely associated with an increased risk of malignancy, particularly in epithelial tissues?
- Hypertrophy
- Atrophy
- Metaplasia (correct)
- Hyperplasia
An endurance athlete undergoes significant left ventricular hypertrophy (LVH) as a result of intense training. Which molecular mechanism is most directly responsible for the increased cell size in this scenario?
An endurance athlete undergoes significant left ventricular hypertrophy (LVH) as a result of intense training. Which molecular mechanism is most directly responsible for the increased cell size in this scenario?
- Reduced expression of atrial natriuretic factor (ANF) to promote fluid retention.
- Increased apoptosis of cardiomyocytes to remove damaged cells.
- Activation of transcription factors leading to enhanced protein synthesis within cardiomyocytes. (correct)
- Decreased activity of mechanical sensors, reducing cellular response to workload.
A patient with chronic gastroesophageal reflux disease (GERD) develops Barrett's esophagus. Which cellular adaptation is the underlying mechanism for this condition, and what is the primary selective advantage it confers?
A patient with chronic gastroesophageal reflux disease (GERD) develops Barrett's esophagus. Which cellular adaptation is the underlying mechanism for this condition, and what is the primary selective advantage it confers?
In the context of hyperplasia, which of the following scenarios represents a pathologic response to hormonal imbalance?
In the context of hyperplasia, which of the following scenarios represents a pathologic response to hormonal imbalance?
A chronic smoker develops squamous metaplasia in the respiratory tract. How does this cellular adaptation alter the normal mucociliary clearance mechanism, and what is the consequence?
A chronic smoker develops squamous metaplasia in the respiratory tract. How does this cellular adaptation alter the normal mucociliary clearance mechanism, and what is the consequence?
Myositis ossificans involves the transformation of muscle tissue into bone. Which cellular adaptation mechanism underlies this condition, and what triggers this change?
Myositis ossificans involves the transformation of muscle tissue into bone. Which cellular adaptation mechanism underlies this condition, and what triggers this change?
A patient with atherosclerosis experiences reduced blood flow to the kidneys, leading to renal atrophy. Which cellular mechanism primarily contributes to the decrease in kidney size in this scenario?
A patient with atherosclerosis experiences reduced blood flow to the kidneys, leading to renal atrophy. Which cellular mechanism primarily contributes to the decrease in kidney size in this scenario?
During pregnancy, the uterus undergoes both hypertrophy and hyperplasia. Which hormonal influence primarily drives these cellular adaptations, and what is the functional significance of each?
During pregnancy, the uterus undergoes both hypertrophy and hyperplasia. Which hormonal influence primarily drives these cellular adaptations, and what is the functional significance of each?
In the context of cellular adaptation, how does the process of metaplasia differ fundamentally from dysplasia, and why is this distinction clinically significant?
In the context of cellular adaptation, how does the process of metaplasia differ fundamentally from dysplasia, and why is this distinction clinically significant?
Flashcards
Cellular Adaptations
Cellular Adaptations
Reversible changes in cells due to persistent stress, altering number, size, phenotype or metabolic activity. Allows cells to survive environmental changes.
Atrophy
Atrophy
Decrease in cell size or number in an organ due to reduced stimulation or stress Remove the stressor to reverse.
Hypertrophy
Hypertrophy
Increase in cell size, hence organ size, due to increased workload. Occurs in cells unable to divide.
Hyperplasia
Hyperplasia
Signup and view all the flashcards
Metaplasia
Metaplasia
Signup and view all the flashcards
Squamous Metaplasia in Smokers
Squamous Metaplasia in Smokers
Signup and view all the flashcards
Left Ventricular Hypertrophy
Left Ventricular Hypertrophy
Signup and view all the flashcards
Barrett's Esophagus
Barrett's Esophagus
Signup and view all the flashcards
Myositis Ossificans
Myositis Ossificans
Signup and view all the flashcards
Study Notes
- Cellular adaptations are reversible changes in response to persistent stress
- These changes include number, size, phenotype, and metabolic activity of a cell
- The change in phenotype and metabolic activity can change the function of the cells
Atrophy
- Atrophy is a decrease in organ size or number of cells
- Causes include lack of stimulation, blood supply, use, innervation, or nutrition
- Pressure or compression against the cell can decrease its size
- Metabolic changes resulting in decreased synthesis or increased organelle breakdown, and apoptosis can cause atrophy
- Physiologic atrophy includes a post-partum uterus
- Pathologic atrophy includes disuse (arm in cast), aging, loss of innervation, diminished blood supply (atherosclerosis), marasmus (decreased calorie nutrition), or tumor compression
Hypertrophy
- Hypertrophy is an increase in the size of cells or organs
- Hypertrophy occurs in cells that cannot divide
- Physiologic causes include increased left ventricle size in athletes
- Pathologic causes include stenotic valves, such as in the aortic valve
Myocardial Hypertrophy
- Increased workload, agonists, and growth factors stimulate cells to grow
- Mechanical sensors detect the increased workload
- This activates signaling pathways within the cell
- This also causes production of growth factors, vasoactive agents, and agonist production, and activation of transcription factors
- Gene protein expression changes from an adult phase to an embryonic stage
- Embryonic cardiac fibers can withstand mechanical workload
- Production of atrial natriuretic factor increases sodium excretion, which decreases blood volume and pressure
Hyperplasia
- Hyperplasia is an increase in the number of cells
- It is caused by increased workload or stimulus
- Hormones and growth factors promote cell division
- Both physiological and pathological causes exist
Metaplasia
- Metaplasia is a change in cell phenotype
- It is reversible and involves triggering stem cells to change phenotype
- This causes altered cell differentiation
- It mainly occurs in epithelial cells
- Metaplasia can increase the risk for malignancy or reduce function due to altered function
- Normal columnar cells can undergo squamous metaplasia due to smoking
- Vitamin A deficiency and salivary duct stones are also causes
- Squamous to columnar metaplasia happens with Barrett's esophagus and chronic reflux esophagitis
- Connective tissue metaplasia is rare, but muscle cells may change into bone cells, known as myositis ossificans
Clinical Correlation: Squamous Metaplasia
- A smoker with wheezing, crackles, cyanosis, and ankle edema may have squamous metaplasia
- Pulmonary function tests show decreased FEV1/FVC ratio and increased TLC, indicating chronic bronchitis
- Fumes destroy cilia in normal ciliated pseudostratified columnar epithelium
- Squamous metaplasia forms a protective barrier against heat and smoke fumes, preventing mucus removal
- Submucosal glands will hyperplace and secrete more mucus due to the lack of cilia
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
