Cardiovascular System (Part 2) Flashcards
Define anastomosis
intercommunication between 2 arteries ensuring blood flow to area even if one artery blocked
How long are the P wave, PQ segment, and ORS interval?
0.08 seconds
How long is the ST segment?
0.12 seconds
How long is the T wave?
0.16 seconds
How long is the PR interval?
0.16 seconds
How long is the QT interval?
0.36 seconds
What type of training increases EDV? How?
endurance
by increasing SV and decreasing HR
In moderately trained or untrained people SV increases with exercise intensity up to __-__% of peak oxygen consumption.
40-50
True or False
Stroke volume increases at greater intensities
False
Why does stroke volume decrease at higher intensities?
Because of lactic acid accumulation
As percent peak oxygen consumption increases end-diastolic volume _____.
increases
As peak oxygen consumption increases SV, CO, and HR all ______.
increase
What is the rate of blood flow proportional to?
The pressure difference between 2 ends of vessel or between 2 chambers
In increase in pressure difference between blood vessels or heart chambers leads to _____ in blood flow
increase
How do you calculate blood flow?
Blood flow = change in pressure/resistance to flow
In order to maximally increase blood flow resistance _____ and the radius of the vessel _____.
decrease
increase
Increased cardiac output (as in exercise) leads to ______ BP
increased
What is capacitance?
the ability of a blood vessel to stretch
Increased capacitance leads to _____ BP
decreased
Plasma constitutes __-__% of total blood volume
55-60
Plasma may decrease in volume as much as __% during intense exercise, why?
10
water loss due to sweating
__% of plasma is water, _% is plasma proteins, and _% is other materials
90
7
3
Plasma may increase as much as __% at rest, why?
10
Adaptation to training
Exercise longer than __-__ minutes may require electrolyte replenishment
30-40
Formed elements (RBCs, WBCs, and Platelets) constitutes __-__% of total blood volume
40-45
__% of the formed elements in blood are RBCs and _% are WBCs and platelets
99
1
What is hematocrit?
The percentage of total blood volume composed of formed elements
What is normal WBC count?
3500 – 10,500
A WBC count less than what is concerning?
1000
What is normal hemoglobin for men and for women?
Men: 13.5 – 17.5
Women: 12 – 15.5
A hemoglobin less than what is concerning?
8
What is normal platelet count?
150,000 – 450,000
A platelet count less than what is concerning?
20,000
RBCs transport oxygen via what?
hemoglobin
What is hemoglobin?
The protein (globin) and iron-containing pigment (heme) necessary for binding oxygen
Where is hemoglobin produced in adults?
bone marrow of long bones
Can RBCs repair themselves? Why or why not?
No, because nuclei are removed from RBCs when produced
What is the lifespan of RBCs?
4 months
RBC count ____ at high altitude
increases
What is the acute effect of aerobic or weight training on RBCs?
Increased number of RBCs per unit volume of blood which increases the oxygen-carrying capacity
What is the effect of prolonged aerobic training on plasma volume?
decreases 10-20%
What is the effect of prolonged aerobic training on plasma volume?
decreases 0-22%
What is the chronic effect of long-term aerobic training on plasma volume?
increases 12-20%
What are the 3 adaptations due to endurance training?
- Increased cardiac output during endurance activity
- Increased oxygen delivery to skeletal muscle
- Increased endurance performance
What is the 1 adaptation due to weight training?
Increased ability to maintain cardiac output against increased BP
What is Arterial-venous oxygen difference (a-v O2 diff)?
The amount of oxygen per 100 mL of arterial blood entering a tissue minus that leaving tissue
What is a-v O2 diff at rest?
4-5 mL O2 per 100 mL of blood
What happens to the a-v O2 difference during exercise?
It increases
What is a-v O2 diff during exercise?
15 mL O2 per 100 mL of blood
Given the a-v O2 diff how do you calculate oxygen delivery to tissues?
Oxygen Delivery (VO2) = Blood Flow (Q) × a-vO2 diff
So, increasing either Q or a-v O2 diff will lead to a(n) _____ in VO2 for the whole body
increase
At rest __-__% of cardiac output goes to skeletal muscle
15-20
During exercise __-__% of cardiac output goes to skeletal muscle
80-85
What are the 4 factors that affect the redistribution of blood during exercise?
- Parallel circuitry
- Vasodilation to skeletal muscles
- Vasoconstriction to GI system
- Precapillary sphincters
At rest the majority of blood is distributed where?
to the liver and kidneys
The release of what neurotransmitter causes vasoconstriction?
norepinephrine
The release of what neurotransmitter can cause vasoconstriction and vasodilation?
epinephrine
What provides intrinsic control of vasoconstriction and vasodilation?
autoregulation
What 3 things increase venous return during exercise?
- Venoconstriction
- Muscle pump
- Respiratory pump
