1 - Body Fluids

Bolded numbers are recommended numbers to remember if you don't want to remember the range. These values were provided on the lecture slides as a study tool.

What percentage of total body weight is fluid?

60%

What fraction of body fluid is inside/outside the cells?

Inside: 2/3, Outside: 1/3

What makes up extracellular fluid (and in what proportions)?

Plasma (1/4) and Interstitial Fluid (3/4)

Describe the Gibbs-Donnan effect.

Plasma has slightly greater Na+ and K+ than interstitial fluid.

Why do Transcellular fluids have unique compositions to plasma/interstitial fluid?

Separated by cellular/membrane barriers (Synovial fluid, CSF, Pericardial fluid, etc.)

What are two examples of minor ECF secretions?

Fluids with fluctuating composition (saliva) and short-lived fluids (GI juices, sweat)

What percentage of total body weight (TBW) is Fluid/ICF/ECF?

60% / 40% / 20%

(60:40:20 rule)

What is the average volume of total body fluid in a “standard” male?

42 L

What is the average volume of ECF fluids (plasma and interstitial fluid) in a “standard” male?

3 L plasma

11 L interstitial fluid

What is the average volume of ICF in the “standard” male?

28 L

What is the average blood volume and percentage TBW in adults?

5 L

7% TBW

What fluid represents the whole of intravascular volume?

Plasma

What is intravascular volume essential for?

Tissue perfusion

Organ damage prevention

Heart contraction

What is Hematocrit?

Fraction of the blood composed of packed RBCs

What is a normal hematocrit in men and women?

0.40 men

0.36 women

How does severe anemia affect Hematocrit proportion?

Lowers as far as 0.10

What is the maintenance of nearly constant conditions of the ECF?

Homeostasis

(T/F)

Statement 1: Every cell in the body contributes and benefits from homeostasis.

Statement 2: Homeostasis is disrupted by external conditions.

Both are true.

What controls organ function subconsciously?

Autonomic Nervous System

What makes up the Hormonal system?

Endocrine glands

How does the body maintain parameters in physiological ranges?

Feedback control mechanisms

(T/F) The body has total control over how much water is lost.

False.

Insensible water loss (800 mL) due to evaporation in resp. tract and epidermis diffusion can’t be controlled.

What is the function of the kidneys?

Maintenance of balance between intake/output of water and electrolytes

Define the Rule of 3s (adults).

3 min w/o air

3 hrs w/o shelter

3 days w/o water

3 wks w/o food

What is ECF transport?

Rapid movement of plasma in blood vessels and rapid exchange of fluid between blood capillaries and intercellular spaces.

How often does blood circulate at rest and in activity?

Once/min (rest)

6x/min (activity)

What is ECF mixing and how does it occur?

Maintains ECF homogeneity

Occurs by diffusion

What system is able to sense and minimize disturbances?

Control system

What mechanisms counteract initial disturbances against the initial stimulus?

Negative feedback control systems

What measures the system’s degree of effectiveness of the control system?

Gain (correction ÷ error)

What are mechanisms that act in the same direction of the initial disturbance?

Positive feedback control mechanisms

What results from positive feedback control mechanisms?

Amplification of the initiating event

What composes the ECF?

• Proteins

• Hormones

• Electrolytes

• Nitrogenous waste

• Gases

• Amino Acids

• Lipids

• Sugars

“PHENGALS”

What does [Na+] regulation control?

Fluid osmolarity/volume, blood pressure, nerve and muscle function

What is the function of HCO₃ - and and CO₂ in plasma?

pH buffer

What are the 8 analytes in the Basic Metabolic Panel?

1. Glucose (energy)

2. Na (electrolyte)

3. Cl (electrolyte)

4. K (electrolyte)

5. Ca (electrolyte)

6. CO₂  (electrolyte)

7. BUN - blood urea nitrogen (kidney)

8. Creatine (kidney)

BMP Glucose range?

65-100 mg/dL

BMP Na range?

135-145 mmol/L (140)

BMP Cl range?

96-106 mmol/L (100)

BMP K range?

3.5-5 mmol/L (4)

BMP Ca range?

8.5-10.5 mg/dL (8)

BMP CO₂ range?

22-28 mmol/L (24)

BMP BUN range?

6-20 mg/dL (6)

BMP Creatinine range?

0.6-1.2 mg/dL (0.6)

What is a normal adult body temperature (^oC)?

37

What is the range for normal heart rate in adults?

60-99 bpm

What is the range for normal mean arterial pressure in adults?

70-110 mmHg

What is the normal blood pressure range for an adult?

120/80 mmHg

What is the normal range for respiratory rate in adults?

12-16 breaths/min

What is the normal oxygen saturation range in adults?

95-100%

What is the normal body pH range in adults?

7.3-7.5 pH

Functional tissue of an organ is called?

Parenchyma

All other cells of an organ besides the parenchyma are called?

Stroma

Fluid-filled space between cells in an organ is called?

Interstitium

What provides substrate for cell adhesion and regulates movement, growth, and differentiation?

ECM

What consists of a network of crosslinked structural proteins and interstitial ground substances?

ECM

What are the structural proteins?

1. Collagens

2. Elastins

3. Fibronectin

4. Basement membranes

What is a primary component of ground substance?

Proteoglycans

What is the function of the interstitium?

Cell signaling & substance/water exchange

What is unique about skin interstitium structure?

Presence of keratins

Examples of negative feedback control systems

Body temperature, ECF [O₂], ECF [CO₂]

Examples of positive feedback control mechanisms

Action potentials, child-birth, blood coagulation

What are the liver components of the Comprehensive Metabolic Panel?

• ALP

• AST

• ALT

• Bilirubin

What are the protein components of the Comprehensive Metabolic Panel?

• Total Protein

• Albumin

• Globulin