Cell Biology: Adaptations and Homeostasis

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Questions and Answers

What is the main aim of cellular adaptations?

To cause pathological changes in cells

To maintain homeostasis

To induce physiological changes

To escape cell injury and preserve viability (correct)

Which of the following is an example of physiological hypertrophy?

Hypertrophy of liver cells in response to toxin

Uterine hypertrophy in pregnancy

LVH in systemic hypertension

Hypertrophy of cardiac muscle in athletes (correct)

What is the result of increased functional demand or specific hormonal stimulation on cells?

Metaplasia

Atrophy

Hypertrophy (correct)

Hyperplasia

What is the term for the maintenance of dynamically stable internal machinery in a cell?

Homeostasis Signup and view all the answers

What is the name of the process by which cells increase in size to increase the size of the relevant organ?

Hypertrophy Signup and view all the answers

What is the result of both hyperplasia and hypertrophy of uterine smooth muscle cells during pregnancy?

An increase in the mass of smooth muscle in the uterus Signup and view all the answers

What is the term for the process by which cells respond to external disturbances to maintain viability?

Adaptation Signup and view all the answers

What is the most likely cellular alteration that will be seen in the heart of the 51-year-old male due to untreated high blood pressure?

Hypertrophy Signup and view all the answers

What is the term for an increase in the number of cells in an organ or tissue leading to an increase in its size?

Hyperplasia Signup and view all the answers

Which of the following is an example of physiological hyperplasia?

Uterus in pregnancy Signup and view all the answers

What is the term for a decrease in the size of cells, leading to a decrease in organ or tissue size?

Atrophy Signup and view all the answers

What is the most likely cause of atrophy of the brain in an old male with atherosclerotic disease?

Reduced blood supply Signup and view all the answers

What is the term for a change in the type of cells in a tissue or organ?

Metaplasia Signup and view all the answers

What is the term for the effect of growth factors on target cells, leading to an increase in cell number?

The effect of growth factors on target cells Signup and view all the answers

Which of the following is an example of compensatory hyperplasia?

Following partial liver resection Signup and view all the answers

Study Notes

Cell Specificity and Homeostasis

Each cell has a specific function, determined by its genetic setup, machinery, and metabolic pathways.
Homeostasis is the state of equilibrium with the external environment and dynamically stable internal machinery, where input is orchestrated with output.

Cellular Adaptations

Cellular adaptations occur in response to external disturbances, including physiological and pathological changes in cell machinery.
The goal of adaptation is to escape cell injury and preserve viability by establishing a new steady state.

Types of Cellular Adaptations

Atrophy: a decrease in the size of cells, leading to a decrease in organ or tissue size, often as an adaptive response to decreased workload, denervation, ischemia, under nutrition, or loss of endocrine stimulation.
Hypertrophy: an increase in the size of cells, resulting in an increase in organ size, caused by increased functional demand or specific hormonal stimulation, and can be physiological or pathological.
Hyperplasia: an increase in the number of cells in an organ or tissue, leading to an increase in its size, often occurring together with hypertrophy.
Metaplasia: a change in cell type, not mentioned in the provided text.
Dysplasia: a change in cell growth or development, not mentioned in the provided text.

Examples of Cellular Adaptations

Hypertrophy: athletes, mechanical workers, uterus in pregnancy (also involves hyperplasia), and left ventricular hypertrophy (LVH) in systemic hypertension.
Hyperplasia: physiological (e.g., uterus in pregnancy, compensatory hyperplasia following partial liver resection), and pathological (e.g., estrogen-induced endometrial hyperplasia, viral warts).

Comparison of Normal and Adapted Cells

Uterine smooth muscle cells: normal cells are small and spindle-shaped, while hypertrophied cells are larger and plump.
Heart cells: normal heart cells are smaller and more organized, while hypertrophied heart cells are larger and more disorganized.

Endometrial Hyperplasia

Characterized by prominent folds of endometrium in the uterus, involving both endometrial glands and stroma.
Can be caused by excessive hormonal stimulation or the effect of growth factors on target cells.

Atrophy of the Brain

Characterized by a decrease in brain size and a narrowing of gyri and widening of sulci.
Caused by aging and reduced blood supply, leading to loss of brain substance.

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Description

This quiz covers the concepts of cell specificity, homeostasis, and adaptations in cellular biology. Learn about the genetic setup, machinery, and metabolic pathways that enable cells to maintain a dynamically stable internal environment and respond to external disturbances.