As the myocardium stretches, the strength of the subsequent contraction increases.
Which artery supplies oxygen and nutrients and removes waste from the myocardium?
Coronary artery
End-diastolic volume
Preload
Resistance to left ventricular contraction
Afterload
Name some drugs that increase the force of myocardial contractions.
(3)
digitalis
epinephrine
sympathetic drugs
Which nervouse system influences the rate of impulse generation, speed of transmission through the pathways, and strength of atrial and ventricular contractions?
Autonomic Nervous System
Nerve fibers that decrease the rate and also innervate all parts of the atria and ventricles, and SA and AV nodes.
Parasympathetic Nerve fibers
Mediates impulse between the atria and ventricles.
AV node
What is the intrinsic rate of the AV node?
40-60bpm
What is the intrinsic rate of the bundle of HIS and Purkinje fibers?
20-40bpm
Where is oxygen exchanged for with CO2?
alveoli
What are the 3 steps necessary for oxygentation?
ventilation
perfusion
diffusion
Process of moving gases into and out of the lungs.
ventilation
Which nerve controls the diaphragm?
Phrenic nerve
Ability of cardiovascular system to pump oxygentated blood to the tissues and return deoxygentated blood to the lungs.
perfusion
An active process that is stimulated by chemical reeptors in the aorta.
Inspiration
Passive process that depends on elastic recoil properties of the lungs.
expiration
Where does diffusion of respiratory gases occur?
Alveolar capillary membrane
The thickness of the alveolar capillary membrane determines rate of _______.
diffusion
3 factors that determine capacity of blood to carry oxygen
-Amount of dissolved O2 in the plasma
-Amount of hemoglobin
-Tendency of hemoglobin to bind with oxygen
This protein is a carrier of oxygen in the blood.
Hemoglobin
What molecule is formed when hemoglobin and oxygen combine?
oxyhemoglobin
What 3 things do neural regulators control?
Respiratory:
-Rate
-Depth
-Rhythm
Chemical regulators control these two things...
Respiratory Rate and Depth
Decreases the oxygen carrying capability of blood by decreasing the amount of available hemoglobin.
Anemia AND inhalation of toxic substances (CO)
S/S of Anemia
fatigue
decreased activity tolerance
increased breathlessness
pallor
increased HR
Part of the brain that delivers impulses to the respiratory motor neurons by way of spinal cord. Accommodates speaking, eating and swimming.
cerebral cortex
In charge of automatic control of continous respiration.
Medulla oblongata
Cervical trauma to these 2 vertebrae usually results in phrenic nerve damage.
C3 and C5
Tachydysrhythmias and bradydysrhythmias lower ________ and _______.
cardiac output
blood pressure
Reduces cardiac output by decreasing diastolic filling time.
Tachydysrhythmias
Lower cardiac output by the decrease in heart rate.
Bradydysrhythmias
-Chaotic electrical ompulse in the atria
-Irregular
-Normal QRS complex at irregular rhythms
-Described as irregular irregular rhythm
Atrial Fibrillation
-Abnormal impulse originating above ventricles
-Abnormal placement of P wave
supraventicular dysrhythmias
-A sudden rapid onset of tachycardia originating above the AV node
-Begins and ends spontaneously
-Sometimes caused by excitement, fatigue, caffeine, smoking, and alcohol
paroxysmal supraventicular tachycardia
Medications used to treat paroxysmal supraventricular tachycardia
(4)
adenosine
diltiazem
digitalis
beta blockers
S/S of left-sided heart failure
fatigue
breathlessness
dizziness
confusion as a result of hypoxia
Clinical findings from left-sided heart failure
crackles in auscultation
hypoxia
shortness of breath on exertion and rest
cough
Findings if clients with right-sided heart failure
weight gain
distended neck veins
hepatomegly
splenomegaly
dependent peripheral edema
Occurs when blood flow through the valves is obstructed
Stenosis
Occurs when there is a backflow of blood into an adjacent chamber.