Human Physiology Exam 1

Physiology

the study of the function of the human body

Major component to diagnosing patient’s diseases

identifying cause and effect in the body

How compartments are separated

physical barriers (eg. linings of blood vessels, lining of lungs, lining of GI tract, extracellular matrix)

circulatory system

transports O₂ and water-soluble chemicals between compartments (eg. from lungs to tissues, or from gut to tissues)

requirement for transport between compartments

bulk transport, diffusion, and cell membrane transport

epi

outside

endo

inside

thelium

lining

glyco

associated with glucose and/or polysaccharides

glycoproteins

have polysaccharide side chains

plasma membrane of cells

selectively permeable phospholipid bilayer

barrier to large, polar molecules, e.g. proteins, nucleic acids

permeable to many smaller molecules

mechanisms of transport across membrane

simple diffusion

carrier-mediated transport

types of simple diffusion

lipid-soluble molecules

ions through channel proteins

osmosis

types of carrier-mediated transport

facilitated diffusion

active transport

simple diffusion

molecules diffuse across membrane (lipids, gases)

osmosis

diffusion of water through aquaporin channels across a semipermeable membrane

water moves from low solute concentration to high solute concentration until the solute concentration is the same on both sides of the membrane

how solute moves

down concentration gradient (moves from region of high concentration to region of low concentration)

rate of diffusion

increases with temp

increases with conc. gradient

increases with surface area of membrane

decreases with distance

efficient distance for diffusion

100 micro meters or less (all tissues of the body are within 100 micro meters of blood capillary)

molecules that can diffuse across the membrane

lipids

small gas molecules

ions through protein channels in the membrane

factors of diffusion rate that can be exploited or overcome

concentration gradient

surface area of membrane

constant factor in mammals for rate of diffusion

temperature

factor of rate of diffusion kept within 100 micro meters

distance

when diffusion can occur across a semipermeable membrane

when the solute molecules can penetrate the membrane

osmotic pressure

how strong a concentrated solution pulls water by osmosis across the membrane

osmotic pressure of pure water

zero

isotonic

equal osmotic concentration on each side

hypotonic

less concentrated solution: lower osmotic pressure

hypertonic

more concentrated solution: higher osmotic pressure

osmo

to push

iso

same

hypo

under/ less than

hyper

above/more than

-tonic

pressure

higher concentration solution

greater osmotic pressure (draws in more water, faster)

osmolarity (Osm)

number of particles in moles / liter solution

molarity (M)

number of compound molecules per liter of solution

homeo

the body

stasis

to keep constant

homeostasis

body tries to maintain constant osmotic concentration of 0.3 Osm for both intracellular and extracellular fluids

concentration of blood plasma

Na+: 150mM

K+: 5mM

Ca2+: 5mM

Cl-: 105mM

HCO₃-:25mM

Proteins (-): 35mM

osmolarity of blood

0.3 osm