C&R Phys Flashcards
1.Isovolumic (Isovolumetric)Contraction Phase:
•Time between ___ valves closing and ____ valve opening therefore both sets of valves are closed
• First heart sound occurs when ___ valves close.
• Onset of this phase linked to beginning of ventricular _____ (QRS—linked to peak of R)
• Associated with ______ volume of blood in ventricles (end diastolic volume or EDV)
• Linked to “c” wave of atrial pressure
• Ends with aortic valve opening which begins the next phase
AV
aortic
AV
systole
highest
2.Ejection Phase:
•Time between the opening of aortic (and pulmonary) valve and the closing of the
aortic (and pulmonary) valve.
•Aortic pressure increases from 80 mmHg to 120 mmHg during this phase (BP is highest)
•Rapid ejection of blood occurs in the first 1/3 of ejection phase and ___% of blood volume is ejected
• Slow ejection is the final ___% of the blood volume ejected and takes the remaining 2/3 of ejection time.
•Ends when ______ valves close
•2nd heart sound occurs when _________
valves close
70%
30%
semilunar
semilunar
- Isovolumic (Isovolumetric) Relaxation Phase:
•Time between aortic valve closing and AV valves opening therefore both sets of valves are closed
• 2nd heart sound (semilunar valves close)
• Associated with end of ___wave on ECG
•Ventricular volume following ejection (end systolic volume or ESV—______ ventricular volume)
•Associated with “__” wave of atrial pressure
•Aortic pressure is decreasing back to 80 mmHg but the small increase after the aortic valve closes is called an ______ or dicrotic notch—caused by a small amount of backflow from the closure of the aortic valve.
T
lowest
v
incisura
4.Rapid Inflow (Filling) Phase:
•First ____of filling time— blood accumulating in the atria pushes the AV valves _____ and blood rapidly fills the ventricles
1/3
open
- Diastasis Phase:
•Second ___ filling time—blood returning to the heart continues to pass through to
ventricles
1/3
- Atrial Systole Phase:
•Last 1/3 filing time
•Atria contracts (__ wave on ECG) giving the last push of blood into the ventricles.
•Accounts for about __% of total ventricular volume
P
20
regulation of cardiac output:
1. Intrinsic Regulation: Frank-Starling Law- deals with relationship between ____ and Q.
•_____ _______ has the biggest impact on maintaining and increasing Q
•Other intrinsic factors that regulate Q are ___, SV and contractility.
preload
Venous Return (VR)
HR
2. Extrinsic Regulation: Autonomic NS A.Parasympathetic NS •\_\_\_\_\_\_ nerve primarily ↓ HR •Can ↓ SV •\_\_\_\_ binds to specific cholinergic (M2 muscarinic) receptors to \_\_\_\_ HR
B.Sympathetic NS
•Sympathetic nerves ↑ HR and ↑ SV
•_________ and Epinepherine
bind to specific (β1) receptors
Vagus
ACh
slow
Norepinepherine
normal conduction of the heart is:
SA node–>___ ____ –>bundle of his–> R and L bundle branches–> ______ fibers
AV node
purkinje
•S-A node-Dominant pacemaker with an
intrinsic rate of ___-__ beats/minute.
•A-V node-Back-up pacemaker with an
intrinsic rate of ___-___ beats/minute.
•Purkinje fibers-Back -up pacemaker with
an intrinsic rate of 15-40 beats/min.
70-80
40-60
velocity of action potentials: •SA node—0.3 to 0.5 m/sec •AV node—0.02 to 0.05 m/sec •Purkinje fibers—1.5 to 4.0 m/sec •Myocardium—0.3 to 0.5 m/sec
- what has the most rapid conduction rate?
purkinje fibers (.06 sec??)
- P wave =_____ _______
- ____ ______=Ventricular depolarization
- __ wave= Ventricular repolarization
Atrial depolarization
QRS Compex
T
____ ______ represents the interval between atrial depolarization and the initiation of ventricular depolarization so the AV node
delay
PR Interval
__ _______ represents the beginning of
ventricular depolarization through the end of ventricular repolarization
QT Interval
__ ______ represents the time between the end of ventricular depolarization and the beginning of ventricular repolarization
ST Segment
the Three Layers of a blood vessel are:
1._____ _____- contains the endothelium that lines the lumen. Smooth layer that
minimizes friction.
2.Tunica media—circular smooth muscle and elastic fiber. Thickest layer. Regulates __________ and ___________
3. Tunica externa (adventitia)—collagen fibers that reinforce the vessel. Contains nerve fibers, lymph vessels, and blood vessels (____ ______) so the exterior of
the vessel is nourished.
Tunica intima
vasodilation and vasoconstriction.
vasa vasorum
- Distensibility is the ability of the blood vessel to stretch, expand, or dilate.
- Walls of the veins are __ times more distensible than arteries.
- Compliance is the ability of the blood vessel to stretch etc. but also includes the ______ of blood that is stored in the vessel.
- Compliance =distensility X______
8
quantity
volume
Four Sources of Resistance to Flow
- Blood vessel length—the longer the vessel, the greater the resistance.
- Blood vessel diameter —contributes the most in altering peripheral resistance (occurs in the arterioles). ________ “fourth power” law—if the radius of the blood vessel doubles the amount of flow does not double, it increases by a power of ___: 2 x 2 x 2x 2 = 16
- Series or _______ blood vessels—occurs in the capillaries. Although smaller in diameter, the vessels are smoother so less resistance. Also smaller in length so less resistance.
- Blood viscosity- normal viscosity of blood is 3 to 4 times the thickness of water. If other factors are equal (same length and diameter), the more viscous the blood the more ________ to flow.
Poiseuille’s
4
Parallel
resistance
flow = change in pressure over _________
if resistance goes up then flow goes down…
resistance
There are four primary forces (called starling forces) that determine if fluid will
move out of the blood into the interstitial space (filtration) or from the interstitial
space into the blood (absorption).
1.Capillary pressure (Pc)—tends to force fluid outward from the blood
2.Interstitial fluid pressure (Pif)—tends to force fluid into the blood when Pif is (+)
and outward if Pif is (-).
3.Plasma colloid osmotic pressure— tends to cause ______ of fluid into the
blood.
- Interstitial fluid colloid osmostic
pressure—tends to cause osmosis of fluid
outward from blood.
osmosis
- If mean capillary pressure increases,this causes a higher net filtration of fluids into the interstitial space. If the fluid amount is
higher than what the lymphatic system can carry back to blood circulation, the concentration of fluid in the interstitial spaces causes ______. - If mean capillary pressure falls, net reabsorption increases resulting in more fluid coming inward to the blood causing and increase in ______ _______.
edema
blood volume
Control of Blood Flow
I.Acute control—occurs within second to minutes (vasodilation or vasoconstriction) based on metabolic needs of tissue:
A.________ Theory—↑ metabolism or ↓ O2
concentration, causes a release of vasodilator substances (adenosine) which causes vasodilation
B. _______ Demand (Oxygen Lack) Theory— O2 is needed for smooth muscle to contract so if ↓O2 concentration then the smooth muscle of the blood vessels would simply relax causing vasodilation
Vasodilator
Oxygen
Control of Blood Flow
II. Autoregulation—maintaining BF when arterial pressure changes:
A._______ Theory—as MAP decreases, delivery of O2 and nutrients decrease
thus vasodilator substances are released.
B._______ Theory—when MAP decreases, arterioles vasodilate in response to a decrease in blood vessel wall tension
Metabolic
Myogenic
Control of Blood Flow
III. Long-term regulation—takes weeks or even months to establish new BF
A.Increase in tissue vascularity— angiogenesis is growth of new blood vessels; collateral circulation results from vessel ________
blockage
______ _____ is the volume of blood
pumped out of the heart per minute:
Cardiac Output
CO = VR
_______ _______ is the volume of blood
returning to the heart each minute
Venous Return
CO = VR
___ varies depending on several factors:
- Level of metabolism at rest
- Metabolic rate during exercise
- Size of the body—surface area of ht. and wt.
- Age—consistent with decrease in activity
**Under normal, resting conditions, CO is controlled by total peripheral blood flow
CO
_______ ______ is the increase in CO as a result of an increase in metabolism—there is more blood in the ventricles than what is pumped out each beat under normal, resting conditions. So the immediate increase (within seconds) in metabolism is covered by this cardiac reserve to initially increase CO.
Cardiac reserve
Frank-Starling Law
•________ circulation normally controls VR and CO.
•Frank-Starling is an autoregulatory
mechanism that signals the heart to automatically pump out the same amount of blood that is returned to the heart
•Therefore, an increase in VR results in an increase in CO
Peripheral
Inspiration
•The diaphragm contracts and moves
downward (flattens) and the ribs
move ________ and ________.
upward and outward
Expiration
•The diaphragm relaxes and the ______ _______ of the lungs, chest wall, and
abdominals compresses the lungs and
the ribs return to normal position.
elastic recoil
(exercise,frieghtened, stress, etc.) • Under these conditions, the muscles that pull the rib cage downward and inward during expiration include the (1) rectus abdominus and (2) the\_\_\_\_\_\_\_ intercostals.
• The energy required for respiration (pulmonary ventilation) at rest is ___-___% of
the total energy expenditure. During heavy exercise that percentage of energy expenditure can increase ___-fold.
internal
3 to 5%
50
____ ______—the volume of air
inspired and expired in a normal (resting)
breath. VT is usually 500 mls for an adult.
Tidal Volume (VT)
Inspiratory Reserve Volume (IRV)— the
maximum volume of air that can be forcefully _______ above VT
.
inspired
Expiratory Reserve Volume(ERV)— the
maximum volume of air that can be forcefully ______ at the end of VT expiration.
expired
_______ _______— the volume of air
remaining in the lungs after the most
forceful expiration.
Residual Volume(RV)
______ ______—starting IRV at the end of a normal expiration and forcefully taking in as much air as possible. VT+ IRV
Inspiratory Capacity (IC)
Functional Residual Capacity (FRC)— the
amount of air remaining in the lungs after a
normal ________. ERV + RV
expiration
_____ ______ —this is the maximum
amount of air a person can forcefully expire
then take in a maximal inspiration. IRV+ERV
Vital Capacity(VC)
______ _____ _______—represents the
greatest volume the lungs can expand with the greatest possible effort. VC + RV
Total Lung Capacity (TLC)
This curve shows that as PO2 increases, more O2 binds to Hb. This is called the percent ______ of hemoglobin.
-the usual oxygen saturation of systemic arterial blood averages ___%
-saturation of hemoglobin averaging ___%
at 40 mmHg
saturation
97%
75%
- The shift to the right and downward as a result of increased H+ or increased CO2 is called the _____ ______.
- This shift to the right forces O2 away from the Hb and into the cells—delivering more O2 to the tissues that need it.
•The shift to the left means a higher affinity to retain O2 when blood becomes more
_______ (higher pH)
Bohr Effect
alkalitic
_______ Center neurons are located in the superior portion of the pons and mainly control rate and depth of breathing
-the primary effect of this center is to control
the “_____-___” point of inspiration
Pneumotaxic
switch-off
______ _______ _____ neurons located at the dorsal portion of the medulla and mainly cause inspiration as expiration is
passive under quiet breathing conditions
• Most of the neurons of the DRG are located within the nucleus of the tractus
solitarius
- action potential begins to weakly increase
steadily in a ____ manner for about 2 seconds
Dorsal Respiratory Group (DRG)
ramp
_____ ________ ______ neurons are located on the ventrolateral portion of the medulla and seem to be involved with
inspiration and expiration only when increased pulmonary ventilation is necessary.
Ventral Respiratory Group (VRG)
•This mechanism of controlling respiration is called the _____-_____ inflation reflex.
this reflex seems to be activated only when TV increases to more than three-fold
•Therefore, this reflex seems to be a protective mechanism to prevent
_______ the lungs and not part of the “normal” control of breathing.
Hering-Breuer
overinflating
_____ ______ protect the muscle fibers from tearing
______ _____ _____ protect muscle from not being torn from the bony attachment
Muscle Spindles
Golgi Tendon Organs
_____ ______ is the amount of blood pumped out of the heart per beat
_____ _____ is the amount of blood pumped out of the heart per minute
stroke volume (SV)
cardiac output (CO)
- VE at rest = __ L of air/min
- VE at max exercise = over ___ L of air/ min
5
100
** in regards to temperature** Too low—\_\_\_\_\_\_ (generate heat from skeletal muscle contractions) and goose bumps (smooth muscle contractions which decrease body surface area).
•Too high—______—water vapor has a
cooling effect.
shivering
sweating
- _______—heat given off in the form of infrared rays. The skin constantly radiates heat to surrounding objects (walls, other
people, etc.). Primary method of heat loss __ _____. - _________—heat given off in the form of vapor (water) which is sweat. Primary method of heat loss _____ ______.
Radiation
at rest
Evaporation
during exercise
