Biology [2 Mark Question Answer]

Part 1 (Pulmonary artery) → Deoxygenated blood

Part 2 (Aorta) → Oxygenated Blood

Ventricular muscles are contracting during this phase because the valves between the two ventricles and pulmonary artery and aorta are open while the atrio-ventricular valves are closed.

The lymph supplies nutrition and oxygen to those parts where blood cannot reach. The lymph drains away excess tissue fluids and metabolites and returns proteins to the blood from tissue spaces.

The structure 3 represents the heart. It forms the centre of double circulation and is located between the liver and the head (as per the diagram). Also the blood circulation (indicated by 1) begins from heart to lungs.

1 → Red Blood Cell (RBC),

2 → White Blood Cell (WBC),

3 → Blood Platelet

4 →Blood Plasma.

People have a common belief that the heart is located on the left side of the chest because the narrow end of the roughly triangular heart is pointed to the left side and during its working, the contraction of the heart is more powerful on the left side which can be felt.

The first sound LUBB is produced when the atrio-ventricular valves i.e. tricuspid and bicuspid
valves close at the start of ventricular systole.
The second sound DUP is produced at the beginning of ventricular diastole, when the pulmonary
and aortic semilunar valves close.

During blood transfusion, it is necessary to know the blood groups before transfusion because it is important that the blood groups of the donor and the recipient are compatible. In case of an
incompatible blood transfusion, the recipient develops antibodies that attack the antigens present on the RBCs of the donor causing the blood cells to clump together which may result in death.

The right ventricle pumps blood to the lungs for oxygenation whereas the right auricle
receives the blood from vena cavae and passes it to the right ventricle. Therefore, walls of
the right ventricle are thicker than those of the right auricle.

The left ventricle pumps blood to the farthest points in the body such as the feet, the toes and
the brain against the gravity while the right ventricle pumps the blood only up to the lungs.
Therefore, the left ventricle has thicker walls than the right ventricle.

Spleen: The spleen is a large lymphatic organ. The spleen acts as a blood reservoir in case of
emergency such as haemorrhage, stress or poisoning. It produces lymphocytes and destroys
worn out RBCs.

Blood clotting is not dependent on the exposure of blood to air. In fact, clotting can be caused
by the movement of blood over a rough surface such as on cholesterol deposit inside of a blood
vessel of the skin.

Rh factor - It is an inherited antigen often found on the blood cells. Some individuals
have these antigens and are thus Rh positive (Rh+) while others who do not have this antigen
are Rh negative (Rh-).

The functions of blood plasma are:
(a) Transports of digested food from the alimentary canal to tissues.
(b) Transports excretory materials from tissues to excretory organs.
(c) Distributes hormones from the glands to their target site.
(d) Distributes heat in the body to maintain the body temperature.

Arteries are responsible to carry oxygenated blood from the heart to the tissues. The blood
flows in the artery under high pressure and in spurts. If arteries are located superficially then
there is a high possibility of their damage which could lead to a lot of blood loss. To prevent
this damage and blood loss, the arteries are deep seated in the body.

Atrial wall is less muscular than the ventricular wall because the major function of atria is
to receive blood from the body and pump in into very next ventricles. While the ventricles
pump the blood out of the heart. Right ventricle to the lungs and the left ventricle to all the
body parts.

Veins carry the blood from the body part towards the heart while the arteries carry the blood
from the heart. Veins carry the blood against the force of gravity. Therefore, only the veins
and not the arteries are provided with valves.

The blood from stomach and intestines enters the liver via hepatic portal vein because the
liver monitors all the substances that have to be circulated in body. The excess nutrients such
as glucose, fats are stores in the liver. Excess amino acids are broken down by the process
deamination. Toxic substances are detoxified.

The left ventricle pumps blood to the farthest points in the body such as the feet, the toes and
the brain against the gravity. Thus, it requires greater force to push the blood. In order to
with stand with the force applied the walls of the left ventricle are thicker than the walls of
all the chambers.

Hepatic portal system : This system is a network of veins that carries blood from the gastrointestinal organs and spleen to the liver. This system includes the portal vein and its tributaries. It's essential for transporting nutrients absorbed from the digestive tract to the liver, where they can be processed, stored, detoxified, or passed into general circulation.