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Practice each question, then open the answer or worked solution.
The walls of ventricles are much thicker than atria. Explain.
Ventricles function as a pumping agent of blood to all organs so that they have to exert more pressure. The atria receive blood so they have fewer loads to take, hence thinner walls.
Differentiate between
a. Blood and Lymph
b. Basophils and Eosinophils
c. Tricuspid and bicuspid valve
a. Blood is a part of our circulatory system which is red due to the presence of haemoglobin whereas lymph is a part of our lymphatic system which is colourless due to the absence of haemoglobin.
b. Basophils are bean-shaped nucleus stained with basic dye whereas the eosinophil is two-lobed nuclei which are stained with acidic dyes.
c. The tricuspid valve is formed by three flaps and it guards the opening between atrium and right ventricle whereas the bicuspid valve is formed by two flaps which it opens between the left atrium and left ventricle.
Briefly describe the followings:
a. Anaemia
b. Angina Pectoris
c. Atherosclerosis
d. Hypertension
e. Heart failure
f. Erythroblastosis foetal
a. Anaemia is a disorder that occurs due to the lesser count of RBC or a reduced amount of haemoglobin than the normal value.
b. Angina Pectoris is caused when adequate oxygen does not reach the heart muscles leading to chest pain and discomfort.
c. Atherosclerosis is the cause of disease when the fat takes place at the walls of the artery.
d. Hypertension is the condition in which there is a constant increase in normal blood pressure, which is 120/80 mm Hg.
e. Heart failure is a serious condition when the heart fails to pump enough blood to meet the requirements.
f. Erythroblastosis foetal is a condition there is a destruction of foetal RBC’s due to an incompatibility between the mother and foetus’s Rh factor
Explain the advantage of the complete partition of ventricle among birds and mammals and hence leading to double circulation.
In birds and animals, the two ventricles are separated by the inter-ventricular septum. Oxygenated blood received by the left atria passes to the left ventricle and Deoxygenated blood received by the right atria passes to the right ventricle without getting mixed. Deoxygenated and oxygenated blood remains separated and do not mix.
What is the significance of the hepatic portal system in the circulatory system?
The hepatic portal system directs deoxygenated blood from the parts of the gastrointestinal tract to the liver and finally taking it to the heart. This provides the liver with metabolic substrates.
Explain the functional significance of the lymphatic system?
The fluid lymph carries hormones and nutrients and also maintains a fluid balance between blood and tissues. The fat absorption takes place through the lymph.
Write the features that distinguish between the two
a. Plasma and Serum
b. Open and closed circulatory system
c. Sino-atrial node and atrioventricular node
a. Plasma is a liquid form of blood which does not have cells and is treated with EDTA like anticoagulant whereas serum is a liquid form of blood after coagulation
b. In an open circulatory system, the blood flows through large vessels into sinuses whereas in the closed circulatory system the blood flows through a closed network of blood vessels.
c. Sino-atrial node is present in the right atrium near the opening of superior vena cava whereas the atria-ventricular node is present in the right atrium near the base of the interatrial septum.
Thrombocytes are essential for the coagulation of blood. Comment.
They are also known as platelets which are found in the blood. Thrombocytes are formed in the bone marrow. For example, when an injury occurs, the bleeding starts and platelets will disintegrate. They release clotting factor III known as thromboplastin. Thromboplastin in the presence of calcium ions activates prothrombokinase and leads to a series of reactions causing a blood clot.
Answer the following
a. Name the major site where RBCs are formed.
b. Which part of the heart is responsible for initiating and maintaining its rhythmic activity?
c. What is specific in the heart of crocodiles among reptilians?
a. In the early embryonic stage, RBC’s are produced in Yolk Sac
In later embryonic stage RBC’s are produced in Liver and Spleen
In mature adults, RBC’s are produced in Bone Marrow
b. SA node or Sino Atrial Node is responsible for the rhythmic activity.
c. Reptilians have a three-chambered heart (2 atria and 1 ventricle) whereas crocodiles have a four-chambered heart (2 atria and 2 ventricles) in which the mixing of oxygenated and deoxygenated blood does not take place.