10) Pulse: Physiology And Regulation Flashcards
1
Q
What is the pulse?
A
- The bounding or pulsation of arterial blood flow
- Palpable at various points on the body
- Indicates status of the circulatory system
2
Q
How should the pulse be assessed?
A
- Palpate to assess contour, amplitude, and strength of each beat
- Compare characteristics on right and left sides
- Palpate carotid pulses separately to avoid compromising brain blood flow
3
Q
What should be noted when palpating pulses?
A
- Pressure or volume of pulse wave (normal, bounding, thready, absent)
- Rigidity or hardness of the vessel wall
- Presence of any palpable vibration (thrill)
4
Q
What indicates vascular dysfunction?
A
- Diminished or absent pulse distal to an injury site
5
Q
What are normal pulse findings in older adults?
A
- Either dorsalis pedis or posterior tibial pulse may be difficult to locate, but not both on same foot
6
Q
What creates the palpable pulse?
A
- Intermittent ejection of blood from the heart into the aorta
- Expansion and recoil of the arterial wall with each blood injection
7
Q
What information does pulse palpation provide?
A
- Pulse rate
- Rhythm
- Strength
- Equality between sides
8
Q
What regulates the pulse rate (heart rate)?
A
- Sympathetic nervous system (increases rate via epinephrine/norepinephrine)
- Parasympathetic nervous system (decreases rate via acetylcholine)
9
Q
What initiates cardiac contraction?
A
- Electrical impulses originating from the sinoatrial node
10
Q
What is the stroke volume?
A
- Approximately 60-70 mL of blood entering the aorta with each ventricular contraction
11
Q
How is the pulse wave created?
A
- Aortic wall distends with stroke volume ejection
- Pulse wave travels to distal arteries
12
Q
How is the pulse rate measured?
A
- By palpating a peripheral artery against bone/muscle
- Counting pulsing sensations in 1 minute
13
Q
What is cardiac output?
A
- The volume of blood pumped by the heart in 1 minute
- The product of heart rate and stroke volume
14
Q
What is a typical adult cardiac output?
A
- About 5000 mL/minute
- E.g. 70 beats/min x 70 mL stroke volume = 4900 mL/min
15
Q
Does a change in heart rate or stroke volume always change cardiac output?
A
- No, cardiac output or blood in arteries may not change
16
Q
What factors regulate stroke volume?
A
- Mechanical factors
- Neural factors
- Chemical factors
17
Q
How does heart rate affect blood pressure?
A
- Increasing rate decreases filling time, lowering BP
- Decreasing rate increases filling time, raising BP
18
Q
What indicates a health problem?
A
- Inability of BP to respond to heart rate changes
19
Q
How does an abnormal pulse affect cardiac output?
A
- Slow, rapid, or irregular pulse alters cardiac output
20
Q
How is cardiac output assessed?
A
- Palpate peripheral pulses
- Listen to apical heart sounds
