RESPTRATORY SYSTEM

Introduction

In our daily life, we use oxygen to breathing. During cellular respiration, oxygen is used up in cells and carbon dioxide is given out. Therefore, all organisms must take in oxygen from the surrounding and release carbon dioxide from its body. This process of exchanging one gas for another is called gaseous exchange. There are two respiratory cycle in a single cycle which are inhaled and exhaled. The main organ that useful in this system is heart and lungs.

Function of Heart in Human Body

According to the author of Fundamental of Anatomy and Physiology, the heart is located near the anterior chest wall, directly posterior to the sternum. A midsagittal section through the trunk would not divide the heart into two equal halves because the heart lies slightly to the left of the midline, sit at an angle to the longitudinal axis of the body, and is rotated toward the left side. The heart is surrounded by the pericardial cavity, located in the anterior portion of the mediastinum, which separates the two pleural cavities, also contains the thuymus, esophagus and trachea.

The human heart is an organ that provides a continuous blood circulation through the cardiac cycle and is one of the most vital organs in the human body. The heart is divided into four main chambers: the two upper chambers are called the left  and right atria (singular atrium) and two lower chambers are called the right and the left ventricles. There is a thick wall of muscle separating the right side and the left side of the heart called theseptum. Normally which each beat the right ventricle pumps the same amount of blood into the lungs that the left ventricle pumps out into the body. Physicians commonly refer to the right atrium and right ventricle together as the right heart and to the left atrium and left ventricle as the left heart.

Function of The heart in Human Body

1. The right side of the heart (see right heart) is to collect de-oxygenated blood, in the right atrium.
2. The left side (see left heart) collects oxygenated blood from the lungs into the left atrium.

The Respiratory Cycle

Respiratory consists of two cycle, which is:

• INHALED

When the partial pressure of carbon dioxide increases, which make pH levels drops blood acidic increase to many hydrogen. The chemoreceptors cell are stimulated to send impulses to the respiratory centre. From the inspiratory centre, impulses are sent to diaphragm via the efferent intercostals nerve, causing the lungs to expand. Then, the diaphragm become flat, and outer intercostals will also expand. When the inhale process occur the exhale process is switched off.

•  ENHALED

Exhalation is generally a passive process; however, active or forced exhalation is achieved by the abdominal and the internal intercostals muscle. During this process air is forced or exhaled out. The lungs have a natural elasticity: as they recoil from the stretch of inhalation, air flows back out until the pressures in the chest and the atmosphere reach equilibrium. During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostals muscles, generate abdominal and thoracic pressure, which forces air out of the lungs.

Respiration and the Brain

The respiratory center is located in the medulla oblongata, a part of the brain known as the brainstem. The medulla sends stimuli down to the muscles that control breathing, and prompts them to take a breath. This process is conducted under the umbrella of the autonomic nervous system (ANS), meaning it is automatic and cannot be consciously controlled.

The muscles that respond to the stimuli, however can be voluntarily controlled as is evidenced by the act of holding in a breath. Hold it in for too long though and the brain will find a way to seize control and resume the act of breathing.

Respiration: Rate and Quality

When health professionals assess the rate of respiration they also examine the quality of a breath. After the rate is determined-normal, rapid or slow the quality of the breath is evaluated and labeled either normal, shallow, labored or noisy.

Normal breathing is determined by the rise and fall of the chest, which should be of average depth without the use of what are titled “accessory muscles.” Accessory muscles are always utilized when a person is having difficulty breathing and can be seen in the pronounced movement of the shoulders, nasal flaring, retractions at the collarbone and abdominal breathing. In children, retraction can also be witnessed between the ribs.

Quality is important in assessing respirations. A person may be breathing but it doesn’t mean that he is breathing well. A fast, shallow breath can be as hazardous as a slow, labored breath if a person is unable to get the quantity of air needed for body maintenance.

Variations in the rate of breathing can be caused by factors such as age, size, sex, physical condition, emotional states and obviously, trauma and respiratory diseases like emphysema, bronchitis and chronic obstructive pulmonary disorder (COPD). Trained health professionals rely on respiration sounds to offer clues for a diagnosis.

Muscles Used in Exhalation

Exhalation is either passive or active, depending on the level of respiratory activity. When exhalation is active, it may involve one or more of the following muscles:

The internal intercostals and transversus thoracic muscles depress the ribs and reduce the width and depth of the thoracic cavity.

The abdominal muscles, including the external and internal oblique, transversus abdominis, and rectus abdominis muscles, can assist the internal intercostals muscles in exhalation by compressing the abdomen and forcing the diaphragm upward.

Respiration Rates

Normal respiratory rates in a person at rest, in breaths per minute are:

• Newborn = 40 – 60 bpm
• 1 year = 30 – 40 bpm
• 3 years = 25 – 30 bpm
• 5 – 7 years = 20 – 25 bpm
• 10 – 15 years = 15 – 20 bpm
• Adult = 12 – 20 bpm

A person takes between 12 – 20, breaths per minute. That equals 750 – 1,200 breaths per hour and 17,280 – 28,800 breath per day.

Learning how to take a respiration is simple. Always ensure that a baseline respiration rate is take first, both at rest and after exercise. This baseline respiration can then be used as a comparison if rates begin to vary at a later date. While the respiration rate and quality will not specifically diagnose a condition, it can offer tremendous clues for health professionals to pursue.

BREATHING

Breathing is the process is that moves air in and out of the lungs. Breathing is only one process that delivers oxygen to where it is needed in the body and removes carbon dioxides. Another important process involves the movement of blood by the circulatory system. Gas exchange occurs in the pulmonary alveoli by passive disfussion of gases between the alveolar gas and the blood in lung capillaries. Once these dissolved gases are in the blood the heart powers their flow around the body (via a circulatory system). The medical term for normal relaxed breathing is eupina. To removing carbon dioxide, breathing results in loss of water from the body. Exhaled air has a relative humidity of 100% because of water diffusing across the moist surface of breathing passages and alveoli.

In addition, our respiratory exchange surfaces are just as delicate as those of an aquatic organism, but they are confined to the inside of the lungs – in the warm, moist, protected environment. Under these conditions, diffusion can occur between the air and the blood. Our circulating blood carries oxygen from the lungs to peripheral tissues, it also accepts and transports the carbon dioxide generated by those tissues, delivering it to the lings.