Path 1: cell pathology

Almost all cells in human body have the same basic components:

1. Plasma membrane

2. Nucleus

3. Cytoplasm (mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, cytoskeleton)

Nucleus is the essential part of most living cells except:

RBC and platelets

Contains genetic material which consists of genes

DNA

Based on gene expression cells are:

Differentiated and undifferentiated

Differentiated cells

Muscle cells, liver cells etc

Stem cells

undiffrentiated cells

The balance between ______________ and ____________________ change in pathological conditions

Cellular fluid; structure in cytoplasm

Cytoplasm consists of:

1. hyaloplasm (matrix)

2. Cytoplasmic organelles

What are in the hyaloplasm (matrix)?

Biochemically: H2O, minerals, proteins, lipids, carbohydrates

Cytoskeleton: fibril meshwork

What are principle organelles found in cytoplasm?

Mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes

Mitochondria

-surrounded by double membrane

-have cristae (fold in inner membrane)

-full of oxidative enzymes

-generate energy —> ATP

What kind of cell are rich in mitochondria?

Cells with complex functions: liver, kidneys

What cells have few mitochondria?

Undifferentiated cells - tumors

Small granules composed of RNA

Ribosomes

Synthesis of proteins for internal purpose

Free ribosomes "polysomes"

Meshwork of membranes with attached ribosomes

Rough ER

What are the function of Rough ER?

Synthesis of proteins for export and secretion (liver cells produce albumins and clotting factors)

What are the functions of Smooth ER?

1. Catabolism: metabolic degradation of drugs, hormones, and nutrients

2. Synthesis of steroid hormones

Smooth ER is prominent in:

Liver, adrenal cells, leydig cells

Protein synthesized in ER pass through ________________

Golgi apparatus

What is the function of Golgi apparatus?

Modify and pack proteins into secretory granules

Lysosomes

Digestive organelles which are rich in lytic enzymes

contain inactive digestive enzymes

Primary lysosomes

In neutral pH, lysosomal enzymes are:

tightly enclosed by membrane—-> do not harm the cell

In acidic environments (cell injury cause cytoplasm pH become acid, lysosomal enzymes are:

released———> may cause cell damage

What are secondary lysosomes?

Heterophagosomes and autophagosomes

Heterophagosomes

Transport final product of digestion into Cytosol (cell reused it)

Secondary lysosomes that are involved in the digestion of a cell's own organelles

Autophagosomes

Cytoskeleton consists of 3 types of filaments:

microtubules, microfilaments, intermediate filaments

Composed of tubulin

Microtubules

Composed of actin and myosin

Microfilaments

Composed of cell-specific proteins

Intermediate filaments

Tumor cells retain the same ______________ as the normal cells from which they arise—-> pathologist use tests to diagnose a type of tumor (epithelial, muscle, bone origin)

Intermediate filaments

Rupture of cell membrane leads to:

Cell death

State of balance between opposing pressure operating in and around a cell or tissue state of equilibrium

Homeostasis

Equilibrium between cells and their envrionment

Steady state

If demands exceed the capacity of the cell to adapt to disequilibrium it cannot return to original state and lead to:

Cell injury and/or cell death

The increased or decreased functional adaptations are ____________

Reversible

If response passes beyond the point of no return, the cell injury becomes ____________

irreversible

The range of the steady state is determined by:

The reactivity of each cell and the ability of the cells to respond to increased demands or stimuli