Pathology: cells and cell death

Question 0

Necrosis

Answer 0

exogenously induced cell death due to irreversible cell injury caused by toxins anoxia, etc.

1. Coagulative necrosis: Most common, happens when cell proteins are altered or denatured, rapid inactivation of cytoplasmic hydrolytic enzymes which prevents lysis of tissue
2. Liquefactive necrosis: Dead cells liquefy under the influence of certain enzymes, mostly seen in the brain. Coagulative necrosis may liquefy, secondary liquefaction
3. Caseous necrosis: typically found in tuberculosis/fungal infection, center of a tuberculous granuloma becomes necrotic and the cell becomes cheesy, yellow-white
4. Fat necrosis: special form of liquefactive necrosis limited to fat tissue especially around the pancreas caused by the action of lipolytic enzymes. Pancreatic enzymes reliease into the fat tissue degrade fat into glycerol and free fatty acid

Question 1

Apoptosis

Answer 1

endogenously (from within) programmed cell death
Required ATP, genes and enzymes
Initial event can be endogenous or exogenous
Affect single cell
Lack of apoptosis may cause pathology
Webb of hands and feet, menstruation

Question 2

Gangrene

Answer 2

Dead tissue

Necrotic tissue can undergo secondary changes such as calcification

Question 3

Diagnosis

Answer 3

Identification of a specific disease through evaluation of signs, symptoms, lab findings

Question 4

Etiology

Answer 4

The causative factors in a particular disease, e.g. congenital, virus, malignancy

Question 5

Idiopathic

Answer 5

the cause is unkonw

Question 6

latrogenic

Answer 6

caused by treatment, procedure, error

Question 7

pathogenesis

Answer 7

the development of the disease or the sequence of events involved in the specific disease process

Question 8

Onset

Answer 8

Acute- sudden and obvious, short term
Gradual - milder conditions, developing over time
Insidious - gradual progress with vague or mild signs

Question 9

Manifestations

Answer 9

the clinical evidence or effects
signs - objective indicators
symptoms - subjective indicators

Question 10

Syndrome

Answer 10

collection of signs and symptoms that usually occurs together in response to a certain condition

Question 11

Complications

Answer 11

secondary or additional problems that arise after the original disease begins

Question 12

Prognosis

Answer 12

the probability or likelihood for recovery

Question 13

Communicable

Answer 13

infections that can be spread from one person to another

Question 14

Contatious

Answer 14

easily transmittable

Question 15

contamination

Answer 15

in any health care setting, hand hygiene after patient contact can do more than any other intervention to limit the spread of pathogenic microorganisms

Question 16

Cell structure and function

Answer 16

Plasma membrane
Nucleus
Cytoplasm
cytosol
organelles

Question 17

Plasma membrane

Answer 17

• outer surface of the cell, consists of a lipid bilayer
• Membrane proteins functions as cannel, carriers, receptors, ligands, enzymes, linkers, identity markers.
• require active expenditure of energy
• selectively permeable
• integrity is a prerequisite for the maintenance of all essential cellular functions
• rupture or damage that can not be repaired inevitable leades to cell death

Question 18

Cytoplasm

Answer 18

• consists of cytosol, organelles, cytoskeleton
• volume of cytoplasm varies
• N: C Ratio Nucleocytoplasmic ratio - higher in undifferentiated adult cells, fetal cells, tumour cells

Question 19

Cellular organelles

Answer 19

Nucleus
Mitochondria
Ribosomes
Endoplasmic reticulum
Golgi complex
Lysosomes

Question 20

Necleus

Answer 20

Essential part of most human cells
Separated from the rest of the cell by nuclear membrane
Consists of DNA organized into chromatin
Condenses into Chromosomes during cell division
Blue print for protein synthesis

Question 21

Mitochondria

Answer 21

Double membrane involved in cellular energy production
Energy demanding cells (liver, nerve) are mitochondrial rich
Undifferentiated cells, including may malignant tumour cells have few mitochondria

Question 22

Ribosomes

Answer 22

Small RNA granules found free floating or on RER
Involved in protein synthesis
Proteins for internal purposes - free ribosommes
Export or luxury proteins - RER

Question 23

Endoplasmic Retinulum

Answer 23

Meshwork of membranes continuous with plasma membrane and nuclear membrane
Rough ER involved in protein synthesis, studded with ribosomes.
Smooth ER involved in catabolism of drugs, hormones, nutrients doesn’t contain ribosomes

Question 24

Golgi apparatus

Answer 24

Adjacent to nucles Composed of membrane bound cisternas Biochemically modifies, sorts and packages

Question 25

Lysosome

Answer 25

``` Membrane bound digestive organelle Rich in lytic enzymes Fused with vesicles to digest material E.g. worn out structures, bacteria, etc Can release its content into the cell to lyse cell ```

Question 26

Cell projectsion

Answer 26

``` passive projections Microvilli (e.g. intestine) do not require ATP, function to increase the surface are of the cell Active projections Require ATP (expenditure of energy) 1. Cilia 2. Flagella ```

Question 27

Integration

Answer 27

1. Autocrine stimulation - cell secretes substance that stimulate itself, simplest form 2. Paracrine stimulation - cell secretes a substance that stimulates a nearby cell 3. Endocrine stimulation - cell releases a substance into the bloodstream that is then able to stimulation a fa way cell. Highest form of integration of cell function, can involve cells of anatomically distinct organs

Question 28

Causes of cell injury

Answer 28

Hypoxia, ischemia, anoxia Physical agents (temp/vibration/radiation) Mechanical damage (trauma) Abnormal metabolite accumulation Fluid or electrolyte imbalance Chemicals Microbiological agents (bacteria/viruses) Immunological reactions (autoimmune/host cells) Genetic defects Nutritional imbalances Aging

Question 29

cellular response to injury

Answer 29

Reversible : within range of homeostasis, membrane left relatively intact. Mitochondria able to sustain energy demands Irreversible: accumulation of amorphous, Ca-rich densities in the mitochondrial matrix extensive plasma membrane damage Lysosomal swell Nuclear change, Decrease energy production, metabolism, in ph

Question 30

Atrophy

Answer 30

Decrease in the size of cels resulting in reduced tissue mass, can be caused by poor nutrition, again, immobility

Question 31

Hypertrophy

Answer 31

increase in the size of individual cells resulting in enlarged tissue mass, can be due to extra work on the tissue Working out striated muscle, cardiovascular diseases - cardiac muscle

Question 32

Hyperplasia

Answer 32

increased number of cells resulting in enlarged tissue mass, can occur in conjunction with hypertrophy - endometrial thickening of the uterus

Question 33

Metaplasia

Answer 33

occurs when one mature cell type is replaced by a different mature cell type: e.g. in smokers, ciliated columnar epithelia of the respiratory tract changes to stratified squamous epithelia

Question 34

Dysplasia

Answer 34

cells of a tissue vary in size and shape, large nuclei area present and the rate of mitosis increases, may indicate a precancerous state

Question 35

Intercellular accumulations

Answer 35

May occur as a result of an overload of various metabolites or exogenous material or may be due to prevention of excretion of metabolic byproducts or normal secretions Black lung - accumulation of coal particles Fatty liver - damage to liver cells, causes decrease in lipoprotein production, therefore an increase in lipid storage