cardiorespiratory sys. and gas exchange Flashcards
(44 cards)
2 systems function..
1) provide oxygen and nutrients to the body under various changes
2) clearing metabolic by-product from muscle
blood structure
plasma 55%, leukocytes & platelets 1%, erythrocytes 45%;
Ph 7.4
reason for blood PH changes
exercise, stress, deases
physiological tolerance for changes in PH of arterial blood and muscle
- 9 - 7.5;
6. 63 - 7.1
ph is regulated by
bicarbonate, ventilation and kidney function
oxygen presents in the blood in 2 forms
dissolved in blood (0.3ml/100ml) and carried via hemoglobin
hemoglobin
iron-containing protein within the red blood cells that can bind 1-4 oxygen molecules.
1 gr hemoglobin can carry …ml of oxygen
1.39ml
healthy blood hemoglobin capacity
15gr per 100 ml = 20.8ml oxygen/ 100ml
healthy (non-anemic) adult blood volume
5L or 7% of the body weight
oxygen-hemoglobin dissociation curve
the curve is S-shaped/ sigmoidal.
As O2 partial pressure increases hemoglobin affinity for Os increases and plateaus at O2 pressure 60mmHg and 90% hemoglobin saturation. O2 of 100mmHg = 98% hemoglobin saturation
the partial pressure is
pressure exerted by one gas in a mixture of gasses and calculated as the product of total pressure of a gas mixture and % of concentration of the specific gas.
example: atmospheric pressure=760 mmHg; O2 concentration=20.93%; O2 partial pressure= 760 x 20.93/100=159mmHg
factors influencing O2-hemoglobin curve
1) decrease in body t shifts the curve to the left
2) increase - to the right
arterial blood acidity: acidic or low pH - to the right;high pH (alkalosis) - to the left.
3) exercise - higher body t - O2 is released at a higher partial pressure so to be used by muscles
cardiac morphology
- mononucleated cardiac muscle
- 4 chambers (right/left atrium and ventricle)
- is under involuntary neural control
- SA= sinoatrial node or pacemaker of the heart
SA function
generates the electrical impulse (at speed 0.08m/s) - to the both atrium - to the AV node (atrioventricular) impulse slows down; - to the left and right bundle branches into the Purkinje system - ventricular contraction. The total impulse time - 0.2 s
the Purkinje system is
a series of fibers that surround ventricles which then stimulate ventricular contraction.
venous blood route
right atrium (superior &inferior vena cava) - right ventricle - lung (via pulmonary artery) - gas exchange (load with O2 and remove metabolic by-products).
superior/ inferior vena cava fuction
superior returns blood from head and upper extremities
inferior - trunk, lower extremities
arterial blood route
left atrium (via pulmonary vein) - left ventricle - through the body via aorta - organs, tissues via vasculature
central and peripheral circulation
heart and lungs = arterial system; the rest of the body = venous system.
ECG (electrocardiogram)
detects electrical impulses of the heart by the surface electrodes (10-12 places on the chest) and presented as distinct pattern.
Is taken in a clinical setting to examine the heart under stress.
ECG components
1) P-wave (represents atrial depolarization on SA-AV way)
2) QRS (ventricular depolarization on AV-Purkinje way)
3) T-way (electrical recovery/repolarization of the ventricles)
Note: atrial repolization can’t be seen as it takes place during QRS complex.
blood circulation system is composed of
- arteries (carry blood from heart to the tissues and organs)
- veins (carry blood from the tissues and organs back to the heart)
- the pulmonary veins (carry oxygenated blood from the lungs to the heart)
artery and vein blood pressure
arteries: for the systematic circulation it’s high (100mmHg in the aorta and 60mmHg in the arterioles)
veins; very low; due to this veins have one-way valves and smooth muscle bands that continue moving venous blood toward the heart as we move and contract muscles in our extremities.
