Circulatory System Flashcards

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1
Q

Perfusion

A

Flow of blood through a tissue

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2
Q

Ischemia

A

Inadequate blood flow

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3
Q

Hypoxia

A

Adequate circulation but oxygen supply reduced

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4
Q

Arteries

A

Carry blood away from the heart at HIGH pressure

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5
Q

Veins

A

Carry blood to the heart at LOW pressure

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6
Q

Arterioles

A

As arteries get further from the heart, pressure decreases and the arteries branch into arterioles

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7
Q

Arteries branch into arterioles which then branch into

A

Capillaries

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8
Q

Arterioles have ____ which can control the amount of blood entering the capillaries

Capillaries are

A

Smooth muscle that can restrict or increase blood going to capillaries which are very small vessels (often only wide enough for one blood cell to pass) that allow exchange of material from the blood and tissues

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9
Q

After blood passes through arteries branch into arterioles which then branch into capillaries, the blood enters:

A

Small veins called Venules which takes the blood to the veins for return to the heart

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10
Q

Endothelial cells make up

Endothelial cells and the capillaries

A

Inner linings of all blood vessels

Capillaries are a single layer of endothelial cells

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11
Q

Endothelial cells role in vascular function (4)

A

Vasodilation and vasoconstriction
Inflammation
Angiogenesis (forming new blood vessels)
Thrombosis (blood clotting)

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12
Q

Angiogenesis

A

Forming new blood vessels

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13
Q

Right side of the heart pumps blood to

A

Lungs

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14
Q

Left side of the heart pumps blood to

A

Rest of body (other than the lungs)

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15
Q

Pulmonary Circulation

A

Flow of blood from the heart to the lungs and back to the heart (right side)

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16
Q

Systemic circulation

A

Flow of blood from the heart to the rest of the body and back again (left side)

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17
Q

Most blood flows through only one set of capillaries before returning through the heart

EXCEPT

A

Portal systems in which blood goes through multiple system’s capillaries

Direct transport systems to connect two areas without passing through the whole body

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18
Q

Right ventricle and left ventricle

Deoxygenated or oxygenated blood?

A

R: deoxy

L: oxy

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19
Q

Atria

A

“Waiting rooms” where blood can collect from the veins before getting pumps to the ventricles

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20
Q

Ventricles

A

Pump blood out of the heart at high pressures into arteries

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21
Q

Right atrium receives ____ from the ___ and pumps ____

A

Deoxygenated blood from the systemic circulation (S&I Vena Cava) and pumps to right ventricle

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22
Q

From the right ventricle, blood passes through the

A

Pulmonary arteries and through the lungs to get oxygenated

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23
Q

Oxygenated blood from the lungs arrives back into the heart at the ____ via the _____

A

Left atrium

Pulmonary arteries

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24
Q

When oxygenated blood arrives through the left atrium, it is

A

Pumped into the left ventricle before being pumped out of the heart in a single large artery, the AORTA to systemic circulation

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25
Q

Do all arteries carry oxygenated blood?

A

No the pulmonary arteries carry deoxygenated blood to the lungs

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26
Q

Antroventricular valve is necessary to prevent

A

Backflow from the ventricles to the arteries due to the high ventricular pressure and low atrial pressure

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27
Q

AV valve between the left atrium and left ventricle is called the ____ valve

A

Mitral/bicuspid

Must withstand enormous pressures

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28
Q

AV valve between the right atrium and ventricle is called the ____ valve

A

Tricuspid

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29
Q

Semilunar valves include which valves (2)?

Separate what?

A
  1. Pulmonary valves
  2. Aortic semilunar valves

Between the ventricles and the arteries they pump blood into

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30
Q

Function of valves throughout the circulatory system / body

A

To create a driving force for blood to get back to the heart

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31
Q

Cardiac cycle consists of two parts:

A

Diastole and systole

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32
Q

Diastole

A

Ventricles relax and blood flows into them from the atria

Atria actually contract during this stage to put blood into the ventricles

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33
Q

Systole

A

Begins when ventricles start to contact, pressure buildup causes AV node to shut and eventually causes the semilunar valve to open and blood to shoot into the aorta and pulmonary artery

End: ventricles nearly empty and done contracting, back flow begins to occur but the semilunar valves slam when the pressure in the ventricle is less than the pressure in the arteries

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34
Q

Which is shorter: systole or diastole?

A

Systole is shorter (occupies space between Lub and dub while Diastole occupies space between Lub-dub and another Lub-dub)

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35
Q

Heart rate/pulse

A

Number of times the S/D cycle occurs in one minute

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36
Q

Normal HR / pulse

A

Around 1beat/second (45-80 is normal range)

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37
Q

Stroke volume

A

Amount of blood pumped with each systole

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38
Q

Why is 45 bpm or 80 bpm normal?

A

Stronger heart pumps more blood in one contraction (athletes) and weaker heart pumps less blood in one contraction (elderly/babies)

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39
Q

Cardiac output

A

Amount of blood pumped per minute

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40
Q

Cardiac output =

A

CO = HR x SV

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41
Q

Frank-Starling mechanism to increase cardiac output

A

If venous return(return of blood to the heart) is increased, the heart fills more, stretching it more, contracting it more forcefully

Increases SV significantly

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42
Q

Functional Syncytium

A

In cardiac muscle cells, the gap junctions through which different cells can communicate is found in intercalated disks, connections between cardiac muscle cells

AP can be communicated directly through the cytoplasm to the neighboring cardiac muscle cells

I.E. electrical synapse, no chemical

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43
Q

Intercalated disks

A

connections between cardiac muscle cells

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44
Q

Cardiac conduction system

A

AP fired in the heart is transmitted from the atrial syncytium to the ventricles

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45
Q

Fast vs slow sodium channels involvement in cardiac muscle action potentials

A

Fast are important like in neurons but:

Slow stay open longer causing depolarization to last longer in cardiac muscles than in neurons producing a plateau phase

Contraction lasts longer, so more force expels the blood

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46
Q

T tubules

A

Maximize amount of Ca2+ entering the cell by running the length of the cell to allow depolarization and activation of the sarcoplasmic reticulum to release calcium

Makes a combo of intracellular and extracellular calcium

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47
Q

Combo of intracellular and extracellular calcium around the cell causes

A

Contraction of actin-myosin fibers

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48
Q

SA Node

A

Initiates AP in the heart (pacemaker of the heart)

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49
Q

SA Node AP phases

A

0, 3 and 4 (NO 1 and 2 LIKE OTHER CARDIAC MYOCYTES)

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50
Q

SA Node is unique because it has an unstable resting potential which is:

A

Phase 3 (automatic slow depolarization) caused by sodium leak channels which brings the cell potential to threshold for VG Ca2+ channels

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51
Q

When VG Ca2+ channels open, ___ begins:

A

Phase 0

Drives membrane potential of the SA node toward positive Ca2+ equilibrium potential GRADUALLY because the channels operate more slowly than Na+ in other AP

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52
Q

Phase 3 of SA Node AP

A

Repolarization

Caused by the closure of the Ca2+ channels and opening of K+ channels leading to K+ exiting the cell to drive membrane potential toward the negative K+

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53
Q

Phase 0,3,4 occurs

A

Once per heart beat

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54
Q

The SA node has the most ____ which means it _____ and therefore sets the rate of contraction for the heart

A

Na+ leak channels

Depolarizes first

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55
Q

When the SA node is injured,

A

The AV node or Purkinje fibers will take over but the heart will be set at a slower rate

56
Q

Cardiac muscle cells of the heart have an action potential that differs from the SA node and other conduction systems:

A

Threshold is -90 mV
AP have a longer duration
Phases 0-4

57
Q
Phase 0 
Phase 1
Phase 2
Phase 3
Phase 4
A

0: Depolarization due to influx Na+
1: Initial repolarization Na+ close and K+ open
2: Plateau because Ca2+ channels open and influx balances K+ efflux
3: Depolarization when Ca2+ close and K+ still open/leave
4: Resting membrane potential dictated by action of the Na+/K+ ATPase (pump) and K+ leak channels

58
Q

Internodal tract

A

Connects the SA and AV node to transmit AP rapidly without contracting

59
Q

Impulse travels to the AV node ___ than it does to the atria

At the AV node the impulse is ___ before traveling to the ___
This part of the conduction pathway is known as the ___

A

Faster

Delayed
Ventricles via the conduction pathway

AV bundle

60
Q

AV bundle divides into the ___ and then the ___

A
Right and left bundle branches 
Purkinje fibers (allow impulse to spread over both ventricles)
61
Q

Where do the purkinje fibers spread on the ventricles and why?

A

Purkinje fibers spread over the bottom portion of the ventricles because contraction here pushes blood up toward the arteries and valves

62
Q

Intrinsic firing of the SA node is 120bpm but the heart rate is approx. 60

Why?

A

Because the parasympathetic nervous system constantly inhibits the heart from contracting

63
Q

What inhibits the SA node?

A

The vagus nerve releases ACh to inhibit depolarization by binging to cell receptors on the SA node

64
Q

Vagal tone

A

Constant inhibition by the vagus nerve

65
Q

Sympathetic nervous system excites the heart in fight or flight: how?

A

Epinephrine

66
Q

Peripheral resistance equation

A

Change in pressure = cardiac output x resistance

67
Q

Precapillary sphincters

A

Primary determinant of resistance

Degree of constriction of arteriolar smooth muscle

68
Q

Adrenergic tone

A

Constant sympathetic nervous system input to innervate the precapillary spinchters

69
Q

Systemic arterial pressure

A

Blood pressure

70
Q

BP=120/80

What do the two numbers mean?

A

Numerator: Systolic pressure (highest ARTERIAL pressure gets as ventricles contract: systole)
Denominator: Diastolic pressure (lowest ARTERIAL pressure gets as ventricles relax: diastole)

71
Q

Local autoregulation

A

Tissues in need of extra blood flow are able to requisition it themselves

When a tissue is underperfused waste builds up and vasodilation occurs causing the smooth arteriolar smooth muscle to relax and increased blood flow arrives when the diameter of the artery is larger

72
Q

Blood has a ___ portion and a ___ portion

A

Liquid portion and a cellular portion

73
Q

Liquid portion of blood is called:

Cellular components of blood are called:

A

Plasma

Formed elements

74
Q

Principle blood buffer found in plasma that keeps the blood at pH of 7.4 Is

A

Bicarbonate (HCO3-)

75
Q

Principle sugar in the blood’s plasma is

A

Glucose

Constant concentration must be maintained for nutrients to be given to the organs

76
Q

Proteins in the plasma in the blood:

  • Albumin
  • Immunoglobulins
  • Fibrinogen
  • Lipoproteins
A
  • Albumin: maintains osmotic pressure in capillaries
  • Immunoglobulins: immune system role
  • Fibrinogen: blood clotting
  • Lipoproteins: fats, cholesterol and carrier proteins
77
Q

Principle metabolic waste product in the blood (2)

A

Urea
-Breakdown of Amino Acids

Bilirubin
-Breakdown of heme

78
Q

Centrifuging blood results in the breakdown of

A

54% plasma
45% hematocrit (35-40 in females)
1% leukocytes

79
Q

Hematocrit

A

Red blood cells

80
Q

What does plasma contain?

A

Water, electrolytes, glucose, hormones, wastes, plasma proteins, lipoproteins

81
Q

Erythropoeitin

A

Made in the kidney

Stimulates RBC production in the bone marrow

82
Q

Aged RBC’s are

A

Eaten by phagocytes in the spleen and liver

83
Q

Erythrocyte is a cell with no nucleus or organelles but it still requires ___ and it gets it from the ___

A

ATP

Glycolysis from ATP synthesis

84
Q

Purpose of RBC is to

Hence RBC require

A

Transport O2 to the tissues from the lungs and CO2 from the tissues to the lungs

Large surface area for gas exchange

85
Q

RBC is able to carry oxygen because it contains

A

hemoglobin

86
Q

Blood group antigens (which determine blood type) have two major groups:

A

ABO blood group

Rh blood group

87
Q

ABO blood group consists of 3 alleles:

A

Ia, Ib and i

88
Q

Rh blood group consists of

A

RR, Rr (blood type +) and rr (blood type -)

89
Q

Type IaIb or ii

A

IaIb is AB and ii is O

90
Q

Transfusion reaction

A

Clumping and destruction of RBC bearing the incorrect antigen

91
Q

Example: Person with A+ blood produces anti-B antibodies

If transfused with type B blood,

A

Antibodies will clump and destroy the donated type B cells leading to death of the recipient

92
Q

Hemolytic disease of the newborn

A

When the mother has the FIRST child with + blood when she has -, she will become sensitized upon first exposure and her body will begin to produce the antigens

Upon SECOND baby with + blood, antibodies can cross the placental barrier to clump or destroy the baby + blood cells

93
Q

Two unique types of blood types

AB+
O-

Why?

A

AB+ does not make antibodies to any other groups because their blood cells possess all the antigens already = “universal acceptors”

O- do not possess any of the antigens that can cause the antibody formation so = “universal donors”

94
Q

White blood cells function

A

Fight infection and deposit debris

95
Q

WBC have all the normal cell organelles present in eukaryotes

They also exhibit amoeboid mobility which is ___ and is important for

A

Crawling

Squeeze out of capillary intercellular junctions to roam free in the tissues, hunting for foreign particles and pathogens to rid

96
Q

Chemotaxis

A

Movement directed by chemical stimuli which can be toxins and waste products released by pathogens or chemical signals released from other WBC

97
Q

Macrophage

A

WBC monocyte
Phagocytose debris and microorganisms
Crawling
Chemotaxis

98
Q

B cell

A

WBC Lymphocyte

Mature into plasma cell and produce antibodies

99
Q

T cell

A

WBC Lymphocyte
Kill virus infected cells, tumor cells, and reject tissue grafts
Control immune response

100
Q

Neutrophil

A

WBC Granulocytes
Phagocytose bacteria resulting in pus
Crawling
Chemotaxis

101
Q

Eosinophil

A

WBC Granulocytes
Destroy parasites
Allergic reactions

102
Q

Basophil

A

WBC Granulocytes
Store and release histamine
Allergic reactions

103
Q

Platelets are like RBC in that they

A

Have no nucleus and a limited lifespan

104
Q

Megakaryoctes

A

Bone marrow cells that five rise to platelets

105
Q

Function of platelets

A

Aggregate at the site of damage to blood vessel wall forming a platelet plug to stop bleeding

106
Q

Hemostasis

A

Prevents bleeding

107
Q

Fibrin

A

Threadlike protein which forms a mesh holding the platelet plug together

108
Q

When fibrin mesh dries,

A

It forms a scab

109
Q

Thrombus

A

Scab circulating in the bloodstream

110
Q

Hemophilia is caused by ____ from a mutation on the ____ and results in ___

A

Defects in proteins necessary for activating thrombin and fibrinogen

X chromosome

Excess bleeding

111
Q

Hemoglobin

A

Four subunit protein each containing molecule of heme (single iron atom at its center)

112
Q

Heme role

A

Bind O2

113
Q

How many oxygen molecules can each hemoglobin carry

A

4 (one for each subunit with a heme molecule)

114
Q

Hemoglobin subunits do not bind oxygen independently of each other

When none have oxygen bound,

When one of the subunits binds oxygen,

Thus, oxygen is said to bind ____

A

hemoglobin has a TENSE configuration of its subunits and does not have an affinity for oxygen

the hemoglobin relaxes when one subunit binds oxygen so the other subunits have a higher affinity for oxygen

Cooperatively

115
Q

Result of hemoglobins cooperative bonding:

A

Oxygen is picked up in the lungs and most is released in tissues that need oxygen

116
Q

Certain factors that stabilize the tense configuration of hemoglobin: (3)

A

Decreased pH
Increased CO2 in the blood
Increased temperature

117
Q

Bohr effect

A
Fact that :
Decreased pH 
Increased CO2 in the blood
Increased temperature
Stabilizes tense hemoglobin and reduces oxygen affinity
118
Q

Certain factors that stabilize the tense configuration of hemoglobin:
Decreased pH
Increased CO2 in the blood
Increased temperature

Where are these factors optimal?

A

In active tissues that need oxygen

119
Q

Percent saturation (% sat) =

A

% sat = (# O2 molecules bound) x (# of O2 binding sites) x 100%

120
Q

73% of CO2 transport is accomplished by:

A

Conversion of CO2 to carbonic acid by catalyst carbonic anhydrase

Water soluble compounds which can be easily carried in the blood

ALSO Principal pH buffer

121
Q

Some CO2 (20%) is transported by:

A

Stuck onto hemoglobin sites (not the oxygen ones)

Stabilizes tense Hb

122
Q

CO2 is transported (7%) by:

A

Dissolving in the blood and being carried from tissues to the lungs

Virtually no oxygen can be dissolved

123
Q

Intercellular clefts

A

Spaces between the single layered endothelial cells that make up the capillary wall allowing exchange between blood and tissues

124
Q

There are three types of substances that must be able to pass through the intercellular clefts of capillaries:

A

WBC, nutrients and wastes

125
Q

Do O2 and CO2 need to pass through the intercellular clefts to enter the blood cell?

A

No they can enter the cell via simple diffusion

126
Q

Hepatic portal vein carries

A

AA and glucose to be absorbed in the digestive tract and carried to the liver

Connects two capillary beds (one inside intestines and other inside liver)

127
Q

Fats are absorbed from the intestine and packaged into ____, which are a type of lipoprotein. The chylomicrons enter tiny lymphatic vessels in the intestinal wall called _____

Hence lipids bypass the hepatic portal vein and travel through the blood steam resulting in milky blood after eating a fatty meal (term for this is ____)

A

Chylomicrons

Lacteals

Lipemia

128
Q

Lipemia

A

Lipids travel through the blood not the hepatic vein

129
Q

Adipocytes

A

Target destination of lipoproteins

Fat cells for storage

130
Q

The liver removes wastes and converts them into forms to be excreted in poop

These compounds passed through the gut are referred to as

A

Bile

131
Q

Two of six types of WBC that can squeeze through the clefts are the ___ and ____ because they can ____

A

Macrophages and neutrophils

Amoeboid motility

132
Q

Water has a tendency to flow out of tissues through the capillary intercellular clefts: why? (2 reasons)

A

Pressure created by the heart tends to squeeze water out of the capillaries

High osmolarity of the tissues tends to draw water out of the blood stream

133
Q

How does the circulatory system deal with the tendency of water to flow out of the capillaries via the intercellular clefts

A

A high plasma osmolarity is provided by high concentrations of large plasma proteins (Albumin which is too large to pass out of the capillaries and their presence keeps water inside the cell too)

134
Q

Oncotic pressure

A

Pressure created by the plasma proteins albumin

135
Q

Cycle of capillaries life in regards to pressure and osmosis stages

A
  1. Hydrostatic pressure is high, water squeezes out
  2. Plasma proteins concentration increases
  3. Hydrostatic pressure is low, blood is concentrated so oncotic pressure is high and water flow into capillaries from tissues