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
- The right side of the heart (see right heart) is to collect de-oxygenated blood, in the right atrium.
- 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.
