Cardiovascular Physiology Quiz

Study Notes

Wave of blood forced through arteries by contraction of the left ventricle
Waves of blood created by alternating expansion and recoil of arteries during each cardiac cycle
Tap felt in arteries caused by waves of blood forced through it by contraction of the left ventricle

Controlled by the cardiac centers located in the medulla of the brain stem through sympathetic or parasympathetic innervations
Can be sped up or slowed down in response to sensory impulses from the heart
Excessive stretch of the aortic arch by increased blood volume stimulates a reflex slowing of the heart rate through the parasympathetic nervous system
Decreased blood volume (as in hemorrhage) stimulates an increase in heart rate

Rate/Frequency: number of pulsations felt per minute (60-100 bpm)
Rhythm/Regularity: time intervals between pulse beats (abnormal rhythm is called arrhythmia or dysrhythmia and can be assessed by an EKG)
Volume/Amplitude/Strength: amount of blood ejected against the arterial wall with each heart contraction
- Normal pulse: full, easily palpable, not easily obliterated
- Weak pulse: difficult to palpate, easily lost during palpation
- Bounding pulse: easily palpated, difficult to obliterate

Age: pulse rate decreases with age
- Infants (1m-1yr): 120-160 beats/min
- Toddlers: (1-3 yr): 90-140 beats/min
- Preschool (3-6 yr): 80-110 beats/min
- School age (6-12 yr): 75-100 beats/min
- Adolescents/Adults: 60-100 beats/min
Sex: female pulse rate is slightly higher than male due to increased nervousness
Exercise/Muscular Activity: increases pulse rate, rest and sleep decrease it
Temperature: pulse rate increases by 10 beats/min for every degree of temperature elevation
Stress/Emotions: fear, anger, anxiety, surprise all increase pulse rate due to sympathetic stimulation
Medications:
- Positive chronotropic drugs (e.g., atropine) increase pulse rate
- Negative chronotropic drugs (e.g., digoxin) decrease pulse rate
Hemorrhage: increases sympathetic stimulation and increases pulse rate
Position Changes: pulse rate is higher in standing or sitting than lying down
Pulmonary Conditions: poor oxygenation due to diseases increases pulse rate
Disease Conditions:
- Conditions that increase pulse rate: infection, thyrotoxicosis, pulmonary embolism, anemia
- Conditions that decrease pulse rate: heart block

Difference between the apical and radial pulse rate
Occurs when an inefficient heart contraction fails to transmit a pulse wave to the peripheral pulse site

Tachycardia: abnormally elevated pulse rate (over 100 bpm in adults)
Bradycardia: abnormally slow pulse rate (under 60 bpm in adults)
Pulsus Bigeminus (Bigeminy): premature beat (weak) alternates with normal sinus beat (strong)
Pulsus Trigeminus (Trigeminy): premature beat alternates with two normal sinus beats
Ventricular Tachycardia: weak pulse (150-250 bpm) due to discharging impulses from hyperexcitable focus in the ventricles, causes palpitation
Atrial Fibrillation: irregular pulse, very weak, causes pulse deficit and palpitation due to multiple excitable areas in the atria working independently and not coordinating, AV node and bundle of His cannot conduct high atrial excitation rates

Palpation: use the tips of the middle three fingers on one hand to apply light pressure to the strongest pulsation
Auscultation: use a stethoscope to auscultate the apical pulse, providing more accurate assessment for difficult or irregular pulses