Chapter 2 Flashcards
(42 cards)
Cardiovascular system functions
- transports nutrients
- removes metabolic waste products
- blood transports oxygen from lungs to the tissues for use in cellular metabolism and transports carbon dioxide from tissue to the lungs, where it is removed from the body
Blood Characteristics
*plasma (55%),
*leukocytes platelets (<1%)
* erythrocytes (45%)
normal ph range is 7.4, between 6.9 and 6.63
muscle ph range is between 6.63 and 7.10
Hemoglobin
iron-containing protein within the red blood cells that has the capacity to bind between one and four oxygen molecules
- carries 1.39 ml of oxygen
- healthy blood has 15g of hemoglobin pero 100 ml
Partial pressure
pressure exerted by one gas in a mixture of gasses and is calculated as the product of total pressure of a gas mixture and the percent concentration of the specific gas.
Cooperative Binding
oxygen binds to hemoglobin it facilitates subsequent binding of oxygen molecules
*as oxygen partial pressure increases, hemoglobin becomes saturated, and saturation begins to plateau
factors influencing oxygen-hemoglobin curve
decrease in core temp: shift curve left
increase in core temp: shift curve right
Arterial blood acidity: low-shift right
high- shift left
SA node
sinoatrial node, primary pacemaker of the heart
Purkinje system
series of fibers that surround the ventricles, which then stimulate ventricular contraction
Cardiac Morphology
SA node –> AV node –>Purkinje fibers –>contraction of ventricles
approximately 0.2 seconds
inferior vena cava
returns deoxygenated blood from the trunk and lower extremities
superior vena cava
returns deoxygenated blood from the head and upper extremities
pulmonary artery
where gas exchange occurs
deoxygenated blood is loaded with oxygen while the metabolic by-products are removed
pulmonary vien
delivers oxygenated blood to the left atrium
arterial system
carries blood away from the heart
venous system
returns blood toward the heart
ECG
electrocardiogram-examen heart under stress
1) P-wave: atrial depolarization (when impulse travels from SA node to AV node)
2) QRS complex: ventricular depolarization (when the impulse continues from AV node to the purkinje fibers)
3) T-wave: electrical recovery/repolarization of the ventricles
Arteries
carry blood away from heart toward the tissues and organs
*high pressure system, from 100mmHG in the aorta to 60mmHg in the arterioles
veins
carry blood from the tissues and organs back to the heart
except: pulmonary veins carry oxygenated blood from the lungs to the heart
* low pressure system
Total peripheral resistance
resistance of the entire systemic circulation
Sympathetic nervous system stimulation
stimulates arterial vasodilation, which increases blood flow to working muscles
Cardiac cycle
heartbeat to heartbeat
diastole: relaxation, heart fills with blood
systole: contraction
SBP
Systolic blood pressure
*pressure exerted against the arterial walls as blood is forcefully ejected during the ventricular contraction (systole)
rate-pressure product (RPP)
estimate of the work of the heart
*RPP=SBP x HR
DBP
Diastolic blood pressure
*pressure exerted against the arterial walls when no blood is being forcefully ejected through the vessels
