L2: Cellular adaptation & degeneration Flashcards
Developmental abnormalities of cell growth
Occurs due to defective fetal development in uterus.
They manifest at birth or shortly after.
Either hereditary or congenital.
What are the causes of developmental abdnormalities of cell growth?
Hereditary abnormalities:• Inherited from the parents. e.g. Genetic disease
Congenital abnormalities:• Due to affection of the normal fertilized ovum by adverse factors as infection, chemicals, irradiation or an increased maternal age.
What are the congenital disorders of cell growth?
Agenesis Aplasia Hypoplasia Atresia Heterotobia(choristoma) Hamartoma
What is agenesis?
Congenital absence of an organ e.g. solitary kidney.
What is aplasia?
The organ is represented by a rudimentary structure
What is hypoplasia?
The organ is a normal structure but fails to reach adult size e.g. kidney.
What is atresia?
- Absence of a normal opening
* Failure of canalization of hollow organ e.g. intestine
What is Heterotobia(choristoma)?
• Presence of normal tissue in abnormal sites
• e.g pancreatic tissue in stomach or thyroid tissue in
the base of the tongue.
What is hamartoma?
• Formation of a mass of mature tissue of the locality, but in abnormal arrangement or quantity as pigmented nevi.
What are the cellular adaptations to stress?
Reversible changes in the number, size, phenotype, metabolic activity, or functions of cells.
What are the types of cellular adaptations to stress?
Physiologic adaptations:-
In response to normal stimulation e.g. by hormones
Pathologic adaptations:-
In responses to stress
What are acquired disorders of growth?
1- Atrophy 2- Hypertrophy 3- Hyperplasia 4- Metaplasia 5- Dysplasia
What is the definition of atrophy?
Decrease in organ size by decrease in size and/or the number of its cells.
What is the classification of atrophy?
Physiological and pathological
What are the types of physiological atrophy?
- General (Senile): It is an aging process.
- Local: Involution of an organ due to loss of its physiologic function. and its causes are (After labor: ↓ uterus, After child weaning: ↓ breast size)
What are the types and causes of pathological atrophy?
-General (Senile)
-Causes
Starvation.
Toxic.
Hormonal.
Local
-Causes Disuse Atrophy. Neurogenic atrophy. Ischemic atrophy. Pressure atrophy. Thermal.
What is the gross morphology of atrophy?
General Atrophy All organs are affected to a variable extent: 1. Skin is wrinkled 2. Loss of fat of adipose tissue 3. Wasting especially of liver, muscles 4. Brown atrophy of heart.
Local Atrophy
The organ is decreased in size and weight.
What is the microscopic morphology of atrophy?
1- Reduction of cytoplasmic mass.
2- The nucleus is apparently normal.
3- Spaces created by atrophied cells are occupied by fibrous tissue or fat.
What is hypertrophy?
Increase in organ size due to increase in the size of its constituent cells.
What is the classification of hypertrophy?
Pathological and physiological
What are examples of physiological hypertrophy?
➢ In response to hormones: Smooth muscles of the pregnant uterus.
➢ Excess functional demand: skeletal muscles in manual workers and
athletes.
What are examples of pathological hypertrophy?
Hormonal:
- Occurs with an excess growth hormone of the anterior pituitary, leading to gigantism and acromegaly.
Excess functional demand:
1- To overcome distal resistance: in hollow organs
2- Compensatory hypertrophy: in paired organs.