quiz 7 Flashcards
sympathetic nervous system innervates
smooth muscle in arteries and arterioles
baseline sympathetic activity =
vasomotor tone
increase sympathetic activity
increase vasoconstriction
4 chambers of the heart
right and left atria
and right and left ventricles
right and left atria
top chambers
- recieve from vena cava
recieve from pulmonary vein
right and left ventricles
bottom chambers
- pump to pulmonary artery
-pump to aorta
myocardium
cardiac muscle
- type 1 muscle
high number of mitochondria and capillary
cardiac muscle fibers physically connected by
intercalated disks and desomones
cardiac muscle fibers are electrically connected by
gap junctions
where is the most myocardium
left ventricle
intrinsic conduction system
SA node to AV node to AV bundle to Purkinje fibers
intrinsic heat beat is set at
100 beats per min
SA node
initiates contraction signal and stimulates right atria
AV nodes
relays signal to ventricles
delay in RA allows
ventricles to fill during diastole
AV bundle
relays to right and left ventricle
- sends signal to apex of heart
-ventricles contract from bottom up
Purkinje fibers
send signal into right and left ventricle
-ends of right and left bundle branches
-spread throughout entire ventricle
extrinsic: parasympathetic nervous system
reaches heart via vagus nerve
-creates vagal tone
- carries impulses SA and AV nodes
-releases ACH and decreaes HR
extrinsic: sympathetic nervous system
carries impulse to SA and AV nodes
-releases norepinephrine facilitates depolarization
-increases HR
diastole
relaxation phase
-chambers fill with blood
systole
contraction phase
-blood leaves chambers
cardiac cycle
- venous return to the right atrium
- venous flow arrives in the right ventricle
- venous blood is sent in the lung via the pulmonary artery
- after oxygenated in the lung the blood returns to the left atrium
- red blood arrives in the left ventricle
- red blood is sent in the arteries to the issue
p wave
atrial depolarization
QRS
ventricular depolarization
T wave
ventricular repolarization
ventricle systole (contraction)
QRS complex
-ventricle depolarization and repolarization
lub heart sound
atrial valves close
ventricles contract =
depolarization
end systolic volume
remaining blood in ventricle after contraction
ventricle diastole (diastolic blood pressure)
T wave
relaxation begins
-
2nd heart sound - dub
aortic valve closes
end diastole volume
maximum volume of blood in ventricle
stroke volume
volume of blood pumped in one heartbeat
SV EQUATION
EDV-ESV=SV
ejection fraction
EDV-ESV/EDV OR SV/EDV=EF
brachaycardia
slow HR
-larger LV nad bigger SV
tachycardia
fast HR
premature ventricular contraction
heart skips a beat
vascular system
arteries: carry blood away from heart
arterioles: carry blood away from heart
capillaries: site of nutrient and waste exchange
venules: collect blood from venules back to heart
veins: carry blood from venules back to heart
120/80
systolic pressure/ diastolic pressure
purpose of respiratory system
to bring O2 and remove CO2 from the body
respiratory system carried out by 3 processes
- pulmonary ventilation -breathing
- pulmonary diffusion -movement of gases
- gas exchange -transport gases via blood
pulmonary ventilation
moving air into and out of lungs
nose/mouth–pharynx—larynx—trachea—-bronchial tree–alvoli
exchange zone
gas exchange between lung alveoli and capilarries
pulmonary diffusion
gases diffuse from high to low concentrations until PO2 and PCO2 equilibrium
arterial blood has higher ___and lower ___
O2 and CO2
venous blood has highe ___ and lower___
CO2 and O2
pulmonary gas exchange
replenishes blood oxygen and removes carbon dioxide
systemic arteries PO2 and PCO2
PO2= 100 and PO2=40
systemic veins PO2 and PCO2
PO2=40 and PCO2=46
venous PO2 is always ____ than air we breathe
lower
lower venous O2 =
bigger PO2 concentration gradient
only bottom 1/3 of the lung with blood b/c
of vascualr shunting
top 2/3 of the lung with blood b/c
of exercise
system blood pressure increases
during exercise
capilary diffusion =
gas exchange at the muscles
Hemoglobin transports O2 from
lungs to muscle
myoglobin transports O2 within
the muscle
loading =
hemoglobin/myoglobin binding O2
unloading=
hemoglobin/myoglobin binding O2 go
useful for HB to have tight grip on O2 in
the lungs
useful for HB to have a loose grip on O2 in
the muscle
high affinity
tight grip
low affinity
weak grip
myoglobin affinity?
high affinity for O2
factors influencing O2 delivery and uptake by the muscle
- O2 content of blood
- blood flow
- local conditions (ph, temperature PCO2)
high O2 content of air =
greater diffusion of O2 into blood in lung
decrease blood flow =
decrease opportunity to deliever O2 to tissues
decrease in PH, increase in temperature and increase PCO2 =
promote unloading in tissue
hemoglobin makeup
4 subunits, each with a heme group
heme binds to
O2
as more O2 unloads from HB =
the affinity for remaining O2 is lessened
Hb is loaded with O2 at
the lungs and pumped to systemic circulation
high PO2 in the
lungs
low PO2 in
body tissues
Bohr effect
increased affinity =less unloading
decreased affinity = more unloading
acidity increases
unloading
warmer blood temperature increases
unlaoding
transport of CO2 in the blood in 3 ways
- a biocarbonate ions - HCO3
- dissolved in plasma
- bound to HB (carbaminohemoglobin)
H+ binds to Hb triggers
Bohr effect
acids
low ph and high H+
bases
high ph and low H+
role of cardiovascular system on acid-base balance
transport HB and RBC (bohr effect and production of bicarb)
-gas exchange (CO2 and O2)
