Скачать или смотреть animal circulatory system type bengali/cockroach circulatory system/human double circulation bangla

animal circulatory system type bengali/cockroach circulatory system/human double circulation bangla bengali/malda life science/biology class 11 malda /biology bengali

class 9 life science bangla circulation chapter 3/wbbseclass9 lifescience chapter 3
The heart of cockroach is an elongated contractile, narrow tube lying along the mid-dorsal line of thorax and abdomen just beneath the terga. The heart is enclosed in a pericardial sinus, the wall of which has segmented bundles of alary mus­cles and a dorsal fenestrated diaphragm.

The wall of the heart is composed of outer con­nective tissue and median muscle cells. The cavity of the heart is lined by the sarcolemma of median muscle cells. The heart consists of thirteen funnel-shaped and segmentally arranged chambers, each communicating by a valvular opening with that lying in front of it.
The body cavity of cock­roach is not a true coelom but a haemocoel containing blood (haemolymph).
The diaphragm or the dorsal fenestrated partition divides the haemocoel into three sinuses:

(i) The dorsal or pericardial sinus surroun­ding the heart, aorta and alary muscles,

(ii) The middle or perivisceral sinus contai­ning the alimentary canal (Fig. 2.66) and

(iii) The ventral sternal or perineural sinus enclosing the ventral nerve cord. It also extends into the legs as septa, dividing the cavity of each leg into two sinuses, one for the outward and the other for the inward flow of blood. The diaphragm being perfo­rated, permits the blood to flow from one sinus into another.
Two Types of Circulation: Double Circulation in Human
Pulmonary Circulation and systemic circulation
Lungs are involved in this type of circulation.

In this pathway, when deoxygenated blood is transferred to the lungs via the pulmonary artery and that deoxygenated blood comes from the right atrium to the right ventricle and then pulmonary artery.

Now, carbon dioxide is removed and oxygen enters as a result of which blood carries oxygenated blood.

This oxygenated blood is carried by Pulmonary Vein to the Left Atrium. Further, this blood goes to the Left Ventricle.

Systemic Circulation
All systemic organs and tissues are involved in this type of circulation.

Oxygenated blood will go to the tissues and organs via Aorta when then becomes deoxygenated as a result of by-products (CO2) of metabolic and respiration processes.

This deoxygenated blood is carried by Vena Cava to the right atrium and then further into the right ventricle.

And the cycle follows, the deoxygenated blood from the right ventricle goes to the lungs via the pulmonary artery. The CO2 is exhaled out from the lungs at that spot. If anyone asks to define double circulation, you can easily talk about pulmonary and systemic circulation and describe how blood enters twice to the heart and escapes twice out of the heart in the whole process. Therefore, it is known as double circulation.