Pathophysiology key points

Health definition

This is a state of complete physical, mental and social well-being. Not just the absence of disease or illness.

Disease

Disease is referred to as the aberrant manifestation of deregulated homeostasis caused by harmful factors

Subhealth definition

This is a situation in which a person does not show specific symptoms and sign, but lives a low quality of both mental and physical health

Indicators of brain death

This is the irreversible loss of all brain and brainstem function

1. Unresponsiveness

2. Absence of brainstem reflexes

3. Apnea

4. No motor response

5. Exclusion of reversible causes

Hypertonic dehydration mechanism

This occurs when water loss is greater than sodium loss leading to increased plasma, osmolarity and hypernatremia

1. Excessive water loss

2. Rise in plasmasodium concentration

3. Increase in extra cellular fluid osmolarity

4. Shift of water from ICF to ECF

5. Decrease in intracellular fluid volume

6. Overall, volume depletion

Hypotonic dehydration mechanism

This occur when sodium loss is greater than water loss leading to decrease plasma osmolality and hyponatremia

1. Excessive sodium loss

2. Decrease in plasma sodium concentration

3. Decrease in extra cellular fluid osmolarity

4. Shift of water from ECF to ICF

5. Cellular swelling

6. Decrease in ECF volume

Manifestation of two kinds of dehydration: Hypertonic dehydration

Thirst

Dry mouth and mucous membranes

Weight los

Concentrated urine

Cells shrink

Neurological symptoms due to cell shrinkage

Hypotonic dehydration

Less thirst

Dry skin and mucous membrane

Weak pulse

Dizziness

Muscle cramps

Hyperkalemia

This is a condition in which the serum postassium level is more than 5.5mol/L

Hypokalemia

This is a condition in which the serum potassium is less than 3.5mol/L

Mechanism of edema

1. Increased capillary, hydrostatic pressure

2. Decreased plasma, oncotic pressure

3. Increased capillary permeability

4. Impaired lymph flow

5. Sodium and water retention

Main buffer system

1. Bicarbonate buffer system

2. Plasma protein buffer system

3. Phosphate buffer system

4. Hemoglobin and oxyhemoglobin buffer system

Types of acid based imbalance

Metabolic acidosis- AG change

Occurs due to bicarbonate loss with compensating chloride increase

Types of metabolic acidosis

1. High AG metabolic acidosis mechanism:

   accumulation of unmeasured acids

   H+ is buffered

   Conjugate anions remains

   CAUSES: KULT DUMP

2. Normal AG metabolic acidosis mechanisms:

   loss of bicarbonate

   no accumulation of acids

   CAUSES: Diarrhea, renal tubular acidosis, early renal failure

Difference of metabolic acidosis and respiratory acidosis

1. Metabolic acidosis has low bicarbonate, Respiratory acidosis has high carbon dioxide

2. Metabolic has low pH, respiratory has low pH

3. Metabolic involves the kidney, respiratory involves the lungs

4. Metabolic acidosis is caused by acid accumulation, respiratory acidosis is caused by hyperventilation

5. Metabolic acidosis’s breathing pattern is rapid and deep, respiratory acidosis is low and shallow

6. Onset of metabolic acidosis is rapid, respiratory is acute or chronic

Hypoxia

This is the reduction of oxygen supply or cellular oxygen consumption in one or more tissues

Cyanosis

This the a bluish discoloration of the skin, lips and nail beds and mucous membranes due to increased of concentration of deoxygenated hemoglobin in the blood

Enterogenous cyanosis

This is the type of cyanosis caused by methemoglobinemia resulting from the intestinal production and absorption of nitrites which convert hemoglobin to methemoglobin

Skin color

Pale- Anemia

Cherry red- carboxyhemoglobin

Scarlet-increased hemoglobin affinity

Coffee- Methemoglobinemia

4 types of hypoxia

Hypotonic

Hemic hypoxia

Circulatory hypoxia

Histotoxic hypoxia