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Compared to the lungs' apex, the ventilation rate is 50% greater at the base. The V/Q ratio in the apex is roughly 3.3 and 0.63 in the base, which indicates that perfusion is greater than ventilation towards the base, and the ventilation rate is greater than perfusion towards the apex. [3]
Turbulent flow is present in circumstances under which Re > 4000. The range of 2000 < Re < 4000 is known as the transition range. Most blood flow in humans is laminar, having a Re of 300 or less, it is possible for turbulence to occur at very high flow rates in the descending aorta, for example, in highly conditioned athletes.
Venous return (VR) is the flow of blood back to the heart. Under steady-state conditions, venous return must equal cardiac output (Q), when averaged over time because the cardiovascular system is essentially a closed loop. Otherwise, blood would accumulate in either the systemic or pulmonary circulations.
The artery supplies the anterior region of the left ventricle, including: the anterolateral myocardium, apex, anterior interventricular septum, and anterolateral papillary muscle. [8] The LAD typically supplies 45–55% of the left ventricle and is therefore considered the most critical vessel in terms of myocardial blood supply.
Given the proposed manner of action of the muscle pump to increase arterial blood flow, it would seem impossible for a muscle contraction and skeletal muscle hyperemia to be uncoupled. Another experiment recently was only able to find evidence that vasodilation , not the skeletal muscle pump, was responsible for maintaining proper pressure and ...
The apex beat may also be displaced by other conditions: Pleural or pulmonary diseases; Deformities of the chest wall or the thoracic vertebrae; Sometimes, the apex beat may not be palpable, either due to a thick chest wall, or conditions where the stroke volume is reduced; such as during ventricular tachycardia or shock.
Axonal transport, also called axoplasmic transport or axoplasmic flow, is a cellular process responsible for movement of mitochondria, lipids, synaptic vesicles, proteins, and other organelles to and from a neuron's cell body, through the cytoplasm of its axon called the axoplasm. [1]
It is known as the calming portion of the autonomic nervous system. [16] While the sympathetic nervous system is activated, the parasympathetic nervous system decreases its response. Efferent vagal fibers originating from the nucleus ambiguous fire in parallel to the respiratory system, decreasing the vagal cardiac parasympathetic tone. [ 17 ]