General Pathology – Seminar 2

Necrosis

Atrophy - causes

Jaroslava Dušková

Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague

http://www1.lf1.cuni.cz/~jdusk/

Deathirreversible damage of the

morphological & functional integrity of

organism cells

Cell Death

apoptosis necrosis

Apoptosis induced (from outside) or genetically programmed cell

death

(cell execution / suicide)

logical and functional contrary to mitosis a system for the removal of unnecessary,

aged, or damaged cells

• Triggered by a wide range of stimuli.

• Cell surface receptors like Fas or

tumor necrosis factor receptor 1 (TNFR1).

• Interplay of proapoptotic (Bax, Bad, Bid, Bik,

and Bim) and antiapoptotic (Bcl-2 and Bcl-XL)

proteins

Apoptosis -1

ApoptosisMorphology

– chromatin condensation

– cell shrinkage– budding and forming of apoptotic bodies

(emission of pseudopodia)

– karyorrhexis (not pathognomonic for apoptosis)

ApoptosisMeaning

physiological process necessary for right organ formatting and life course

pathological process leading to organism damage - e.g. atrophy

ApoptosisOntogenesis

intestinal mucose, genit. tract, immune system - T lymphocytes

Regeneration of tissues and organs intestinal mucose, blood

Physiological involution neonatal adrenal cortex, thymus, breast after lactation period

Atrophy preassure, hyperplasia regression, slight ischemia

Necrosis

cell death caused from external insult

NecrosisBiochemistry

– no expression of genes de novo– energy dependent membrane

systems damaged hypoxia, toxins

– changes in concentrations of ions– increased water volume (oncosis)

– autolysis

NecrosisMorphology

– pyknosis, karyorhexis, karyolysis

– denaturation of proteins - eosinophilia

– cell swelling– cell budding (cytoplasmic protrusions)

NecrosisMeaning

pathological process

leading to a temporary

organism damage or death

Necrosis Classification according to the tissue macroscopy:

– simple– liquefaction– coagulation

+ special types: caseation, Zenker´s of waxy appearance

Necrosis - further development:

– no death of organism

– gangrene sicca (dry g.) humida (wet g.) emphysematosa (gas

g.)– demarcation, sequestration

regeneration repair

Necrosis - Causes:

chemical– chlorinated hydrocarbons, heavy metal

compounds, ethyl- alcohol, aphlatoxins, ... physical

– mechanical trauma, UV light, ionizing radiation, heat, cold, ….

biologic– bacteria, viruses, fungi...

Atrophy diminution of organ or tissue after full development has been attained (versus hypoplasia, aplasia) simple (x hypertrophy) numerical (x hyperplasia)

Atrophy - causes:

vascular pressure inactivity inanition neurogenic ionizing radiation

involution senile postinflammatory endocrine

unknown cause

Atrophy - meaning:

may be reversible loss of specialised structures

& hypofunctionclinically silent or unimportant

(involution)clinically apparent

metaplasia, increase of the supportive tissues - pseudohypertrophy