RESPIRATION IN HUMANS

 Respiration in Humans; Human beings has a well defined respiratory system Air that we breathe in enters through the nostrils which are line by hairs to filter the air that enters, Nostrils are also lined with mucous which is sticky in nature and absorbs any dust and other particles that enters, After that air passes through trachea. Trachea has rings of cartilage which prevents from collapsing if air enters through  great force.

 Trachea bifurcate after descending a little and forms two bronchi . Bronchi  then enters the Lungs.and inside the lungs it branches to form fine network like structure called bronchiloes. Human being posses a pair of lungs. Functional unit of lungs is called as Alvulus ( pl.Alveoli). It is a sac or balloon like structure. Alveoli is surrounded by blood capillaries and helps in the exchange of gasses.

Process of respiration in human can be divided into two main parts - Inhalation and Exhalation or Inspiration and Expiration. In inhalation or inspiration we take oxygen from the mixture of gases and in exhalation or expiration we give out carbondioxide as waste gas from our body. Different organs of our body like ribs, diaphragm, intercostal muscles etc.plays a great role in the process of respiration.

RESPIRATION

 Respiration: Respiration is a biochemical process in which the food materials are broken down to give energy. We human beings and other higher organism  take oxygen to break down the food materials to get energy. The food that we take is glucose and glucose is six carbon molecule. In the first step six carbon compound glucose breaks down in the  cytoplasm to give pyruvic acid. Pyruvic acid is also called as pyruvate which is a three carbon molecule. After the formation of pyruvate, next step differ from organism to organism. In lower organism like Yeast, Bacteria etc. braking down of pyruvate takes place in absence of oxygen, this is called as fermentation and produces Energy, Ethanol and carbon dioxide. Process is also termed as Anaerobic process.

 In our case and all the higher organism Pyruvic acid breaks down to form Energy, Carbon dioxide and moisture. Here the breaking down of pyruvic acid takes place in presence of oxygen so it is termed as Aerobic process.

Sometimes there may be lack of oxygen in our muscles  even though our respiration is aerobic then this type of respiration is termed as Lack of oxygen respiration. It leads to the formation of  Lactic acid and releases energy.Due to the accumulation of lactic acid it leads to the occurrence of  cramps.

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BLOOD CIRCULATION : HUMAN HEART

BLOOD CIRCULATION : HUMAN HEART - Human heart is a muscular organ and it is the size of our fist. Heart is the central pumping and pumps blood to the different parts of the body. Heart consist of four chambers- two Auricles and two Ventricles. The chambers are named as right and left- auricles and ventricles. The heart is placed in between the lungs.The heart is protected by double wall membrane called pericardium. In between the two layers of pericardium there is the occurrence of  pericardial fluid, which protect the heart from heat, shock etc. 

Some of the points regarding Heart we need to know before knowing circulation , like-

Impure blood from different parts of the body reaches the heart through veins. Impure blood is also called Deoxygenated Blood. 

Pure Blood from the heart reaches different part of the Aorta. Arteries carry pure blood . Pure blood is also known as oxygenated blood

Pulmonary Artery is the only artery in our body that carries impure blood.

Pulmonary Vein is the only vein in our body that carries pure blood.

Blood from the heart goes to the lungs for purification. In this case impure blood from right ventricle moves to the lungs. In the lungs purification of blood takes place. Blood from Deoxygenated become oxygenated. 

Colour of the heart is brown, where as auricles are lighter than ventricles. And again out of the two ventricles left ventricle is darker. The reason behind the dark colour is that both the auricle pour its blood to ventricles which are located below the auricles. But auricles need to pump blood outside the heart.

Left ventricle is darker than right ventricle because the left ventricle need to pump blood to different parts of the body where as right auricle pumps blood to the lungs.

Transportation of blood takes place through definite vessels called blood vessels. Different types of blood vessels are Arteries, veins and capillaries.

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STOMATA

 STOMATA: Stomata are minute pores present on the surface of the leaves.Generally the number of stomata are more on the lower surface than on the upper surface. Stomata helps in the exchange of gases and transpiration. Plants perform photosynthesis by taking carbon dioxide through stomata and gives out oxygen in this process through the stomata. In respiration plants takes oxygen through stomata. Excess amount of water from the plant body is also given out through stomata, this is called transpiration.

Guard cells are present around the stomata.