Cell Pathology

nucleus

DNA, RNA, proteins, ctrl center of cell, necessary for life

Cytoplasm

hyaloplasm (fluid), cytoskeleton (filament network). Provides shape, structure, movement, and space for cell division

Plasma membrane

internal layer enclosing cytoplasm, ER, has selective permeability. Outer layer other cells/environment, channels, receptors, communication, and uptake

mitochondria

energy supply, increased amount of this increases cellular energy

Endoplasmic Reticulum and Ribosomes

continuous with cell and nuclear membranes

Rough ER

contains ribosomes/RNA does protein synthesis and secretion

Smooth Er

metabolism and some hormone synthesis

Golgi apparatus

modifies and packages proteins from rER to be secreted

Lysosomes

Made by golgi for digestive phagocytic function

functions of cells

structure and support, growth, transportation, energy production, metabolism, reproduction, response to stimulation

homeostasis

state of balance between the environment and cells/tissues

what is needed for homeostasis?

oxygen, nutrients, water, essential minerals, excretion of wastes

causes of cell injury

hypoxia, anoxia, toxin exposure, microbial pathogens, genetic and metabolic disturbances, inflammation and immune reactions

reversible cell injuries (can return to homeostasis)

brief hypoxia or anoxia, hydropic change, reduced energy production, decreased protein synthesis, increase autophagocytosis

Irreversible cell injury (cannot return to homeostasis)

changes to nucleus that cause it to be non-viable, energy production by mitochondria is too low, ability or plasma membrane to regulate what comes in and out, enzyme damage

atrophy

adaptation for decreased cell size

hypertrophy

adaptation for increased cell size

hyperplasia

increased cell number

hypertrophy and hyperplasia

increased cell size and number

metaplasia

cell transformation of type

dysplasia

precursor to neoplasia

neoplasia

uncontrolled cell growth; cancer

anthracosis

accumulation of coal particles

hemosiderosis

accumulation of blood-derived brown pigment called hemosiderin

lipid

accumulation of lipids/fats

hypoxia

reduced oxygen

anoxia

complete lack of oxygen

toxin exposure

substances that are directly toxic or substances that become toxic when metabolized

microbial pathogens

bacteria, viruses, fungi, parasites

intra-cellular accumulations

overabundance of outside materials or internal metabolites, disturbs metabolism and results in build up and reduced excretion

Cellular aging

presents variably and results in atrophy and diminished function of cells, tissues, and organs

Wear and Tear hypothesis of cellular aging

cells eventually fail, especially those that cannot regenerate

Genetic hypothesis of cell aging

cells fail but the process and timing is different for every person

Autolysis

when an individual’s heartbeat and respiration ceases, the result is death of all cells and tissues

Necrosis

when something outside the cell results in irreversible cell injury and ultrimately cell death. Affects groups of cells and/or organs

Coagulative necrosis

most common necrosis, often the result of anoxia, results in loss of original shape and less solid structure; involves solid internal organs

liquefactive necrosis

primary or secondary state: primary occurs most often in the brain; tissues “dissolve” and become soft and liquefied. Solid tissue that is irreversibly damaged becomes necrotic, leukocytes start removing dead cells from the necrotic tissue, solid tissues are broken down and become pus

caseous necrosis

associated with tuberculosis and fungal infections: special form of necrosis where there are coagulative and limited liquefaction components

Enzymatic fat necrosis

form of liquefactive necrosis that is limited to fat tissue; often found in pancreas post trauma

wet gangrene

coagulative necrosis→ bacterial infection of necrotic tissue→ liquefactive necrosis (secondary)

dry gangrene

coagulative necrosis → bacterial infection of necrotic tissue → liquefactive necrosis → necrotic tissues dry out

calcification deposits

calcium salts are deposited within necrotic tissues, noticeable by imaging

apoptosis

internal cell signalling programmed to cause cell death, requires energy to occur and signalling from specific genes. Usually involves single cells and is regulated and timed

physiological apoptosis

part of development (tissue between fingers and toes that goes away)

pathologic apoptosis

cell death induced by endogenous factors such as poor genetic signaling (muscle atrophy) OR cell death induced by exogenous factors (immune resistance of organ transplants)

lack of apoptosis

when necessary, physiologic apoptosis does not occur it can result in congenital deformation of structures and in some cases a form of neoplasia and/or build up of inflammatory cells that should be disposed of

pathology

the science of causes and effects of disease

cell pathology

cells

histopathology

tissues

organ pathology

organs