-> Trachea divides it into thinner tubes called bronchi.
As it enters the thoracic cavity:-
-> right bronchus divided into three bronchi.
-> left bronchus divided into two bronchi.
Function- They help to carry the air from the trachea to the lungs.
Lungs
-> They are spongy and elastic organs located in the thoracic
cavity. There are two lungs present in our human body i.e.
right lung and left lung.
-> Right lung divided into three lobes (regions).
-> Left lung divided into two lobes (region).
They are enclosed by a two-layer membrane called pleura and space
between this two-layered membrane is called
pleural cavity.
The pleural cavity contains a pleural liquid that is used to
lubricant and prevent friction. ↓
to make the surface slippery
So,
Lungs play an important role in breathing and in gaseous
exchange.
Bronchioles and Alveoli
-> Each bronchus further divided into finer branches called
bronchioles.
Each bronchioles end with a cluster of tiny chambers called
alveoli. They are
balloon-shaped filled with air.
So,
Alveoli are balloon-shaped structures present at the end
of each bronchiole.
Alveoli provide a surface where the exchange of gases takes
place because the walls (surface) of the alveoli contain an extensive network of blood vessels (Capillaries).
↓
smallest blood-vessels
The walls (surface) of the alveoli are very thin and are in
direct contact with blood vessels. So, the alveoli transfer the
air (O2) to the blood, and then blood
transfer the air (O2) to all
the parts of the body.
Thus,
Alveoli are the functional unit of the lungs and also they are the
sites of gaseous exchange in the human body.
Diaphragm
-> A large muscular surface act as a floor in a cavity called
Diaphragm.
During inhalation, the rib cage moves up and outward
direction. As a result of this, the diaphragm moves down and due
to this, space increased in our chest cavity and air rushes into
the lungs.
During exhalation, the rib cage moves down and inward
direction. As a result of this, the diaphragm moves up and retains
its original position. Due to this, the space is increased in our
chest cavity and the air is pushed out from the lungs to the
atmosphere.
Transportation
-> Transport means to carry things from one place to
another.
So,
Transportation is a life process in which various
substance (oxygen, carbon dioxide, urea, Nutrition, etc.) are
transported from one part of the body to other parts of the
body of an organism.
Blood
-> The red-colored liquid present in our body is called blood.
* It is red because of the presence of hemoglobin.
* Blood is connective tissue.
The main components of blood are:-
* Plasma
* RBC (red blood cells or corpuscles)
* WBC (white blood cells or corpuscles)
* platelets
Plasma
-> The colorless liquid or fluid of blood consists of water
with many substances dissolved in it such as proteins, salt
carbon dioxide, oxygen, etc. is called plasma.
It contains 90% water.
Function- It carries all the dissolved substance from
one part to another part in the body.
Note- RBC, WBC, and platelets have emerged in this liquid.
-> RBCs carry oxygen from the lungs to all the cells of the body.
* They are circular in shape.
* They don't have a nucleus.
* They live for about 2 to 4 months.
* RBCs are made in the bone marrow. they don't live long because
they don't have a nucleus.
* RBCs are red in color because of the presence of hemoglobin.
↓
It is a type of protein present in RBCs.
Note- The deficiency of hemoglobin in the blood of a person
reduces the oxygen-carrying capacity of the blood. As a result,
that person may suffer from breathing problems, tiredness, and lack of energy.
Thus, that person looks pale and loses weight.
WBCs
-> The cells that fight infection and protect us from various
disease called WBC. they are called “soldiers of the body”
because they manufacture antibody to fight against infection
and protect us from disease-causing germs (pathogens) and
other harmful materials.
* They are either spherical or irregular in shape.
* They have a nucleus but the shape of the nucleus is different in each type of WBC.
* They are smaller in number than RBC.
* They live about 40 to 50 days.
Platelets
-> The cells which have tiny fragments formed in the bone
marrow called platelets.
* They don't have a nucleus.
Function- They help in coagulation or clotting of blood when
any of the blood vessels get damaged.
The ratio of RBCs, WBCs, and platelets is 600 : 1 : 40.
Function of Blood
* Blood carries oxygen from the lungs to the other parts of
the body.
* It carries CO2 from body cells to the lungs for breathing out.
* Blood carries digested food from the small intestine to all the
cells of the body.
* Blood carries waste products such as urea from the liver to
the kidney for excretion in the form of urine.
* It protects us from diseases because of the presence of WBCs.
* it regulates the body temperature. this is because the blood
capillaries in our skin help to keep our body temperature
constant i.e. 37°C or 98.6°F.
Circulatory System
-> Transport of oxygen, water, food, hormones, etc. to
different parts of the body are called internal transport and the internal transportation system in human beings is called
circulatory system.
The word circulatory comes from “circulation”.
It consists of:-
* Heart
* Arteries
* Veins
* Capillaries
* Blood
* Lymph
Significance of circulatory system
* It helps to transport gases like oxygen, carbon dioxide, etc.
* It also helps to transport nutrition.
* Helps to transport hormones.
* helps to transport waste material (like Sweat, Urea) from
the body.
* helps to transport heat to maintain body temperature.
* It contains those cells that fight infection and it built the
immunity of our body against disease.
There are two types of circulatory system:-
* Open circulatory system * Closed circulatory system
Open circulatory system
* They have a hemolymph i.e. a mixture of blood and simple
tissue fluid.
* Blood is pumped by the heart in body cavities.
* Found in Mollusca, Arthropoda, Hydra, etc.
Examples of Mollusca
0 Comments
If you have any queries, Please let us know.