W2 PP2 Fluids& Electro

Question 1

2 main locations of fluids

Answer 1

Intercellular and extracellular

Question 2

Extracellular spaces

Answer 2

Interstitial-fluid btn cell’s
Intravascular Space- fluid within veins, arteries and capillaries 
Synovial Joints
Lymph Space
CSF
Intraoccular space
Intestinal space
Pericardial space

Question 3

Pleural effusion

Answer 3

When water accumulates in the pleural space could be serum, blood, chyle , or pus

Question 4

Two main types of pleural effusions

Answer 4

The trasudative is secondary to starlings forces (change in hydrostatic pressure)
Causes by a disease process that causes a change in pressure like left ventricular failure or cirrhosis liver disease

Exudative pleural effusion is due to local factors that effect the secretion and absorption of water, usually a malignancy/cancer.

Question 5

Pressure vs Hydrostatic pressure

Answer 5

Defined as the force exerted on an area
Hydrostatic pressure is the force exerted by a fluid due to the force of gravity
Hydrostatic pressure helps to determine the movement of fluid into or out of the cell along with other forces

Question 6

Oncotic forces

Answer 6

Form of osmotic pressure exerted by the large osmolarity proteins found in serum. These proteins are too big to escape the vessel wall so water gets pulled into vessel. Albumin causes most of this pressure.
High oncotic pressure draws water into the vessel while a low oncotic pressure draws it out.

Question 7

Starling’s forces

Answer 7

Discuss the movement of fluid secondary to their filtration through a semi-permeable membrane. Takes into account capillary, interstitial, oncotic and hydrostatic pressures. The movement depends on all of these factors
Not all capillaries are the same. The glomerular capillaries have no protein permeability so water is always coming in while the Hypatic Sinusoids of the liver are very permeabkento proteins. It’s where albumin is manufactured and it’s permeability allows it to enter blood

Question 8

Water movement depends on

Answer 8

membrane permeability, hydrostatic pressure, oncotic pressures
It’s the different gradients btn these spaces that determines where water will move
Capillary and interstitial hydrostatic and oncotic pressures all interact to determine movement of water

Question 9

Water coming out or out of vessels is determined by

Answer 9

Vessel permeability
The dimension of the lumen
The oncotic and hydrostatic pressures

Question 10

What causes water to move from the ICF to the ECF

Answer 10

Aquaporins- integral membrane protein. Allows for rapid movement of water depending on cell’s needs

Sodium- in high concentration in ECF and draws ware out of the cell
Potassium- most prominent electrolyte inside he cell. Draws water back in
Proteins- in and outside the cell that are involved in water movement as well

Question 11

Diabetes insipidous

Answer 11

Mutation in aquaporin is a disorder of the kidney and patients secrete large amount of dilute urine. Called diabetes insipidous. Usually secondary to a deficiency in anti diuretic hormone or bc or some toxicological events

Question 12

How does posterior pituitary effect water flow?

Answer 12

Regulated by ADH
Osmoreceptors and baroreceotors detect changes in osmolarity and changes in BP. Constantly send signals to retain or excrete water. The body needs to retain water, ADH is secreted from the pituitary gland. ADH acts by inserting aquaporins in the distal tubules of the kidneys. Allow for the tea reabsorption of water and water is retained
ADH levels are low, water is excrete

Question 13

SIADH

Answer 13

The Syndrome of Inappropriate ADH

Overexcretion of ADH

Excessive water retention leading to pulmonary edema, edema, and water overload

Question 14

Is edema a disease in itself?

Answer 14

No it’s usually a manifestation of other disease processes

Question 15

When does edema occur

1- proteins explain

Answer 15

• If there’s a < in plasma oncotic pressure (secondary to a < in plasma proteins-usually albumin)
• if proteins are not available in the vascular space water is gonna leak out like in liver failure. Liver doesn’t produce albumins so then there’s a decrease in intravascular oncotic pressure, when that happens, water can move out of the vessel and into the interstium manifesting as edema or ascities

Question 16

When does edema occur

2- capillary HP

Answer 16

Increased capillary hydrostatic pressure

When there’s an > volume in the vessel. Secondary to > in water retention or > in water intake

Question 17

Left Ventricular Hypertrophy

Increased Capillary Hydrostatic Pressure Example

Answer 17

When there’s failure of the left ventricle to affectingly pump blood which results in a backup of blood volume to the pulmonary vasculiture
This > the capillary hydrostatic pressures in the pulmonary vasculiture and fluid starts to leak out into the interstitium
This is pulmonary edema

Question 18

High Altitude Pulmonary Edema

Increased Capillary Hydrostatic Pressure Example

Answer 18

Altitudes greater than 8200 ft. Incidence <1%
Hypoxia can ensue when people are at 8200ft or high for extended periods of time and hypoxia will induce pulmonary artery vasoconstriction
This > the pressure in that vessel and the capillary pressures which causes fluid to leak out giving you fluid in the interstitial space

Question 19

When does edema occur

3- capillary permeability

Answer 19

Increased capillary permeability
Burns.
Increase vascular permeability and fluid leaks out
Second or third degree burns have lots of edema, it’s secondary to the capillary > in permeability

Question 20

When does edema occur

4- lymph

Answer 20

Lymphatic obstruction
Causes backup of cellular recycling. Increase of pressure in vascular space and fluid will leak out
See this in people who have had lymph nodes removed bc if tumor or cancer. Mastectomy, one of their arms may have lymphodema

Question 21

High Altitude &; Edema

Answer 21

Occurs at altitudes > 8200ft. Only occurs in 1% of people who probably have a different ACE enzyme. There are only low levels of o2in the atmosphere that that altitude, so hypoxia ensues. The pulmonary arteries construct/tighten up. >pulmonary capillary pressures, you’ll have a leaking of fluid through those capillaries into the interstitium giving you PE. Why it occurs in people with this Angiotensin-Converting Enzyme Polymorphism, no one knows

Question 22

Sodium fun facts

Answer 22

Alkali metal
Large part of our diet, important for food preservation. Wars have been fought over salt. “Wich” towns were salt producing towns

Question 23

Sodium affects water movement in the body (shocking)

Answer 23

Sodium is about 90% of ECF cations
Regulates osmotic forces and water balance
Serum Na:135-145 mEq/L
Controlled by Aldosterone

Question 24

Excreting or retaining Sodium Pathway

Answer 24

If volume is < secondary to blood loss or dehydration or other volume loss states, you hold onto Na+ bc water will follow and total body volume will>. Barorecepters and osmoreceptors will notice this change but so will other cells

Question 25

Name the 6 components involved in volume changes

Answer 25

``` Juxtaglomerular cells Angiotensinogen Angiotensin 1 (ACE) Angiotensin 2 ( intraglomerular mesangial cells) Aldosterone ```

Question 26

Juxtaglomerular Cells and Sodium

Answer 26

Specialized smooth muscle cells found int the walls of the afferent renal arterioles. Have beta receptors that secrete renin enzyme in respond to a < in renal profusion. Renin will be released into the central circulation where it will cleave zymogen (inactive peptide) Angiotensinogen.

Question 27

Zymogen

Answer 27

Inactive peptide

Question 28

Angiotensinogen and salt

Answer 28

“A” is a liver derived peptide and it can circulate without any effect as an inactive molecule until it interacts with Renin. When this occurs, “A” is cleaved into Angiotensin 1, which is further metabolized by ACE (enzyme derived in the lung), into Angiotensin 2 then interacts with the smooth muscle of the renal arterioles causing them to constrict. “A”2 also stimulates the secretion of aldosterone from the adrenal cortex. Aldosterone then interacts with kidney causing sodium retention, water follows.

Question 29

What happens with aldosterone sodium and water retaining system is overactivated?

Answer 29

Hypertension (elevated BP) ACE inhibitors PREVENT HP&>BP and block the system ARBs “Angiotensin Receptor Blockers” also PREVENT the system Direct renin inhibitors ALSO prevent

Question 30

Chloride &; Potassium

Answer 30

Chloride sometimes follows sodium. Is important in membrane activity and inactivity. Potassium is the major intracelular cation. Important in establishing the testing membrane potential of cells

Question 31

An 83 yo F presents to her PC office bc of progressive weakness and malaise. She hasn’t been feeling well due to a recent URI (Upper Respiratory Infection) and hasn’t been eating well either. She is on the diuretic chlorthalidone Her measured K+ is 2.2 mEq/ Normals is 3.5-4.5

Answer 31

Hypokalemia

Question 32

Hypokalemia

Answer 32

Low potassium level Major intercellular cation, maintained by the Na+K+ ATPase pump, resting membrane potential of the cell The electrical gradient of the cell at rest A change has major effects

Question 33

How does hypokalemia occur?

Answer 33

Can occur bc if < intake Usually, from excess K+ loss bc of diuretic use, burns, or GI losses (vomiting diarrhea) Weakness and fatigue due to muscles failure to repolarize Can result in life threatening cardiac arrhythmias A change in the resting membrane potential can result in a delayed repolarization of the ventricles making one susceptible to arrhythmias.

Question 34

How does hypokalemia affect the heart?

Answer 34

Prolongation of P-R interval-> showing atrial repolarization And T-wave flattening, the electrical manifestation of ventricular repolarization. If hypokalemia ensues, this can make one prone to other arrhythmias like ventricular tachycardia or ventricular fibrillation

Question 35

72 year old M s/p R hip replacement on ibuprofen for pain Present to the ED with a complain of weakness, lethargy, and 2 days of abdominal cramping and diarrhea and dark urine Cr (creatine): 2.2. K: 5.8 Normal Cr:0.5-1. K: 3.5-4.5

Answer 35

Hyperkalemia | Secondary to renal disfunction due to non-steroidal anti inflammatories (ibeprophen)

Question 36

An > in K+ can be caused by:

Answer 36

Overt renal insufficiency Medications that interfere with excretion (ibuprofen, some antibiotics) Some diseases that cause hyperkalemia like Addison’s, or excess release of K+ from the cells from an injury, burn, or certain toxins

Question 37

T or F | An increase in intraceullar levels of K+ can lead to an increase level of the extracellular levels of potassium

Answer 37

True! This can lead to membrane excitability. This increase can result in a change of the Na/K+ channel/pump’s activity The overall result is impaired function of muscles the GI tract. Life threatening arrhythmias are the most detremental manifestation.

Question 38

What does hyperkalemia do to the heart

Answer 38

Very tall T waves, demonstrating a susceptible left ventricle to extra impulses that could induce ventricular fibrillation or ventricular tachycardia which are lethal arrhythmias.

Question 39

42 yo marathon runner Found lethargic, muscle twitching, hypotensive and confused on trolley Measured Na: 128 mEQ/L Normal range 135-145

Answer 39

Hyponatremia | Low sodium level

Question 40

Causes of hyponatremia

Answer 40

Water loss Sodium can flow water out of body!! Also have water loss!, but with no electrolyte replacement Over dilution an also have water overload like in CHF or liver failure, leading to hyponatremia < in ability of cell to depolarize

Question 41

Treat for hyponatremia

Answer 41

``` SLOW CAREFUL Na+ replacement Overaggressive sodium replacement (Central pontine monolynolysis) Complication of overaggressive sodium replacement, destroys myelin sheaths Coma, spasms, bad stuff ```

Question 42

66 yo M w Hx of DM Has been sick with pneumonia Confused, lethargic, hypotensive, & tachycardic Glucose: 760mg/dL Na: 150 mEq/L

Answer 42

Hypernatremia Not often caused by an increase in sodium but rather a deficit in fee water (volume or water loss like dehydration. Can occur if someone is drinking seawater (too much Na+) but usually lack of water. High glucose levels lead to excessive water loss. Glucose stuck outside of cells and water follows it outside Tachycardic bc of increased excitability Volume shifts too quickly=edema Give insulin and carefully replace water