Cardiorespiratory System Flashcards
Blood is separated into
55% plasma
<1% leukocytes
45%platelets and erythrocytes
Blood is responsible for transporting
Oxygen, nutrients, metabolic byproducts.
Normal blood pH range and influential factors
7.4 normal
Between 6.9 and 7.5
Exercise, stress, disease
MusclenpH range
6.63 - 7.10
pH is regulated by buffers such as
Bicarbonate, ventilation, kidney function
O2 transport quantities
Dissolved O2 is .3 ml O2 per 100ml of blood or 2%.
Via hemoglobin:
Each gram of hemoglobin can carry 1.39 ml of O2
Healthy blood carries 15 grams of hemoglobin per 100 ml.
Therefore blood carries 20.8 ml O2/100ml blood
Average body carries 5 liters blood, about 7% of body weight
Partial pressure
Pressure exerted by one gas in a mixture of gasses. Calculated at the product of total pressure of a gas mixture and the % concentration of the specific gas.
Normal atmospheric pressure = 760mmHg
O2 percent concentration in the atmosphere is 20.93%. It partial pressure 159mmHg (760x[20.93/100])
O2-hemoglobin dissociation curve
The relationship of O2 and O2 saturation is sigmoidal due to cooperative binding. The O2 molecule binding to hemoglobin increases hemoglobin affinity for O2
Saturation begin to plateau at 60 mmHg. 90%
An increase from 60 mmHg to 100 mmHg -> 99% hemoglobin saturation with O2
Factors affecting oxyhemoglobin curve
Decreased body temp- shifts left
Inc body temp- shirts right
Low pH (acidity) - shifts right High pH (alkalosis) - shifts left
O2 is released from hemoglobin at a higher partial pressure so it can be used by working muscles.
The heart is copses of
Cardiac muscle
Mononucleated
4 chambers
Under involuntary neural control
SA node - primary intrinsic pacemaker generating electrical impulse across the atrium .08m/s. to the
AV node - spreads the impulse through the R&L bundle branches into the purkinje system, fibers that surround the ventricles. -> ventricular contraction.
Electrocardiogram
P wave - atrial depolarization. The impulse travels from the mSA node to the AV node
QRS wave - ventricular depolarization. The impulse continues from the AV node tot he Purkinje fibers throughout the ventricles.
T wave - repolarization (electrical recovery) of the ventricles.
Arteries pressure system
100 mmHg in aorta to 60 mmHg in arterioles
Veins pressure and structure
Low pressure, one way valves, smooth muscle bands facilitated by muscular contraction.
Total peripheral resistance
Resistance of the entire circulation
Affected by vessel constriction or dilation from exercise , sympathetic nervous system, metabolism, environmental stressors,
Cardiac cycle
From the start of one heart beat to the start of another.
Includes the diastolic pressure exerted on the arterial walls when the heart is filing with blood and no blood is being ejected.
The systolic BP exerted against the arterial walls during ventricular contraction
Rate-pressure product
RPP = SBP x HR
Describes the work of the heart and provides an estimate of myocardial o2 uptake. Also referred to as double product.
Mean arterial pressure
Ther mean BP throughout the cardiac cycle
MAP = DBP + [.333 x (SBP - DBP)]
Cardiac output.
The amount of blood pumped by the heart in one min.
Q = SV x HR
Stroke volume
The amount of blood ejected per HB
SV = EDV - ESV
Frank-starling principle
Based on the length tension relationship
The more more the left ventricle is stretched the more forceful the contraction and greater the volume.
An increase in preload EDV is directly influenced by the feart volume and venous return
Respiratory structure
Nasal cavities for warming moisturizing purifying -> trachea -> bronchi -> bronchioles (23 generations) -> alveoli
Respiratory muscles at est
Rest
Inhalation - diaphragm & external intercostal contract. Lung space incrrases, pressure decreases, air enters.
Exhalation - passive relaxation of diaphragm and ext. int. decrease volume & increases pressure. .