Pathophysiology revision - SECTION 1: GENERAL PRINCIPLES

Cell membranes are composed of mainly proteins and phospholipids. Phospholipids Proteins Ion channels Lipids( Phospholipids, Proteins, Ion channels, Lipids ) have a glycerol backbone that is hydrophilic (water-loving) hydrophobic (water-hating) soluble( hydrophilic (water-loving), hydrophobic (water-hating), soluble ) and fatty acid tails which are hydrophobic (water-hating) hydrophillic (water-loving) soluble( hydrophobic (water-hating), hydrophillic (water-loving), soluble ). Proteins are embedded in the phospholipid bilayer and play an important role by forming ion channels fatty acid tails diffusion trails( ion channels, fatty acid tails, diffusion trails )

Two solutions with equal osmolarities are said to be iso-osmotic osmolaric bi-osmolar in aquatic equilibrium( iso-osmotic, osmolaric, bi-osmolar, in aquatic equilibrium ). If two solutions have different measures osmolarities, the solution with the higher osmolarity is said to be hyper-osmotic hypo-osmotic super-osmotic minor-osmotic( hyper-osmotic, hypo-osmotic, super-osmotic, minor-osmotic ) and that with lower osmolarity is said to be hypo-osmotic hyper-osmotic super-osmotic minor-osmotic( hypo-osmotic, hyper-osmotic, super-osmotic, minor-osmotic ).

An isotonic soloution will have no change in cell volume will cause cells to shrink will cause cells to swell( will have no change in cell volume, will cause cells to shrink, will cause cells to swell ). A hypertonic solution will cause cells to shrink will cause cells to swell will have no change in cell volume( will cause cells to shrink, will cause cells to swell, will have no change in cell volume ). A hypotonic solution will cause cells to swell will have no change in cell volume will cause cells to shrink( will cause cells to swell, will have no change in cell volume, will cause cells to shrink )

The process by which molecules can be moved from an area of low concentration to high is known as active transport diffusion osmosis Collapsing pressure( active transport, diffusion, osmosis, Collapsing pressure ). This uphill movement requires energy in the form of ATP a differential pressure a group of enzymes lipid molecules( energy in the form of ATP, a differential pressure, a group of enzymes, lipid molecules )

Water comprises of approximately 60% 70% 50% 40%( 60%, 70%, 50%, 40% ) of total body weight in males and 50% 60% 70% 80%( 50%, 60%, 70%, 80% ) in females. Obese individuals tend to have 25-30% 35-40% 15-20% 5-10%( 25-30%, 35-40%, 15-20%, 5-10% ) less body water and newborns will comprise of 75-80% 65-70% 55-60% 45-50%( 75-80%, 65-70%, 55-60%, 45-50% ) body water

Water in the body is divided into intracellular intramuscular intrafiberous intraglobular( intracellular, intramuscular, intrafiberous, intraglobular ) (first space), intravascular intracardiac intralunar intracirculatory( intravascular, intracardiac, intralunar, intracirculatory ) (second space) and extravascular extracirculatory extralumbar extrasynovial( extravascular, extracirculatory, extralumbar, extrasynovial ) (interstitial, third space) compartments. 40% 30% 20% 10%( 40%, 30%, 20%, 10% ) of total body water is found in the cells, 5% is found intravascular intracardiac intralunar intracirculatory( intravascular, intracardiac, intralunar, intracirculatory ) and 15% 20% 25% 10%( 15%, 20%, 25%, 10% ) is contained in the interstitiam

One law which relates best to the movement of fluids through the capillaries is Starling’s Law Boyle's Law La Places' Law Charles' Law( Starling’s Law, Boyle's Law, La Places' Law, Charles' Law ). This explains the distribution of fluids from a high pressure to a low pressure

0.9% Saline 25% saline 5% dextrose tap water( 0.9% Saline, 25% saline, 5% dextrose, tap water ) and Ringer’s Lactate 25% saline 5% dextrose tap water( Ringer’s Lactate, 25% saline, 5% dextrose, tap water ) are both considered to be istonic solutions and used to provide immediate expansion of circulatory volume. However, because of their tonicity, they will eventually distribute into the third space therefore, expanding interstitial intracellular intravascular( interstitial, intracellular, intravascular ) rather than intravascular interstitial intracellular( intravascular, interstitial, intracellular ) volume. 5% dextrose 0.9% saline 25% saline Ringer's Lactate( 5% dextrose, 0.9% saline, 25% saline, Ringer's Lactate ) is considered a hypotonic solution and can be used to keep a cannulated vein open.

Colloid solutions include 5% and 25% albumin and hetastarch. They are used to increase plasma volume increase glucose concentration decrease lactate decrease extracellular pressure( increase plasma volume, increase glucose concentration, decrease lactate, decrease extracellular pressure ) in the blood vessels as the large molecules can not pass through membranes as easily as crystalloids

The partial pressure of Oxygen (P02) roughly 100 mmHg 80 mmHg 50 mmHg 40 mmHg( 100 mmHg, 80 mmHg, 50 mmHg, 40 mmHg ) in the atmosphere and 40mmHg 30 mmHg 50 mmHg 20 mmHg( 40mmHg, 30 mmHg, 50 mmHg, 20 mmHg ) in the pulmonary arties. The partial pressure of Carbon Dioxide (PC02) in the atmosphere is roughly 40mmHg 50 mmHg 30 mmHg 20 mmHg( 40mmHg, 50 mmHg, 30 mmHg, 20 mmHg ) and 45mmHg 55 mmHg 35 mmHg 50 mmHg( 45mmHg, 55 mmHg, 35 mmHg, 50 mmHg ) in the pulmonary arteries coming from the right ventricle. Hence, oxygen is diffused into the returning pulmonary vein and carbon dioxide diffuses out into the atmosphere

Oxygen is normally carried around the body bound to haemoglobin fatty cells protine molecules macrophages( haemoglobin, fatty cells, protine molecules, macrophages ). The percent saturation (SP02) haemosaturated pressure gradient red blood cell count fluid distribution curve( percent saturation (SP02), haemosaturated pressure gradient, red blood cell count, fluid distribution curve ) describes the amount of oxygen molecules bound to haemoglobin

A shifting of the oxygen dissociation curve to the right left upwards segment downwards segment( right, left, upwards segment, downwards segment ) decreases haemoglobin’s affinity for oxygen. This makes it easier for haemoglobin to release oxygen but may lead to hypoxia due to the molecule being less willing to carry it. Acidotic patients have curves shifted to the right as a “protective” mechanism, so the body can offload O2 rapidly when it needs (Bohr Effect). This also effects people at high altitude

A shifting of the oxygen dissociation curve to the left right upwards gradient downwards gradient( left, right, upwards gradient, downwards gradient ) increases haemoglobins affinity for oxygen. Examples of this include carbon monoxide poisoning, increase in PH and decrease in temperature

CO2 is transported to the lungs by plasma lipids proteins active transport( plasma, lipids, proteins, active transport ) and red blood cells white blood cells macrophages free floating lipids( red blood cells, white blood cells, macrophages, free floating lipids ) via the bicarbonate buffer system. C02 is transformed into bicarbonate by the carbonic anhydrase enzyme

The autonomic nervous system has three essential divisions which are the sympathetic symphonic adregenic systemic( sympathetic, symphonic, adregenic, systemic ), parasympathetic parasymphonic parametabolic paranervous( parasympathetic, parasymphonic, parametabolic, paranervous ) and enteric enerdrenic energetic enertonic( enteric, enerdrenic, energetic, enertonic ) systems. These all control and regulate cardiac muscle, smooth musle and various glands.

In the autonomic nervous system, the neurons from each division connect outside the central nervous system in cell clusters known as ganglia gang junctions neuronic junctions central nervous buffers( ganglia, gang junctions, neuronic junctions, central nervous buffers )

Ganglia which are located in the innervated organs; neurons exiting from the craniosacral division; pre-ganglionic neurons being longer than post-ganglionic nerons – all describe the parasympathetic sympathetic enteric( parasympathetic, sympathetic, enteric ) nervous system

Ganglia which are located closer to the spinal chord; neurons which leave the CNS at the thoracolumbar division; pre-ganglionic neurons being shorter than post-ganglionic neurons – all describe the sympathetic parasympathetic enteric( sympathetic, parasympathetic, enteric ) nervous system

Neurotransmitters function as chemical bridges to relay signals from neuron to neuron . In both sympathetic and parasympathetic divisions, the major neurotransmitter is acetylcholine epinephrine cortisol glutamate( acetylcholine, epinephrine, cortisol, glutamate ). In postganglionic fibres leading to innervated tissue, acetylcholine epinephrine norepinephrine seratonin( acetylcholine, epinephrine, norepinephrine, seratonin ) acts as the main neurotransmitter for the parasympathetic system while norepinephrine epinephrine acetylcholine seratonnin( norepinephrine, epinephrine, acetylcholine, seratonnin ) is released in the sympathetic system.

In pre-hospital care, many of the medications administered work at the receptor level of the sympathetic and parasympathetic divisions of the autonomic nervous system. These receptors are either ADRENERGIC which include Alfa and Beta receptors or CHOLINERGIC which include nicotinic and muscarinic receptors.

Alpha-1 Alpha-2( Alpha-1, Alpha-2 ) and Beta-1 Beta-2( Beta-1, Beta-2 ) receptors produce an excitatory response.

Alfa-1 Alfa-2( Alfa-1, Alfa-2 ) and Beta-1 Beta-2( Beta-1, Beta-2 ) receptors usually produce an inhibitory/relaxing response.

Alfa-1 Alfa-2 Beta-1 Beta-2( Alfa-1, Alfa-2, Beta-1, Beta-2 ) receptors are usually located on smooth muscle and are sensitive to norepinephrine and epinephrine

Alfa-1 Alfa-2 Beta-1 Beta-2( Alfa-1, Alfa-2, Beta-1, Beta-2 ) receproes are usually located in smooth muscle as well as in platelets and fat cells

Alfa-1 Alfa-2 Beta-1 Beta-2( Alfa-1, Alfa-2, Beta-1, Beta-2 ) receptors are located primarily in the heart

Alfa-1 Alfa-2 Beta-1 Beta-2( Alfa-1, Alfa-2, Beta-1, Beta-2 ) receptors are located in vascular smooth muscle, gastrointestinal tract and bronchial smooth muscle

Nicotonic Muscarinic( Nicotonic, Muscarinic ) receptors are found at the neurotransmitter junction and in autonomic ganglia. They allow the cells to exchange sodium and potassium and produce excitation when stimulated

Muscarinic Nicotonic( Muscarinic, Nicotonic ) receptors are located in the heart and smooth muscles. They cause an inhibitory response in the heart but an excitatory reponse in the smooth muscle

The study of pharmacokinetics attempts to define the dynamics of drug behaviour in the body. The biological fate of a drug after it has been administered depends on four essential processes which are defined as:

- The rate and quality of a drug that is introduced into the body (Absorbtion Quantification pharmalocation injestion( Absorbtion, Quantification, pharmalocation, injestion ))

- The movement or temporary storage of a drug (distribution movement placement deliverance( distribution, movement, placement, deliverance ))

- The process of chemical conversion of the original drug to metabolite (metabolism transformation conversion depletion( metabolism, transformation, conversion, depletion ))

- Removal of the drug from the body (elimination extraction vacation evacuation( elimination, extraction, vacation, evacuation ))

Solubility, rate of dissolution, presence of other drugs, obesity or anything which affects the gastrointestinal tract all effect the absorption distribution metabolism elimination( absorption, distribution, metabolism, elimination ) of drugs.

Blood flow, diffusion and active transport all rate to the distribution absorption metabolism elimination( distribution, absorption, metabolism, elimination ) of a drug.

The process by which most drugs are converted in the liver is the metabolism distribution absorption elimination( metabolism, distribution, absorption, elimination ) of a drug

The kidneys, lungs, liver and body fluids are all responsible for the elimination distribution metabolism absorption( elimination, distribution, metabolism, absorption ) of a drug.

The rate in which a drug is excreted from the body is known as its half life elimination time destruction segment split point( half life, elimination time, destruction segment, split point ). This is the amount of time it takes to remove 50% of the drug and generally 6 4 8 2( 6, 4, 8, 2 ) of these are required to remove 98% of the drug. 10 8 12 9( 10, 8, 12, 9 ) of these completely eliminate the drug

The amount of drug in systemic circulation is usually a fraction of the original dose – this is known as bioavailability half life drug dose percentage pharmainventory( bioavailability, half life, drug dose percentage, pharmainventory ). For drugs given IV, this is approximately 100% 90% 50% 40%( 100%, 90%, 50%, 40% ) and those given oraly depends on the four essential processes of drugs. Over time, this will equal the rate of elimination and this is known as the steady state half life bioavailability pharmavailability( steady state, half life, bioavailability, pharmavailability ) which usually takes 4 6 8 10( 4, 6, 8, 10 ) half lives to achieve.

The action by which drugs are removed or partially metabolised by the liver after being absorbed by the gastrointestinal tract is known as the first pass hepatic effect hepatic re-directive hepatic metabolite confirmation hepatic elimination drive( first pass hepatic effect, hepatic re-directive, hepatic metabolite confirmation, hepatic elimination drive ). Drugs which are particularly affected by this process are aspirin, morphine adderall Amoxicillin Suprophen( morphine, adderall, Amoxicillin, Suprophen ) and propranolol

The relationship between pressure and volume is Boyle’s Law Charles' Law Dalton's Law Henry's Law Starling's Law La Places' Law( Boyle’s Law, Charles' Law, Dalton's Law, Henry's Law, Starling's Law, La Places' Law ). This related to the ventilation of the lungs and movement of air into/out of them.

The relationship between temperature and volume is Charles’ Law Boyle's Law Dalton's Law Henry's Law Starling's Law La Places' Law( Charles’ Law, Boyle's Law, Dalton's Law, Henry's Law, Starling's Law, La Places' Law ). This relates to the warming of air through the sinuses in order to increase volume. If you breathe in cold air, there is less volume.

Illustrating that the pressure of gas is directly related to the number of moles and that total pressure of the mixture of gasses is equal to the sum of them (PA + PB + PC) is Dalton’s Law Boyle's Law Charles' Law Henry's Law Starling's Law La Places' Law( Dalton’s Law, Boyle's Law, Charles' Law, Henry's Law, Starling's Law, La Places' Law ). This relates to climbers ascending heights where the partial pressure of oxygen is lower and hence, creates hypoxia.

The principle that all gases are soluble in liquids relates to Henry’s Law Boyle's Law Charles' Law Dalton's Law Starling's Law La Places' Law( Henry’s Law, Boyle's Law, Charles' Law, Dalton's Law, Starling's Law, La Places' Law ). More gas dissolves at high pressure and hence, as the pressure decreases that gas will begin to expand back into the blood stream. If this happens too quickly, organs will suddenly depressurise, collapse and sudden death will occur. The bends relates to Nitrogen expanding into the joints causing pain as well as CO2 expanding out and causing the blood to become foamy.

Both Henry’s Law Boyle's Law Charles' Law( Henry’s Law, Boyle's Law, Charles' Law ) and Starling’s Law Dalton's Law La Places' Law( Starling’s Law, Dalton's Law, La Places' Law ) relate to the gaseous exchange in the alveoli.

La Places’ law Boyle's Law Charles' Law Dalton's Law Henry's Law Starling's Law( La Places’ law, Boyle's Law, Charles' Law, Dalton's Law, Henry's Law, Starling's Law ) explains how a decreasing radius within the alveoli relates to an increased collapsing pressure due to surface tension as well as the need for surfactant.

The body usually maintains a PH of around 7.4 7.0 7.9 6.8( 7.4, 7.0, 7.9, 6.8 ). Control of the acid-base balance is through the lungs, kidneys and buffer system.

Lungs – fast response slow response, takes days/hours instantaneous, works in seconds( fast response, slow response, takes days/hours, instantaneous, works in seconds )

Kindeys – slow response, takes days to work and several hours to respond

Buffer system – instantaneous, works in seconds reasonably fast response slow response( instantaneous, works in seconds, reasonably fast response, slow response )

Decreased ability to breathe due to severe chronic lung disease leads to respiratory acidosis respiratory alkalosis metabolic acidosis metabolic alkalosis( respiratory acidosis, respiratory alkalosis, metabolic acidosis, metabolic alkalosis ) and is corrected by increasing excretion of acid in the urine excretion of alkali in the urine breathing rate to retain C02 breathing rate to rid C02( excretion of acid in the urine, excretion of alkali in the urine, breathing rate to retain C02, breathing rate to rid C02 )

Hyperventilation due to anxiety leads to respiratory alkalosis respiratory acidosis metabolic alkalosis metabolic acidosis( respiratory alkalosis, respiratory acidosis, metabolic alkalosis, metabolic acidosis ) and is corrected by increased excretion of alkali in the urine excretion of acid in the urine breathing rate to retain C02 breathing rate to reduce C02( excretion of alkali in the urine, excretion of acid in the urine, breathing rate to retain C02, breathing rate to reduce C02 )

Loss of stomach acid due to vomiting leads to metabolic alkalosis metabolic acidosis respiratory acidosis respiratory alkalosis( metabolic alkalosis, metabolic acidosis, respiratory acidosis, respiratory alkalosis ) and is corrected by decreased breathing rate to retain CO2 breathing rate to expel C02 excretion of acid in the urine excretion of alkaline( breathing rate to retain CO2, breathing rate to expel C02, excretion of acid in the urine, excretion of alkaline )

Increased acid production due to DKA leads to metabolic acidosis metabolic alkalosis respiratory acidosis respiratory alkalosis( metabolic acidosis, metabolic alkalosis, respiratory acidosis, respiratory alkalosis ) and is corrected by increased breathing rate to decrease C02 breathing rate to retain C02 excretion of acid in the urine excretion of alkaline in the urine( breathing rate to decrease C02, breathing rate to retain C02, excretion of acid in the urine, excretion of alkaline in the urine )