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Upon stimulation by an action potential, skeletal muscles perform a coordinated contraction by shortening each sarcomere. The best proposed model for understanding contraction is the sliding filament model of muscle contraction. Within the sarcomere, actin and myosin fibers overlap in a contractile motion towards each other.
The muscles of respiration are the muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity. The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during quiet breathing. The elasticity of these muscles is crucial to the health of the respiratory system ...
Various cell types play a role in HR, including astrocytes, smooth muscle cells, endothelial cells of blood vessels, and pericytes. These cells control whether the vessels are constricted or dilated, which dictates the amount of oxygen and glucose that is able to reach the neuronal tissue. Brain blood vasculature as a function of blood flow.
The skeletal muscle pump or musculovenous pump is a collection of skeletal muscles that aid the heart in the circulation of blood. It is especially important in increasing venous return to the heart, [ 1 ] but may also play a role in arterial blood flow .
Ventilation refers to the in-and-out movement of air of the lungs and perfusion is the circulation of blood in the pulmonary capillaries. [1] In mammals, physiological respiration involves respiratory cycles of inhaled and exhaled breaths.
The pulmonary circulation collects oxygen from the lungs and delivers carbon dioxide for exhalation. The systemic circuit transports oxygen to the body and returns relatively de-oxygenated blood and carbon dioxide to the pulmonary circuit. [1] Blood flows through the heart in one direction, from the atria to the ventricles, and out through the ...
Cardiac muscle cells are joined to neighboring cells by intercalated discs, and when joined in a visible unit they are described as a cardiac muscle fiber. [8] Smooth muscle cells control involuntary movements such as the peristalsis contractions in the esophagus and stomach. Smooth muscle has no myofibrils or sarcomeres and is therefore non ...
Ventilation is the movement of gas during breathing, and perfusion is the process of pulmonary blood circulation, which delivers oxygen to body tissues. [2] Anatomically, the lung structure, alveolar organization , and alveolar capillaries contribute to the physiological mechanism of ventilation and perfusion. [ 1 ]