Body Fluids and Circulation Practice Questions

Flashcards covering key definitions, percentages, cell counts, blood group dynamics, and clotting mechanisms from the Body Fluids and Circulation lecture notes.

Which organisms circulate water from their surroundings through their body cavities to facilitate cell substance exchange?

Sponges and coelenterates.

Is lymph involved in the transport of substances within the human body?

True. Lymph helps in the transport of certain substances such as nutrients and hormones.

What are the two primary components that constitute human blood?

Plasma and formed elements.

What color is blood plasma, and what percentage of total blood volume does it constitute?

Plasma is straw-colored and constitutes nearly $55\%$ of blood.

What percentages of plasma are constituted by water and proteins, respectively?

Water constitutes $90\text{--}92\%$ of plasma, while proteins constitute $6\text{--}8\%$ of plasma.

What are the three major proteins found in blood plasma?

Fibrinogen, globulins, and albumins.

What is the primary function of fibrinogen in blood plasma?

It is needed for clotting or coagulation of blood.

What is the primary function of globulins in blood plasma?

They are primarily involved in defense mechanisms of the body.

What is the primary function of albumins in blood plasma?

They help in maintaining osmotic balance.

What is blood plasma without clotting factors called?

Serum.

What percentage of blood volume is made up of formed elements?

$$45\%$$

What is the most abundant cell type in human blood?

Red Blood Cells (RBCs) or erythrocytes.

What is the average RBC count in a healthy adult man?

$5\text{--}5.5\text{ million}\,mm^{-3}$ of blood.

Where are RBCs formed in adult humans?

Red bone marrow.

What key cellular feature are RBCs devoid of in most mammals, and what is their shape?

RBCs are devoid of a nucleus in most mammals and are biconcave in shape.

How much haemoglobin is present per $100\,cm^3$ (or $100\,mL$) of blood in a healthy individual?

$$12\text{--}16\,g$$

What is the average lifespan of human RBCs, and where are they destroyed?

They have an average lifespan of $120\text{ days}$ and are destroyed in the spleen.

Are leucocytes (WBCs) nucleated or non-nucleated, and why are they colorless?

Leucocytes are nucleated and are colorless due to the lack of haemoglobin.

What is the normal total leucocyte (WBC) count per cubic millimeter of blood?

$$6000\text{--}8000\,mm^{-3}$$

What are the two main categories of White Blood Cells (WBCs)?

Granulocytes and agranulocytes.

Which cell types are classified as granulocytes?

Neutrophils, eosinophils, and basophils.

Which cell types are classified as agranulocytes?

Lymphocytes and monocytes.

What percentages of total WBCs are constituted by neutrophils, eosinophils, basophils, lymphocytes, and monocytes?

Neutrophils: $60\text{--}65\%$, Eosinophils: $2\text{--}3\%$, Basophils: $0.5\text{--}1\%$, Lymphocytes: $20\text{--}25\%$, Monocytes: $6\text{--}8\%$.

Which two WBC types act as phagocytic cells to destroy foreign organisms entering the body?

Neutrophils and monocytes.

What three chemicals are secreted by basophils, and what reactions are basophils involved in?

Basophils secrete histamine, serotonin, and heparin, and are involved in inflammatory reactions.

Which WBC type is associated with allergic reactions and resists infections?

Eosinophils.

What are the two major types of lymphocytes responsible for immune responses?

B lymphocytes and T lymphocytes.

What is another name for platelets, and from which specialized cell type are they produced?

Platelets are called thrombocytes, and they are produced from megakaryocytes in the bone marrow.

What is the normal platelet count in human blood?

$1,500,000\text{--}3,500,000\,mm^{-3}$ (or $1.5\text{--}3.5\text{ lakh}\,mm^{-3}$).

Which blood groups are considered the Universal Donor and Universal Recipient?

Universal Donor is $O\text{-negative}$, and Universal Recipient is $AB\text{-positive}$.

Where does the Rh antigen derive its name, and what percentage of humans possess it?

It derives its name from the Rhesus monkey, and it is present in approximately $80\%$ of humans.

Under what Rh incompatibility condition does Erythroblastosis foetalis develop?

It develops when the mother is $Rh\text{-negative}$ and the fetus is $Rh\text{-positive}$.

Why do fetal Rh antigens usually NOT mix with maternal Rh-negative blood during the first pregnancy?

Because the maternal blood and fetal blood are well separated by the placenta during gestation.

When is maternal blood exposed to small amounts of Rh-positive fetal blood, and what effects can Erythroblastosis foetalis cause in subsequent babies?

Exposure occurs during the delivery of the first child. Erythroblastosis foetalis can cause severe anemia and jaundice in the baby.

How can Erythroblastosis foetalis be avoided after the delivery of the first child?

By administering anti-Rh antibodies to the mother immediately after the delivery of the first child.

How is active thrombin formed during blood coagulation?

Thrombin is formed from inactive prothrombin with the help of the enzyme complex thrombokinase.

How are fibrins formed in the blood clotting cascade?

Fibrins are formed from inactive fibrinogen in plasma by the catalytic action of the enzyme thrombin.

Is a clot or coagulum formed by a network of threads called thrombins?

False. A clot or coagulum is formed by a network of threads called fibrins, in which dead and damaged formed elements are trapped.

Which mineral ion acts as an essential cofactor during blood clotting?

Calcium ions ($Ca^{2+}$).

Through which fluid does the exchange of nutrients, gases, and metabolites occur between blood and tissue cells?

Lymph (interstitial fluid).