cardiovascular system Flashcards
functions of cardiovascular system
works with the pulmonary system
> cardiopulmonary or cardiorespiratory system
purposes of CVS
- O2
- CO2
- body temperature
adjustments of blood flow during exercise
- cardiac output
- blood flow
components of CVS
- Heart
- Blood Vessels
> capillaries
> arteries & arterioles
> veins & venules
heart location
located in thoracic cavity
- in the mediastinum
- slight left lean (1/3 to right of sternum and 2/3 to left
- surround by a wall of pericardium
3 layers of heart
epicardium
myocardium
endocardium
right side of heart
pulmonary
left side of heart
systemic
myocardium
the heart wall, receives blood supply via coronary arteries
myocardial infarction (MI)
heart injury when coronary blood flow is disrupted for more than several minutes leading to permanent damage to the heart tissue
heart muscle
-actin & myosin present
- shorter muscle fibers & branching
- single nuclei
- z discs present
- striated
skeletal muscle
protective effect of exercise
> Cardio-protection: reduces heart attack incidence
Damage Reduction: survival rate is higher in active vs. sedentary individuals
conduction system
- SA node (pacemaker)
- AV node
- bundle branches
- purkinje fibers
p wave
atrial depolarization
QRS complex
Ventricular depolarization and atrial repolarization
T wave
ventricular repolarization
diagnostic use of EKG during exercise
> graded exercise test to evaluate cardiac function
– observe ECG during exercise
– also observe changes in BP
atherosclerosis
– fatty plaque that narrows coronary arteries
– reduces blood flow to myocardium
» myocardial ischemia
S-T segment depression
- suggests myocardial ischemia
systole
portion of cardiac cycle in which the ventricles are contracting
diastole
period of filling of the heart between contractions
