Circulatory system

Oxygen, water and digested food are to be transported in all the parts of the body in Human beings. Waste products have to be removed from the body and for that, they have also carried away from all the parts of the body.

The circulatory system is responsible for all the trans portation processes in the body. It includes blood, blood vessels and heart.

Blood

All the substances in the body are transported by the blood. There is a fluid part in the blood called plasma and some cells like white blood cells (WBC), Red blood cells (RBC) and platelets.

1. Red blood cells

There is a pigment in red blood cells which is called as hemoglobin and it is responsible for transporting oxygen.

2. White blood cells

White blood cells give us protection from diseases and also fight against the germs.

3. Platelets

Platelets help in the blood clotting.

Blood vessels

Blood vessels are of three types-

  • Arteries

Arteries are involved in the process of carrying the blood which is rich in oxygen to various parts of the body. They contain thick walls.

  • Veins

Veins are involved in the process of carrying the blood which is rich in carbon dioxide to various parts of the body.

The walls they have are thin.

  • Capillaries

These are the blood vessels which are very thin and join veins and arteries.

Pulse/Pulse Rate

Pulses are the movements caused by the flow of the blood at a high pressure through arteries. Pulse rate is the rate of the number of pulses beating in a minute.

Heart

The organ responsible for pumping the blood to all other parts of the body is known as Heart. It is similar to the size of a fist. It consists of four chambers. Atria are the upper chambers and ventricles are the two lower chambers.

There is a partition in the middle of the heart which does prevent the mixing of rich blood in carbon dioxide and rich blood in oxygen.

 Heartbeat

Muscles together make up the walls of the heart. Heartbeat is produced when these muscles contract and relax. The heart beats can be felt by putting the hand on the left of chest

The device used to understand and hear the sound of beats is called as Stethoscope. It has two earpieces and one chest piece.

Science Class 7 Transportation in Plants and Animals Heart beatExcretion in Animals

The process of removing the waste products from the body of animals is called as excretion. The excretory system does this process.

The system consists of ureters, urinary bladder, urethra and kidneys.

The waste product is brought to the kidneys by the blood which then gets filtered and removed through urine. Urinary bladder gets the urine from the ureters which then pass out from the urethra.

 Transportation in Plants

There are some special tissues in plants called as vascular tissues which transport water, food and minerals.

The tissue is considered to be a group of cells which is known to perform functions which are specialized. Xylem and phloem are two types of vascular tissues. Water is transported through xylem tissue and phloem transports food.

Transpiration

The process through which water is given out by the plants in the leaves through stomata.

Science Class 7 Transportation in Plants and Animals Transpiration

 

Recap

  • Circulatory system is responsible for all the transportation processes in the body.
  • Oxygen, water and digested food are to be transported in all the parts of the body in Human beings.
  • All the substances in the body are transported by the blood.
  • Pulses are the movements caused by the flow of the blood at a high pressure through arteries.
  • The process of removing the waste products from the body of animals is called as excretion.
  • There are some special tissues in plants called as vascular tissues which transport water, food and minerals.