The regulation of the cardiovascular system allows the body to adapt to various demands and maintain homeostasis.
The regulation of the cardiovascular system involves the autonomic nervous system (ANS), baroreceptors, and chemoreceptors, ensuring that heart rate and blood pressure are appropriately modulated in response to varying physiological demands.
The ANS comprises two main divisions: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system enhances cardiovascular function by increasing heart rate, accelerating impulse conduction through the atrioventricular (AV) node, and strengthening atrial and ventricular contractions. Beta (β)-adrenergic receptors intervene in these effects, which respond to norepinephrine and epinephrine. Conversely, the parasympathetic nervous system, primarily through the vagus nerve, slows heart rate by reducing impulses from the sinoatrial (SA) node and decelerating conduction through the AV node. This balance between sympathetic and parasympathetic input is vital for the dynamic regulation of heart rate.
Baroreceptors in the aortic arch and carotid sinus are sensitive to changes in arterial pressure. When these receptors detect increased pressure, they relay signals to the brainstem's vasomotor center, reducing sympathetic activity and increasing parasympathetic influence. This results in decreased heart rate and vasodilation. Conversely, a drop in arterial pressure prompts the opposite response, enhancing sympathetic outflow to increase heart rate and induce vasoconstriction, stabilizing blood pressure.
Chemoreceptors are strategically positioned in the aortic, carotid, and medulla bodies. These receptors respond to fluctuations in blood chemistry, particularly elevated levels of carbon dioxide (hypercapnia), decreased pH (acidosis), and reduced oxygen levels (hypoxia). Activating chemoreceptors stimulates the vasomotor center to increase blood pressure, primarily by enhancing sympathetic stimulation. This increases heart rate and myocardial contractility, Ensuring sufficient oxygen delivery and removing carbon dioxide from tissues.
Bölümden 13:
Now Playing
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
182 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
254 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
267 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
769 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
308 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
373 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
403 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
407 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
218 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
115 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
121 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
136 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
131 Görüntüleme Sayısı
An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities
56 Görüntüleme Sayısı
JoVE Hakkında
Telif Hakkı © 2020 MyJove Corporation. Tüm hakları saklıdır