BIOLOGY [1 Mark Question Answer]

The left side of the heart contains oxygenated blood.

Blood becomes oxygenated in the lungs. The oxygenated blood is returned to left verticles by the pulmonary vein.

The haemoglobin is the respiratory pigment which is formed of the iron containing part known as haemin and protein part known as globin. It helps to transport respiratory gases (oxygen).

The four blood groups in humans are A, B, AB and O.

The liquid part called plasma.
The cells or corpuscles which are further of three types:

1. RBC (red blood cell)
2. WBC (white blood cell)
3. platelets.

Stethoscope

Blood circulates throughout the body and performs the following functions

1. It carries or transports food and oxygen to each body cell.
2. It carries away waste products to organs (like kidneys, lungs and intestine) from where they are excreted out of the body.
3. It protects the body against infection by destroying germs.
4. It helps in blood clotting, thereby preventing excessive blood loss.
5. It regulates body temperature

The platelets help in clotting of blood, whenever there is a blood flow due to some injury.

White blood cells (WBCs) help in fighting infection as they destroy the germs

: Veins are the blood vessels which carry deoxygenated (impure) blood from the body cells to the heart.

Red blood cells (RBCs) contain haemoglobin which carries oxygen throughout the body. It also transports nutrients to cells.

Antibodies are chemical substances made by the body in response to foreign substances (antigens). They destroy antigens

Antigens are foreign substances in the body which stimulate the production of antibodies.

Blood pressure rises if we do activities like running, cycling etc. or if the arteries become narrower.

The pressure exerted by blood on the wall of the blood vessels is called blood pressure.

Constant high blood pressure puts a strain on the heart and can also cause an artery to burst open. If this happens in the brain, it causes stroke.

A disabling attack or loss of consciousness by an interruption in the flow of blood to the brain is called a stroke

The sound or movement of the heart as it sends blood around the body is called heartbeat. Every heartbeat causes a pulse in the arteries.

Lungs

Arteries are the blood vessels in which oxygenated blood is going away from the heart to all parts of the body.

Haemoglobin

Veins

5.5 litres of blood

Aorta

70-72 per minute.

The main parts of the circulatory system are:

1. Heart
2. Blood vessels
3. Blood

Circulatory system is a transport system moving substances throughout our body with the help of blood