شرح الباب الاول بالفديو لبيولوجي2

[احمد مرعي]

Summary:
Pulmonary circulation
Rt. Ventricle ---> pulmonary artery ---> Lungs ---> 4pulmonary vein ---> Lt Atrium
2- Systematic circulation
Lt. ventricle ---> aorta ---> body organs ---> superior & inferior VC. ---> Rt. atrium
3- Hepatic portal circulation
Villi blood capillaries ---> hepatic portal V. ---> hepatic V. ---> Inf.V.C --->Rt. Atrium
Formation of the blood clotting
a ) Blood platelets + destroyed cells -- clotting factors--> thromboplastin

b ) Prothrombin --- Thromboplastin +clotting factors, Ca++ --> thrombin

c ) Fibrinogen --- thrombin--->Fibrin

Why blood does not clot inside blood vessels
Because
1. Blood runs inside blood vessels in a regular speed and does not slow down.
2. Blood platelets slide easily inside the blood vessels in order not to be broken.
3. The liver secretes heparin to prevents the conversion of prothrombin into thrombin

The lymphatic system is the immunity system of the body because it has the ability to protect the body against the harmful bacteria and the foreign particles and produce the antibodies which responsible for the body immunity.
An Experiment: to show that water ascent through Xylem vessels
Apparatus: as diagram.
Steps of experiment
1. Fill a test tube with eosin solution.
2. Carefully remove a small flowering plan from the
soil and immerse the plant roots in the eosin solution.
3. Close the tube with a cotton wool plug.
4. Keep the tube in a vertical position for a few hours.
5. Cut a thin transverse section of the plant stem, and examine the section under the microscope.
Observation
1. The leaf petioles and its veins change to pink.
2. Under the microscope, xylem tissue only is stained by eosin.
Conclusion
1. Water is absorbed by roots.
2. Water ascent through xylem tissue of the stem to the leaves.