1. The Respiratory System
The lungs are composed of air sacs (alveoli) surrounded by
small blood vessels (capillaries). With each breath, air is carried through the
airway (nose, mouth, throat, larynx, trachea and bronchi) and into the alveoli.
Breathing is controlled by nerve impulse from the brain to
chest muscle and the diaphragm as well as by a build-up of carbon dioxide in
the body.
Gas exchange occurs in the small air sacs called alveoli.
Small blood vessels (capillaries) surround the alveoli are responsible for the
uptake of oxygen into the blood. Carbon dioxide, a waste product of the cells,
is released from the body and enters from the capillaries into the alveoli. It
is then removed from the body through the act of exhaling.
The Respiratory System
Respiration
Respiration is the exchange of gases between the body and
the surrounding air. Specifically, it is the absorption of oxygen and the elimination of carbon dioxide. The air that we breathe in
contains 21% oxygen and 78% nitrogen. Small amounts of other gases make up the
remaining 1%.
The
blood does not use all the inhale oxygen as it passes through the body. Exhale
air contains 16%-17% oxygen and 3%
to 5% carbon dioxide; the rest is nitrogen. This 16% to 17% concentration of
oxygen is adequate to support a victim who is not breathing as you provide
mouth-to-mouth rescue breathing.
Mechanism of Respiration
This
is the process by which the lungs expand to take in air then contract to expel
it. The cycle of respiration, which occurs about 12 times per minutes or 1
breath every 5 seconds in an adult, consist of three phases:
1. Inspiration
2. Expiration
3. Pause
Normal Breathing Rate
Adult : 12-20 breaths per minute
Child : 20-24 breaths per minute
Infant : 24-28 breaths per minute
Child : 20-24 breaths per minute
Infant : 24-28 breaths per minute
Note:
The
breathing rate in a person can be observed by counting the number of times the
chest rises in a minute. The character of breathing can be described as slow or
fast (rapid) from the rate obtained, shallow or deep breathing, gasping,
snoring or gurgling.
2. The Circulatory System
Blood
circulates around the body in a continuous cycle, pumped by the heart in
rhythmic contraction and relaxation. Oxygen and nutrients are carried to the
body’s cells and waste product including carbon dioxide are removed.
The
blood circulates within the blood vessels. There are three types of blood vessel:
Veins, Arteries and Capillaries.
Veins carry blood to the heart, and arteries carry blood away from the heart.
Capillaries are tiny, thin-walled vessels that connect arteries and veins.
The
force that the heart pumps the blood through the vessels and around the body is
known as the “blood pressure “.
The
wave of pressure that passes along the arteries created by each beat or the
heart is known as “pulse”.
Blood Circulation through Heart and Lungs
The heart has four chambers with valves that regulate the
flow of blood. The heart pumps blood to the lungs, where oxygen is added; then
this oxygenated blood return to the heart and it is then being pumped to all
parts of the body. All body cells require oxygen to carry out their normal
functions.