Podcast
Questions and Answers
Which type of cells has no regenerative ability?
Which type of cells has no regenerative ability?
What is the primary difference between hyperplasia and hypertrophy?
What is the primary difference between hyperplasia and hypertrophy?
Which type of tissues can undergo hyperplasia?
Which type of tissues can undergo hyperplasia?
What is the result of repeated cell divisions in hyperplasia?
What is the result of repeated cell divisions in hyperplasia?
Signup and view all the answers
What is the main difference between physiological and pathological hyperplasia?
What is the main difference between physiological and pathological hyperplasia?
Signup and view all the answers
What is the result of atrophy in a tissue?
What is the result of atrophy in a tissue?
Signup and view all the answers
What is the difference between atrophy and metaplasia?
What is the difference between atrophy and metaplasia?
Signup and view all the answers
What is the result of inadequate nutrition on tissues?
What is the result of inadequate nutrition on tissues?
Signup and view all the answers
What is the result of pressure on tissues?
What is the result of pressure on tissues?
Signup and view all the answers
What is the result of ageing on tissues?
What is the result of ageing on tissues?
Signup and view all the answers
What is the primary mechanism by which cell proliferation is controlled?
What is the primary mechanism by which cell proliferation is controlled?
Signup and view all the answers
What is the consequence of a cell passing the restriction point in the cell cycle?
What is the consequence of a cell passing the restriction point in the cell cycle?
Signup and view all the answers
What is the primary function of cyclin-dependent kinases (CDKs) in the cell cycle?
What is the primary function of cyclin-dependent kinases (CDKs) in the cell cycle?
Signup and view all the answers
What is the term for the ability of cells to replace destroyed cells or tissues with identical functionality?
What is the term for the ability of cells to replace destroyed cells or tissues with identical functionality?
Signup and view all the answers
What is the Hayflick limit?
What is the Hayflick limit?
Signup and view all the answers
What is the primary factor that determines the size of a cell population?
What is the primary factor that determines the size of a cell population?
Signup and view all the answers
What is the consequence of a cell being unable to progress through the cell cycle?
What is the consequence of a cell being unable to progress through the cell cycle?
Signup and view all the answers
What is the primary function of the restriction point in the cell cycle?
What is the primary function of the restriction point in the cell cycle?
Signup and view all the answers
What is the primary characteristic of metaplasia?
What is the primary characteristic of metaplasia?
Signup and view all the answers
Which of the following is an example of aplasia?
Which of the following is an example of aplasia?
Signup and view all the answers
What is the main difference between hypoplasia and aplasia?
What is the main difference between hypoplasia and aplasia?
Signup and view all the answers
What is the term for the normal programmed shrinkage of an organ?
What is the term for the normal programmed shrinkage of an organ?
Signup and view all the answers
Which of the following is an example of atresia?
Which of the following is an example of atresia?
Signup and view all the answers
What is the primary characteristic of dysplasia?
What is the primary characteristic of dysplasia?
Signup and view all the answers
Which of the following is a pre-cancerous condition?
Which of the following is a pre-cancerous condition?
Signup and view all the answers
What is the term for the replacement of a lost part of the body?
What is the term for the replacement of a lost part of the body?
Signup and view all the answers
Study Notes
Cellular Adaptations
- Cells can adapt through:
- Hyperplasia: increase in cell numbers above normal
- Hypertrophy: increase in cell size
- Atrophy: cells become smaller
- Metaplasia: cells are replaced by cells of a different type
Hyperplasia
- Increase in tissue or organ size due to increased cell numbers
- Occurs in labile or stable tissues
- Caused by increased functional demand or hormonal stimulation
- Remains under physiological control and is reversible
- Can occur secondary to a pathological cause, but the proliferation itself is a normal response
Examples of Physiological and Pathological Hyperplasia
- Physiological: uterine growth during pregnancy, muscle growth in response to exercise
- Pathological: breast tissue growth in response to hormonal stimulation, prostate growth in response to androgens
Hypertrophy
- Increase in tissue or organ size due to increased cell size
- Occurs in labile, stable, and especially permanent tissues
- Caused by increased functional demand or hormonal stimulation
- Cells contain more structural components, sharing workload with a greater mass of cellular components
Examples of Physiological and Pathological Hypertrophy
- Physiological: muscle growth in response to exercise, heart muscle growth in response to increased blood pressure
- Pathological: cardiac hypertrophy in response to chronic hypertension, kidney hypertrophy in response to diabetes
Atrophy
- Shrinkage of a tissue or organ due to an acquired decrease in size and/or number of cells
- Cells shrink to a size at which survival is still possible
- Reduced structural components of the cell and cell function
- May eventually result in cell death
Examples of Physiological and Pathological Atrophy
- Physiological: uterine atrophy after childbirth, muscle atrophy after disuse
- Pathological: muscle atrophy after denervation, skin atrophy due to peripheral vascular disease
Metaplasia
- Reversible change of one differentiated cell type to another
- May represent adaptive substitution of cells that are sensitive to stress by cell types better able to withstand the adverse environment
- Metaplastic cells are fully differentiated and the process is reversible
Examples of Metaplasia
- Barrett's epithelium and oesophageal adenocarcinoma
- Intestinal metaplasia of the stomach and gastric adenocarcinoma
Cell Proliferation
- Controlled by chemical signals from the microenvironment
- Signals stimulate or inhibit cell proliferation
- Receptors are usually in the cell membrane, but can be in the cytoplasm or nucleus
Cell Cycle
- Mitosis: nuclear division
- Cytokinesis: cell division
- Checkpoints: restriction (R) point, most critical checkpoint
- Cell cycle can be controlled by cyclins and cyclin-dependent kinases (CDKs)
Cell Growth and Differentiation
- Proliferation: increase in cell numbers
- Growth: increase in cell size
- Differentiation: acquiring a specific morphology and function
Cell Regeneration
- Regeneration: the ability to replace cells or tissues, destroyed by injury or disease (identical functionality)
- Labile cells: high regenerative ability and turnover
- Occurs only in labile or stable cell types
- Involves expression of a new genetic programme
Aplasia and Hypoplasia
- Aplasia: complete failure of a specific tissue or organ to develop
- Hypoplasia: underdevelopment or incomplete development of tissue or organ at the embryonic stage
- Examples: thymic aplasia, aplasia of a kidney, renal hypoplasia, breast hypoplasia
Involution and Reconstruction
- Involution: normal programmed shrinkage of an organ
- Examples: uterus after childbirth, thymus in early life, pro and mesonephros
- Reconstruction: replacement of a lost part of the body
- Examples: angiogenesis, replantation of a severed limb
Atresia and Dysplasia
- Atresia: no orifice, congenital imperforation of an opening
- Examples: pulmonary valve atresia, anal atresia, vaginal atresia
- Dysplasia: abnormal maturation of cells within a tissue
- Potentially reversible
- Often pre-cancerous condition
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers different types of cells, including stable and permanent cells, and how cells adapt through various mechanisms such as hyperplasia, hypertrophy, atrophy, and metaplasia.
