Cardiovascular Abdurap

8/17/2019 Cardiovascular Abdurap

1/108

Blood Vessels

Blood is carried in a closed system of vessels that begins and ends at the heart

The three major types of vessels are arteries,

capillaries, and veins

Arteries carry blood away from the heart, veins

carry blood toward the heart

Capillaries contact tissue cells and directly serve

cellular needs


2/108

Generalized Structure of Blood Vessels

Arteries and veins are composed of three tunics –

tunica interna, tunica media, and tunica externa

Lumen – central bloodcontaining space surrounded

by tunics

Capillaries are composed of endothelium with sparse basal lamina


3/108

Blood Vessels: The Vascular System

• Taking blood to the tissues and back

• Arteries• Arterioles

•Capillaries

•Venules

•Veins


4/108

The Vascular SystemThe Vascular System

Figure 11.8b


5/108

Differences Between Blood Vessel Types

• Walls of arteries are the thickest

• Lumens of veins are larger

• keletal muscle !milks" blood in veinsto#ard the heart

• Walls of capillaries are onl$ one cell

la$er thick to allo# for e%changesbet#een blood and tissue


6/108

Blood Vessels: Anatomy

• Three la$ers &tunics'•Tunic intima

•(ndothelium

•Tunic media

•mooth muscle

•Controlled b$ s$mpathetic nervouss$stem

•Tunic e%terna

•)ostl$ fibrous connective tissue


7/108

Tunics

Tunica interna !tunica intima"

#ndothelial layer that lines the lumen of all vessels

$n vessels larger than % mm, a subendothelial

connective tissue basement membrane is present

Tunica media

&mooth muscle and elastic fiber layer, regulated bysympathetic nervous system

Controls vasoconstriction'vasodilation of vessels


8/108

Tunics

Tunica externa !tunica adventitia"

Collagen fibers that protect and reinforce vessels

Larger vessels contain vasa vasorum


9/108

Elastic (Conductin! Arteries

Thic(walled arteries near the heart) the aorta and its

major branches

Large lumen allow lowresistance conduction of

blood

Contain elastin in all three tunics

*ithstand and smooth out large blood pressure

fluctuations

Allow blood to flow fairly continuously through the

body


10/108

"uscular (Distri#utin! Arteries and Arterioles

+uscular arteries – distal to elastic arteries) deliver blood to body organs

ave thic( tunica media with more smooth muscle

and less elastic tissue

Active in vasoconstriction

Arterioles – smallest arteries) lead to capillary beds Control flow into capillary beds via vasodilation

and constriction


11/108

Capillaries

Capillaries are the smallest blood vessels

*alls consisting of a thin tunica interna, one cell

thic(

Allow only a single -BC to pass at a time

.ericytes on the outer surface stabili/e their walls

There are three structural types of capillaries0

continuous, fenestrated, and sinusoids


12/108

Continuous Capillaries

Continuous capillaries are abundant in the s(in andmuscles, and have0

#ndothelial cells that provide an uninterrupted

lining

Adjacent cells that are held together with tight

junctions

$ntercellular clefts of unjoined membranes that

allow the passage of fluids


13/108


Continuous capillaries of the brain0

ave tight junctions completely around the

endothelium

Constitute the bloodbrain barrier


14/108


1igure %234a


15/108

$enestrated Capillaries

1ound wherever active capillary absorption or

filtrate formation occurs !e3g3, small intestines,

endocrine glands, and (idneys"

Characteri/ed by0

An endothelium riddled with pores !fenestrations"

5reater permeability to solutes and fluids than other

capillaries


16/108

$enestrated Capillaries

1igure %234b


17/108

Sinusoids

ighly modified, lea(y, fenestrated capillaries withlarge lumens

1ound in the liver, bone marrow, lymphoid tissue,

and in some endocrine organs

Allow large molecules !proteins and blood cells" to

pass between the blood and surrounding tissues

Blood flows sluggishly, allowing for modification in

various ways


18/108

Sinusoids

1igure %234c


19/108

Capillary Beds

A microcirculation of interwoven networ(s of

capillaries, consisting of0

6ascular shunts – metarteriole–thoroughfare

channel connecting an arteriole directly with a

postcapillary venule

True capillaries – %7 to %77 per capillary bed,capillaries branch off the metarteriole and return to

the thoroughfare channel at the distal end of the bed


20/108

Capillary Beds

1igure %238a


21/108

Capillary Beds

1igure %238b


22/108

Blood $low Throuh Capillary Beds

.recapillary sphincter

Cuff of smooth muscle that surrounds each true

capillary -egulates blood flow into the capillary

Blood flow is regulated by vasomotor nerves and

local chemical conditions, so it can either bypass or

flood the capillary bed

Diff i t C ill B d


23/108

Diffusion at Capillary Beds

Figure 11.*+


24/108

Venous System: Venules

Are formed when capillary beds unite

Allow fluids and *BCs to pass from the

bloodstream to tissues .ostcapillary venules – smallest venules, composed

of endothelium and a few pericytes

Large venules have one or two layers of smooth

muscle !tunica media"


25/108


26/108

Venous System: Veins

6eins have much lower blood pressure and thinner

walls than arteries

To return blood to the heart, veins have specialadaptations

Largediameter lumens, which offer little resistanceto flow

6alves !resembling semilunar heart valves", which

prevent bac(flow of blood

6enous sinuses – speciali/ed, flattened veins with

extremely thin walls !e3g3, coronary sinus of the

heart and dural sinuses of the brain"


27/108

Vascular Anastomoses

+erging blood vessels, more common in veins than

arteries

Arterial anastomoses provide alternate pathways

!collateral channels" for blood to reach a given bodyregion

$f one branch is bloc(ed, the collateral channel can

supply the area with ade


28/108

Blood $low

Actual volume of blood flowing through a vessel, anorgan, or the entire circulation in a given period0

$s measured in ml per min3

$s e


29/108

Blood $low: %ressure Chanes

1igure %8> 0 .ressure gradient in the blood vessels

Some %hysics of $luid "o&ement: Blood $low


30/108

1low rate0 !L'min"

1low velocity? rate'C& area of vessel

-esistance slows flow 6essel diameter !radius"

Blood viscosity

Tube length

*hich > above arerelatively constant@

Some %hysics of $luid "o&ement: Blood $low

1igure %88 c0 .ressure differences of static and flowing fluid


31/108

> factors effecting blood flow0 %3 .ressure gradientand >3 -esistance !6#&L $A+#T#-, tube

length, blood viscosity"

Blood viscosity and tube length are basically

constant3

6essel diameter has the most influence on bloodflow3

'ow &elocity of #lood flow is effected #y cross


32/108

'ow &elocity of #lood flow is effected #y cross

sectional area (A!

1igure %890 1low rate versus velocity of flow

"o&ement of Blood Throuh Vessels


33/108

"o&ement of Blood Throuh Vessels

• )ost arterial blood is

pumped b$ the heart• Veins use the milking

action of muscles to

help move blood

Figure 11.,

)&er&iew of &ascular components and #lood distri#ution


34/108

)&er&iew of &ascular components and #lood distri#ution

Pulmonary blood

vessels 12%

Capillaries 5%

Systemic arteries

and arterioles 15% Systemic veins

and venules 60%

Lymphatic

capillary

Precapillarysphincter

Metarteriole

Terminalarteriole

rterioles!resistancevessels"

rteriovenous

anastomosis

Postcapillary

venule

Sinusoid

Capillaries

!e#chan$e

vessels"

Thorou$hare

channel

Venous

system

Lar$e

veins

Lar$e

lymphaticvessels

Small

veins

Arterial

system

Lymphnode

Lymphatic

system

Muscular arteries

!distributin$

vessels"

&lastic arteries

!conductin$

vessels"

'eart

'eart (%

!a"

!b"

C a p a c i t a n c e v

e s s e l s

Cardio&ascular *esponse to E+ercise


35/108

1igure >:0 istribution of cardiac output at rest and during exercise

Cardio&ascular *esponse to E+ercise

Copyright >778 .earson #ducation, $nc3, publishing as Benjamin Cummings

Effect of e+ercise on #lood distri#ution


36/108

Effect of e+ercise on #lood distri#ution

Blood %ress re (B%!


37/108

Blood %ressure (B%!

1orce per unit area exerted on the wall of a bloodvessel by its contained blood

#xpressed in millimeters of mercury !mm g"

+easured in reference to systemic arterial B. in

large arteries near the heart

The differences in B. within the vascular system provide the driving force that (eeps blood moving

from higher to lower pressure areas

*esistance


38/108

*esistance

-esistance – opposition to flow +easure of the amount of friction blood encounters

as it passes through vessels

5enerally encountered in the systemic circulation

-eferred to as peripheral resistance !.-"

The three important sources of resistance are bloodviscosity, total blood vessel length, and blood vessel

diameter

*esistance $actors: Viscosity and Vessel


39/108

-esistance factors that remain relatively constant

are0

Blood viscosity – thic(ness or Dstic(inessE of the

blood

Blood vessel length – the longer the vessel, the

greater the resistance encountered

*esistance $actors: Viscosity and Vessel

,enth

*esistance $actors: Blood Vessel Diameter


40/108


Changes in vessel diameter are fre


41/108


&malldiameter arterioles are the major determinants

of peripheral resistance

1atty pla


42/108

Systemic Blood %ressure


43/108


The pumping action of the heart generates blood flow

through the vessels along a pressure gradient, alwaysmoving from higher to lowerpressure areas

.ressure results when flow is opposed by resistance

&ystemic pressure0

$s highest in the aorta

eclines throughout the length of the pathway

$s 7 mm g in the right atrium

The steepest change in blood pressure occurs in thearterioles



44/108


1igure %23:

Arterial Blood %ressure


45/108


Arterial B. reflects two factors of the arteries closeto the heart

Their elasticity !compliance or distensibility"

The amount of blood forced into them at any given

time

Blood pressure in elastic arteries near the heart is pulsatile !B. rises and falls"



46/108


&ystolic pressure – pressure exerted on arterial walls

during ventricular contraction

iastolic pressure – lowest level of arterial pressure

during a ventricular cycle

.ulse pressure – the difference between systolic and

diastolic pressure

+ean arterial pressure !+A." – pressure that propels the blood to the tissues

+A. ? diastolic pressure F %'4 pulse pressure

Capillary Blood %ressure


47/108

Capillary Blood %ressure

Capillary B. ranges from >7 to 87 mm g

Low capillary pressure is desirable because high B.

would rupture fragile, thinwalled capillaries

Low B. is sufficient to force filtrate out into

interstitial space and distribute nutrients, gases, and

hormones between blood and tissues

Venous Blood %ressure


48/108

Venous Blood %ressure

6enous B. is steady and changes little during the

cardiac cycle

The pressure gradient in the venous system is only

about >7 mm g

A cut vein has even blood flow) a lacerated artery

flows in spurts

$actors Aidin Venous *eturn


49/108


6enous B. alone is too low to promote ade


50/108


1igure %239

"aintainin Blood %ressure


51/108


+aintaining blood pressure re


52/108


The main factors influencing blood pressure are0

Cardiac output !C="

.eripheral resistance !.-"

Blood volume

Blood pressure ? C= x .-

Blood pressure varies directly with C=, .-, and blood volume

Cardiac )utput (C)!


53/108

Cardiac )utput (C)!

Cardiac output is determined by venous return and

neural and hormonal controls

-esting heart rate is controlled by thecardioinhibitory center via the vagus nerves

&tro(e volume is controlled by venous return !enddiastolic volume, or #6"

Gnder stress, the cardioacceleratory center increases

heart rate and stro(e volume

The end systolic volume !#&6" decreases and +A.increases

Cardiac )utput (C)!


54/108

Cardiac )utput (C)!

1igure %23

Controls of Blood %ressure


55/108

Controls of Blood %ressure

&hortterm controls0

Are mediated by the nervous system and

bloodborne chemicals

Counteract momenttomoment fluctuations in

blood pressure by altering peripheral resistance

Longterm controls regulate blood volume

ShortTerm "echanisms: .eural Controls


56/108

Short Term "echanisms: .eural Controls

Heural controls of peripheral resistance0

Alter blood distribution to respond to specificdemands

+aintain +A. by altering blood vessel diameter

Heural controls operate via reflex arcs involving0

Baroreceptors

6asomotor centers of the medulla and vasomotorfibers

6ascular smooth muscle

ShortTerm "echanisms: Vasomotor Center


57/108

Short Term "echanisms: Vasomotor Center

6asomotor center – a cluster of sympathetic neuronsin the medulla that oversees changes in blood vessel

diameter

+aintains blood vessel tone by innervating smoothmuscles of blood vessels, especially arterioles

Cardiovascular center – vasomotor center plus the

cardiac centers that integrate blood pressure control by altering cardiac output and blood vessel diameter

ShortTerm "echanisms: Vasomotor Acti&ity


58/108

Short Term "echanisms: Vasomotor Acti&ity

&ympathetic activity causes0

6asoconstriction and a rise in blood pressure if

increased

Blood pressure to decline to basal levels ifdecreased

6asomotor activity is modified by0

Baroreceptors !pressuresensitive", chemoreceptors

!=>, C=>, and F sensitive", higher brain centers,

bloodborne chemicals, and hormones

ShortTerm "echanisms: Baroreceptor/nitiated


59/108

$ncreased blood pressure stimulates the

cardioinhibitory center to0

$ncrease vessel diameter

ecrease heart rate, cardiac output, peripheral

resistance, and blood pressure

Short Term "echanisms: Baroreceptor /nitiated

*efle+es

ShortTerm "echanisms: Baroreceptor/nitiated


60/108

eclining blood pressure stimulates the

cardioacceleratory center to0

$ncrease cardiac output and peripheral resistance

Low blood pressure also stimulates the vasomotor

center to constrict blood vessels

p

*efle+es

Baroreceptor *efle+es


61/108

1igure %23I

p

ShortTerm "echanisms: Chemical Controls


62/108

Blood pressure is regulated by chemoreceptorreflexes sensitive to oxygen and carbon dioxide

.rominent chemoreceptors are the carotid and

aortic bodies

-eflexes that regulate blood pressure are integrated

in the medulla

igher brain centers !cortex and hypothalamus" can

modify B. via relays to medullary centers

Chemicals that /ncrease Blood %ressure


63/108

Adrenal medulla hormones – norepinephrine and

epinephrine increase blood pressure

Antidiuretic hormone !A" – causes intense

vasoconstriction in cases of extremely low B.

Angiotensin $$ – (idney release of renin generates

angiotensin $$, which causes intense vasoconstriction

#ndotheliumderived factors – endothelin and

prostaglandinderived growth factor !.51" are

both vasoconstrictors

Chemicals that Decrease Blood %ressure


64/108

Atrial natriuretic peptide !AH." – causes bloodvolume and pressure to decline

Hitric oxide !H=" – has brief but potent vasodilator

effects

$nflammatory chemicals – histamine, prostacyclin,

and (inins are potent vasodilators Alcohol – causes B. to drop by inhibiting A


65/108

0idney Action and Blood %ressure


66/108

y

Jidneys act directly and indirectly to maintain long

term blood pressure

irect renal mechanism alters blood volume

$ndirect renal mechanism involves the renin

angiotensin mechanism



67/108

y

eclining B. causes the release of renin, which

triggers the release of angiotensin $$

Angiotensin $$ is a potent vasoconstrictor thatstimulates aldosterone secretion

Aldosterone enhances renal reabsorption and

stimulates A release



68/108

y

1igure %232

"onitorin Circulatory Efficiency


69/108

#fficiency of the circulation can be assessed by

ta(ing pulse and blood pressure measurements

6ital signs – pulse and blood pressure, along with

respiratory rate and body temperature

.ulse – pressure wave caused by the expansion and

recoil of elastic arteries

-adial pulse !ta(en on the radial artery at the wrist"is routinely used

6aries with health, body position, and activity


70/108

"easurin Blood %ressure


71/108

The first sound heard is recorded as the systolic

pressure

The pressure when sound disappears is recorded as

the diastolic pressure

Variations in Blood %ressure


72/108

Blood pressure cycles over a >8hour period

B. pea(s in the morning due to waxing and waning

levels of retinoic acid

#xtrinsic factors such as age, sex, weight, race,

mood, posture, socioeconomic status, and physical

activity may also cause B. to vary


73/108


74/108

'ypertension


75/108

ypertension maybe transient or persistent

.rimary or essential hypertension – ris( factors in

primary hypertension include diet, obesity, age, race,

heredity, stress, and smo(ing

&econdary hypertension – due to identifiable

disorders, including excessive renin secretion,arteriosclerosis, and endocrine disorders

Blood $low Throuh Tissues


76/108

Blood flow, or tissue perfusion, is involved in0

elivery of oxygen and nutrients to, and removal of

wastes from, tissue cells

5as exchange in the lungs

Absorption of nutrients from the digestive tract

Grine formation by the (idneys Blood flow is precisely the right amount to provide

proper tissue function

Velocity of Blood $low


77/108

Blood velocity0

Changes as it travels through the systemic

circulation

$s inversely proportional to the crosssectional area

&low capillary flow allows ade


78/108

1igure %23%4


79/108

"eta#olic Controls


80/108

eclining tissue nutrient and oxygen levels are

stimuli for autoregulation

emoglobin delivers nitric oxide !H=" as well as

oxygen to tissues

Hitric oxide induces vasodilation at the capillaries to

help get oxygen to tissue cells

=ther autoregulatory substances include0 potassiumand hydrogen ions, adenosine, lactic acid,

histamines, (inins, and prostaglandins


81/108

Blood %ressure measurement


82/108

• )easurements b$ health professionalsare made on the pressure in largearteries

•$stolic - pressure at the peak ofventricular contraction

•iastolic - pressure #hen ventricles rela%

• /ressure in blood vessels decreases asthe distance a#a$ from the heartincreases


83/108

0lood /ressure C2/ 3 peripheral resistance

C2/ troke volume 3 heart rate

troke volume affected b$4

5 6egative pressure in thora% cavit$5 )uscle pump5 Vein valve

5 7ntra abdominal pressure

)easuring Arterial 0lood /ressure)easuring Arterial 0lood /ressure


84/108

Figure 11.18


85/108


86/108

.hase % !J%"0 Clear tapping sounds representing systolic

pressure

.hase > !J>"0 =nset of swishing sound or murmur

.hase 4 !J4"0 Loud slapping sound

.hase 8 !J8"0 +uffled Tones sounds representing diastolic

pressure

.hase : !J:"0 Tones cease

Silent ap or auscultatory ap


87/108

$nterval of pressure

where (orot(off soundsindicating true systolic

pressure fade away and

reappear at a lower

pressure point during

the manual

measurement of blood

pressure by auscultatory

method3

=ccurs when the firstJorot(off sound fades

out for about >7:7

mmg only to return3

0lood /ressure4 (ffects of Factors0lood /ressure4 (ffects of Factors


88/108

•

6eural factors• Autonomic nervous s$stem adustments

&s$mpathetic division'

•9enal factors•9egulation b$ altering blood volume

•9enin - hormonal control

0lood /ressure4 (ffects of Factors0lood /ressure4 (ffects of Factors


89/108

• Temperature

•:eat has a vasodilation effect

•Cold has a vasoconstricting effect

• Chemicals

•Various substances can cause increases ordecreases

• iet

Variations in 0lood /ressureVariations in 0lood /ressure


90/108

•:uman normal range is variable•6ormal

•1;+-11+ mm :g s$stolic

•

8+-'

•2ften associated #ith illness

•:$pertension

•:igh s$stolic &above 1;+ mm :>'

•Can be dangerous if it is chronic

The Seventh )eport o the *oint +ational Committee on

Prevention -etection &valuation and Treatment o


91/108

Prevention, -etection, &valuation, and Treatment o

'i$h .lood Pressure

Simtom 1ardinal


92/108

&.H#G

##+A

C#.AT L#LA

BATGJ – #+=.T=#

.AL.$TA&$

&$HJ=.#

H#-$ AA


93/108

Sin1ope


94/108

Jehilangan (esadaran a(ibat gangguan perfusi ota(

.erfusi ota(

%alpitasi


95/108

ebar jantung yang (uat

enyut jantung yang cepat

isritmia (ordis

D3S%.E4


96/108

yspneu dKeffort

.aroxysmal nocturnal dyspneu

yspneu istirahat

'eart $ailure (C'$!


97/108

ecline in pumping efficienc$ of heart

7nade?uate circulation

/rogressive@ also coronar$ atherosclerosis@ highblood pressure and histor$ of multiple )$ocardial

7nfarctions

Left side fails pulmonar$ congestion andsuffocation

9ight side fails peripheral congestion and edema


98/108

Coronary rtery -isease!C-"


99/108

M ArteriosclerosisM L vs LL

'omeostatic /m#alances


100/108

Angina pectoris

Thoracic pain caused by a fleeting deficiency in blood delivery to the myocardium

Cells are wea(ened +yocardial infarction !heart attac("

.rolonged coronary bloc(age

Areas of cell death are repaired with

noncontractile scar tissue


101/108

Cardiac Catheterization


102/108

Coronary rtery -isease!C-" Treatment


103/108

Coronary bypass grafting !CAB5" .ercutaneous transluminal coronary

angioplasty !.TCA" .ercutaneous Cardiac $ntervention

!.C$"


104/108

%TCA


105/108

%C/


106/108


107/108

0elainan 1elistri1an 5antun


108/108

Cardiovascular Abdurap

Documents

Transcript of Cardiovascular Abdurap