Exam 3 Flashcards

1
Q

Skeletal Muscle Contraction Activation

A

1) The sarcoplasmic reticulum releases Ca2+
2) Ca2+ binds to troponin (which is bound to tropomyosin
3) Troponin changes conformation
4) Tropomyosin is lifted off the myosin binding sites location on actin
5) The Actin-Myosin interaction may occur

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2
Q

Troponin

A

Globular regulatory protein for skeletal and cardiac muscle located on actin which holds down tropomyosin so the myosin sites are blocked. What Calcium ions actually bind to.

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3
Q

Tropomyosin

A

Rod shaped regulatory protein for skeletal and cardiac muscle contraction. Wraps around actin and blocks the myosin binding sites on actin.

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4
Q

Actin

A

Thin filament made of a globular protein chain with cross bridge binding area

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5
Q

Myosin

A

Tick filament made of thick chains with a cross bridge head which has a binding site for actin and ATP/ase

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6
Q

Myoneural Junction

A

Same as a neuromuscular junction. Has an increased surface area with invaginations where acetylcholine receptors are located

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7
Q

Activated Crossbridge Intermediate

A

MyosinADPPi

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8
Q

Sliding Filament Mechanism

A

ATP binds to myosin making activated crossbridge intermediate. Myosin crossbridge binds to actin. Immediately the crossbridge changes conformation pulling actin over and releasing ADP*Pi to make the actin-myosin complex

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9
Q

Skeletal Muscle

A

Large/long cells that are multinucleated and striated with mitochondria on the outside… sarcoplasmic reticulum.

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10
Q

Sarcomeres

A

Repeating patters of actin and myosin

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11
Q

Structure of a Muscle

A

Tendons attach at the origin and insertion points, connective tissue surrounds the muscle fiber (cell), which is composed of many myofibrils that which have many sarcomeres

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12
Q

Actin/Myosin Arrangement

A

For each thick filament there are two thin filaments. But a single myosin is surrounded by six actin and then each actin is surrounded by three myosin making a kind of honeycomb pattern.

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13
Q

Sarcoplasmic reticulum

A

Homologous to the ER in a cell. Forms a series of sleevelike segments around each myofibril. At each end there are terminal cisternase.

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14
Q

Terminal Cisternase

A

Ends of sarcoplasmic reticulum where the Ca2+ is stored and then released from into the cytosol following membrane excitation. Closely associated with the T-Tubules.

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15
Q

Motor Neurons

A

(Somatic Efferent Neurons) The neurons whose axons innervate skeletal muscle fibers, and their cell bodies are located in the brain-stem and the spinal cord.

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16
Q

Motor Unit

A

A motor neuron and the muscle fibers it innervates. A single neuron innervates many muscle fibers but each muscle fiber is controlled by a branch from only one motor neuron.

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17
Q

Motor End Plate

A

The region of the muscle fiber plasma membrane that lies directly under the terminal portion of the axon

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18
Q

Neuromuscular Junction

A

The junction of an axon terminal with the motor end plate

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19
Q

Transverse Tubules

A

(T Tubules) Lies directly between terminal cisternae of adjacent segements of the SR, both of which surround the myofibrils. T-Tubules continuous with the PM and the AP propagating along the surface membrane also travels throughout the interior of the muscle fiber by why the T-Tubule. Lumen is continuous w/ ECF surrounding muscle fiber.

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20
Q

Skeletal Muscle ATP Requirements

A
  • Crossbridge movement
  • Breaking the Actin-Myosin Link
  • For Ca ATPase
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21
Q

Motor End Plate Events

A

1) The action potential causes Ca Channels to open at the axon terminal
2) Increase in intracelluar Ca causes ACH vesicles to migrate and fuse with cell membrane, expelling content
3) Ach binds to the receptor(nicotinic), diffuse away, active reuptake, enzymatic degradation
4) Ach-Receptor opens channels post membrane depolarization
5) Muscle fiber action potential after threshold

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22
Q

Curare

A

Antagonist binds to receptors

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23
Q

Organophosphates

A

Inhibit acetylcholinesterase

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24
Q

Botulism Toxins

A

Blocks Ach release

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25
Q

Mynsthenia Gravis

A

Decrease Ach release

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26
Q

Choline Acetyl Transferase

A

Forms Ach

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27
Q

Acetylcholine Esterase

A

Breaks down Ach

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28
Q

Excitation Contraction Coupling

A
  • Resting state
  • Membrane depolarization and repolarization
  • –Na channels…open,close
  • –K channels….open,close
  • Depolarization sweeps through T-Tubule System
  • T-Tubule system releases Ca stimulating sarcoplamic reticulum
  • To release Ca by channels
  • After Ca release is finished Ca ATPase pups Ca back into SR
  • As Ca is removed troponin-topomyosin goes back to resting state
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29
Q

Activating Actin

A

1) Tropomyosin covers myosin binding sites on actin with troponin keeping it in place
2) Ca2+ levels are increased
3) Ca2+ binds to troponin
4) Binding changes shape of troponin
5) Troponin lifts tropomyosin off the myosin binding site on actin
6) Normal Actin-Myosin interactions can then occur

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30
Q

Sliding Filament Mechanism Major Steps

A

Initiation and Perpetuation. Note initiation happens once and repetition many times.

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31
Q

Dihydropyridine receptor

A

(DHP Receptor) T-Tubule membrane protein that is a modified voltage-sensitive channel whose main job is not to conduct Ca but rather to act as a voltage sensor.

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32
Q

Initiation of The Sliding Filament Mechanism

A

1) Myosin binds to ATP
2) Binding activates actin-binding site on myosin crossbridge by using some of the ATP energy
3) The MyosinADPPi complex binds actin using the myosin crossbridge
4) This binds actin by using energy from the ADPPi and causing crossbridge to move and ADPPi is split from myosin
5) Leaves Actin-Myosin Complex

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33
Q

Perpetuation of The Sliding Filament Mechanism

A

1) Have Actin-Myosin Complex
2) ATP binds myosin and myosin ‘releases’ actin
3) Myosin activated by myosinADPPi
4) The myosinADPPi binds to actin
5) Crossbridge activity so ADP*Pi is lost
6) Back to 1

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34
Q

Rigor Mortis

A

Cross bridges remain bound

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35
Q

Changes During Sliding Filament Mechanism

A

Shortening of the sarcomeres occurs with an additive shortening of the z-lines. The thick and thin filaments do not change size.

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36
Q

Contraction

A

Does not necessarily mean shortening but simply refers to activation of the force-generating sites within muscle fibers known as cross-bridges.

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37
Q

Skeletal Muscle ATP Sources

A

Oxidative Phosphorylation , Glycolysis, and Creatine Phosphate

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38
Q

Oxidative Phosphorylation

A

Uses fat? ADP+Pi—ATP in mitocondria and makes water and CO2

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39
Q

Glycolysis

A

(glucose/glycogen in cytoplasm can make lactic acid if fermented) ADP+Pi—ATP

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40
Q

Creatine Phosphate

A

More of a stop-gate measure to keep it going. Uses the enzyme Creatine kinase to take CP + ADP —-ATP + C

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41
Q

Factors for Muscle Tension

A
  • Number of muscle fibers contraction (recruitment increased by neural input)
  • Amount of tension developed by each fiber
  • Optimal stretch/length (arrangement of actin and myosin)
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42
Q

Single Twitch

A

Normal contraction and relaxation

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43
Q

Muscle Contraction graph

A

Latent period after stimulation and then increase of distance shortened until peak around 80ms followed by a 40ms relaxation

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44
Q

Summation

A

Incomplete relaxation so the muscle contracts and this additional contraction adds onto the previous contraction.

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45
Q

Fusion

A

Incomplete contraction and relaxation. Known as unfused tenanus

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46
Q

Tenanus

A

The muscle is completely twitched maintained maximal response to excessive stimulation for complete contraction

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47
Q

Fatigue

A

Muscle relaxation due to loss of energy/fuel, lack of oxygen, and or change in pH

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48
Q

Disuse Atrophy

A

Decrease in muscle size due to a decrease in myofibrils no cell number because of disuse. SKELETAL MUSCLE IS MADE TO BE USED

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49
Q

Degenerative Atrophy

A

Nerve linkage is lost, trophic components are not being received, shrinks in size.

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50
Q

Muscle Arrangement

A

Antagonistically - Note the muscle arrangement for moving the leg; the more joints involved the faster the movement.

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51
Q

Hypertrophy

A

Increase in muscle size due to an increase in myofibrils, not cell number. Increased protein content and or increased circulation.

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52
Q

Increased Contractile Activity

A

Altered ATP forming capacity and or myofibril number in the cell increases.

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53
Q

Myoglobin

A

Oxygen binding protein of th emuscle fiber M-O2; increases O2 diffusion.

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54
Q

Oxidative Fibers

A

Skeletal muscle fibers with numerous mitochondria and a high capacity for oxidative phosphorylation. Also have high amounts of myoglobin and referred to as “red” fibers.

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55
Q

Glycolytic Fibers

A

Skeletal muscle with few mitochondira but have high concentration of glycolytic enzymes and a large store of glycogen. “white” fibers. Larger diameters and more maximum tension.

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56
Q

Slow-Oxidative Fibers

A

Type 1 skeletal fibers that combine low myosin-ATPase activity with high oxidative capacity. High in myoglobin = dark red. Tension (mg) constant over time.

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57
Q

Fast-Oxidative-Glycolytic Finbers

A

Type 2a skeletal fibers the combine high mysoin-ATPase activity with high oxidative capacity and intermediate glycolytic capacity. High in myoglobin + glycogen = white. Tension (mg) slowly drops off over time.

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58
Q

Fast-Glycolytic Fiber

A

Type 2b skeletal fibers that combine high myosin-ATPase activity with high glycolytic capacity. Low in myoglobin = white. Tension (mg) quickly drops off over time.

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59
Q

Whole Muscle Contraction

A

Each muscle is made of all three fiber types in different ratios. Recruit slow-ox, fast-ox-gly, and fast-gly.

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60
Q

Low-Intensity Exercise

A

Aerobic exercise with low intensity and long duration. Increases mitochondria number in fibers.

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61
Q

High-Intensity Exercise

A

Short duration and high intensity affecting fast-twitch fibers used for strong contractions. Fibers increase in diameter.

62
Q

Smooth Muscle General

A

Small spindle cell, made of actin and myosin, uses Ca ion/Calmodulin control, under autonomic nervous system, and has gap junctions.

63
Q

Smooth Muscle Structure

A

Thick and thin filaments in smooth muscle are arranged in diagonal chains that are anchored to the plasma membrane or dense bodies

64
Q

Dense Bodies

A

Cytoplasmic structure that anchor think filaments in smooth muscle. No set arrangement accounts for lack of striation.

65
Q

Smooth Muscle Contraction Shape

A

When relaxed, the cell is long and thin. When contracted, the cell becomes shorter and wider.

66
Q

Smooth Muscle Contraction

A

Excitation Contraction Coupling

1) Muscle cell action potential
2) Voltage-sensitive Ca2+ channels open
3) Increase in intracellular Ca2+
4) Activates Calmodulin
5) Activates Protein Kinase (myosin (light-chain) kinase)
6) The myosin kinase phosphorylates the myosin crossbridge into myosin-PO4
7) Actin binds and crosbridge moves
8) Ca2+ stays myosin remains.

67
Q

Smooth Muscle Relaxation

A

Myosin light-chain phosphatase must dephosphorylate myosin. Ca2+ channels close and CaATPase removes intracellular Ca.

68
Q

Smooth Muscle Sustained Tension

A

Continues as long as it is phosphorylated. No fatigue.

69
Q

Smooth Muscle Compaired to Skeletal

A

Longer contractions, lacks striations/no sarcomeres, ANS, similar strength, greater effective length/stretch, both use sliding filaments, slow contractions from love myosine ATPase activity.

70
Q

Smooth Muscle Factors

A

Spontaneous electrical activity, neurotransmitters, hormones, local changes, stretch

71
Q

Pacemaker Cells

A

Cells that spontaneously depolarize to threshold potential voltage and act to coordinate other cells. 1%

72
Q

Neurotransmitters Affect Smooth Muscle

A

Sympathetic uses norepinephrine to excite or inhibit. Parasympathetic uses acetylcholine

73
Q

Muscle Tone

A

Prolonged response of smooth muscle fibers where tension is related to intracellular calcium.

74
Q

Smooth Muscle Single Unit

A

Each muscle fiber is linked by gap junctions for electrical communication. Located in intestines, uterus, and small diameter vessels.

75
Q

Smooth Muscle Multiunit

A

Few gap junctions so communication occurs with nerves and rich innervation. Located in trachea, bronchioloes, large arteries, and skin hairs.

76
Q

Asthma

A

Constriction of bronchi smooth muscle

77
Q

Cardiac Musle Cells

A

Striated, contraction Ca activated by Ca stores in sarcoplamic reticulum/ECF, uses actin/myosin with troponin/tropomyosin, regulated by nerves, hormones, stretch, pacemaker cells, slow contraction rate, has gap junctions, and rich in mitochondria.

78
Q

Measurement of Blood by Centrifugation

A

Plasma 55%, Leukocytes and platelets, Erythrocytes 45%

79
Q

Hematocrit

A

Percentage of blood that is erythrocytes/red blood cells. Higher levels increase viscosity.

80
Q

Blood Flow Rate

A

At rest 5800ml/min and 17,500ml/min during strenuous exercise. Blood flow changes based on need.

81
Q

Ventricles

A

Move blood out of the heat when exceeds systemic pressure

82
Q

Blood Flow Path in Heart

A

Superior/inferior vena cave, right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, aorta/arteries, systemic circulation.

83
Q

Systole

A

Ventricular Contraction

84
Q

Diastole

A

Ventricular Relaxation

85
Q

Systolic

A

Sound of ventricular contraction

86
Q

Diastolic

A

Sound of ventricular relaxaion

87
Q

“lub”

A

AV (bi/tricuspid) valves closing

88
Q

“dub”

A

semilunar valves closing

89
Q

Cardiac Output

A

Heart Rate(bmp) X Stroke Volume(liters/beat) = CO(liter/min)

90
Q

Sphygmomanometer

A

Devise used to measure blood pressure and hear rate

91
Q

Korotkoff Sounds

A

First occurs when cuff pressure is just below systolic pressure. Last when cuff pressure drops below diastolic pressure

92
Q

Electrical Heart Signal Pathway

A

Sinoatrial node starts action potential and will depolarize for atrial excitation until it reaches the atrioventricula node where signal is delayed and filtered. Passes on AP though Bundle of His, Bundles of His, up though Purkinje fibers. Contracts down up.

93
Q

Myogenic

A

Contractile event generated by the muscle itself like the heart.

94
Q

Tachycardia

A

Fast heart rate

95
Q

Brachycardia

A

Slow heart rate

96
Q

Grammar of Heart Stuff

A

Imply ventricular unless it says atrial. ic=sound e=contraction

97
Q

EKG P Wave

A

Atrial depolarization and atrial contraction

98
Q

EKG QRS Wave

A

Ventricular depolarization and ventricular contraction

99
Q

EKG T Wave

A

Ventricular repolarization and ventricular relaxation

100
Q

Ectopic Focus

A

an area of the atria or ventricles that initiates another contraction, a contraction that is not in the normal cycle.

101
Q

Heart Contraction Movement

A

Fibers arranged longitudinally then move to a 90* angle. Discontinuous pump that must reload/long refractory period.

102
Q

Nervous System Heart Controls

A

Parasympathetic brings heart rate down and will override the sympathetic that brings heart rate up

103
Q

Increase Heart Rate

A

Increase cardiac sympathetic nerve activity, Increase plasma epinephrine, decrease parasympathetic nerve activity.

104
Q

Increase Stroke Activity

A

Increase cardiac sympathetic activity, increase end-diastolic ventricular volume, increase plasma epinephrine.

105
Q

Stroke Volume

A

Amount of blood moved out of the heart with a contraction

106
Q

Starling’s Law

A

There is a direct relationship between the end diastolic volume of the heart and the force of contraction. Related to venous return.

107
Q

Blood Movement Equation

A

Flow=Change in pressure/resistance (a pump is p and a closed system is delta p)

108
Q

Flow

A

Flow is affected by pressure and resistance

109
Q

Systemic and Pulmonary Pressure

A

Systemic circulation has a higher pressure 80-120 while pulmonary circulation 10-30.

110
Q

Greatest area of resistance

A

arterioles

111
Q

Laminar Flow

A

When there is a normal open valve and it is quiet. Normal closed should also be quiet because no flow.

112
Q

Stenotic Valve

A

Narrowed valve with turbulent flow causing a murmur

113
Q

Insufficient valve

A

leaky and doesn’t close all the way resulting in turbulent back flow and a murmur

114
Q

Changing Pressure

A

All comes from the heart so depends on stroke volume and heart rate

115
Q

Changing Resistance

A

Depends on viscosity, length, and radius.

116
Q

Pressure reservoir

A

arteries

117
Q

variable-resistance outflow tubes

A

arterioles

118
Q

Blood Components

A

Formed elements and plasma

119
Q

Formed Elements

A

RBC 510^9, WBC 710^9, platelets 250*10^6

120
Q

Plama

A

Non cellular, fluid, salt, proteins

121
Q

Hematocrite Percentages

A

43-49% in males, 36-45% in females

122
Q

Resistance

A

Affected by radius, length, and viscosity

123
Q

Length

A

Inversely related so doubling the length halves the resistance

124
Q

Radius

A

Inversely related by the power of 4. Twice the radius is 16x the resistance.

125
Q

Fat Deposit Effects

A

Decrease elasticity, increase resistance, increase blood pressure, increase stenosis

126
Q

Pressure as Blood Flows

A

Heart, Artery 100-200, arterioles 60-70, capillary 30-40, venule 10-20, vein -5-10

127
Q

Arteries - Elastic

A

Has smooth muscle to expand and come back down. Guarantees consistent flow of blood.

128
Q

Arteries - Radius

A

Large for low resistance endothelium. Regulatory component.

129
Q

Arteries - Pule Pressure

A

Determined by stroke volume, volume velocity/flow, and arterial distensibility which decreases with age.

130
Q

Endothelium

A

The inner most single cell layer thick lining of the vessel

131
Q

Mean Arterial Pressure

A

Cardiac Output * Total periphrial resistance OR diastolic+1/3(pulse pressure)

132
Q

Total Peripheral Resistance

A

Viscosity and arteriolar radius (local effects, sympathertic nerves, plasma epinephrine and angiotensin II

133
Q

Local Effects on Total Peripheral Resistance

A

Arterioles vasoconstrict or vasodialte depending on the tissue’s needs. Decrease in O2 or increase in water increases organ blood flow

134
Q

Capillary

A

A single cell thick vessel that provides an area for the movement of molecules between the blood and cells like nutrients and waste products. Greatest cross sectional area for lowest velocity but high constant resistance. Diffusion and active transport area. Flow controlled by precapillary sphincter.

135
Q

Capillary Control

A

Autocontrolled by local pH and precapillary sphicter.

136
Q

Precapillary Sphincter

A

Controls blood flow into capillaries. Only 3% open at a time or else heat would drain of blood.

137
Q

Capillary Physical Pressure

A

Affected by capillary blood pressure. Cell pressure = intersitial pressure = 0

138
Q

Capillary Osmotic Pressure

A

Salt concentration the same between blood and ECT but proteins are large and will not diffuse. Tendency to take in water.

139
Q

Filtration Equation

A

(Pp-Pi) - (OPp-OPi)

140
Q

Arteriole Filtration End

A

Normally positive where water is leaving the capillary

141
Q

Venule Filtration End

A

Physical pressure decreases because resistance usually does yielding negative filtration and water moving in.

142
Q

Venous Return Factors

A

Sympathetic nervous system, skeletal muscle activity, inspiratory movements, blood volume

143
Q

The Lymphocytes

A

Systemic capillaries except the kidneys. Filter 20L/day, Absorb 17L/day, Lymph 3L/day

144
Q

Edema

A

Increase of fluid in tissue or organ from increased intersitial fluid from obstruction

145
Q

Lymph System

A

Return fluid, return proteins, filter/immune

146
Q

Venous System

A

Normally closed system, 60% of volume in venules and veins, pressure 15–0, low resistance from large radius

147
Q

Venous System Driving Forces

A

Closed system (stuff going down pulls other stuff up), large flexible vessels, one-way valves.

148
Q

Venous Link to BP

A

Venous pressure, venous return, atrial pressure, end-diastolic ventricular pressure, stroke volume

149
Q

Atrial Pressure

A

Changes centricular colume. More blood to the atria, the more to the ventricles–venus return

150
Q

Venus Return Factors

A

Sympathetic nervous system contract smooth muscle vein, skeletal muscle activity contractions compress thin walled vessels, inspiratory movements more negative in the chest increased pressure in abdomen, and blood volume