cardiovascular system

the circulatory system is composed of the _____, _____ ________, and _____

heart, blood vessels, blood

function of the circulatory system

• transport essential materials throughout the body to cells: _______, _____ molecules, ________

• collect waste materials generated by the body’s metabolic activity : _____ _______, _______ (lactic acid), _____

oxygen, fuel, hormones, carbon dioxide, lactate, urea

circulatory system is divided into two sections: _________ circuit and __________ circuit

pulmonary, systemic

pulmonary circuit- blood vessels going to and from the _____

lungs

systemic circuit- blood vessels going to and from the rest of the tissues of the ____

body

the heart is a four chamber ________ ______ which propels blood through the blood vessels

muscular pump

atria- the two -____ chambers of the heart

upper

ventricles- two _____ chambers

lower

a ______ divides the left and right sides of the heart, _ pumps

septum, 2

the right ventricle pumps blood through the _________ circuit

pulmonary

left ventricle pumps blood through the ________ circuit

systemic

the wall of the left ventricle is _______ than the wall of the right ventricle because the systemic circulation is a much higher pressure system than the pulmonary circulation

thicker

the direction of blood flow through the heart is controlled by unidirectional _______

valves

_____ ______- valves is damaged or does not close properly → blood regurgitates, ,causing a noise

heart murmur

the heart muscle (myocardium) is a specialized type of muscle- _______ muscle

cardiac

unlike skeletal muscle, all of the fibers or cells in cardiac muscle are anatomically _______________- functional syncytium ,when one fiber contract, all fibers contract

interconnected

the fibers of the atria are ___________ separated from the fibers of the ventricles

electrically

the heart’s inherent contractile rhythm originates in an area of specizlied tissue located in the _________ wall of the _____ atrium: the sion atrial node (_-_ node_

posterior, right, SA node

pathway of conduction of the wave of depolarization (cardiac impulse) across the heart:

__ node (pacemaker) →_______ muscle fibers → ___________ of atria → __________ pathway (only electrical connection atria to ventricle) → __ node → AV ______ → left and right bundle ________ → _________ fibers travel throughout the ventricles → simultaneous contraction of left and right ___________

SA, atrial, contraction, internodal, AV, bundle, branches, purkinjie, ventricles

the wave of depolarization is delayed in the __ node for approximately ____ seconds in order to give the atria time to contract and empty their contents into the ventricles

SA, 0.10

electrocardiography (___)- record the wave of depolarization as it passes across the heart using __________ on the surface of the body

• P wave: represents ______ depolarization

• QRS wave- represents ___________ depolarization

• T wave- represents ventricular ______________

ECG, electrodes, atrial, ventricular, repolarization

arrhythmia- an irregularity in the _______ of the heart beat

rhythm

diagnosing arrhythmias- look at _____ ____, __________ and shapes of the components of the ___ waveform, and ____ intervals

heart rate, amplitude, ECG, time

examples of arrhythmias:

1. atrial- ___________ (fast heart rate), ____________

2. nodal- second and third degree heart ______ (electrical conduction issue)

3. ventricular- __________ ___________ ___________ (PVC), ventricular ___________, ventricular ____________

tachycardia, fibrillation, block, premature ventricular contraction, tachycardia, fibrillation

bradycardia- heart rate is _____ than normal

slower

tachycardia- heart rate is ______ than normal

faster

fibrillation- ________________ is disorganized

electrocardiogram

atrial fibrillation- heart still functions as a ____

pump

ventricular fibullation- heart does not function as an effective ____

pump

the heart muscle is supplied by two major arteries which originate from the aorta just above the aortic valve- left and right ________ artery, the large veins of the heart _________ and empty into the right atrium

coronary, converge

cardiac muscle is highly dependent on aerobic metabolism, it requires a rich _____ supply

blood

at rest, normal blood flow to the myocardium is about _% of the total cardiac output

4

during exercise the blood flow to the heart stays about the same at 4% of cardiac output. cardiac output ___________ substantially with exercise, increasing the flow of blood to the _____

increases, heart

approximately __-__% of the oxygen is extracted from blood flowing in the coronoary vessels compared to an average of __% in other tissues

70-80, 30

___________- arteries under 0.5 mm in diameter

arterioles

_________- blood vessels that carry blood away from the heart. they range in size from the aorta which is about __ mm in diameter in man to arterioles that are about ___ mm

arteries, 25, 0.5

going from large arteries → ______ sized arteries → _____ arteries → ___________, there is less ________ tissue in the wall of the artery and more smooth muscles

medium, small, arterioles, elastic

by constricting or relaxing the thick layer of ______ muscle in the walls of arterioles, blood flow can be increased or decreased to various capillaries

smooth

arteries and arterioles constitute the ____ pressure part of the circulatory system

high

during exercise, the arterioles leading to working muscle are _______, directing blood to flow to active muscle where the oxygen and fuel for ___________ are required

dilated, contraction

___________- very tiny (5-10 microns diameter), thin- walled vessels, site of exchange of ________/ ______ and _____ between the blood and tissues, all other organs of the circulatory system exist only to serve the _________ beds

capillaries, nutrients, wastes, gases, capillary

capillaries have very large surface area and length- ____ sq. meters, ______ km long, twice the mass of the _____

6000, 100000, liver

_______- small vessels which conduct venous blood from capillaries to _____

venules, veins

veins- vessels that convey blood _______ the heart

toward

in general, veins are of greater ________, but thinner- walled than the arteries with which they travel. there are both superficial and deep veins

diameter

veins also have ______ muscle in their walls which allow them to change their diameter

smooth

the venules and the veins constitute the ___ pressure part of circulatory system

low

_____ ________ is the difference between systolic and diastolic pressure readings in arteries

pulse pressure

_______- found in those ______ which carry blood against the force of _______, especially in the veins of the ____

valves, veins, gravity, legs

mechanisms involved in return of blood to the heart:

1. ________ difference between left ventricle and right atrium- 120 mm Hg - 3 mm Hg = 117 mm Hg driving pressure

2. skeletal muscle pump- active muscles squeeze the _____ and push the blood towards the heart

3. respiratory pump:

   • decreased pressure in thoracic cavity during ___________ → easier for blood to return from _____ portions of the body via inferior vena cava → ________ cavity → _____ atrium of heart

pressure, veins, inspiration, lower, thoracic, right

blood is composed of specialized cells ( ___ blood cells, _____ blood cells, __________) suspended in a liquid, ______ which makes up 50 to 60% of blood by volume

red, white, platelets, plasmawhich is a yellowish liquid

the blood volume of the average adult with a normal body composition is approximately _% of body mass. Therefore, a person with a body mass of 70kg has a blood volume of approximately ___L.

8, 5.6

blood volume is _______ for larger, more endurance trained, and heat acclimatized people

greater

plasma- composed of 90% _____ and 10% solutes

plasma

red blood cells (erythrocytes)

• _________ discs about 7 microns in diameter

• in human blood _ to _ million RBC per cubic milimeter of blood

• __________- the ratio of the volume of blood cells to the total volume of blood, expressed as a percentage- usually __-47% in females and 42-__% in males

biconcave, 5-6, hematocrit, 37, 52

RBC’s are continually being formed in ___ ____ ______ in ends of long bones and in flat bones, lifespan: ___ days

red bone marrow, 120

RBC contains __________ which transports oxygen and carbon dioxide, it is an ____ containing protein which reversibly binds with oxygen

hemoglobin, iron

normal values for hemoglobin:

men: __-__g per 100mL blood

women: __-__g per 100mL blood

14-16, 12-14

types of blood doping:

1. blood ___________

2. ___ (or synthetic hormones)

3. synthetic _______ carriers

transfusion, EPO, oxygen

ways to increase RBC count:

1. _______ tents

2. ________ training

hypoxic, altitude

___________ ____- too many RBC, leads to increased blood viscotiy and clotting

polycthemia vera

diffusion- molecules move from and area of ____ concentration to ___ concentration, driven by concentration gradient

high, low

rate of diffusion is increased by:

1. ______ concentration gradient (difference)

2. _______ diffusion distance

3. ______ temperature

4. _______ surface area

higher, shorter, higher, greater

2 sites of gas exchange:

1. ________- capillary membrane in lungs

2. ______- capillary membrane in tissues

alveolar, tissue

alveolar- capillary membrane in lungs:

• net diffusion of O2 from alveoli → _____

• net diffusino of CO2 from blood → _______

blood, alveoli

tissue- capillary membrane in tissue:

• net diffusion of O2 from blood → ______

• net diffusino of CO2 from tissue → _____

tissue, blood

partial pressure of gas- the pressure of a gas in a gas mixture is dependent on:

1. the total _______

2. the fractional _____________ of that gas

For example at sea level, the total pressure of all dry ambient (atmospheric) air gases equals ___ mm Hg which equals barometric pressure

pressure, concentration, 760

O2

concentration: _____%

partial pressure: _____ x 760 = 159.2 mm Hg

20.93, 0.2093

the most important factor determining gas exchange is the _______ ________ (concentration) gradients of the gases involved

partial pressure

_______ air vs ________ air vs ________ air - partial pressure differences

ambient, tracheal, alveolar

the functional ________ capacity serves as a damper so that each incoming breath of air has only a small effect on the composition of alveolar air → partial pressure of gases in the alveoli remains relatively ______

residual, stable

Henry’s law - the amount of gas that dissolves in a fluid is a function of two factors:

1. the ________ of the gas above the fluid. which is given by the gas concentration times the barometric pressure

2. the __________ coefficient of the gas- CO2 is ____ times more soluble in water than O2

pressure, solubility, 20.3

_________ capacity for oxygen- the volume of oxygen that crosses the alveolar- capillary per min per mm Hg between the alveolar air and pulmonary capillary blood

diffusing

besides partial pressure gradients, diffusing capacity can be affected by other factors:

1. the ________ of the respiratory membrane- length of diffusion path. diffusion capacity is decreased in the restrictive lung diseases such as pulmonary fibrosis or pneumonia

2. the number of ___ blood cells and their __________ concentration of both

3. the _______ _____ of the respiratory membrane available for diffusion- diffusing capacity is decreased in emphysema

thickness, red, hemoglobin, surface area

diffusing capacity can increase up to _ times resting values during heavy aerobic exercise.

1. increased lung _________ during exercise → increased surface area for diffusion

2. opening up of more ____________ in the lung and greater volume of blood flowing through the lung

volumes, capillaries

transport of oxygen:

__% of oxygen in the blood is carried in red blood cells in chemical combination with __________

• Hb + O2 → HbO2

• HbO2 = _____________

the other _% is dissolved in ______

98, hemoglobin, oxyhemoglobin, 2, plasma

O2 carrying capacity of hemoglobin- one gram of hemoglobin becomes saturated with O2 when it combines with _____ mL of O2

1.34

hemoglobin concentration equals ___g per 100mL of blood, the O2 carrying capacity of the blood would be ___mL O2 per 100mL of blood

15, 20.1

percent __________ of hemoglobin with O2 (%SO2)- relates the amount of O2 actually combined with hemoglobin to the max O2 capacity of hemoglobin

saturation

arterial blood at rest at sea level: hemoglobin is ____% saturated with O2 = ___ mL O2 per 100mL blood

97.5, 20.1

venous blood at rest at sea level: hemoglobin is __% saturated with O2 = ___ mL O2 per 100mL blood

75, 15.1

arteriovenous oxygen difference= ____ - ____ = ___ mL O2 per 100mL blood, representing how much oxygen is extracted or consumed by the _______ for each 100mL of blood perfusing them

19.5, 15.1, 4.4, tissues

_____________ ____________ curve- plot of the percent saturation of hemoglobin (%SO2) versus the partial pressure of oxygen (PO2)

oxyhemoglobin dissociation

hemoglobin acts as a tissue oxygen ______ system

buffer

the level of alveolar oxygen may vary greatly, from __ to more than ___ mm Hg, still the PO2 in the tissue doesnt vary more than a few mm Hg from normal due to the shape of the ______________ ____________ curve

60, 500, oxyhemoglobin dissociation

Bohr effect- increased body ___________, increased PCO2, decreased __ shift the oxyhemoglobin dissociation curve to the ___ and release more oxygen at the tissue for a given PO3

temperature, pH, right

total blood O2= ________ O2 + __O2

dissolved, Hb

in lungs, PO2 is ____, dribing O2 exchange ____ plasma → high plasma PO2 drives O2 _______ __ Hb

high, into, binding to

in tissues, PO2 is ___, driving O2 exchange ___ __ plasma → low plasma PO2 drives O2 _____ ____ Hb

low, out of, release from

Normal values for gas partial pressures at rest at sea level

• P_AO₂- partial pressure of ________(A) oxygen: 104 mm Hg

• P_ACO_{2- partial pressure of ________ (A) carbon dioxide: 40 mm Hg}

• P_aO₂- partial pressure of ________ (a) oxygen for blood leaving the left ventricle: 95 mm Hg

• P_aCO₂- partial pressure of ________ (a) carbon dioxide: 40 mm Hg

• P_VO₂- partial pressure of ______ (v) oxygen: 40 mm Hg

• P_VCO₂- partial pressure of ______ (v) carbon dioxide: 45 mm Hg

alveolar, arterial, venous