SCC is a place where u can get free study material for academic & competitive exams like CTET,SSC,IIT,NDA,Medical exams etc,

Tuesday, 1 March 2016

CIRCULATORY SYSTEM

CIRCULATORY SYSTEM
Circulatory system:
Efficient distribution system
Network of 100,000 km of blood vessels
Supplies cells with nutrients and oxygen and removes carbon dioxide and waste products
Transports hormones

Plays an important role repairing tissues and protecting the body from infection
Organs of the Circulatory System
* Blood: Type of connective tissue (cells & liquid)
* Heart: Multi-chambered, muscular organ
-Overall flow of blood via blood vessels à from the heart to the tissues
   throughout the body back to the
   heart
- Body contains 5 L of blood

Types of Blood Vessels
1.Capillaries:
Microscopic blood vessels- make contact with all cells of the body
Walls of capillaries consist of a thin layer of epithelial tissue à enables diffusion of nutrients and oxygen out of the blood & the diffusion of waste products into the blood
2.Arteries:
Blood flows from the heart to the capillaries through thick walled blood vessels = arteries
Walls of arteries = epithelial tissue wrapped in layers of smooth muscle and connective tissue
Muscle tissue enables arteries to constrict & dilate; Blood in arteries is under pressure due to the heart’s pumping action
Veins:
Blood returns from the capillaries to the heart through vessels = veins
Walls of veins consist of epithelial tissue surrounded by smooth muscle & connective tissue… but muscle layer is thinner than that in arteries
Blood is under little pressure
Contracting skeletal muscles squeezes the
  veins and forces blood back to the heart 
 circulatory system, sharma sir ,biology notes for 11and 12,
To read this complete topic click here ..........
CIRCULATORY SYSTEM


Read more topics......









Share on Google Plus Share on whatsapp

Search

Popular Posts

Facebook

Blogger Tips and TricksLatest Tips For BloggersBlogger Tricks
SCC Education © 2017. Powered by Blogger.

Total Pageviews