Following are the stages of pathway for conduction of an action potential through the heart.
A. AV bundle
B. Purkinje fibres
C. AV node
D. Bundle branches
E. SA node
Choose the correct sequence of pathways from the options given below. [2024]
E - C - A - D - B
A - E - C - B - D
B - D - E - C - A
E - A - D - B - C
Match List I with List II.
| List I | List II | ||
| (A) | Eosinophils | (I) | 6 – 8% |
| (B) | Lymphocytes | (II) | 2 – 3% |
| (C) | Neutrophils | (III) | 20 – 25% |
| (D) | Monocytes | (IV) | 60 – 65% |
Choose the correct answer from the options given below. [2023]
(A)-(IV), (B)-(I), (C)-(III), (D)-(II)
(A)-(IV), (B)-(I), (C)-(III), (D)-(II)
(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(A)-(II), (B)-(III), (C)-(I), (D)-(IV)
Which of the following statements are correct?
A. Basophils are most abundant cells of the total WBCs.
B. Basophils secrete histamine, serotonin and heparin.
C. Basophils are involved in inflammatory response.
D. Basophils have kidney-shaped nucleus.
E. Basophils are agranulocytes.
Choose the correct answer from the options given below. [2023]
B and C only
A and B only
D and E only
C and E only
(1)
Basophils are least (0.5–1 percent) among the total WBCs. They usually have three lobed nucleus and are granulocytes.
Given below are two statements.
Statement I: The coagulum is formed of network of threads called thrombins.
Statement II: Spleen is the graveyard of erythrocytes.
In the light of the above statements, choose the most appropriate answer from the options given below. [2022]
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
(4)
Clot or coagulum is formed mainly of network of threads called fibrins in which dead and damaged formed elements of blood are trapped.
Persons with ‘AB’ blood group are called as “Universal recipients”. This is due to [2021]
absence of antibodies, anti-A and anti-B, in plasma
absence of antigens A and B on the surface of RBCs
absence of antigens A and B in plasma
presence of antibodies, anti-A and anti-B, on RBCs.
(1)
AB blood group has A and B antigens on RBCs and no antibodies in plasma. So, these persons can accept blood from person with AB as well as the other groups of blood. Therefore, such persons are called universal recipients.
Which enzyme is responsible for the conversion of inactive fibrinogens to fibrins? [2021]
Thrombokinase
Thrombin
Renin
Epinephrine
(2)
Fibrins are formed by the conversion of inactive fibrinogen in the plasma by the enzyme thrombin and thrombins are formed from an another inactive substance present in plasma i.e., prothrombin.
Match the following columns and select the correct option. [2020]
| Column-I | Column-II | ||
| (A) | Eosinophils | (i) | Immune response |
| (B) | Basophils | (ii) | Phagocytosis |
| (C) | Neutrophils | (iii) | Release histaminase, destructive enzymes |
| (D) | Lymphocytes | (iv) | Release granules containing histamine |
A-(iii), B-(iv), C-(ii), D-(i)
A-(iv), B-(i), C-(ii), D-(iii)
A-(i), B-(ii), C-(iv), D-(iii)
A-(ii), B-(i), C-(iii), D-(iv)
Match the items given in column I with those in column II and select the correct option given below. [2018]
| Column I | Column II | ||
| A. | Fibrinogen | (i) | Osmotic balance |
| B. | Globulin | (ii) | Blood clotting |
| C. | Albumin | (iii) | Defence mechanism |
A-(iii), B-(ii), C-(i)
A-(i), B-(ii), C-(iii)
A-(i), B-(iii), C-(ii)
A-(ii), B-(iii), C-(i)
Adult human RBCs are enucleate. Which of the following statement(s) is/are most appropriate explanation for this feature? [2017]
(1) They do not need to reproduce.
(2) They are somatic cells.
(3) They do not metabolise.
(4) All their internal space is available for oxygen transport.
Only (1)
(1), (3) and (4)
(2) and (3)
Only (4)
(4)
Red blood cells of adult humans do not have cell organelles including nucleus, Golgi bodies, mitochondria, ribosomes, etc. It increases the surface area of RBCs and enables them to contain more haemoglobin (the oxygen carrying pigment).
Name the blood cells, whose reduction in number can cause clotting disorder, leading to excessive loss of blood from the body. [2016]
Erythrocytes
Leucocytes
Neutrophils
Thrombocytes
(4)
Thrombocytes are called blood platelets. They are minute disc-shaped cell fragments in mammalian blood. They are formed as fragments of larger cells found in red bone marrow; they have no nucleus. They play an important role in blood clotting and release thromboxane A?, serotonin and other chemicals, which cause a chain of events leading to the formation of a plug at the site of the damage, thus preventing further blood loss. A reduction in their number can lead to clotting factors which will lead to excessive loss of blood from the body.
