Define a cardiac cycle and the cardiac output.
The sequential events in the heart which are repeated cyclically is called cardiac cycle and it consists of systole (contraction) and diastole (relaxation) of both the atria and ventricles. The duration of a cardiac cycle is 0.8 seconds. Periods of cardiac cycle are atrial systole (0.1 second), ventricular systole (0.3 second) and complete cardiac diastole (0.4 second).
The amount of blood pumped by heart per minute is called cardiac output. It is calculated by multiplying stroke volume (volume of blood pumped by each ventricle per minute) with heart rate (number of beats per minute). The heart of normal person beats 72 times per minute and pumps out about 70 mL of blood per beat. Therefore, cardiac output averages 5000 mL or 5 litres.
Given below are the abnormal conditions related to blood circulation. Name the disorders.
(a) Acute chest pain due to failure of 02 supply to heart muscles
(b) Increased systolic pressure
Match Column I with Column II.
Column I Column II
(a) Eosinophils (i) Coagulation
(b) RBC (ii) Universal recipient
(c) AB Group (iii) Resist infections
(d) Platelets (iv) Contraction of heart
(e) Systol (v) Gas transport
Complete the missing word in the statement given below:
(a) Plasma without_______factors is called serum.
(b) _______and monocytes are phagocytic cells.
(c) Eosinophils are associated with reactions.
(d)_______ions play a significant role in clotting.
(e) One can determine the heart beat rate by counting the number of_______in an ECG.
State the functions of the following in blood
(a) Fibrinogen
(b) Globulin
(c) Neutrophils
(d) Lymphocytes
Answer the following:
(a) Name the major formed. Which part of heart is responsible for initiating and maintaining its rhythmic activity? What is specific in the heart of crocodiles among reptilians?
Briefly describe the following:
(a) Anaemia
(b) Angina pectoris
(c) Atherosclerosis
(d) Hypertension
(e) Heart failure
(f) Erythroblastosis foetalis
Explain the advantage of the complete partition of ventricle among birds and mammals and hence leading to double circulation.
How will you interpret an electrocardiogram (ECG) in which time taken in QRS complex is higher?
Name the components of the formed elements in the blood and mention one major function of each of them.
What is the significance of atrio-ventricular node and atrio-ventricular bundle in the functioning of heart?
Define the following terms and give their location.
(a) Purkinje fibre
(b) Bundle of His
What is the significance of time gap in the passage of action potential from sino-atrial node to the ventricle?
In the diagrammatic presentation of heart given below, mark and label, SAN, AVN, bundle of His and Purkinje fibres.
Given below is the diagrammatic represen-tation of a standard ECG. Label its different peaks.
Differentiate between
(a) Blood and lymph
(b) Basophils and Eosinophils
(c) Tricuspid and bicuspid valve
Write the differences between:
(a) Blood and lymph
(b) Open and closed system of circulation
(c) Systole and diastole
(d) P-wave and T-wave
Write the features that distinguish between the two
(a) Plasma and Serum
(b) Open and closed circulatory system
(c) Sino-atrial node and Atrio-ventricular