Assignment on Human Circulatory System (to be done in notebook )

This portion is not coming in exam in first periodical

Q1 what are capillaries ?

A1 They are very thin junction between arteries and veins where exchange of materials take place .They are the site for exchange of materials.

Q2 What is the structure of human heart ?

A2 Human heart is the size of fit located in the thoracic cavity protected by rib cage.

it has muscles called cardiac muscle which work all the time to allow beating of heart day and night .

Human heart has four chambers ,upper two are called right and left atria and the lower two are called right and left ventricles .The right and left heart has no connection as there is a partition called septum between them but the upper and lower chambers i.e. atrium and ventricle have opening guarded by valves .The left atrium  receive  blood from lungs by  pulmonary vein and right atrium receive de oxygenated blood from whole body by inferior and superior vena cava. The left ventricle send oxygenated blood from heart to  the whole body by a major artery  called Aorta ,while the right ventricle send de oxygenated blood to lungs through pulmonary artery for oxygenation .The vessels /which supply blood to the  muscles of heart are called coronary muscles.