Chapter 5B - Applied Physiology

Question 0

Filtration – definition

Answer 0

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

Question 1

Perfusion – definition

Answer 1

To pour through – so it refers to the pumping of blood through blood vessels under pressure (perfusion pressure)

Question 2

Osmosis – definition

Answer 2

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

Question 3

Diffusion- definition

Answer 3

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

Question 4

Ischemia - definition

Answer 4

The lack of perfusion. An area of tissue is not getting supplied with enough blood

Question 5

Homeostasis- definition

Answer 5

The process by which the body maintains balance and equilibrium between all body parts – maintaining the internal environment

Question 6

Edema – definition

Answer 6

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

Question 7

List the important electrolytes (7)

Answer 7

1. Sodium Na+
2. Potassium K+
3. Calcium Ca++
4. Bicarbonate HCO3-
5. Magnesium Mg++
6. Chloride Cl-
7. Phosphate PO4—

Question 8

Sodium – describe

Answer 8

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

Question 9

Potassium – describe

Answer 9

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

Question 10

Calcium - describe

Answer 10

Important in the mechanical contraction of muscles, and nerve conduction of signals

To little –> tetany
Too much -> muscle weakness

Question 11

Bicarbonate – describe

Answer 11

Important in maintaining acid – base balance

-it will buffer acids

Question 12

pH – define

Answer 12

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

Question 13

Acidosis – describe the effects on the body

Answer 13

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

Question 14

Alkalosis – describe the effects on the body

Answer 14

Is also bad for cells, causing them to become irritable. This may lead to twitching or cramping.

This will also lead to vasoconstriction

Question 15

List and describe the three major body fluid compartments

Answer 15

1. Intravascular = within the vessels
2. Interstitial = between the cells
3. Intracellular = within the cells

Question 16

What is the percentage of water for the 3 major body fluid compartments

Answer 16

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)

Question 17

Describe how fluid moves across the three body fluid compartments

Answer 17

Fluid moves by perfusion (pressure filtration), then by osmosis

Question 18

Describe “body fluids” and list the components

Answer 18

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.

Question 19

Describe the bodies process for maintaining water balance

Answer 19

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

Question 20

Acute volume loss - causes (4)

Answer 20

• Hemorrhage
• diarrhea
• vomiting
• burns

Occurs in minutes to hours

Question 21

Acute volume loss – signs and symptoms (7)

Answer 21

• Tachycardia
• pale, cool, diaphoretic skins
  – delayed capillary refill
  – Thirst
  – hypertension
  – nausea
  – altered level of consciousness

Question 22

Chronic volume loss (dehydration) – causes (3)

Answer 22

– Poor intake
– fever
– chronic illnesses

Question 23

Chronic volume loss (dehydration) – signs/symptoms (7)

Answer 23

– Dry mucous membranes 
– poor skin turgor (tenting)
– increased thirst 
– decreased urine output 
– hypertension 
– altered level of consciousness
- sunken fontanelles (in infants)

Question 24

Hypervolemia (overhydration) – causes (4)

Answer 24

- CHF – liver disease – kidney failure – drinking too much water

Question 25

Hypervolemia (overhydration) – signs/symptoms (6)

Answer 25

``` – Rapid weight gain – JVD – peripheral Edema – ascites – SOB – crackles ```

Question 26

Metabolism – define

Answer 26

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)

Question 27

Describe the function of the cell as it applies to metabolism

Answer 27

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

Question 28

Mitochondria – describe

Answer 28

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

Question 29

Lysosomes – describe

Answer 29

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

Question 30

Cell membrane – describe

Answer 30

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

Question 31

Catabolism - describe

Answer 31

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

Question 32

Animalism – describe

Answer 32

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

Question 33

Describe the dietary food sources and their energy amounts

Answer 33

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

Question 34

Aerobic metabolism – defined

Answer 34

Metabolism in the presence of oxygen

Question 35

Aerobic metabolism – list the end products

Answer 35

End products are ATPs (Energy units), carbon dioxide and water and other cellular wastes depending on the energy substrate (whether carbohydrates were burned or proteins or fats) energy produced per unit of sugar is 38 ATPs

Question 36

Anaerobic- define

Answer 36

Metabolism without the presence of oxygen

Question 37

Anaerobic metabolism – list the end products

Answer 37

End products are ATPs (only 2), lactic acid and other cellular waste – the lactic acid waste cannot be breathed off in the lungs and therefore is very difficult to eliminate - it takes the kidneys much longer to do it, and therefore is considered a strong acid – it will need to be buffered (neutralized) by bicarbonate

Question 38

Describe the unique metabolism of the brain

Answer 38

Because the capillaries of the brain are glued together especially tightly, they create something called the blood brain barrier that prevents most things, including dangerous ones, from getting into the brain. The brain thus relays on sugar and oxygen for metabolism – it is unable to burn protein or fat for energy Vulnerable to extreme low blood sugar levels

Question 39

Which neurologic function is the earliest to be adversely affected by a lack of oxygen

Answer 39

Level of consciousness becomes quickly depressed the brain is very sensitive to hypoxia

Question 40

Biological death - define

Answer 40

Is irreversible/permanent brain death due to a lack of oxygen – it occurs 4-6 minutes after clinical death 50% chance of rain damage at four minutes 87% chance of brain damage at six minutes

Question 41

Clinical death

Answer 41

Occurs the moment the heart and lungs stop functioning | – it may be reversible with CPR

Question 42

How long can the brain survive without oxygen

Answer 42

4 to 6 minutes but actually four minutes is a 50-50 chance of permanent brain damage

Question 43

How long can the heart survive without oxygen

Answer 43

1-2 hours

Question 44

How long can the kidneys survive without oxygen

Answer 44

One to two hours

Question 45

How long can the muscles survive without oxygen

Answer 45

1-2 hours

Question 46

Cold – describe the effects body temperature has on oxygen consumption but the tissues

Answer 46

Cold slows consumption of oxygen as metabolism is turned down

Question 47

Cold - effects on O2 consumption by the tissues

Answer 47

In hypothermia states, as in drowning and other cold related situations the brain can last much longer than 4 to 6 minutes without oxygen. There have been successful after 40 minute with no oxygen reaching the brain in Cold water drowning

Question 48

Heat – describe effect temperature has on oxygen consumption by the tissues

Answer 48

Heat increases oxygen consumption

Question 49

Heat – significance of effect on oxygen consumption by the tissues

Answer 49

Fevers often present with increased pulses and increased respiratory rates due to higher oxygen burn rates

Question 50

Osmotic pressure – defined

Answer 50

The theoretical amount of pressure it would take to prevent this water movement

Question 51

Oncotic pressure

Answer 51

The process by which water is pulled towards a colloid (protein and starch) just like osmosis, except it involves colloids instead of crystalloids

Question 52

Glycolysis

Answer 52

The breakdown of glucose (sugar) to produce energy

Question 53

Glycogenesis

Answer 53

The process of creating glycogen for storage in the liver and muscle tissue

Question 54

Glycogenolysis

Answer 54

The process of breaking down glycogen to release sugar the pancreatic hormone glucagon does this

Question 55

Gluconeogenesis

Answer 55

The process by which proteins can be converted to sugar for energy release

Question 56

Oral intake – described in the fluid intake

Answer 56

60% in the form of fluids 30% in foods (solids) 10% as a result of metabolism

Question 57

Describe daily fluid elimination

Answer 57

60% in urine 6% in feces 6% in sweat 28% in respiratory losses

Question 58

Describe

Answer 58

Fluid in jested daily into G.I. tract = 2000 mL Endogenous secretion into G.I. tract = 7000 mL -Salivary glands = 1500 mL -stomach secretions = 2500 mL -bile = 500 mL -pancreatic juice = 1500 mL -intestinal secretions = 1000 mL

Question 59

Describe daily gastrointestinal elimination

Answer 59

Reabsorbed from Jejunum = 5,500 mL - from ileum = 2,000 mL - from colon = 1,300 mL Fluid lost in stools = 200 mL

Question 60

What does pH stand for

Answer 60

Power of hydrogen

Question 61

State the significance of pH

Answer 61

Your body, your nerves, your muscles, your cells will not function properly unless they are in a balanced pH solution

Question 62

What is the pH of blood

Answer 62

7.35–7.45

Question 63

Describe a pH balance is maintained or how it can be restored to If altered

Answer 63

Primary control through chemoreceptors and respiratory elimination of carbonic acid - Respiratory buffering is very rapid - in minutes secondary control is through a buffering system involving the kidneys in bicarbonate (sponging of hydrogen ions) - kidney buffering is very slow – in hours or delays

Question 64

Explain how bicarbonate helps eliminate acidosis

Answer 64

Acidosis in the body is in actuality in excess of free hydrogen ions in solution. Bicarbonate can sponge them up by combining with them to form carbonic acid which is then breathed off the kidneys can make bicarbonate and use it to buffer acidosis, but that would take all day, excreting the hydrogen (acid) and bicarbonate in the urine. (If the lungs cannot breathe it off)

Question 65

Magnesium – describe

Answer 65

Important in activating many enzymes also works opposite calcium in electrical conduction and depolarization of nerves and muscles so magnesium sulfate is sometimes used to stop muscular contractions, as in premature labor

Question 66

Chloride – describe

Answer 66

Combined with sodium and helps maintain water balance and osmotic pressure in the body

Question 67

Phosphate – describe

Answer 67

Important in high-energy bonds as in there is interest phosphate, also has some pH buffer ability

Question 68

Potassium - clinical significance

Answer 68

The magnitude of potassium gradient across cell membranes determines excitability of nerve and muscle cells, including the myocardium. Minor changes in serum potassium concentration can have major effects on cardiac rhythm and function. Of all the electrolytes, rapid changes in potassium concentration can cause the most immediate life threatening consequences Changes in pH inversely affect serum potassium. Acidosis (low pH) leads to an extra cellular shift of potassium, thus raising serum potassium. Conversely, high pH (alkalosis) shifts potassium back into the cell, lowering serum potassium

Question 69

Hyperkalemia – physical symptoms

Answer 69

Includes ECG changes, weakness, ascending paralysis, and respiratory failure. ECG changes suggestive of hyperkalemia include Peaked T waves, flattened P waves, prolonged PR interval is (1st° heart blocks), widened QRS complex and others. Tenting of T waves is one of the prominent early ECG changes. If untreated, hyperkalemia causes progressive heart dysfunction, leading eventually to asystole.

Question 70

Hypokalemia – physical symptoms

Answer 70

Include weakness, fatigue, paralysis, and respiratory difficulty. ECG changes suggestive of hypokalemia include the presence of U waves, T wave flattening, and other dysrhythmias including PEA or asystole

Question 71

Sodium – clinical significance

Answer 71

Is the major positively charged ion in the extracellular space and the major intravascular ion that influences serum osmolality. Acute changes in serum sodium will produce acute free water shifts into and out of the vascular space until osmolality equilibrates in these compartments. An acute fall in the serum sodium and an acute fluid shift into the interstitial space may cause cerebral edema

Question 72

Magnesium – clinical significance

Answer 72

Is the fourth most common mineral in the human body. It is required for the action of many important enzymes and hormones. It is necessary for the movement of sodium, potassium, and calcium into and out of the cells. It is also important in stabilizing excitable membranes and useful for atrial and ventricular of arrhythmias

Question 73

Calcium – clinical significance

Answer 73

Is the most abundant mineral in the body. It is essential for bone strength and neuromuscular functions and plays a major role in myocardial contractions. Half of all calcium in the ECF is bounded to albumin; the other half is in the biologically active, Ionized form Serum ionized calcium is pH depended. Alkalosis reduces serum calcium levels. Conversely, the development of acidosis will produce an increase in serum calcium. Calcium antagonizes the effects of both potassium and magnesium at the cell membrane. Therefore, it is extremely useful for treating the effects of hyperkalemia and hypermagnesemia

Question 74

Tonicity – describe

Answer 74

The osmolality of a solution in relation to plasma

Question 75

Hypotonic solutions - examples

Answer 75

0.45% NS (half normal saline) D5W

Question 76

Hypotonic solutions – use

Answer 76

As a lifeline for later drug administration, the Florida will not remain in the vascular compartment and will therefore not predispose to fluid overload if very hypotonic, may cause hemolysis Has fewer particles than plasma

Question 77

Isotonic solutions – example

Answer 77

Normal saline Lactated Rangers solution

Question 78

Isotonic solution – use

Answer 78

For fluid volume replacement and hypovolemia,the fluid will tend to remain in the vascular compartment at least for an hour equal particles to plasma at a TKO rate, this adds a tiny amount of fluid volume – so it is not a problem in CHF

Question 79

Hypertonic solutions – examples

Answer 79

``` D50W D5 in the 0.45% normal saline Mannitol Sorbitol 7.5% saline with the dextran ```

Question 80

Hypertonic solution - use

Answer 80

osmotically or oncotically pulls fluid across membranes D50W to replace sugar in hyperglycemia – but may cause necrosis if it extravasates More particles than plasma Can cause crenation of RBCs

Question 81

Mannitol

Answer 81

Is used in cerebral edema to pull water out of the brain for elimination

Question 82

Sorbitol

Answer 82

Is used as a cathartic with activated charcoal as it holds water in the bottle, increasing bowl elimination of the charcoal and therefore the toxin

Question 83

7.5% saline with Dextran

Answer 83

Is highly hypertonic and provides osmotic and oncotic pull of physiologic body fluids into the vascular space for volume expansion

Question 84

Alpha cells

Answer 84

Of the islets of langerhans secrete a hormone called the glucagon which, when released from the pancreas flows to the liver and causes the liver to convert glycogen, storage form polysaccharide to simple glucose, a monosaccharide – raising blood sugar levels. This function is dependent upon there being adequate amounts of glycogen stored. If the patient has not eaten in sometime, such as following prolonged vomiting, they will have depleted their glycogen stores, and glucagon won't work

Question 85

Beta cells

Answer 85

Of the islet of langerhans secrete a hormone called insulin which, when released from the pancreas flow throughout the body and causes cells to take up sugar from the bloodstream

Question 86

Delta cells

Answer 86

Of the islet of langerhans secrete hormones called somatostatin which, when released inhibit pancreatic function – that is, it inhibits the secretion of insulin, Glucagon, and pancreatic polypeptide (use indigestion) hypersecretion of somatostatin from a pancreatic tumor can create hyperglycemia – and look like diabetes