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The skeletal muscle pump is vital in negating orthostatic intolerance when standing. [2] When moving upright, the blood volume moves to the peripheral parts of the body. To combat this, the muscles involved in standing contract and help to bring venous blood volume to the heart.
Similar to how reflexes are physically connected and thus do not require control of individual components by the central nervous system, actions can be executed through synergies with minimal executive control because they are functionally connected. Beside motor synergies, the term of sensory synergies has recently been introduced. [37]
Reflex syncope or neurally mediated syncope occurs when blood vessels expand and heart rate decreases inappropriately leading to poor blood flow to the brain. [1] This may occur from either a triggering event such as exposure to blood, pain, strong feelings, or a specific activity such as urination , vomiting , or coughing .
The underlying mechanism involves the nervous system slowing the heart rate and dilating blood vessels, resulting in low blood pressure and thus not enough blood flow to the brain. [2] Diagnosis is based on the symptoms after ruling out other possible causes. [3] Recovery from a reflex syncope episode happens without specific treatment. [2]
Like the knee jerk reflex, the Lazarus sign is an example of a reflex mediated by a reflex arc—a neural pathway which passes via the spinal column but not through the brain. As a consequence, the movement is possible in brain-dead patients whose organs have been kept functioning by life-support machines , precluding the use of complex ...
It permits movement of the body, maintains posture, and circulates blood throughout the body. [1] The muscular systems in vertebrates are controlled through the nervous system although some muscles (such as the cardiac muscle ) can be completely autonomous.
Autonomic nervous system, showing splanchnic nerves in middle, and the vagus nerve as "X" in blue. The heart and organs below in list to right are regarded as viscera. The autonomic nervous system has been classically divided into the sympathetic nervous system and parasympathetic nervous system only (i.e., exclusively motor).
Peripheral Vasoconstriction: Blood vessels in the extremities constrict, reducing blood flow to the limbs. This shunting of blood helps to redirect it to essential organs, such as the heart and brain, preserving oxygen for vital functions. Apnea: The diving reflex triggers an involuntary breath-holding response . This allows individuals to hold ...