Phys Test #1

Front 1

Resting membrane potential

Back 1

-90 mV with a net negative charge in the cell

Front 2

electrochemical gradient created by

Back 2

K+ and its high permeability &
Na+ with its slight permeability through leak channels

Front 3

The action of the Na-K ATPase pump gives

Back 3

(transports 3Na out for 2 K in)
a net negative charge on the inner membrane surface.

Front 4

Which cation has the greatest control and role in setting the membrane potential

Back 4

K+ due to its higher permeability

Front 5

Stages of an action potential

Back 5

Resting State
Depolarization
Repolarization

Front 6

Resting State

Back 6

Polarized membrane

Front 7

Depolarization

Back 7

membrane becomes permeable to Na and there is an influx of large numbers of Na cations through fast sodium leak channels during phase 0

Front 8

Phase 0

Back 8

Upstroke

Front 9

When electrical potential rises slightly passed 0

Back 9

overshoot

Front 10

Repolarization

Back 10

potassium influx from the cell

Front 11

Voltage-gated sodium channel include

Back 11

activation gate (ECF)
inactivation gate (ICF)

Front 12

hyperpolarizing

Back 12

when membrane becomes even more negative than at rest(polarized) for a few milliseconds after the action potential is over

Front 13

hyperpolarized AKA

Back 13

(positive) after potential

Front 14

Initiation requires:

Back 14

a stimulus to cause a threshold for action potential initiation of (-50 to -70 mv)

Front 15

subthreshold

Back 15

stimulus fails to elict an action potential

Front 16

threshold

Back 16

produces a full action potential due to a critical number of sodium channels open and activated

Front 17

A subthreshold response is AKA

Back 17

graded potential

Front 18

A full response

Back 18

Action potential

Front 19

How the Action Potential Spreads

Back 19

Electronic Conduction

Front 20

The threshold is a cue to

Back 20

allow all sodium channels to open

Front 21

Why hyperpolarization occurs

Back 21

some potassium channels stay open and allow K+ to come efflux form the cell even after repolarization is complete

Front 22

Summation of Graded Potentials can be

Back 22

Spatial Summation
Temporal Summation

Front 23

Does summation apply to action potentials?

Back 23

NO. An action potential is generated when the stiumul causes the membrane potential to reach threshold and increasing the stimulus about threshold does not increase ampliture or velocity of the AP

Front 24

Re-establishment is due to increasing number of action potentials which causes

Back 24

intracellular sodium concentrations to rise which activates the Na-K ATPase pump

Front 25

Many tissues (such as the heart beat) have the ability to generate their own AP (AUTOMATICITY) this is due to

Back 25

During resting state, the membrane must be sufficiently permeable to Na+ ions or Na+ and Ca++ ions to allow spontaneous depolarization

Front 26

Occurs in virtually all excitable cells that exhibit

Back 26

automaticity

Front 27

DUring the relative refractory period a cell cannot be unless

Back 27

a stronger than normal stimulus is applied

Front 28

Absolute Refractory Period

Back 28

No stimulus, no matter how large can cause a new action potential

Front 29

Relative Refractory Period

Back 29

Only a stronger than normal stimulus can elicit an action potential

Front 30

No stimulus no matter how large can elicit a second action potential during

Back 30

The Absolute Refractory Period
The Action Potential

Front 31

During the RRP, the second stimulus required to generate the action potential is

Back 31

GREATER than the action potential of the original stimulus and DECREASE as the time interval between stimuli increases

Front 32

Between adjacent Schwann cells the sheath is interuppted by

Back 32

Nodes of Ranvier (an uncovered area)

Front 33

Salatory Conduction

Back 33

AP occur and are only regenerated at nodes and are conducted from node to node.

Front 34

Salatory Conduction does two things

Back 34

Conserves energy
Increase veolcity of nerve conduction

Front 35

The tails of the phosphlipids of the cell membrane contain

Back 35

hydrocarbon unites of fatty acids "hydrophobic"

Front 36

The hydrophobic inner portion of the phospholipid bilayer makes it

Back 36

impermeable to ionic or highly polor, water-soluble substances.

Front 37

Can water cross the phospholipid bilayer?

Back 37

YES! It can move between phospholipids

Front 38

The fluidity of the membrane is determined by

Back 38

the ratio of membrane cholesterol to phosphlipids

Front 39

Fluidity is increased by

Back 39

Lower levels of cholesterol

Front 40

Can dissolve in and span the lipid bilayer

Back 40

intergral proteins or transmembrane proteins

Front 41

Integral proteins can serve as

Back 41

Ion Channels or Pumps
Carriers for Transport Processes

Front 42

Peripheral Proteins serve as

Back 42

intracellular cytoskeleton and
in intracellular molecular signaling processes

Front 43

Carbohydrate Portions of Glycoproteins or Glycolipids are located where?

Back 43

At the outer membrane in contact with the ECF.

Front 44

The function of the cell membrane

Back 44

Highly Selectively permeability barrier that regulates the composition of the ICF and allows the ICF to maintain different composition that the ECF

Front 45

The Rough Endoplasmic Reticulum has a presence of

Back 45

ribosomes

Front 46

Where protein synthesis occurs

Back 46

ribosomes

Front 47

What happens at the smooth endoplasmic reticulum?

Back 47

Presence of oxidizing enzymes that metabolize foreign chemicals, including drugs

Front 48

What is the golgi apparatus responsible for?

Back 48

Formation of lysosomes and secretory vesicles

Front 49

What is the function of a lysosome?

Back 49

Intracellular digestion
-damaged cell structures
-foreign material

Front 50

Lysosomes are also known as

Back 50

hydrolases (granules containing digestive enzymes)

Ex. proteases

Front 51

Peroxisomes contain oxidizing enzymes responsible for

Back 51

intracellular formation of hydrogen peroxide

Front 52

Hydrogen peroxide is reduced to water by

Back 52

Catalase (enzyme)

Front 53

The mitochondria's inner matrix is responsible and contains enzymes for

Back 53

oxidative phosphorylation

Front 54

Oxidative Phosphorylation is

Back 54

the process by which nutrients (primarily glucose) are oxidized ti yield CO2 and water while releasing large amounts of energy and heat

Front 55

Energy obtained from oxidative phosphorylation is used in the synthesis of

Back 55

ATP

Front 56

What is the function of the cytoskelton?

Back 56

To provide structural support for the cell membrane and other structures.

Front 57

The cytoskeleton is composed of:

Back 57

filaments (for contractile mechanism)
Microtubles

Front 58

What is endocytosis?

Back 58

The uptake and internalization of extracellular material and very large molecules by cells by using ATP

Front 59

What does endocytosis do:

Back 59

-transports large molecules into the cell that cannot pass by diffusion or carrier-mediated transport
-clearance of proteins or pathogens from the EC comparment follwed by IC lysosomal digestion and degradation

Front 60

Receptor-mediated endocytosis is

Back 60

the specific uptake of a substance by the cell with the plasma membrane receptors for that substance (AKA ligand)
Ex. LDL low-density lipoproteins

-Also allows absorption of specific substances from the ECF which cannot be absorbed by diffusion or transport

Front 61

When a receptor binds to the membrane it causes a

Back 61

conformational change and allows for the membrane to retract inward

Front 62

Receptor-mediated endocytosis requires

Back 62

ATP, energy

Front 63

On average how much total body water do we have?

Back 63

42L

Front 64

The amount of Intracellular fluid is

Back 64

28L (2/3 amount of water in our bodies)

Front 65

Extracellular fluid consists of

Back 65

Intravascular Volume and Interstitial Volume

Front 66

Intravascular volume is

Back 66

5L, however plasma volume only accounts for 3L & the other portion or hematocrit counts for 2L- Therefore the plasma Volume is only 3L

Front 67

Hematocrit

Back 67

"packed" RBC volume representing the fraction of blood volume that is RBC

Front 68

Interstitial Fluid Volume

Back 68

Total of ECF Volume minus plasma volume ---> 11L

Front 69

Fluid and plasma proteins that escapes the plasma volume is returned to the circulation by means of

Back 69

lymphatic vessels

Front 70

Sodium is in higher concentration in the

Back 70

Extracellular Fluid

Front 71

Potassium is in higher concentration

Back 71

Intracellular Fluid

Front 72

Cation that is toxic to the ICF which is why we have so little of it inside our cells

Back 72

Calcium

Front 73

Due to metabolic reactions the inside of our cells are slightly

Back 73

acidic

Front 74

Fluid exchange between the ECF and ICF is regulated by

Back 74

osmotic forces exterted by small solutes

Front 75

Osmosis is

Back 75

the net movement of water between compartments due to a concentration difference
-from a higher concentration to a lower concentration

Front 76

Osmotic Pressure

Back 76

the amount of pressure required to stop the osmotic movement of water between the two compartments

Front 77

Water moves from

Back 77

A region of low solute concentration to high solute concentration

Front 78

The concentration difference of water is determined by

Back 78

dissolved solute particles

Front 79

Osmotic pressure is determined by

Back 79

the number of osmotically active particles in solution

Front 80

Osmolarity of the ECF

Back 80

300 mOsM

Front 81

Isomotic

Back 81

two solutions exert identical osmotic pressures

Front 82

Example of Hyperosmotic

Back 82

If solution A exerts a greater Osmotic pressure than solution B then A is hyperosmotic with respect to B

Front 83

Example of Hypoosmotic

Back 83

If solution A exerts a lower osmotic pressure than solution B then A is hypoosmotic in comparison to B

Front 84

Tonicity

Back 84

effects on volume of cells caused by osmotic pressure exerted by an aqueous medium

Front 85

In a solution that is isotonic with respect to the plasma

Back 85

RBC's will have the identical cell volume as they do in plasma

Front 86

In a solution that is hypertonic with respect to the plasma

Back 86

RBC's will shrink (crenation) since the osmotic pressure of the medium is greater than in the RBC.

Front 87

If a RBC is placed in a hypertonic environment

Back 87

The cell will shrink in attempts to equalize the pressures on both sides of the RBC membrane. The RBC volume will decrease and the medium's volume will increase.

Front 88

In a solution that is hypotonic with respect to the plasma,

Back 88

RBC's will expand since the osmostic pressure of the medium is lower than in the RBC.

Front 89

If a RBC is placed in a hypotonic environment

Back 89

water will enter the RBC increasing the volume of the RBC in order to equalize the osmotic pressure on both sides of the RBC membrane.

Front 90

Lysis

Back 90

when the RBC volume expansion is so great that it actually changes the membrane permeability properties

Front 91

The final cell volume ultimately depends on

Back 91

the concentration of impermeable solutes

Front 92

Since gylcerol is a permeable solute (small & water soluble) its concentration is

Back 92

quickly equilibriated on both sides of the RBC membrane.

Front 93

IN order to move between the ICF and ECF cells must undergo

Back 93

a transport process

Front 94

Two types of Diffusion

Back 94

Simple
Facilitated

Front 95

Does either type of diffusion - simple or facillatated require energy?

Back 95

NO.

Front 96

Lipid-soluble movement of substance through the cell membrane is determined by

Back 96

concentration gradient

Front 97

Concentration gradient refers to

Back 97

the tendency for a substance to move from a region of higher concentration to a region of lower concentration

Front 98

Lipid Solubility Diffusion is determined by

Back 98

the ability to dissolve through the phospholipid bilayer and permeate through the membrane

Front 99

Lipid Solubility is determined by

Back 99

The partition coefficient, Kp

Front 100

The higher the KP

Back 100

the more soluble the substance

Front 101

For simple diffusion of water soluble substances, the ions are transported accoring to their

Back 101

electrochemical gradient for that ion.

Front 102

Facilitated Diffusion

Back 102

movement of a substance through a cell membrane along its electrochemical gradient which requires a specific carrier molecule (Integral protein)

Front 103

Is energy required for facilitated diffusion?

Back 103

no energy is required since a gradient must be present for movement to occur.

Front 104

Rate of movement for Facilitated Diffusion depends on:

Back 104

1. All factors affecting simple diffusion (concentration, amount of kinetic energy, and surface area or membrane)
2.above a maximal substance concentration, the carrier mlcls become saturated and reach a Vmax (maximal transport velocity)

Front 105

At Vmax

Back 105

transport will not increase no matter the increase in substance concentration

Front 106

Usually in facilitated diffusion, the transported substances are

Back 106

ions or large polar mlcls whose rates of diffusion by passive transport would be extremely slow or for which passive diffusion might not even occur.

Front 107

The carrier mechanism increases

Back 107

rate of transport unobtainable from simple diffusion by making the membrane permeable to substances which would otherwise be impermeable.

Front 108

Properties of Carrier mediated transport (Facilitated and Active Transport)

Back 108

1.chemical specificity
2. sterospecificity
3. competition

Front 109

Active Transport is

Back 109

"uphill" movement of a substance against its electrochemical gradient requiring energy.

Front 110

Primary Active Transport

Back 110

Energy input derived from ATP

Front 111

Secondary Active Transport

Back 111

Energy input derived from stored "potential" energy in the form of a concentration gradient created by another primary active transport process

Front 112

All active transports require

Back 112

a carrier protein which has the same properties as facilitated diffusion.

Front 113

Na+K+ Pump is an example of what and does what

Back 113

1. Primary Active Transport
2. Pumps 3 Na out of the cell for 2 K into the cell

Front 114

The purpose of the Na/ K pump is to

Back 114

maintain Na concentrations in the ECF and K concentrations in the ICF

Front 115

Since the Na+/K+ pump maintains a constant cell volume by reducing the ion concentrations in the cell,

Back 115

it reduces the osmotic flow of water into the cell

Front 116

Two types of Secondary Active Transport

Back 116

1. Cotransport
2. Countertransport

Front 117

Cotransport of substances with sodium cations

Back 117

Since the Na+/K+ pump creates a large concentration gradient for Na+, the movement of Na down its concentration gradient creates stored energy which is the used to transport other substances.

Front 118

Countertransport with sodium cation

Back 118

Movement of sodium and other substances in opposite directions

Front 119

Transepithelial transport sites

Back 119

1. GI tract
2. renal tubules

Front 120

In transpithelial transport

Back 120

cells are polarized with respect to transport properties

Front 121

The resting membrane potential is due to :

Back 121

1. Electrochemical potential created by postassium alone (high permeability of K)
2. Electrochemical potential created by Na alone (slight membrane permeability through leak channels)
3. action of the Na/K ATPase pump
4. negative net charge on the inner membrane surface

Front 122

Difference Between Graded Potential and Action Potential's Response

Back 122

1. Graded Response, amplitude varies with conditions of the initating event
2. ALl or nothing response, amplitude is independent of the initiating event

Front 123

Difference Between Graded Potential and Action Potential's Ability to have summation

Back 123

1. Graded has the ability to be summed
2. Action potential does not

Front 124

Difference Between Graded Potential and Action Potential's Threshold

Back 124

1. Graded has no threshold
2. Action potential has a threshold usually between 10 to 15mV depolarized relative to the resting potential

Front 125

Difference Between Graded Potential and Action Potential's Refractory Periods

Back 125

1. Graded has no refractory period
2. Action Potential has a refractory period

Front 126

Difference Between Graded Potential and Action Potential's Conduction

Back 126

1. Graded is conducted decrementally, amplitude decreases with distance
2. Action Potential is conducted with decrement; amplitude is constant

Front 127

Difference Between Graded Potential and Action Potential's Duration

Back 127

1. Graded potentials duration depends on the initiating conditions
2. Action potentials duration is constant for a given cell type

Front 128

Can Graded Potential or Action Potential be Depolarized or Hyperpolarized?

Back 128

1. Graded potential can be depolarized or hyperpolarized
2. Action potential has depolarization (with overshoot)

Front 129

Individual muscle fibers which are long, cylindrical,and multi nucleated

Back 129

Myocytes

Front 130

Cell membrane of a muscle fiber

Back 130

sarcolemma

Front 131

Myofibrils extend the entire length of the muscle and consist of longitudinally arranged bundles of

Back 131

Thick and thin filaments

Front 132

Myosin

Back 132

Thick filament

Front 133

Actin

Back 133

Thin Filament

Front 134

Sympathetic Autonomic Nervous System has what kind of fibers

Back 134

Short Preganglionic fibers
Long Postganglionic fibers(traveling to effector target organ)

Front 135

Innervation of the adrenal medulla consists of

Back 135

Preganglionic fiber going directly to adrenal medulla and terminating on chromaffin cells which are capable of secreting NE and EPI

Front 136

Adrenal Medullary Cells are analagous to

Back 136

postganglionic neurons

Front 137

Parasympathetics nerves originate as

Back 137

Cranial Nerves
Sacral Nerves

Front 138

Parasympathetic Nervous System has what kind of fibers

Back 138

Long Preganglionic- going all the way to ganglia at or near target organ walls
Short Postganglionic- distributes thoughout the organ

Front 139

Cholergenic fibers secrete

Back 139

ACh

Front 140

Adrenegic Fibers Secrete

Back 140

NE

Front 141

In both SNS and PNS the preganglionic fibers are

Back 141

Cholergenic

Front 142

Postganglionic Fibers in PNS are

Back 142

Cholergenic

Front 143

Postganglionic Sympathetic Fibers are

Back 143

Adrenergic except for sweat glands and pilorector muscles

Front 144

ACh is terminated by

Back 144

Hydrolysis by the enzyme acetylocholinesterase (AChE)

Front 145

NE is terminated by

Back 145

(80%) through uptake into the nerve terminal by an active transport mechanism.

Front 146

Cholinergic receptors are either

Back 146

Muscarinic or nicotinic

Front 147

Muscarinic are located at

Back 147

parasympathetic postganglionic sites and at some sympathetic sites (sweating)

Front 148

Nicotinic are located at

Back 148

1. synapses between preganglionic and postganglionic fibers in both systems
2. Adrenal Medulla
2. NMJ (not in PANS)

Front 149

Adrenergic Receptors are classified as

Back 149

Alpha or Beta

Front 150

Alpha1 Receptors

Back 150

located at sympathetic postganglionic sites (smooth muscle)
-increased intracellular calcium

Front 151

Beta Receptors are located

Back 151

Located at Sympathetic postganglionic sites

Front 152

Beta Receptors are divided into 3 subgroups:

Back 152

1. beta1 receptors (visceral organs)
2. beta2 receptors (vascular and visceral smooth muscle)
3. beta3 receptors (fat cells)

Front 153

Parasympathetic Response of Pupil

Back 153

Miosis (constriction)

Front 154

Parasympathetic response to exocrine glands

Back 154

copious, watery secretion (nasal, saliva, RT, GIT)

Front 155

SNS and PNS response to cardiac muscle

Back 155

1. increased contractibility (beta1)
2.decreased contractibility

Front 156

SNS and PNS response to SA node

Back 156

1. increased rate (beta1)
2. decreased rate

Front 157

SNS and PNS response to vascular smooth muscle

Back 157

1. contricted (alpha1)
2. no response

Front 158

SNS and PNS response to bronchiolar smooth muscle

Back 158

1. dilated (beta2)
2. contricted

Front 159

PNS response to gut wall

Back 159

1. increased peristalsis

Front 160

SNS response to sphincters

Back 160

contracted (alpha 1)

Front 161

PNS response to skin

Back 161

contracted

Front 162

PNS response to bladder

Back 162

contracted (urination)

Front 163

SNS response to sphincter

Back 163

contracted (alpha 1)

Front 164

PNS response to penis

Back 164

Erection

Front 165

Sympathetic responses to metabolism

Back 165

liver-glycogenolysis
BMR-increased up to 100%
adrenal medulla-increased secretion
skeletal muscle-glycogenolysis
fat-lipolysis (beta3)
kidney-renin secretion(beta1)

*Parasympatheic has no metabolic responses*

Front 166

Sympathetic stimulation of the adrenal medulla causes

Back 166

release of NE (20%) and EPI (80%) into the blood & resulting end organ effects lasting 5-10 times as long as the effects by sympathetic nerve stimulation alone

Front 167

Without the prescrence of _____ there would be no mechanism for dilation.

Back 167

tone

Front 168

Inhibition of normal tone allows for

Back 168

dilation

Front 169

Sympathetic stimulation increases

Back 169

vasoconstriction(sympathetic tone)

Front 170

SNS effects are

Back 170

massive, rapid activation of the SNS to provide activation in response to powerful stimuli

Front 171

SNS produces what type of response

Back 171

fight or flight

Front 172

Responses of activation to powerful stimuli by the SNS include

Back 172

1. increased arterial pressure and heart rate
2. increased blood flow to skeletal muscles
3.decreased blood flow to the GI and GU tracts
4.increased blood glucose and metabolic rate
5. increased glycogenolysis in liver and muscle

Front 173

PNS repsonses are

Back 173

localized and discrete