The Cardiovascular System
The human body is made up of various systems that work in close coordination to maintain homeostasis and normal body function (Inthavong & Ahmadi 2013). Such systems include the digestive system, the respiratory system, the circulatory system, the lymphatic system, endocrine system, and etcetera. The coordination between these systems is vital for normal body function to maintain a stable or constant internal body environment is vital for survival. This paper gives a detailed report on laboratory experiments that were carried out to investigate the relationship between heart rate, air flow and temperature during exercise. Therefore, the functions of the respiratory and circulatory systems during exercise will be discussed.
The Respiratory System
The human body cells require a continued supply of oxygen for normal function. The respiratory system exists so as to supply cells with oxygenated air while expelling carbon IV oxide from the body. The respiratory system is made up of the following structures;
• Nose and Nasal Cavity
The nose is the external opening of the respiratory system through which oxygenated air leaves the body and deoxygenated air leaves. The nasal cavity is lined with a mucous membrane and hairs. These trap dust particles in
the inhaled air, preventing them from the internal organs of the respiratory system where they would cause damage. As the air passes over the nasal cavity, it is warmed and moistened. In addition to these functions, the lining of the nasal cavity is made up of cells that are sensitive to smell.
Most of the breathing takes place through the nose. However, in some cases, breathing takes place through the mouth. The mouth does not warm nor moisten the inhaled air, neither does it have hairs to trap dust particles. However, air inhaled through the mouth covers a shorter distance to the lungs as compared to air going in through the nose. In addition, larger volumes of air are inhaled through the mouth. Breathing through the mouth mostly occurs when there is a huge demand for oxygen by the body (Erdemli n.d.).
The pharynx, otherwise known as the throat is a muscular funnel through which air passes during inhalation and exhalation. It contains the epiglottis, a flap of cartilage, which covers the opening of the trachea when food is being swallowed to prevent it from getting into the trachea and subsequently the lungs.
The larynx is also known as the voice box. It connects the laryngopharynx to the trachea. It is made up of numerous pieces of cartilage which form the vocal chords. These vibrate as air passes over them during speech to produce sound (West 2011).
This is a cartilaginous tubule, otherwise known as the windpipe, through which air moving in and out of the lungs passes (Johnson 2012). It is made of C-shaped cartilages which are ciliated on the inside. It connects the larynx to the bronchi. The cartilages prevent it from collapsing. The ciliated inner lining consists of an epithelial lining, whose cells produce mucus that, together with the cilia, traps dust particles. The streaming movement of the cilia pushes the particles trapped in mucus towards the pharynx where it is expelled through coughing or is swallowed.
• Bronchi and Bronchioles
The trachea splits into two bronchi, each of them leading into either the left or right lobes of the lungs. The bronchi further divide into numerous bronchioles which terminate in alveolar sacs.
These are spongy organs found in the chest, above the diaphragm. They are covered by a pleural membrane on the outside. The left lung is smaller and consists of two lobes while the right is bigger and has three lobes (Johnson 2012). The lungs contain billions of alveoli (air sacs) which are covered by networks of capillaries. Gaseous exchange in the lungs takes place across the alveolar membranes through diffusion.
The Cardiovascular System
The cardiovascular system, otherwise known as the circulatory system is made up of the heart, the blood vessels and the blood. The system serves the important role of transporting nutrients, oxygen, hormones and other components to tissue cells while transporting waste products from tissue cells to excretory organs for excretion.
• The Heart
The heart is a muscular organ which pumps blood around the body through the blood vessels. The heart’s muscles are myogenic. The sino arterial node acts as a natural pacemaker, regulating the rate at which the heart beats. The heart is divided into four compartments: two auricles and two ventricles. The ventricles have more muscular walls since they pump blood for longer distances. Valves separate the auricles from the ventricles and they prevent the backflow of blood during pumping. Deoxygenated blood from various body parts is pumped to the lungs for oxygenation, after which it is pumped again to the tissues. The rate at which the heart beats varies; it increases during exercise.
• Blood Vessels
These include the arteries, veins and capillaries. The arteries have the thickest walls since they carry blood under the highest pressure while capillaries have the thinnest walls. However, arteries have the narrowest lumen, while capillaries have the widest. All arteries, in exception of pulmonary artery, carry oxygenated blood while all veins, in exception of pulmonary vein, carry deoxygenated blood. While veins contain valves, the more elastic arteries do not.
Blood is the transport medium in the human body. It consists of blood cells, clotting factors, platelets, plasma and hemoglobin (Tallitsch, Martini & Timmons 2006). Dissolved nutrients, hormones, oxygen, etcetera is transported throughout the body in blood. In addition, waste products of the respiration process dissolve in blood and are transported to excretory organs.
The experiment was aimed at determining the effects of exercise intensity and type on recovery rates. Measures of heart rate, air flow and temperature before exercise (dumbbell lifting and treadmill), during exercise and after exercise were recorded. The collected data was then analyzed to determine the working relationship between the cardiovascular system and the respiratory system.
The graphs above show that heart rate increases with exercise. Additionally, the recovery rate slowed with increase in the intensity of exercise as well as duration of exercise. The rate of breathing, heart rate and body temperature increased gradually as the individual exercised, after which the scores started to fall during rest.
During exercise, there is an increased demand for energy production. Therefore, the rate at which glucose is broken down to produce NAD+ and NADH+ increases (Engineer 2013). This reaction occurs in the presence of oxygen. At the same time, waste products like carbon IV oxide are produced. With increased oxidation of glucose, the amount of
oxygen available in the body gets depleted quickly, creating an oxygen debt hence the need for increased oxygen supply. To compensate for the shortfall in oxygen supply, the rate and depth of breathing increases. Where high
volumes of oxygen are required urgently, breathing takes place through the mouth in what is referred to as panting. This way, oxygen rich air covers a shorter distance to the lungs and in high volumes where it oxygenates oxygen deficient blood.
Additionally, the heart rate increases to increase the rate at which oxygenated blood is pumped to the muscles, and deoxygenated blood to the lungs and other excretory organs like the kidneys. Blood vessels also vasodilate to increase the size of the lumen. This increases the volume of blood flowing to and from the muscles to supply oxygen and glucose and remove accumulating waste products. The oxidation of glucose to produce energy molecules leads to an increase in body temperature. More blood flows closer to the skin to release this heat (Sherwood 2011). Additionally, sweating occurs so as to cool the body.
The human body is an intricate system made of various sub-systems that work in sync to accomplish vital roles that allow human beings to adapt to various situations and environments. The circulatory system and the respiratory system, for example, work in close coordination during exercise to supply the oxygen and glucose required in high amounts by muscle cells while removing carbon IV oxide from the muscles (Korthuis 2011). The increase in heart rate, breathing rate and depth as well as temperature during exercise, is part of the involuntary reflexes (Korthuis 2011).