Cell adaptation and Injury

Prelim exam med histo lab

Capability of cell to adjust their structure and functions in response to various physiological and pathological conditions

Cellular Adaptation

What is cellular adpaptation

Capability of cell to adjust their structure and functions in response to various physiological and pathological conditions.

2 types of stress in normal cell

1. Physiological

2. Pathological

In Physiological has =

In Pathological has =

• cell adaptation

• cell injurt

Cell adaptation includes (6)

• Atrophy

• Hypertrophy

• Hyperplasia

• Metaplasia

• Aplasia

• Hypoplasia

Cell injury can be:

• Reversible

• Irreversible

In cell injury, Irreversible undergoes cell deaths (Give the 3 types of cell death)

• Apoptosis

• Necrosis

• Autolysis

• It is a decrease in organ size

• Decrease number of cells via apoptosis

• Decrease in cell size by ubiquitin - proteosome degradarion of cytoskeleton and autophagy of cellular components

Atrophy

Atrophy

• It is a ___ in organ size

• Decrease number of cells via ____

• Decrease in cell size by ___ - ____ degradation of ____ and ____ of cellular components

• decrease

• apoptosis

• ubiquitin

• proteosome, cytoskeleton

• autophagy

2 types of Atrophy

• Physiologic atrophy

• Pathologic atrophy

It occurs in early development.

ex. Thymus gland undergoes ____ atrophy during childhood

Physiologic Atrophy

It occurs as a result of decreases in workload, use, pressure, blood, supply, nutrition, hormonal and nervous stimulation.

Pathologic Atrophy

Physiologic Atrophy

It occurs in ___ development.

ex. ____ gland undergoes physiologic atrophy during ___.

Pathologic Atrophy

It occurs as a result of ___ in workload, use, pressure, blood, supply, nutrition, hormonal and nervous stimulation.

• early, thymus, childhood

• decreases

• An increase in the size of the cells & consequently in the size of the affected organ.

• It involve gene activation, protein synthesis, and production of organelles.

Hypertrophy

Hypertrophy

• An ____ in the size of the cells & consequently in the size of the ___ organ.

• It involve gene activation, protein synthesis, and production of organelles.

• increase, affected

hypertrophy means the cells of the uterus become larger during ___

pregnancy

During pregnancy, __ and __ generally occur together

Hypertrophy and Hyperplasia

Hypertrophy

During pregnancy (patho or physio)

physiology

Hypertrophy

Hypertrophic cardiomyopathy (physio or path)

pathologic

2 ex. of hypertrophy

1. Pregnancy

2. hypertension (cardiomyopathy)

Hypertrophy

• heart is secondary to ____

• Cardiac ___ undergo hypertrophy in response to systematic hypertension

• hypertension

• myocytes

• an increase in the number of cells resulting from an increased rate of cellular division.

• It involves production of new cells from stem cells

Hyperplasia

Two types of Physiologic/ normal hyperplasia:

1. Hormonal

2. Compensatory

It occurs chiefly in estrogen dependent organs such as uterus and breast due to proliferation of the glandular epithelium of the female breast at puberty and during pregnancy.

Hormonal hyperplasia

It is an adaptive mechanism that enables certain organ to regenerate.

Compensatory hyperplasia

What is this Hormonal or Compensatory

ex. removal of part of the liver leads to hyperplasia of the remaining liver cells to ___ for the loss.

Compensatory

compensate

It is an abnormal proliferation of normal cells and can occur as a response to excessive hormonal stimulation or the effects of growth factors on target cells.

Pathologic hyperplasia

It causes excessive mentrual bleeding, is under the influence of regular growth-inhibition control. If these controls fail, hyperplastic endometrial cells can undergo malignant transformation

Pathologic hyperplasia

What disease causes of excessive mentrual bleeding and what type of hyperplasia is this?

Endometrial Hyperplasia

Pathologic

Give the 3 characteristics of Hyperplastic cells

1. Pronounced (noticeable) nuclear enlargement

2. clumping chromatin

3. more enlarged nucleoli

Normal cells may become cancer cells (steps)

Normal - Hyperplasia - Dysplasia - Cancer

• It is a reversible replacement of one mature cell by another, sometimes less differentiated.

• a change in stress on an organ leads to a change on cell type

Metaplasia

What cells are better able to handle new stress?

• most commonly involves change of one type of surface ___ (squamous, columnar, urethelial) to another.

Metaplastic cells

• epithelium

Under persistent stress metaplasia can progress can lead to ___

dysplasia

Metaplasia ex. is replacement of normal columnar ciliated epithelial cells of the ___ (airway) lining by ___ ___ ___ cells.

• bronchial

• stratified squamous epithelial cells

Classic example of metaplasia, a disease usually caused by long-term acid reflux or GERD.

Barett esophagus

What deficiency can result to metaplasia

Vitamin A deficiency

Vit A is necessary for differentiation of specialized epithelial surfaces such as the ___ covering the eye

conjuctiva

In vitamin A deficiency the thin squamous lining of the conjuctiva undergoes metaplasia into stratified keratining squamous epithelium known as ___

Keratomalacia

Mesenchymal CT can also undergo metaplasia. It is a muscle tissue changes to bone during healing after traums

Myositis ossificans

A failure of cell production

Aplasia

The failure of an organ or tissue to develop or to function normally.

• During fetal development aplasia results in __, or absence of an organ due to failure of production.

• Late in life, it can be caused by permanent loss of precursor cells in proliferation tissues, such as ___ ___.

• agenesis

• bone marrow

Ex. of Aplasia disease

Aplasia cutis congenita

on the scalp (most common location) shortly after birth. Its like butas in puyoo

Aplasia cutis congenita

• It is a decrease in cell production that is less extreme than in aplasia.

• It is seen in partial lack of growth and maturation of gonadal structures in Turner syndrome and Klinefelter syndrome

Hypoplasia

Missing and X chromosome on 23 pair (in female)

Turner syndrome

genetic condition in males where there is an extra X chromosome.

Klinefelter syndrome

Klinefelter syndrome:

Normal male: 46, XY
Klinefelter syndrome: 47, _ _ _

Turner syndrome:

Normal female: 46, XX
Classic Turner syndrome: 45, _

• XXY

• X

Hypoplasia

• It is a decrease in cell production that is less extreme than in aplasia.

• It is seen in partial lack of __ and __ of gonadal structures in Turner syndrome and Klinefelter syndrome

• growth

• maturation