Lecture 11 Flashcards by Sydney Perry

what are the two functional parts of the circulation?

Pulmonary circulation
systematic circulation

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what is pulmonary circulation?

flow of blood through the lungs for oxygenation

-deoxygenated blood flows from the right ventricle to the lungs where it is oxygenated and then returned to the left atrium`to go to body

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what is systematic circulation?

supplies blood fow to all the tissues of the body except the lungs

then come back into right atrium
also called greater circulation or peripheral circulation

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stronger part of the heart that pushes blood out

ventricles

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entire blood volume is about ____.

___% of whole volume is in systemic circulation
- ____% in veins
- ____% in arteries
- ____% systemic arterioles and capillaries

____% of whole volume is in Pulmonary circulation
- ____% in heart
- ____% in pulmonary vessels

5 Liters

84% in systemic
64% in veins
13% in arteries
7% arterioles and capillaries

16% in pulmonary
7% in heart
9% in pulmonary vessels

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blood goes from _____ to lungs to get oxygenated.
Then back to _______.

_____ pumps blood out to go to body through the ______. goes through ______ where oxygen is dropped off.

makes its way to _____ then ____ returns blood to heart.

right ventricle
left atrium

left ventricle
aorta
arterioles and capillaries

veins
inferior vena cava

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basic blood flow from the left ventricke?

elastic arteries
muscular arteries
arterioles
capillary beds
venules
veins
right atrium

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main function of venous vessels are _______

blood reservoirs
-major storage compartment for blood

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what is the relationship between cross-sectional areas to velocity of blood flow?

inversely proportional
- veleocity is slowest where cross sectional area is greatest

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blood flow becomes ____ the farther away from the heart and is slowest in ______

when venules unite to form veins the total cross-sectional area becomes _____ and flow becomes _____

slower
capillaries

smaller
faster

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the capillaries are located _______

at the far end of the blood flow loop

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heart pumping is _____ and the arterial pressure alternates between ______ and ______

mean pressure is ____

pulsatile

systolic (120)
diastolic (80)

relatively high

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which side of heart has more pressure

left

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largest drop in arterial pressure occurs in the _____ from ____ to ___

arterioles

70 to 35

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Rate of blood flow of each tissue of the body is almost always precisely controlled in relation to ______

tissue need

increased flow = increased metabolic demand

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cardiac output (CO) is controlled mainly by the ________

sum of all the local tissue flows

all blood flowing thru tissue must return to heart
increased flow thru tissue determines increased flow to the heart which increases CO

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in general the arterial pressure is controlled ________ of _________

independently of local blood blow or CO control

baroreceptor reflex
- increases heart rate
- generalized vasoconstriction

endocrine hormonal secretion

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when blood flows at a steady rate through a long smooth vessel in streamlines, with each layer of blood remaining the same distance from the vessel wall

laminar flow

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in laminar flow velocity of the blood in the center of the vessel is ______ than the outer edges

greater

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in laminar flow the conductnce of blood in a vessel increases to the _____ of the vessel ______

fourth power
diameter

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when the fluid molecules touching the wall barely move because of adherence to the vessel wall.

parabolic profile

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the farther the layer of blood is from the vessel wall, the ____ it is.

less impeded (less stuck)

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blood flowing in all directions in a vessel and continually mixing within a vessel

turbulent flow

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what can cause turbulent flow

when it passes an obstruction in a vessel or passes over a rough surface

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what is it called when the blood in turbulent flow moves backward in a whorl

eddy currents

eddy currents cause much more ______

resistance

turbulent flow is seen in ________ it generates sound waves that can be heard with a stethoscope as _____ or _____ turbulent flow can lead to ______

diseased and stenotic arteries and heart valves murmors or bruits decrease in flow and blood clot formation and ischemia

the quantity of blood that passes a given point in the circulation in a given period of time

blood flow ml/min CO amout of blood pumped into the aorta by the heart/min - 5000 ml/min

what main factors effect blood flow through a vessel

pressure difference (gradient) resistance

pressure difference or gradient is?

pressure difference of the blood between the two ends of the vessel

what is resistance?

impediment to flow due to friction between blood and endothelium of the vessel wall

P1 vs P2

P1 is beginning P2 is end

flow through the vessel can be cslculated using ____

Ohm's Law

what is ohms law equation

F = (P1-P2) / R R=resistance

Ohm’s law demonstrates that: Blood Flow is _____proportional to the pressure difference and _______ proportional to the resistance. Put simply, as blood flow increases: The pressure gradient _____ The resistance __________

directly inversely increases decreases or stays the same

what influences vascular resistance

size of lumen blood viscosity total blood vessel length

how does the size of the lumen influence vascular resistance?

the smaller the lumen of blood vessels, the greater the resistance

vasoconstriction ____ the diameter and vasodilation ____ the diameter

narrows widens

normally moment to moment fluctuations in blood flow through a given tissue are dependent upon whether the _____ in that tissue are under _______ control

arterioles sympathetic

what is blood viscosity?

resistance to flow depends on the ratio of RBC to plasma (hematocrit) and to a smaller extent the concentration of plasma proteins

how does blood viscosity influence vascular resistance?

the higher blood viscosity, the higher the resistance

hematocrit for males and females

RBC to plasma males = 42 women = 38

high blood viscosity found in conditions of ________ and ________

dehydration and polycythemia - high #RBC - increases blood pressure

what influences does total blood vessel length have on vascular resistance?

resistance of blood flow through a vessel is directly proportional to total blood vessel length longer = more resistance

why do obese have higher rates of hypertension

additional blood vessels increase blood vessel length, so more resistance

the ______ has a cardiovascular center that regulates heart rate, contractility (force of contraction), and blood vessels diameter

medulla oblongata

CVC controls neural, hormonal, and local _____ systems that regulate blood flow to specific tissues

negative feedback systems

some neurons in the CVC in medulla oblongata stimulate heart (_______ center) or inhibit the heart (______ center).

cardiostimulatory center cardioinhibitory center

some neurons in CVC control blood vessel diameter by causing _________ in ______ center

vaso constriction or dilation vasomotor center

neurons regulating blood vessel diameter

vasomotor neurons

sympathetic neurons that reach the heart and increase heart rate

cardiac accelerator nerves

parasympathetic neurons that reach the heart and decrease heart rate

vagus nerve

input to CVC by what three main sensory receptors?

Proprioceptors Baroreceptors Chemoreceptors

what are proprioceptors

monitor joint movement and provide input to CVC during physical activity increased movement = increased blood flow requirement - also increase activity when postural muscles are firing at a high rate (indicating standing position)

what are baroreceptors responsible for ?

pressure sensitive sensory receptors - carotid sinus - wall of ascending aorta - walls of these vessels stretch stimulating baroreceptors drop in BP : increase sympathetic stimulation, increase HR and contractility. This increases CO, vascular resistance, and BP (negative feedback) increase in BP : increase in parasympathetic, decrease in HR and contractility. This decreases CO, vascular resistance, and BP (negative feedback) (baroreceptor reflex)

carotid sinus is _____ nerve

glossopharyngeal nerve CN IX

ascending aorta and arch of aorta is _____ nerve

vagus nerve CN X

what are chemoreceptors responsible for?

monitor chemical composition of blood - detect changes in blood O2, CO2, and H+

_________stimulates the chemoreceptors to send signals to the CVC. The CVC then ____ ____ stimulation to arterioles and veins producing _________ and an _______ in BP as well as stimulating the respiratory center to _______ breathing.

hypoxia, acidosis, or hypercapnia increases sympathetic vasoconstriction increase increase

where is chemoreceptors found

close to baroreceptors od the carotid sinus and arch of aorta found in small structures called carotid bodies and aortic bodies

Blood pressure measured in _____ by ______. A pressure of 120 mmHg in a blood vessel will push a column of mercury to 120 mm height in a vertical column.

mmHg mercury manometer

regulation of blood pressure and blood flow

intrinsic regulation - autogenic regulation

explain autogenic regulation in blood pressure and blood flow

increase in arterial pressure = immediate rise in blood flow. in less than a minute, the blood flow in these tissues return back to normal even though arterial pressure is still elevated.

what two theories try to explain autogenic regulation

metabolic theory myogenic theory

metabolic theory

when arterial pressure becomes too great, the excessive flow provides too much oxygen and nutrients to the tissues. -The nutrients, especially excess oxygen, cause the blood vessels to constrict and the flow to return to normal despite the increased pressure.

myogenic theory

sudden stretch of blood vessels walls causes the smooth muscle of the wall to contract for a few seconds. - high arterial pressure stretches the vessel, causes vascular constriction that reduces blood flow nearly back to normal - elicited by stretch induced depolarization, which rapidly increases calcium ion entry from the ECF into cells causing them to contract. - Conversely at low pressures the degree of stretch is less, so that the smooth muscle relaxes and the flow increases.

several types of cells release a wide variety of ______ that alter _______

chemicals blood vessel diameter

vasodilation chemicals

potassium hydrogen lactic acid ATP prostacyclin nitric oxide kinins histamine

vasoconstricting chemicals

Thromboxane A2 superoxide radicals serotonin endothelins EPINEPHRINE.