Cell Components Flashcards
Building block for all systems; operates using oxygen and energy from food or metabolized and stored energy
Cell
2/3 body water; 60% body fluid; contains potassium
Intracellular fluid
1/3 of body water, 40% of fluid, contains Na, Cl, HCO3, O2, glucose, and amino acids
Extracellular fluid
Movement between the intracellular and extracellular spaces occurs via a …..
Concentration gradient (high to low)
Extracellular fluid is made up of ….
Interstitial fluids and plasma volumes
Where is the interstitial fluid found?
Between the vascular bed and intracellular space
The interstitial space is an “out-of vessel” space that moves particles, meds, and molecules but cannot move …..
Large proteins
What are plasma volumes preserved by?
Osmotic pressure of large plasma proteins(often albumin)
What is critical in maintaining the the total and intravascular fluid?
Plasma
How are water/ water-soluble things move between the interstitial and plasma spaces?
Water via kenesis
Water-soluble Ions via facilitated diffusion (ex: glucose needs insulin)
True or false: fat soluble substances can pass through the lipid bilayer
True: ex-oxygen, nitrogen, and carbon dioxide
What is used to move substances that are too large/ not lipid soluble through the lipid bilayer?
Channels and transport proteins
What is the most recognized transport protein across the lipid bilayer and how does it work?
The Na/K ATPase pump. It converts ATP to ADP with the resulting energy being used to move ions AGAINST the concentration gradient across the cells membrane. 3 Na are moved externally and 2 K enter
How do I on channels work to help move things across the lipid bilayer?
Pores for ion movement. Must be “activated” by the binding a neurotransmitter agent to the channel to open or close to pore. Seen in the neuromuscular junction as depolarization to contract a muscle.
Ion channel proteins can be enzymatic. What does this mean?
Catalyze elements from one state to another. Ex: ATPase changing ATP to ADP to create energy for ion movement
What are the 2 key methods carrier proteins become activated to open?
- Voltage gating via electrical stimulation
2. Ligand gating via binding of a chemical or neurotransmitter to a receptor
What is a prime location for drug therapy?
Propagation of action potentials and signaling of intracellular activites
What provides drainage for the extracellular space?
Lymphatic system
How does edema occur in the interstitial space?
- Failure of the lymphatic system
- Breakdown of the capillary membrane via
- increased capillary pressure
- increased inflow vs outflow of blood in the tissue
- decreased plasma proteins(osmotic pressure) to counteract hydrostatic pressure
- membrane damage that leaks protein/ fluid into tissue
The pressure the “pushes” water into the interstitial space. Can also be thought of as blood pressure.
Hydrostatic pressure
Pressure created by plasma proteins to “pull” fluid into the plasma—ensures that some fluid is always within the capillary
Osmotic pressure
4 reasons edema occurs
- Increased filtration s/t increased BP or increased capillary permeability (seen in immune reactions, toxins, bacterial infections, ischemia, and burns)
- Obstruction of lymphatic drainage (think pt with mastectomy)
- Decreased reabsorption seen with decreased blood albumin from low protein
- Increased pressure in the vasculature without evacuation (venous occlusion)
Substances that can out pass through the lipid belayer and require facilitated diffusion
Water-soluble ions
What are examples of fat-soluble ions that can easily pass through the cellular lipid bilayer
Gases-oxygen, nitrogen, and carbon dioxide
What are the 2 methods of transport across the cellular lipid bilayer for substances that are not lipid soluble or are too big?
Ion channels and transport proteins
What are the 2 types of ion channels and how do they operate?
- Voltage gating- electrical stimulation opens channel
2. Ligand gating- chemical or neurotransmitter binds to open channel
Proteins in the cell wall that act as “pores” and open when bound to a chemical or neurotransmitter
Ion channel
Describe the mechanism of the Na/K ATPase Pump
Converts ATP to ADP creating energy to move ions against the gradient (3 Na out, 2 K in)
Whether of a solution will cause a cell to shrink or swell
Tonicity
What is a solution made up of?
A solvent (dissolver) and a solute (substance being dissolved)
Type of IV fluid that has an equal osmolarity to existing plasma resulting in limited fluid shifts when entering the plasma
Isotonic
After giving an isotonic fluid, what is suspected to happen to cells after 1 hour of administration?
Most of the fluid moves into the interstitial space because metabolism has caused a shift of the solute (Na) there— resulting in edema. Typically, the body accommodates for this with compensatory mechanisms in the circulatory and renal system
Type of IV fluid with a decreased osmolarity in relation to the existing fluid—>causes shifts of fluid into the cellular space which may result in cellular swelling/ rupture
Hypotonic
IV fluid that has an increased osmolarity compared to the existing plasma, moving fluid from the interstitial space into the plasma. It is desirable in increased interstitial swelling like organ swelling
Hypertonic
Transport vehicle for molecular products inside the cell
Endoplasmic reticulum
Smooth=no ribosomes
Rough=ribosomes that synthesize proteins
What part of the cell plays a part in malignant hyperthermia
Sarcoplasmic reticulum (in the muscle cells and holds Ca): in MH, there is a genetic issue which leads to Ca dumping—increased metabolism, increased CO2, and muscle tetany
Found in secretion cells and stores proteins and lipids for secretions
Golgi apparatus
Clean up the cell as an intracellular digestive system-autophagy
Lysosomes
What part of the cell is and enzyme container that extracts energy from nutrients producing ATP; also contains some DNA to replicate
Mitchondria
Part of the cell that contains DNA comprising the genes that outline cell protein function
Nucleus
What are the 3 key roles of ATP?
- Facilitate transport through the cell membrane (Na/K Pump)
- Synthesis of intracellular substances
- Mechanical work—muscle contraction
What are the mechanisms of water loss (3 answers)
- Insensible water loss—resp through vapors (300-400 mL/day) and evaporation (300-400 mL/day)/ sweat (up to 1-2L/day)
- Renal excretion
- Trace loss via feces and emesis
