Parts & Functions of the Respiratory System

RESPIRATORY SYSTEM

Respiratory System Organs and Its Functions

Introduction to the respiratory system organs:
The respiratory system is the system of the human body by which it produces energy needed for life processes.
This energy is produced by the breaking down of glucose molecules in all living cells of the human body.

Introduction to the respiratory system organs:
In simple terms, Oxygen taken in to the body through air breathed in is transported to all parts of the body, and it is used in the process of burning of food molecules (that is, breaking down of glucose molecules) at the cellular level in a series of chemical reactions.
This breaking down of glucose molecules releases energy in the form of ATP, which can be utilized by the human body in order to carry out essential life processes.

RESPIRATORY ORGANS OF HUMAN

Structures and Functions
The Nose
Structure:
→ septum - made up of cartilage which separates the two nostrils.
→ nasal chamber
→ Hairs are present in the inner walls of the nostrils.

The Nose
Functions:
→ Air passes in through the nostrils and in to the nasal chamber
→ The hairs in the inner walls of the nostrils prevent dust particles and other particulate matter present in the air to enter into the nasal chambers.
→ The inner lining of the nasal chambers is supplied with blood vessels, so it warms up the air passing into the respiratory system organs.
→ It also has a lining of mucous secretion, so the air traveling inside is also moistened by it.
→ The mucus lining prevents bacteria and other microorganisms to go further into the human body.

The Pharynx
Structure:
→ It is a wide cavity continuous with the nasal chambers.
→ It is situated at the back of the mouth.
→ It leads into the trachea and the food pipe.
→ A entry to the trachea is protected by a flap called epiglottis.

The Pharynx
Functions:
→ It is a common passage for air and food, as it leads into the trachea (for passage of air) and the food pipe (for passage of food).
→ It prevents entry of food into the trachea (or the wind pipe) by the functioning of the epiglottis.

The Larynx
Structure:
→ It has a hollow cartilaginous structure located at the base of the pharynx, just at the start of the trachea.
→ This is the structure that rises and falls when we swallow food. One can feel it in the front part of the neck.
→ It is in the shape of two ligamentous folds.

The Larynx
Functions:
→ When air is expelled forcibly out through these ligamentous folds, it produces sound.
→ There are a set of muscles that help control the tension in the vocal cords, and this helps in production of a range of voices.

The Trachea
Structure:
→ This is the wind pipe. It emerges from below the Larynx.
→ Its walls are made up of C shaped rings of cartilage.

The Trachea
Functions:
→ This is the wind pipe through which air travels in and out of the body.
→ Its C shaped rings provide strength to the trachea, keep it flexible and distended permanently.

The Bronchi
Structure and Functions:
→ The trachea divides into two tubes which enter each lungs. These are called bronchi (singularly bronchus).
→ Each bronchi divides into fine tubes called secondary bronchi. The secondary bronchi divide into still smaller tubes called tertiary bronchi. The tertiary bronchi further divide into smaller and finer tubes called Bronchioles. The Bronchioles are 1mm in diameter, and by subsequent division, they form clusters of very tiny air sacs called alveoli. Alveoli have walls that are one cell thick. They are very moist and provide for the diffusion of respiratory gases in and out of the blood stream.

The Lungs
Structure:
→ The lungs are a pair of spongy organs. They are made up of thousands of air sacs.
→ They are roughly cone shaped.
→ The lungs are lobed, and the right lung has three lobes and the left lung has two lobes. The left lung is slightly smaller than the right lung to accommodate for the heart in between.

The Lungs
Structure:
→ They are covered by two membranes, the inner – visceral pleura, and the outer – parietal pleura. The space in between these membranes – the pleural cavity – is filled with a watery fluid called the pleural fluid. This provides for the lubrication and free movement for the expansion and contraction of lungs.

The Lungs
Functions:
→ The lungs provide a large surface area for the diffusion of oxygen from the air into the blood stream. This is achieved via the one cell thick walls of the air sacs called alveoli. The air is filled in the alveoli on one side and the other side is in contact with the blood stream of blood vessels. Respiratory gases are able to diffuse through the one cell thick walls of the alveoli.

RESPIRATION PROCESS

BREATHING AND RESPIRATION
Respiration is the exchange of gases between living matter and its surroundings.

Functions:
Oxidation of food by living cells;
Transport of oxygen to the body cells and the removal of carbon dioxide from the lungs; exchange of gases between your blood and lungs; and
The breathing process.

Breathing - is a mechanical process that helps get air in and out of the lungs.
Two stages of Breathing
Inspiration – During this process, you breath in or inhale to bring fresh supply of air into your lungs,
Expiration - during this process, you breath out or exhale to get rid of carbon dioxide or waste gases not needed by your body.

What is the normal rate of your breath?
Infants breath 30 to 40 times a minute.
At about six years of age, the breathing rate slows down to about 22 times a minute.
At your age (preferably adolescents stage), until you are about 25, the rate is further slowed down, about 16 to 18 times a minute. An exception is when you are an athlete or when you engage in hard work. Your breathing rate in such cases will be higher.

Phases in Human Respiration * External Respiration – is the exchange of gases between the atmosphere and the blood.

* Internal Respiration – is the exchange of gases between the blood and the body tissues. It occurs in every living cell.

Phases in Frog Respiration * Cutaneous Respiration - is the gaseous exchange between the skin of the frog and the external environment –water and air. The skin of the frog is supplied with blood capillaries and contain glands called the cutaneous glands, which secrete mucous and keeps the skin always moist and retains a thin film of water underneath the surface of the skin. This condition enables the exchange of air between the blood vessels and the outside environment. * Buccal Respiration - When the frog floats on the surface of water or while resting on land they respire through the buccal cavity. Atmospheric air is sucked in through the nasal openings when the floor of buccal cavity is lowered .In the same manner the air is send out when the cavity rises. The alternate lowering and rising of the buccal cavity, buccal respiration is bought about. The buccal respiratory system of the frog accounts for 5% of the oxygen intake. * Pulmonary Respiration - This type of respiration comprises of the nasal cavity, buccal cavity, larynx, trachea, a pair of lungs and the alveoli inside them. The adult frog has very simple, pinkish, sac like organs called lungs. They are not well developed and are placed in the anterior of the frog’s body .The numerous sac like structures inside the lung called the alveoli are richly supplied with blood capillaries. Pulmonary respiration accounts for 65% of total oxygen intake.
The frog has uses a very unique technique of breathing in and breathing out air.
The throat of the frog moves down wards, which enables the air to be sucked into the cavity of the mouth, which then moves down to the lungs. Gaseous exchange takes place between the thin walls of the alveoli, which are supplied with blood capillaries. The impure air containing carbon dioxide is sucked out in the same way.

REFERENCE http://sciencewithme.com/learn-about-respiration/ http://www.healthhype.com/process-of-respiration-in-humans-diagram.html