Block 1 Lectures Flashcards
Human composition
96.5% oxygen, carbon, hydrogen, and nitrogen
Humans have a similar amount of microbes compared to cells
3.7x10^13
What makes something larger?
Number of cells, NOT cell size
Which cells modulate their size as a response to rates of fluid flow?
Kidney epithelial cells
Which cells increase 25% in size during pregnancy due to insulin demand?
Pancreatic beta cells
When pancreatic beta cells die proliferation…
increases but not cell size
Liver size increases during pregnancy via…
hepatocyte hypetrophy
Liver regeneration after surgery occurs by…
increased hepatocyte proliferation
Are humans in equilibrium?
No we are typically in steady-state
Negative feedback loops
Loops that correct for a change from a set point (more common)
Cell swelling
Osmotic effect of macromolecules that are fixed in a cell because they cannot pass through the membrane
Most abundant cell
Red blood cells
Endocrine communication
Via blood stream
Paracrine communication
Message to neighboring cells
Autocrine communication
Message to self-cell
Amphipathic
Both polar and nonpolar parts
Glycerophospholipid
Amphipathic
Glycerol backbone
2 fatty acyl tails in ester linkage
Sphingolipids
Amphipathic
Sphingosine backbone
1 fatty acide tail in amide linkage
Main lipid constituent of plasma membrane
Glycerophospholipids (phospholipids)
Cholesterol
Amphipathic
Sterol
Essential membrane component
Effects fluid by interacting with hydrocarbon groups on phospholipid tails
Sodium concentration
HIGH outside LOW inside
Potassium concentration
LOW outside HIGH inside
Chloride concentration
HIGH outside LOW inside
If K+ channels are open…
membrane voltage is negative
If Na+ channels are open…
membrane voltage is positive
Nernst equation
Calculates the membrane potential when an ion is at equilibrium
