Introduction
The cardiovascular system is made of organs responsible for blood circulation. The organs include the heart, blood vessels, and blood. The heart receives deoxygenated blood from the rest of the body, pumps it to the lungs for oxygenation, and then pumps the oxygenated blood to the rest of the body—the blood vessels transport blood to the rest and the heart. The blood is made of different components, including plasma, the fluid which carries blood cells, and blood cells which include platelets, red blood cells, and white blood cells. The blood cells are responsible for different bodily functions, including fighting disease and wound healing (Parrish, 2017). Therefore, this paper discusses the role of blood components in wound healing and how the endocrine and nervous systems work together with the cardiovascular system in response to injury and wound healing.
Components of Blood that Participate in Wound Healing
Blood comprises plasma and three cells: platelets, red blood cells, and white blood cells. These components work together to promote wound healing, survival, and maintenance of everyday health (Gonzalez et al., 2016). Plasma is the fluid that carries the other components of blood. Its primary roles include transporting blood cells, nutrients, endocrine factors, and metabolic waste products. It also plays a crucial role in wound healing. The plasma provides clotting factors that the prothrombin and fibrinogen to promote coagulation during injury. Platelets are non-nucleotide cells whose main functions under injury circumstances include hemostasis and inflammation. Platelets are derived from megakaryocytes which reside in the bone marrow. Platelets contain cytokines, hormones, and growth factors necessary for wound healing. It is important to note that under normal circumstances, platelets circulate in plasma in their inactive form and are activated in the presence of injury by the tissue factor and collagen exposed at the injury site. Once activated, platelets drive the clotting process, stop bleeding at the site of injury, and initiate the inflammation process of wound healing by releasing growth factors and bioactive molecules. The bioactive molecules are responsible for activating tissue repair and acute inflammation (Gonzalez et al., 2016).
White blood cells are the other components of blood involved in wound healing. They exist in an inactive form in the normal body state and get activated when an imbalance, such as wound healing and infection, occurs. Their primary role is to prevent infection and wound decontamination. The cells debride dead and damaged tissue at the wound site, after which they activate growth factors that convert fibrin into viable tissue and vascularization. The white blood cells can be classified into two main classes: granulocytes and mononuclear cells. Granulocytes include neutrophils whose primary function is to produce immune-regulating cytokines, proteases, and lipids, engulfing foreign bodies and producing antimicrobial granules.
On the other hand, mononuclear cells include lymphocytes and monocytes, whose functions are to control the growth of cells for an extended period after injury to facilitate wound healing and regulate the inflammation process of wound healing. Red blood cells transport oxygen to the rest of the body and carry carbon dioxide back to the heart to facilitate gaseous exchange. In wound healing, oxygen is required in the right balance; hence red blood cells have an essential role in the growth and rebuilding (Parrish, 2017).
Compare the Process by which a Hormone and a Neurotransmitter will be Secreted in response to injury.
The sympathetic nervous system innervates blood vessels. Therefore during injury, the sympathetic nervous system is activated to release a neurotransmitter that facilitates vasoconstriction of the blood vessels affected to help in hemostasis. The neurotransmitter that will be released in this aspect is norepinephrine which is also referred to as noradrenaline. For example, when one has a cut at the foot, the postganglionic endings of the sympathetic nervous secrete norepinephrine in response to the injury sustained. Cut injury leads to blood loss, resulting in hypovolemia and hypotension. Due to hypotension or hypovolemia, the kidney is stimulated to release renin. This hormone facilitates the activation of the renin-angiotensin-aldosterone system, which facilitates the regulation of body fluid balance and blood pressure (Gordan et al., 2015).
The Action of a Neurotransmitter Compared to that of a Hormone on the Physiology of the Heart and Blood Vessels as a Result of Sustaining Injury.
The sympathetic nervous system is a part of the autonomic nervous system whose responsibility is to control the body’s reactions during a stressful event or emergency. Therefore, the cardiac is innervated by sympathetic ganglia consisting of sympathetic preganglionic and postganglionic fibers. The postganglionic neurons of the sympathetic system release norepinephrine referred to as adrenergic fibers. Therefore, during an acute injury, the norepinephrine released activates the alpha 1 and 2 adrenergic receptors, which are located at the vascular smooth muscles proximal and distal to sympathetic nerve terminals hence, causing vasoconstriction of the blood vessels and facilitating cessation of bleeding (Gordan et al., 2015).
Cut injury can lead to hypovolemia and hypotension, stimulating the kidneys to secrete renin hormone. The activation occurs when the baroreceptors in the carotid sinus detect hypotension, reduced blood flow, or reduction in sodium chloride concentration in the blood. Renin leads to the conversion of angiotensinogen to angiotensin I. The liver produces angiotensinogen. Angiotensin-converting enzyme convert angiotensin I to angiotensin II, which is necessary for maintaining body hemostasis. Therefore, angiotensin II is a vasoconstrictor, thus causing direct effects on increasing systemic blood pressure. It also stimulates the aggregation of platelets hence prothrombotic effects necessary for hemostasis. In the kidneys, it increases the reabsorption of sodium. It causes the release of aldosterone by the adrenal cortex, which increases potassium excretion and sodium retention, increasing blood pressure and water retention (Gordan et al., 2015).
Conclusion
The body is made of different organ systems that work together to facilitate normal body function and state. Therefore, the endocrine and nervous systems, directly and indirectly, affect the cardiovascular system when carrying out its function. For example, in the case study, an acute injury directly involves the cardiovascular system to facilitate clotting and wound healing. The endocrine and nervous systems are indirectly activated in the process, and hormones and neurotransmitters play roles in wound healing. The interplay of these systems in wound healing is vital to maintain the body’s hemostasis and facilitate normal body functioning.
References
Gonzalez, A. C. de O., Costa, T. F., Andrade, Z. de A., & Medrado, A. R. A. P. (2016). Wound healing – A literature review. Anais Brasileiros de Dermatologia, 91(5), 614–620. https://doi.org/10.1590/abd1806-4841.20164741
Gordan, R., Gwathmey, J. K., & Xie, L.-H. (2015). Autonomic and endocrine control of cardiovascular function. World Journal of Cardiology, 7(4), 204. https://doi.org/10.4330/wjc.v7.i4.204
Parrish, W. R. (2017). Physiology of Blood Components in Wound Healing: an Appreciation of Cellular Co-Operativity in Platelet Rich Plasma Action. Journal of Exercise, Sports & Orthopedics, 4(2), 1–14. https://doi.org/10.15226/2374-6904/4/2/00156
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