Body Fluids, Solutes and Solutions and Membranes Flashcards
In leans adult herbivores, what is the total body water of body weight?
70%
In the average animal, what is the total body water of body weight?
60%
What are the fluid compartments of the cell?
ECF and ICF
How much does ECF make up in the total body weight and body weight?
33% of TBW
20% of the body weight
How much does ICF make up in the total body weight and body weight?
67% of TBW
40% of body weight
What makes up the ECF?
Plasma, Interstitial fluid, Lymph and Transcellular fluid
How much of the ECF does PLASMA take up?
25%
5% of body weight
How much of the ECF does INTERSTITIAL FLUID take up?
70%
15% body weight
What makes up transcellular fluid?
Cerebral spinal fluid (CSF), intracoular, pleural, peritoneal, pericardial, synovial, digestion secretions
Anions in ECF
Cl- (108)
HCO3- (24)- bicarbonate
Cations of ECF
Na+ (142 mmol/L)
K+ (4.2)
Mg2+ (0.8)
Nutrients within ECF
O2, glucose, fatty acids, and amino acids
Wastes of ECF
Co2, urea, uric acid, excess water and ions
Anions of ICF
Cl- (4)
HCO3- (10)
Phosphate ions (HPO42-)
Cations of ICF
Na+ (14)
K+ (140)
Mg2+ (20)
Why are phosphate ions seen in the ICF?
Because the cells are producing ATP
Nutrients within ICF
High concentrations of proteins
What does balancing the anions and cations do for the blood?
maintains the pH of 7.2
Why is Ca important for both ECF and ICF?
Ca maintains the homeostasis of the bones (ECF and ICF have different Ca concentration)
What are the most important regulators for osmotic pressure?
Na and K
What controls the fluid of the body?
Thirst
Sweat
Renal control (aldosterone)
Neuronal (osmoreceptors, baropreceptors)
Osmoreceptors
Osmotic Pressure
Located at the hypothalamus glands to regulate water volume
Baroreceptors
Located in the heart
Regulates blood pressure
Dehydrations
Loss of water in the body
Leads to decrease in both ECF and ICF volumes
Decrease of osmolarity in both
General signs of dehydration
Thirst Dry tongue Loss of skin elasticity Soft eyeballs (due to lowering intraocular tension) Decrease blood pressure if 4-6 L loss Decrease Hb and Hct (packed cell volume)
What is the affect of losing water from the ECF?
Increase of ion concentration, this will attract water from ICF
Solvent
Anything liquid
Water (universal)
Solutions of electrolytes
NaCl (disassociates once it hits the water)
Solutions of nonelectrolytes
Glucose
Normal Saline
0.9% NaCl solution- Physiological saline- 0.9 g NaCl in 100 ml water
Maintains the concentration of NaCl in ECF and ICF
Weight of solute
Moles, equivalents, or osmosis
Concentration of solutes
Moles per lter (mol/L)
Equivalents per liter (Eq/L)
Osmoles per liter (Osm/L)
Equivalents (EQ)
Concentration of electrolytes in a solution
Amount of charged (ionized solutes)
EQ = Mole of solute x valence
Transport through cell membranes
Diffusion
Facilitated Diffusion
Osmosis
Active Transport
Diffusion
Net movement of molecules from a region of their high concentration to a region of their low concentration
Molecules that diffuse through cell membranes (Diffusion)
Plasma Membrane only lets in molecules that are lipid soluble and gases (CO2, O2, H2O)
EX: vitamin A, estrogen, progesterone
Facilitated Diffusion
Molecule is too large or charged to diffuse on its own
Can diffuse if there’s a specific transport protein (channel)
Will bind to molecules to let them inside the cell
Will stop when concentrations are equal for ECF and ICF
Osmosis
The diffusion of water from an area of high concentration of water molecules to an area of low concentration of water molecules across a semi-permeable membrane
When is Osmotic pressure exerted
When a solute can’t cross the membrane (water will follow the solute to maintain balance)
Where solute decreases water will increase, vice versa
Isotonic Solution
Cells in the body are normal (normal levels of solute and water)
Hypotonic Solution
Low concentration of solute, high concentration of water
Cell pulls in water and it sweels
Hypertonic Solution
Low concentration of water, high concentration of solute
Pulls water from the cell, cell shrinks
Active Transport
Requires ATP to pump a molecule in or out of the cell
Cells must maintain very high or low levels of some molecules
Osmole
Solute concentration in terms of the number of particles dissolved
EX: 1 mole NaCl = 2 osmoles
1 mole glucose = 1 osmole
Osmolarity (M)
Number of discrete particles in 1 L solution
Osmolality (m)
Number of discrete particles in 1 kg of solution
Milliosmole
1 milliosmole= one millimole of undissociable solution
EX: 1 milimole NaCl= 2 milliomoles
1 milimole glucose = 1 milliomole glucose = 1 milliosmole
What is the normal osmolality of ECF and ICF?
300 milliosmole per kg of water
What is the major determinant of plasma osmolality?
Na+
Organic substances in body fluids
Glucose Amino Acids Fatty acids Hormones Enzymes
Inorganic Substances in Body Fluids
Sodium Potassium Calcium Magnesium Chloride Phosphate Sulphate
What is the most abundant cation in ECF and what is the function?
Na+
Muscle contraction, impulse contraction, fluid and electrolyte balance
What is the most abundant anion in ECF and what is the function?
Cl-
Regulates osmotic pressure
Forms HCl in gastric acid
What is the most abundant cation in ICF and what is the function?
K+ Resting membrane potential Action potentials Maintains intracellular vol. Regulation of pH
Na+/K+ pumps role
Keeping K+ high inside cells and Na+ high outside the cell
Plasma Membrane
Cell’s outer skin
Impermeable to large molecules
Selectively permeable to small molecules
Is a phospholipid bilayer with embedded proteins
Mobility of lipids within a bilayer
Cholesterol aids in stiffening the membrane and can flip easily
Phospholipids can more laterally, rotate or flex (rarely flipping the other leaflet)
Membrane proteins
Peripheral and Integral
Peripheral proteins
Noncovalently bonded with integral proteins
Integral Proteins
Most have membrane-spanning alpha-helical domains of 20 animo acids
Some have multiple membrane-spanning domains
Ion channels
How are some integral proteins are linked to membrane phospholipids?
Via an oligosaccharide or linked directly to fatty acids or prenyl groups
What are the functions of the membrane proteins?
- Transport
- Enzymatic Activity
- Receptors for signal transduction
- Intercellular joining
- Cell-cell recognition
- Attachment tot the cytoskeleton and ECM
How do membrane proteins function in TRANSPORT?
Provide a hydrophilic channel across the membrane that is selective for a particular solute
or
Hydrolyze ATP as an energy source to actively pump substances across the membrane
Membrane protein enzymatic activity
A protein built into a membrane may be an enzyme, a team of enzymes will catalyze sequential steps of a metabolic pathway
How are membrane proteins receptors for signal transduction?
When the protein is exposed to the outside of the cell, they’ll have a biding site with a specific shape that fits the shape of a chemical messenger (hormone)–> the external signal will cause a change in the protein that initiates a chain of chemical reactions in the cell
Membrane protein function in intercellular joining
Proteins of adjacent cells may be hooked together in intercellualr junctions. Some proteins (CAMs) provide temporary binding sites that guide cell migration and other cell-to-cell interactions
Membrane proteins roll in cell-cell recognition
Some glycoproteins (bonded to short chains of sugars) are identification tags that are recognized by other cells
Membrane proteins and their attachments to ECM and cytoskeleton
ECM and cytoskeleton anchored to proteins to help maintain cell shape and fix the location of certain proteins, cell movement, or binding adjacent cells together
