Chapter 5B - Applied Physiology Flashcards
Filtration – definition
Involves passing body fluids and other dissolved elements through a selectively permeable membrane (like the capillary wall) that allows some things, such as water, sugar and protein to pass, but keeps the red blood cells inside the capillary
requires hydrostatic pressure like perfusion pressure, or blood pressure
Perfusion – definition
To pour through – so it refers to the pumping of blood through blood vessels under pressure (perfusion pressure)
Osmosis – definition
The process by which water is pulled towards a crystalloid (a salt or sugar)
– the water (a solvent) is pulled towards a salt or sugar (a solute)
usually across a semi-permeable membrane
Diffusion- definition
The process by which a gas, or a substance in solution, spreads (because of the moment of its particles) from areas where there are a lot of them to areas where there are less, to evenly fill all the available space
Molecules are in continuous random movement
– he speeds up this movement
– cold slows it down
Ischemia - definition
The lack of perfusion. An area of tissue is not getting supplied with enough blood
Homeostasis- definition
The process by which the body maintains balance and equilibrium between all body parts – maintaining the internal environment
Edema – definition
The buildup of fluid in the tissues usually interstitial
sometimes called third spacing because the interstitial space is the third space, after intravascular and intracellular
List the important electrolytes (7)
- Sodium Na+
- Potassium K+
- Calcium Ca++
- Bicarbonate HCO3-
- Magnesium Mg++
- Chloride Cl-
- Phosphate PO4—
Sodium – describe
Most common electrolyte, is important in the cellular depolarization, nerve conduction, muscle contraction (including the heart and brain) important in control of water balance
– attracts and hold water so it tends to increase BP
most common extracellular ion
Potassium – describe
Important in cellular depolarization, nerve conduction, muscle contraction (including the heart and brain), and the electrical stability of the heart
– intake tends to lower BP
– most common intracellular
– often lost with diuretic use
– vital to normal heart function
– too much or too little will cause cardiac dysrhythmias
Calcium - describe
Important in the mechanical contraction of muscles, and nerve conduction of signals
To little –> tetany
Too much -> muscle weakness
Bicarbonate – describe
Important in maintaining acid – base balance
-it will buffer acids
pH – define
is a unit of measurement of acid/base balance – it is a scale of 1 to 14 where 1 is the strongest acid, and 14 is the strongest alkali (base) and 7 is neutral (the pH of water). The pH of blood is 7.4, so we are slightly alkaline
Acidosis – describe the effects on the body
Causes cells to become permeable, and leak fluids. It causes cells to depolarize and relax, being unable to repolarize.
This will also lead to vasodilation
Alkalosis – describe the effects on the body
Is also bad for cells, causing them to become irritable. This may lead to twitching or cramping.
This will also lead to vasoconstriction
List and describe the three major body fluid compartments
- Intravascular = within the vessels
- Interstitial = between the cells
- Intracellular = within the cells
What is the percentage of water for the 3 major body fluid compartments
Intravascular = 10% of body water (this determines tissue perfusion)
interstitial = 25% of body water (16% of body weight)
intracellular = 65% the body water (40% of body weight)
Describe how fluid moves across the three body fluid compartments
Fluid moves by perfusion (pressure filtration), then by osmosis
Describe “body fluids” and list the components
Body fluids are composed of water and substances dissolved in it: electrolytes (charged ions), and non-electrolytes such as glucose, proteins, urea, etc.
60% of the bodyweight is water
– the loss of 1% will cause a compensation effort to begin
- loss of 10% will cause a risk of collapse and possible death
Water acts a lubricant, assists temperature regulation and the transportation of nutrients, wastes, and hormones.
Describe the bodies process for maintaining water balance
The hypothalamus helps regulate water balance by containing the body’s thirst center. It also communicates with the pituitary gland which causes the kidneys to save or eliminate water
Thirst cannot be relied upon to maintain fluid balance – you are usually a quart low before thirst kicks in to help you drink
Acute volume loss - causes (4)
- Hemorrhage
- diarrhea
- vomiting
- burns
Occurs in minutes to hours
Acute volume loss – signs and symptoms (7)
- Tachycardia
- pale, cool, diaphoretic skins
– delayed capillary refill
– Thirst
– hypertension
– nausea
– altered level of consciousness
Chronic volume loss (dehydration) – causes (3)
– Poor intake
– fever
– chronic illnesses
Chronic volume loss (dehydration) – signs/symptoms (7)
– Dry mucous membranes – poor skin turgor (tenting) – increased thirst – decreased urine output – hypertension – altered level of consciousness - sunken fontanelles (in infants)
Hypervolemia (overhydration) – causes (4)
- CHF
– liver disease
– kidney failure
– drinking too much water
Hypervolemia (overhydration) – signs/symptoms (6)
– Rapid weight gain – JVD – peripheral Edema – ascites – SOB – crackles
Metabolism – define
The process where the cells of the body take in fuel and oxygen and “burn” it, creating energy for body processes, and releasing heat and other by-products such as carbon dioxide (CO2) H2O and possibly other waste products also
– We use oxygen to oxidize carbohydrates, proteins and fats to produce the energy needed for life processes (in the form of high energy packets called ATPs = that is a triphosphate)
Describe the function of the cell as it applies to metabolism
The Cells take up oxygen from the blood (and interstitial fluid) by diffusion, and sugar and nutrients by active transport (usually using insulin). The mitochondria oxidize the sugar producing energy (in the form of ATP’s) and waste products such as heat and carbon dioxide. ATPs are necessary for all bodily functions, from muscle contractions (think diaphragm and heart) and nerve conduction, etc.
- this is called the critic acid or Krebs cycle
Mitochondria – describe
Are small organelles found inside the cells that operate as small energy factories. The sugar and oxygen go here, and the mitochondria manufacturer Adenosine triphosphates (provides the energy to make the nerves and muscles work).
- we give the patient oxygen so that the mitochondria can make ATP’s
Lysosomes – describe
Are small organelles found inside cells that contain enzymes that will dissolve the cells and completely destroy it if they are released. They are there to erase the cell from existence upon its death. Otherwise we would clog up with a dead cell debris.
- These cause problems in cases of prolonged anoxia, as they burst and release the enzymes, tearing apart surrounding cells
Cell membrane – describe
The outer wrapper on a cell keeps the right things in, and prevents the wrong things from coming in. It has pores or openings like doors through which it’s food enters, or wastes exit. Acidosis makes this membrane very leaky, basically leaving all the doors open
– high levels of oxygen or lowering carbon dioxide levels by hyperventilation of patients helps stabilize of these so membranes
Catabolism - describe
Is the process described where foods are broken down to liberate or produce energy, or is the wasting process of breaking down tissues and muscles
Animalism – describe
Is the process of building up or storing things for later use. So, the making of fat or glycogen (the end storage forms for foods we eat, or the building of muscle, etc. Is an anabolic process) any excess calories eating get stored as fats
- insulin is anabolic
Describe the dietary food sources and their energy amounts
Carbohydrates = 4 kcal/Gram = sugars and starches
= simple = various types of sugars
= complex = starches
Proteins = 4kcal/gram = amino acids
Fats (lipids) = 9 kcal/gram = fatty acids
Alcohol = 7 kcal/gram = ethanol
