principels of pathophysiology

pathology

study of how diseases effect the function of the body

cell memebrane

protects and selectively allows water and other substances in and out of the cell

mitochondria

converts glucose and other nutrients into ATP

no ATP

cells specialized structures cannot function

cell water balance

too little water = dehydration and cell dies

too much water = basic cellular functions interrupted

electrolytes and water

electrolyte levels in water impact electrical functions

glucose

building block for energy, supply of insulin must math glucose requirements

aerobic metabolism

cellular functions USING oxygen

anaerobic metabolism

cellular function NOT using oxygen, less energy more waste, body becomes acidic impairing many functions

ineffective cell membrane

allows in substances that shouldn’t be in the cell, can interfere with regulation of water

homeostasis

regulated in the brain, maintained through nervous system feedback, medulla and hypothalamus

parasympathetic system

part of autonomic, regulates digestive and reproductive systems, reduces heart rate and BP

sympathetic

fight or flight, epinephrine and norepinephrine, increases protective protocols, heart rate, and BP

cardiopulmonary system

cardiovascular + respiratory system,

beigne oxygen into the body, distributes cells, removes waste products.

airways obstructions

upper obstructions are most common, causes by forge in bodies, infection, or trauma

lungs (airway)

lower part of the airway,

tidal volume

volume of air moving in and out in each breath cycle

minute volume

tidal volume * respiratory rate

respiration dysfunctions

anything impacting the medulla can effect minute volume

distribution of pressure (in the lungs)

a hole in the chest wall can mess with the correct amount of pressure required to keep the lungs adhered to the chest wall

air/fluid may enter the pleural space

alveoli

exchanges gases

hypoxia

low O2 levels

hypercarpia

high CO2 levels

chemo receptors

detect changing oxygen and carbon dioxide levels

Plasma oncotic pressure

Proteins in plasma attract water away from are around cells and pull it into bloodstream.

• Problems with these proteins can cause an imbalance.

Hydrostatic pressure

Water pushed back out of blood vessels toward cells.

Blood Dysfunction

Without enough blood, oxygen and carbon dioxide cannot be properly moved around.
Where gas exchange takes place
Returns blood to lungs via heart for gas exchange

Blood Vessels pressure

Need adequate pressure to make cycle work
• Pressure controlled by changing diameter of blood vessels
• Stretch receptors monitor pressure

Loss of Tone

Vessels lose ability to constrict and dilate.
– Pressure drops

Excessive permeability

Capillaries leak fluid out their walls.
– Caused by severe infection (sepsis), high altitude, and
certain diseases

Hypertension

Systemic vascular resistance (SVR)
▪ Pressure inside vessels

Loss of regulation in blood vessles

Chemical messengers tell blood vessels when to dilate and constrict

if signals are blocked, lack of sympathetic response can cause shock

average stroke volume

70mL blood output per contraction 

Stroke volume is based on

Preload
▪ Amount of blood returning to heart
– Contractility
▪ How hard heart squeezes
– Afterload
▪ Pressure the heart has to pump against to force
blood out into the system

cardiac output

stroke volume * beats per minute

V/Q match

Must be a balance between ventilation (V) and perfusion (Q) for system to work properly

can be disrupted by any challenge to the
cardiopulmonary system

4 categories of shock

Hypovolemic – low blood volume
• Distributive – low blood vessel tone
• Cardiogenic – heart fails to pump
• Obstructive – blood cannot flow

Body is 60 percent water.

Intracellular (70 percent)
– Intravascular (5 percent)
– Interstitial (25 percent)

fluid balance 

Brain and kidneys regulate thirst and elimination of
excess fluid
• Blood plasma proteins pull fluid into the bloodstream