Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Chapter 1 pgs. 1-18 > Flashcards

Chapter 1 pgs. 1-18 Flashcards

1
Q

Principles of cellular physiology

A

-body fluids- differences in composition of intracellular and extracellular fluid
-creation of concentration differences by transport processes in cell membranes
-origin of the electrical potential difference across cell membranes particularly in excitable cells such as nerve and muscle
-generation of action potentials and their propagation in excitable cells
-transmission of information between cells across synapses and the role of neurotransmitters
-mechanisms that couple the action potentials to contraction in muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

distribution of water in the body fluid compartments: total body water

A

-total body water- 50-70% weight
-total body water correlates inversely with body fat- women have less water due to more adipose tissue
-distributed between 2 compartments:
-intracellular fluid- 2/3rds of total body water*
-extracellular fluid- 1/3 if total body water*
-separated by cell membranes
-Ca and H out
-Na and K in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

ECF

A

-2 compartments
-plasma- the liquid circulating in blood vessels and is smaller portion
-interstitial fluid- fluid between cells and is larger portion
-these fluids are separated by capillary wall
-interstitial fluid is ultrafiltrate of plasma -> formed by filtration processes across capillary wall
-plasma proteins are impermeable to capillary wall -> interstitial fluid was little to no proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

pH

A

-H+ concentration
-H+ concentration is low in body fluids
-1-14
-negative log

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

macroscopic electroneutrality

A

-each compartment must have the same concentration in mEq/L, of positive charges (cations) as of negative charges (anions)
-even when there is a potential difference across a cell membrane charge balance is maintained in bulk (macroscopic) solutions
-concentration and electrocharge are accounted for

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ECF composition

A

-Na+ is the major cation
-Cl- and bicarbonate (HCO3-) are the balancing anions*
-much higher concentration of Ca2+ than ICF
-higher pH than ICF
-ECF osmolarity = ICF osmolarity due to water flowing freely across cell membranes*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ICF composition

A

-K+ and Mg2+ are the cations*
-proteins and organic phosphates are the balancing anions
-low concentration of ionized Ca2+ (pumped out the cell by pumps)
-lower pH- acidic
-due to differing pH in ICF and ECF substances found in high concentration in ECF are found low in ICF (vice versa)
-ECF osmolarity = ICF osmolarity due to water flowing freely across cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

creation of concentration difference across cell membranes: ATP

A

-energy consuming transport mechanisms in cell membranes are responsible
-pumping against gradients
-Na+-K+ ATPase - transports Na from ICF to ECF and K+ from ECF to ICF
-Na and K transported against electrochemical gradient using ATP
-Ca2+ ATPase- pumps Ca2+ against electrochemical gradient
-intracellular Ca2+ is low and pumps it out
-primary active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

creation of concentration difference across cell membranes: Na+

A

utilize transmembrane Na+ concentration gradient as energy source
-create concentration gradient fro glucose, amino acids, Ca2+ and H+ without direct use of ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

differences in composition between ICF and ECF

A

-The resting membrane potential of nerve and muscle critically depends on the difference in concentration of
K+ across the cell membrane
-The upstroke of the action potential of these same excitable cells depends
on the differences in Na+ concentration across the cell membrane
-Excitation-contraction coupling in
muscle cells depends on the differences in Ca2+ concentration across the cell membrane and the membrane of the sarcoplasmic reticulum (SR)
-Absorption of essential nutrients depends on the transmembrane Na+
concentration gradient (e.g., glucose absorption in the small intestine or glucose reabsorption in the renal
proximal tubule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

concentration difference between plasma and interstitial fluids

A

-proteins (albumin) present in plasma compartment
-cant cross membrane into interstitial fluid
-proteins are negatively charged
-Gibbs-Donnan equilibrium- plasma has lower concentration of small anions (Cl-) and slightly higher cations (Na+ and K+) compared to interstitial fluid in order to balance higher concentration of negative plasma proteins
-gibbs donnan ratio- small concentration difference for permeant ions
-minor differences for small cation and anions between plasma and interstitial fluid are ignored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

cell membranes permeability

A

-lipids (majority) and proteins
-lipids- phospholipids, cholesterol, glycolipids -> high permeability to lipid soluble substances (CO2, O2, fatty acids, steroid hormones)
-lipids portion accounts for low permeability to water soluble substances (ions, glucose, amino acids)
-protein- transporters, enzymes, hormone receptors, cell surface antigens, ion and water channels
-can be affected by temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

phospholipid bilayer

A

-phosphorylated glycerol backbone (head) and 2 fatty acid tails
-cholesterol head- hydrophilic
-fatty acid tail- hydrophobic
-amphipathic
-heads face away from each other to dissolve in aqueous solutions of ICF and ECF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

protein component of membrane

A

-integral
-peripheral- one sided
-channel/carrier- can pass through
-fluid mosaic model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

integral protein in membrane

A

-embedded within
-anchored by hydrophobic interactions within membrane (transmembrane proteins)
-interact with ECF and ICF
-ligand binding receptors (for hormones, neurotransmitters)
-transport proteins
-pores
-receptors
-ion channels
-GTP binding proteins
-some dont span it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

peripheral membrane proteins

A

-not embedded
-not covalently bound to cell membrane
-loosely attached to either IC or EC side through hydrogen bonds/electrostatic interactions
-can be removed with mild treatments that disrupt ionic hydrogen bonds
-ex. ankyrin- anchors cytoskeleton of RBC to integral membrane transport protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

primary active transport vs secondary

A

-primary- required direct input of energy
-secondary- uses indirect input of metabolic energy
-molecule being transported against gradient -> coupled with another molecule going down its concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

carrier mediated transport

A

-facilitated diffusion, primary active transport, secondary active transport
-involve integral membrane proteins
-1. saturation- only a certain amount of molecules that can move at a certain amount of time -> transports is high at first and then levels off once at transport maximum
-2. stereospecificity- binding sites on solutes only allow a certain type of molecule through (no isomers)
-3. competition- if there is more a certain molecule (higher concentration) it will take that first -> inhibits the other molecule
-can recognize, bind, and even transport chemically related solutes even though binding sites are specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

simple diffusion

A

-direct relationship -> increase concentration -> increase diffusion
-carrier-mediated transport will transport rapidly at first and then level off
-as a result of random thermal motion of molecules
-5 Permeability influences:
-Concentration gradient
-Partition coefficient (oil versus water)
-Diffusion coefficient (size and viscosity)
-Thickness of membrane
-Surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

net diffusion rate

A

-flux or flow (J)- net diffusion of a solute
-depends on:
-concentration gradient
-partition coefficient- solubility in oil relative to water
-diffusion coefficient- size and viscosity
-thickness of membrane- greater the distance
-surface area- high SA high diffusion rate
-J = (permeability) X (SA) X (concentration gradient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

partition coefficient

A

-solubility
-the greater solubility in oil the higher partition coefficient and more easily solute can dissolve in the cell membrane
-K = concentration in oil / concentration in water
-higher coefficient higher diffusion rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

diffusion coefficient

A

-diffusion coefficient correlates inversely with size of solute and viscosity of medium/solution
-small solute in nonviscous solutions have the largest diffusion coefficienpt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

permeability equation

A

permeability = (partition coefficient) X (diffusion coefficient) / membrane thickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

diffusion of electrolytes

A

-charged ion
-potential difference across membrane will alter net rate of diffusion of a charged solute
-K+ diffusing into an area of positive charge will diffuse slower -> can negate concentration gradient
-charged solute can generate potential difference itself while diffusing down a concentration gradient -> diffusion potential
-positive ion from outside to inside of cell will create a positive charge within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

facilitated diffusion

A

-carrier mediated transport
-non lipid soluble molecule moving
-going down its concentration gradient but needs protein to allow it to pass through
-GLUT4- glucose
-simple diffusion facilitated through protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

primary active transport

A

-high energy phosphate bond is hydrolyzed - ATP -> ADP
-ATP energy source is directly coupled to transport process
-terminal phosphate phosphorylates and dephosphorylates transport protein in cycle
-1. Na+-K+ ATPase - cell membrane
-2. Ca2+ ATPase - SR and ER
-H+-K+ ATPase - gastric parietal cells and renal alpha-intercalated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Na+ K+ ATPase

A

-cell membranes
-Na+ from ICF to ECF
-K+ from ECF to ICF
-ions moving against electrochemical gradient
-for every 3 Na pumped out 2 K is pumped in -> more positive outside cell -> electrogenic- creates charge separation and potential difference
-E1 state- binding sites for Na and K face ICF and enzyme has high affinity for Na
-E2 state- binding sites for Na and K face ECF and enzyme has high affinity for K
-cycles between E1 and E2 through hydrolysis
-E1 is phosphorylated -> binds Na -> high energy state -> conformational change -> E2 -> release Na + binds K -> dephosphorylation -> binds ATP -> E1

28
Q

cardiac glycosides

A

-digitalis and ouabain - class of drugs that inhibit Na-K ATPase
-intracellular Na concentration increases and intracellular K decreases
-bind to E2 ~ P on the extracellular side -> prevents conversion back to E1
-disrupt entire enzyme cycle and transport functions

29
Q

plasma-membrane Ca2+ ATPase (PMCA)

A

-most cell (plasma) membranes
-PMCA
-Ca2+ from cell against electrochemical gradient to outside
-1 Ca per 1 ATP
-E1 binds Ca2+ on intracellular side -> conformation change -> E2 -> release Ca to ECF

30
Q

SR and endoplasmic reticulum Ca2+ ATPase (SERCA)

A

-sacroplasmic reticulum of muscle cells and ER or cells
-2 Ca2+ per ATP
-from ICF to interior of SR or ER
-E1 binds Ca2+ on intracellular side -> E2 releases Ca to lumen of SR or ER

31
Q

H+ K+ ATPase

A

-in stomach
-pumps hydrogen into stomach -> acidic environment
-inhibited by omeprazole (treats peptic ulcer disease)
-in kidneys to pump hydrogen out as well

32
Q

secondary active transport

A

-against concentration gradient
-ATP has been used somewhere else and coupled
-indirect use of ATP
-ex. when transporting glucose you can couple it with Na moving down its concentration gradient into the cell
-Na K pump used ATP to create Na gradient moving into cell (indirect)
-carrier mediate proteins need Na
-inhibitors of the Na-K ATPase cause Na concentration to increase inside the cell -> lack of gradient -> indirectly stops secondary active transport mechanisms due to lack of energy source
-cotransport/symport
-countertransport/antiport/exchange

33
Q

cotransport/symport

A

-solute being transported by carrier mediated proteins are moving in the same direction as Na
-secondary active transport
-ex. Na-glucose, Na-amino acid, Na+-K+-2Cl-

34
Q

countertransport/antiport/exchange

A

-solute being transported is moving in opposite direction of Na
-ex. Ca-Na, Na-H
-pushes Ca against gradient out of the cell along with Ca primary active transport (intracellular Ca concentration is very low)

35
Q

osmosis

A

-flow of water across semi permeable membrane
-diffusion- due to differences in solute concentration
-difference solute concentrations cause osmotic pressure difference
-osmosis occurs due to pressure difference
-diffusion of water is NOT osmosis

36
Q

osmolarity

A

-concentration of solution
-high osmotic solution (hyperosmotic) -> water diffuses in
-low osmolarity solution (hyposmotic) -> water flows out
-trying to achieve isosmotic - same osmolarity
Osm/L

37
Q

osmolality

A

-is the concentration of osmotically active particles
-Osm/kg of water

38
Q

osmotic pressure

A

-driving force/pressure for water moving from one solute to another
-same osmotic pressure -> isotonic

39
Q

reflection coefficient

A

-describes ease of a SOLUTE across a membrane
-between 0 and 1
-0= freely permeable
-1= impermeable

40
Q

ion channels

A

-selective to certain ions determined by the ion channels gates
-conductance of a channel depends on probability that it is open
-higher conductance, higher probability it is open, high permeability (vice versa)

41
Q

sensors

A

-tell ion gates to open
-voltage gated channels
-second messenger gated channels
-ligand gated channels

42
Q

voltage gated channels

A

-changes in membrane potential -> open/close gate
-ex. nerve Na+ channel gate opens by depolarization of nerve cell membrane

43
Q

secondary messenger gated channels

A

-changes in level of intracellular secondary messengers
-intracellular signaling
-cAMP, IP3
-G proteins create cAMP
-accumulation of secondary messages may open gates
-sensors are inside of cell

44
Q

ligand gated channels

A

-controlled by hormones and neurotransmitters (open or close)
-sensors are on extracellular side
-ex. nicotininc receptor on motor end plate opens when ACh binds -> Na and K are permeable

45
Q

diffusion potentials: magnitude

A

-charge that is generated by the movement of electrolyte
-diffusion potentials are caused by diffusion of ions
-magnitude of diffusion potential depends on size of concentration gradient (mV)
-sign of diffusion potential depends on the charge of the diffusion ion
-creation of diffusion potentials are created by movement of only a few ions -> does not change the concentration of ions in bulk solution
-ex. Na+ moving into the cell will significantly change the charge + inside the cell but there was an insignificant concentration change

46
Q

equilibrium potential

A

-Na moves into the cell down its concentration gradient -> eventually the positive charge being created inside the cell will stop diffusion of Na into the cell even through the concentration gradient is still present
-electrical potential > concentration gradient
-stops its own movement
-cancels itself out

47
Q

nernst equation

A

-effect of temp and concentration on an ion to move across membrane
-at what concentration gradient and what membrane potential will cancel each other out
-at what point will movement of solute down its concentration gradient stop due to diffusion potential created
-each solute has its own equilibrium potential- changes based on cell- each cell has different amount of solute coming in and out
-calculates equilibrium potential for an ion at a given concentration difference across a membrane (assuming the membrane is permeable to ion)
-Na = +65
-Ca = +120
-K = -95
-Cl = -90

48
Q

net driving force

A

-charged ions are driven by charge and concentration
-the actual membrane potential is (dependent on cell) - calculated equilibrium potential is for that ion
-ex. -70 - 65 (Na)= -
-if net driving force is neg a cation will enter cell and leave if its anion
-if driving force is positive cation will leave cell and anion will enter

49
Q

ionic current

A

-movement of an ion across a cell membrane
-depending on driving force for ion and conductance
-direction of ionic current is determined by direction of driving force
-magnitude of ionic current is determined by conductance of ion and size of driving force
-ionic current = ionic conductance (driving force on ion X)

50
Q

plasma proteins

A

-negatively charged

51
Q

passive transport

A

-movement of solute down concentration gradient (high ⇒low)
-doesnotrequire energy (ATP hydrolysis)
-3 types:
-Simple diffusion– movement of small or lipophilic molecules (e.g. O2, CO2, etc.) Across a membrane.
-Osmosis– movement of water through aquaporins
-Facilitated diffusion– movement of large or charged molecules via membrane proteins (e.g. ions, sucrose, etc.)

52
Q

active transport

A

-movement of solute againstconcentration gradient(low ⇒high)
-requires energy (e.g. ATP hydrolysis)
-2 types transport with a protein:
-Primary(direct)active transport– Involves the direct use of metabolic energy (e.g. ATP hydrolysis)
-Secondary(indirect)active transport– coupling the molecule with another moving along an electrochemical gradient

53
Q

Clinical box: At his annual physical examination, a 14-year-old boy reports symptoms of frequent urination and severe thirst. A dipstick test of his urine shows elevated levels of glucose. The physician assistant orders a glucose testing, which indicates that the boy has type I diabetes mellitus. He is treated with insulin by injection, and his dipstick test is subsequently normal

A

-Glucose in blood is filtered across glomerular capillaries in kidneys
-epithelial cells that line the renal proximal tubule reabsorb the filtered glucose so that no glucose is excreted in urine
-If epithelial cells in proximal tubule do not reabsorb filtered glucose back into blood -> glucose is excreted
-Na+-glucose cotransporter in the luminal membrane of the proximal tubule-> glucose reabsorption

54
Q

diabetes mellitus type 1

A

-pancreatic beta cells dont produce enough insulin
-insulin is required for normal uptake of glucose into liver, muscle, cells etc.
-bc glucose isnt taken in by cells -> increases blood glucose
-amount of glucose filtered by renal glomeruli exceeds capacity of Na-glucose cotransport
-carrier mediated transport saturation -> excess glucose is spilled into urine

55
Q

treatment of diabetes mellitus type 1

A

-administer exogenous insulin by injection
-promotes glucose uptake into cells
-insulin -> decrease blood glucose -> decrease glucose filtered -> no longer saturated transporter -> all glucose is reabsorbed -> no glucose in urine

56
Q

A 72-year-old man was diagnosed recently with small cell carcinoma of the lung. He tried to stay busy with consulting work, but the disease sapped his energy. One evening, his wife noticed that he seemed confused and lethargic, and suddenly he suffered a grand mal seizure.

A

-In ED his plasma Na+concentration was 113 mEq/L (normal, 140 mEq/L)
-plasma osmolarity was 230 mOsm/L (normal, 290 mOsm/L)
-treated with infusion of hypertonic NaCl
-strict instructions to limit his water intake
-Hyposmolarity With Brain Swelling

57
Q

small cell carcinoma

A

-autonomously secretes antidiuretic hormone (ADH) -> syndrome of inappropriate antidiuretic hormone (SIADH)
-ADH influences how much your body will retain or lose Na and in turn water
-SIADH- high circulating levels of ADH cause excessive water reabsorption by the principal cells of the late distal tubule and collecting ducts
-excess water that is reabsorbed and retained dilutes Naconcentration and osmolarity of the ECF
-decreased osmolarity -> decreased effective osmotic pressure of ECF
-briefly, osmotic pressure of ECF < osmotic pressure of ICF -> brain swelling
-osmotic pressure difference across cell membrane causes osmotic water from ECF -> ICF -> cell swelling
-swelling of brain can cause seizure bc skull limits it

58
Q

treatment of small cell carcinoma

A

-hypertonic NaCl infusion
-quickly raises ECF osmolarity and osmotic pressure
-eliminates effective osmotic pressure difference across brain cell membranes
-stop osmotic water flow and brain cell swelling
-water moves back into plasma

59
Q

digoxin

A

-slows heart rate
-cardiac glycoside (inhibits Na-K pump)
-blocks the sodium potassium pump
-blocks intake of K
-if you give too much it can stop the heart
-no net movement of Na or K
-side effects- blocks Na-K pump in rest of body -> vision changes

60
Q

sodium glucose cotransport

A

-from intestines to blood stream
-within lumen of intestines
-SGLT1
-brings in Na and glucose
-Na and K pump - brings in K and Na out
-Na move in then due to concentration gradient being created -> brings glucose with it

61
Q

Jardiance

A

-blocks sodium glucose cotransport
-lower glycemic levels
-doesnt absorb as much glucose

62
Q

calcium sodium countertransport

A

-muscle cell
-bring in Na and move out Ca
-Na - K pump is pumping out Na and pumping in K -> creates a gradient for Na to flow in

63
Q

ankle swelling

A

-more pressure (gravity)
-osmosis
-pressure gradient
-out of cellular membrane -> fluid moves into interstitial fluid
-standing too much
-too much Na

64
Q

Hemoglobin A1c

A

-how sugar coated your RBCs are
-stick to glycoproteins
-high when constantly coated
-90-120 days

65
Q

metformin

A

pushes more glucose into muscles

66
Q
A

Physiology (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions