Transportation in animals and plants

Start music   Jan 4 2017 || 10:54 PM

Circulatory system

 

Blood

The blood is made up primarily of 3 types of cells and a fluid medium:

  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma (the fluid part)

 

Transport in Blood

  • The red blood cells (RBC) contain a red pigment called haemoglobin
  • Haemoglobin binds with oxygen and transports it to all the parts of the body
  • White blood cells (WBC) fight against germs
  • A clot is formed because of the presence of platelets.

 

Blood vessels

There are different types of blood vessels in the body

  • Arteries – Carry oxygen-rich blood from the heart to all parts of the body
  • Veins – Carry carbon dioxide-rich blood from all parts of the body back to the heart
  • Capillaries – They form the junction where the arteries and veins meet

 

Pulse and pulse rate

  • The throbbing of blood vessels is called the pulse
  • The number of beats per minute is called the pulse rate
  • A resting person, usually has a pulse rate between 72 and 80 beats per minute

 

Heart

The heart has 4 chambers:

  • The two upper chambers are called the atria
  • The two lower chambers are called the ventricles

The partition between the chambers helps to avoid mixing up of blood rich in O2 with the blood rich in CO2

 

Heartbeat

  • The rhythmic contraction followed by its relaxation constitute a heartbeat
  • An instrument called a stethoscope is used to amplify the sound of the heart

 

Do all organisms have a circulatory system?

  • Animals such as sponges and Hydra do not posses any circulatory system.
  • The water in which they live brings food and oxygen as it enters their bodies
  • The water carries away waste materials and carbon dioxide as it moves out

 

Excretory system

 

  • The process of removal of wastes produced in the cells of the living organisms is called excretion

 

In humans

  • The waste which is present in the blood (urea) has to be removed
  • This is done by the blood capillaries in the kidneys
  • The useful substances are absorbed back into the blood
  • The wastes dissolved in water are removed as urine
  • From the kidneys, the urine goes into the urinary bladder through tube-like ureters
  • The urine is passed out through the urinary opening at the end of a muscular tube called urethra
  • The urine consists of 95% water, 2.5% urea and 2.5% other waste products

 

Excretion in other animals

  • Aquatic animals like fishes, excrete cell waste as ammonia which directly dissolves in water
  • Land animals like birds, lizards, snakes excrete a semi-solid, white coloured compound (uric acid)

 

Dialysis

  • Sometimes a person’s kidney may stop working due to infection or injury
  • As a result of kidney failure, waste products start accumulating in the blood.
  • Such persons cannot survive unless their blood is filtered periodically through an artificial kidney.
  • This process is called dialysis

 

 

Transport of substances in Plants

 

Tissue & Vascular tissue

  • A group of cells that perform specialised function in an organism
  • Plants have pipe-like vessels to transport water and nutrients from the soil.
  • The vessels are made of special cells, forming the vascular tissue

 

Xylem & Phloem

  • Vascular tissues called Xylem and phloem transport substances in plants
  • Xylem helps in the transport of water and nutrients in the plant,
  • They form a continuous network of channels that connects all parts of the plant
  • Phloem helps in the transportation of food from the leaves to all parts of the plant

 

Transpiration

  • Water evaporates through the stomata present on the leaves by the process of transpiration.
  • Evaporation of water from leaves generates a suction pull which can pull water to great heights in the tall trees
  • Transpiration also cools the plant.

 

 

Image courtesy - Learnhive.com 

This is purely for educational purpoe