KIN 3515 EXAM 3

cardiorespiratory system

high pressure

distribution circuit, exchange vessels, arteries

low pressure

collection and return circuit, veins

lung functions

transport, communicate, homeostasis, protection

transport

circulate 02 and nutrients, remove CO2 metabolic bypoducts

communicate

transport hormones to target cells and organs

homeostasis

help regulate body temp, pH, H20 content

protection

against disease and infection, stop bleeding after injury

heart

provide unidirectional blood flow

pressure generated vary on Right vs Left side

2 atria, 2 ventricles

what are the 4 chambers w a septum dividing them?

right and left AV, pulmonary and aortic

what are the 4 valves providing unidirectional blood flow and pressure

3 layers

epicardium, myocardium, endocardium

cardiac muscle

myocardial fibers, striated, multinucleated

myofibrils contain actin and myosin

utilize cross bridge cycle and sliding filament theory

(like skeletal muscle)

cardiac

(unlike skeletal muscle) connected in series, intercalated discs

cell membranes fused together, reduced resistance to electrical flow, allow ions to move easy for action potential

cardiac conduction system

sinoatrial node, atrioventricular node, bundles of HIS/AV bundles, bundle branches, purkinje / subendocardial fibers

sinoatrial node

pacemaker, upper right atrium, spontaneously depolarize

atrioventricular node

2nd pacemaker, btwn atria and ventricles

delay action potentials before allowed to travel to ventricles

bundles of HIS/AV bundle

receive electrical stimulus from AV node

in ventricular septum

bundles branches

fibers divided R v L bundle branches

purkinje fibers

subdendocardial fibers, direct action potentials to apex then upward, in free walls of ventricles

electrocardiogram

measure all electrical activity generated by heart @ given time

cells and atria and ventricles de/repolarize creating enough change in voltage that can be detected through skin

leads placed on chest, back, limbs to measure voltage changes, 12+ leads or more give best picture

ECG

reflex movement of action potentials through heart,

resulting in Contraction and Relaxation of heart

p wave

atrial depolarization, atria contract next

qrs complex

ventricular depolarization

q

moving from AV node to bundles

r

moving from bundles up purkinje fibers and ventricle contraction begins

s

move further up purkinje fibers and ventricular contraction continues

t wave

ventricular repolarization and ventricles begin relaxing

pr interval

time fro conduction through AV node

qt interval

time for ventricular depolarization and repolarization

st interval

time for end of ventricular depolarization and end of ventricular repolarization

rr interval

time between successive r waves

tp interval

time between end of ventricular repolarization and subsequent atrial depolarization

veins

bring blood to heart

arteries

take blood away from heart

right atrium

what receives deoxygenated blood from body’s tissues?

tricuspid AV valve to right ventricle

after the RA, blood passes through which valve into which ventricle?

right ventricle

after the AV valve, which ventricle pumps blood into the pulmonary artery to get oxygenated in the lungs

oxygenated blood, left atrium

what type of blood from the pulmonary vein returns to which atrium

bicuspid mitral valve

after pulmonary vein carry oxygenated blood to left atrium, which valve does blood pass to get to the left ventricle?

left ventricle

after the mitral valve, which ventricle ejects blood through aortic semilunar valve into aorta for transport in systemic circuit?

90-120

aortic pressure ranges (low to highest in ejection)

0-10

ventricular pressure ranges (low to highest in beginning of ejection and atrial systole)

systole

phase of heartbeat when heart CONTRACT and pump blood FROM ventricles to ARTERIES

diastole

phase of heartbeat when heart muscle RELAX/REST and allow ventricles to FILL with blood

bradycardia

abnormally slow heart rate,

tachycardia

abnormally fast heart rate, >100 bpm @ rest

arrhythmia

abnormal or erratic heartbeat

arterial system

high pressure tubing propel blood AWAY from heart

no gas exchange, blood leaving left ventricle enter aorta and distributed through smaller arteries into arterioles

blood move DOWN pressure gradient

ayers of connective tissue (elastin and collagen fibers), inner endothelial layer and smooth muscle

smooth muscles

constrict/relax to regulate blood flow, sympathetic neurons

metarterioles

arterioles branch into smaller, less muscular vessels

end up as capillaries

capillaries

microscopically small vessels, bleed w scratch on skin surface

contain 6% of total blood volume, walls are single layered endothelial cells, site of GAS exchange

sphincters (ring of smooth muscle) encircle it @ origin to control blood flow through them

venous system

low pressure tubing returning blood to heart

capillaries fill deoxygenated blood into VENULES that become less branched and larger in diameter till merging into the VENA CAVA

inferior vena cava

what is fed by the abdomen, pelvis and lower extremties?

superior vena cava

what is fed by the head, upper extremities and thorax?

right atrium

the superior and inferior vena cava meet and empty MIXED VENOUS blood into where?

pulmonary circuit

blood flow to and from lungs with LOW PRESSURE

RA→ AV valve→ RV→ Pulmonary Semilunar Valve→ Pulmonary arteries → capillaries around alveoli in lungs → pulmonary veins→ LA

systemic circuit

blood flow to and from body, HIGH PRESSURE

LA→ Mitral valve→ LV→ Aortic Semilunar Valve→ Aorta→ progressively smaller arteries→ capillaries in body systems → larger diameter veins → vena cava → RA

coronary circulation

blood supply of heart

right and left coronary arteries

right and left coronary arteries

greatest volume flow through left coronary artery, LA, LV, RV

normal resting blood flow= 200 mL / min

myocardium

highly efficient, extract 70-80A% 02 from blood @ rest

rely almost only on AEROBIC ENERGY RELEASE

aerobic energy release

largest mitochondrial concentration of all tissues

myocardial energy sources

myocardial energy sources

glucose fatty acids and lactate from muscle glycolysis

glucose fatty acids

@ rest what is the main energy source?

lactate from muscle glycolysis

during exercise what is the main energy source?

increased coronary blood flow during exercise only mechanism to increase 02 supply

blood pressure

arterial vessels of peripheral system DONT permit blood to move as rapidly as it ejects from heart

pressure exerted by blood upon internal walls of blood vessels (mmHg)

aorta

store some ejected blood creating pressure in entire arterial system

arterial blood pressure

reflect combined effect of blood flow per min and resistance to flow in peripheral vasculature

blood flow

continuous circulation of blood through cardiovascular system

driving pressure

flow of blood through systemic circulation depend on pressure differences

aorta and RA, MEAN AORTIC PRESSURE (MAP) 100 mgHg, MEAN RA PRESSURE 0 mgHg

100-0=100mmHg

arteries and large arteries

more elastic fibers, pressure storers

expand and recoil to propel blood

smaller arteries

more smooth muscle and less elastic fibers

arterioles

more smooth muscle, sympathetic neuron innervation

supply 10-100 capillaries

veins

thinner walls than arteries, greater distensibility

volume storers 4x more than arteries

sympathetic neuron innervation

systolic blood pressure SBP

estimate of work heart and force that blood exert against arterial walls during ventricular style

diastolic blood pressure DBP

force exerted by blood during ventricular diastole

indicate peripheral resistance ease that blood flow arteries into capillaries

pulse pressure PP

difference between SDP-DBP

= SDP-DBP

mean arterial pressure MAP

avg force exerted by blood against arterial walls throughout entire cardiac cycle

= DBP + \[0.333 x (SBP-DBP)\]

upper arm

blood pressure measure in blood vessels of ?

large and distensible (dilated) arteries

at same ventricle height as heart

not in left ventricle because not easy or comfortable

normal

what classification has systolic BP of 90-119 mmHg and diastolic BP of 60-79 mmHg

prehypertension

what classification has systolic BP of 120-129 mmHg and diastolic BP of

stage 1 and 2 hypertension

what classification has systolic BP of 13--139, >140 mmHg and diastolic BP of 80-89, >90 mmHg

hypotension

what classification has systolic BP of

precapillary sphincters

blood flow in capillaries leaving arterial system regulated by?

(smooth muscle that encircle capillary origin and control capillary diameter)

sphincter constriction and relaxation

how is blood flow regulated in tissue metabolic requirements?

relaxation

during which sphincter action opens more capillaries?

driving force of increased local BP in inartistic neural control

venous return

which return do the valves in veins allow unidirectional blood food to heart?

small muscular contractions or minor pressure changes in thoracic cavity w breathing compresses veins

alternate compression or relaxation makes milking action

w/o valves blood is stagnant

heart rate HR

how fast heart beats per min, beat/min

stroke volume SV

how much blood pumped from LV + pulmonary veins w each heart beat , mL/ beat

=EDV - ESV

cardiac output

max values reflect functional capacity, mL/min

= SV x HR

end diastolic volume EDV

blood volume in LV @ end of systolic ejection phase, mL

end systolic volume ESV

blood volume in lV prior to contraction, mL

PRELOAD VOLUME

afterload

pressure must work against to eject blood from LV during SYSOTLE, proportional to MAP

aortic pressure load w LV work against to cause EJECTION

HIGHER aortic pressure REDUCES stroke volume

ejection fraction EF

% of blood in LV that ejected/pumped w each contraction

\-not all blood leave during each contraction

= ((EDV-ESV)) / EDV) x 100

EDV higher from increased venous return

strove volume increase due to Frank Starling Law

DONT result in greater ejection fraction

EDV= 140 mL, ESV=46 mL, SV= 94, EF= 67%

SNS stimulation increase contraction on LV

EDV DONT change

greater fraction of blood in LV ejected in systole

EDV= 120 mL, ESV=20 mL, SV=100 mL, EF=83%

intrinsic heart rate

SA node rate = 100bom

Resting HR (healthy)=

extrinsic heart rate

medulla (control center)

sensory input from: central command, arterial baroflex, cardiorespiratory reflex, muscle mechanco, metaboreflex

effects on: heart rate and contractility, arterial resistance and venous tone

cardioinhibitory/acceleratory centers

how does the medulla oblongata (control center) and ANS control heart rate and force of contraction?

integrate, send signals and efferent messages thru PNS and SNS

chronotropy

adjust cardiac output by changing rate