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Chapter Analysis
Intermediate14 pages • EnglishQuick Summary
This chapter explains how living organisms circulate body fluids and the mechanisms that enable the transport of nutrients, oxygen, and waste. It discusses the composition of blood and lymph, and explains the structure and function of the human heart and circulatory pathways. The concept of double circulation is elucidated, along with the regulation and disorders related to the circulatory system.
Key Topics
- •Composition and functions of blood
- •Lymphatic system and lymph
- •Human circulatory system
- •Double circulation
- •Regulation of cardiac activity
- •Disorders of circulatory system
Learning Objectives
- ✓Understand the composition and functions of blood and lymph
- ✓Describe the human circulatory system and its components
- ✓Explain the concept and significance of double circulation
- ✓Identify the regulatory mechanisms of cardiac activity
- ✓Recognize common disorders of the circulatory system
Questions in Chapter
Name the components of the formed elements in the blood and mention one major function of each of them.
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What is the importance of plasma proteins?
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Match Column I with Column II: (a) Eosinophils (b) RBC (c) AB Group (d) Platelets (e) Systole
Answer: (i) Coagulation (ii) Universal Recipient (iii) Resist Infections (iv) Contraction of Heart (v) Gas transport
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Why do we consider blood as a connective tissue?
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What is the difference between lymph and blood?
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What is meant by double circulation? What is its significance?
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Write the differences between blood and lymph, open and closed system of circulation, systole and diastole, P-wave and T-wave.
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Describe the evolutionary change in the pattern of heart among the vertebrates.
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Why do we call our heart myogenic?
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Sino-atrial node is called the pacemaker of our heart. Why?
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What is the significance of atrio-ventricular node and atrio-ventricular bundle in the functioning of heart?
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Define a cardiac cycle and the cardiac output.
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Explain heart sounds.
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Draw a standard ECG and explain the different segments in it.
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Additional Practice Questions
Explain the role of lymph in the circulatory system.
mediumAnswer: Lymph is a crucial component of the circulatory system, acting as an intermediary for the transport of nutrients, gases, and waste between blood and body tissues. It also plays a vital role in the immune response, facilitates absorption of fats from the digestive system, and returns proteins and excess interstitial fluid to the bloodstream.
Discuss how blood pressure is regulated in the body.
hardAnswer: Blood pressure is regulated by a complex interaction of neural, renal, hormonal, and vascular systems. Neural regulation involves signals from the cardiovascular center in the brain, adjusting the heart rate and blood vessel diameter. Hormonal factors like adrenaline, renin, and angiotensin also regulate blood pressure, along with renal mechanisms that control blood volume.
How does the structure of veins differ from that of arteries, and why?
mediumAnswer: Veins have thinner walls than arteries and contain valves to prevent backflow, as they carry blood back to the heart at a lower pressure. Arteries have thick, elastic walls to withstand and maintain high pressure as they transport blood away from the heart. This structural difference is essential for their respective functions in the circulatory system.
What are the effects of high blood pressure on the circulatory system?
hardAnswer: High blood pressure, or hypertension, can lead to severe health issues, including heart disease, stroke, and kidney damage. It places extra strain on blood vessels, leading to their hardening and weakening, thus increasing the risk of vascular complications and decreasing the efficiency of blood circulation.
Describe the differences and significance of P-wave, QRS complex, and T-wave in an ECG.
mediumAnswer: In an ECG, the P-wave indicates atrial depolarization, the QRS complex represents ventricular depolarization and precedes ventricular contraction, and the T-wave signifies ventricular repolarization. These segments are significant in diagnosing cardiac functions, electrical activity, and potential heart abnormalities.
Why do some organisms have an open circulatory system, while others have a closed system?
easyAnswer: In simpler organisms, an open circulatory system allows for sufficient transport of nutrients and gases due to their lower metabolic demands and simpler body structures. Conversely, complex organisms possess a closed circulatory system to meet higher metabolic demands, allowing efficient regulation and faster circulation of blood within the body.
Explain how the heart is supplied with oxygen.
mediumAnswer: The heart is supplied with oxygen through the coronary arteries, which branch off from the aorta and encircle the heart muscle. Blood rich in oxygen is delivered to the heart tissue, ensuring it has the energy required for continuous pumping.