Describe human blood and give its functions.

Human blood is a vital fluid that circulates through the cardiovascular system, consisting of plasma and various types of cells. Here’s an overview of its components and functions: Components of Human Blood: 1. Plasma: This is the liquid component of blood, comprising water, electrolytes, proteins, hormones, and waste products.Represents 55% of total blood volume. 2. Red … Read more

What is blood pressure? How is it measured? Explain factors affecting blood pressure.

Blood pressure: 1. Blood pressure is the force exerted by blood on artery walls. 2. Systolic blood pressure is during ventricular contraction, averaging 120 mmHg in a healthy adult. 3. Diastolic blood pressure is during ventricular relaxation, averaging 80 mmHg. 4. Represented as a ratio like 120/80 mmHg, indicating systolic over diastolic pressure. 5. Pulse … Read more

Describe histological structure of artery, vein and capillary.

Artery histological structure: 1. Arteries are thick-walled vessels carrying oxygenated blood (except for the pulmonary artery, which carries deoxygenated blood to the lungs for oxygenation). 2. All arteries originate from the heart and transport blood away from it. 3. Arteries consist of three layers: tunica externa, tunica media, and tunica interna. 4. Tunica externa (adventitia) … Read more

How is blood kept moving in the large veins of the legs?

1. During systole, the heart exerts pressure, propelling blood into the aorta, initiating blood circulation throughout the body. The aorta branches into the dorsal aorta, supplying the upper body before dividing into arteries that extend into the legs. Blood moves in the legs due to pressure and gravitational forces. 2. Muscles in the legs play … Read more

If the duration of the atrial systole is 0.1 sec and that of complete diastole is 0.4 sec, then how does one cardiac cycle complete in 0.8 sec?

1. It takes 0.8 seconds to complete a single cardiac cycle. 2. The cardiac cycle comprises three crucial phases: atrial systole, ventricular systole, and joint diastole. 3. Under normal conditions, atrial systole lasts for 0.1 second, followed by ventricular systole lasting 0.3 seconds, and joint diastole, or complete diastole, extending for approximately 0.4 seconds. 4. … Read more

Which blood vessel of the heart will have the maximum content of Oxygen and why?

1. The aorta, originating from the left ventricle of the heart, carries blood rich in oxygen. 2. Deoxygenated blood undergoes oxygenation in the pulmonary capillaries surrounding the lung’s alveoli. The resulting oxygenated blood is collected by the four pulmonary veins. 3. These pulmonary veins transport the oxygenated blood to the left atrium of the heart. … Read more

A man’s pulse rate is 68 and cardiac output is 5500 cm3.Find the stroke volume.

Cardiac output refers to the amount of blood ejected per minute in a typical adult human.It is calculated as follows: Cardiac output = Heart rate × Stroke volume Given : Cardiac output = 5500 cm³ Pulse rate = Heart rate = 68 By using these values stroke volume of is calculated as follows: ∴ Cardiac … Read more

Why can you feel a pulse when you keep a finger on the wrist or neck but not when you keep them on a vein?

1) The contraction of the heart generates a pulsating pressure, akin to a wave, pushing blood out of the heart. This pulsation is what you feel as the pulse. However, this pressure is not constant. 2) During systole, when the heart pumps blood, the arteries experience maximum pressure. As this pressure diminishes in capillaries and … Read more

Shreyas went to a garden on a wintry morning. When he came back, he found it difficult to breath and started wheezing. What could be the possible condition and how can he be treated?

(1) Indications suggest that Shreyas might be experiencing allergic reactions, possibly due to exposure to allergens like pollen, dust, pet dander, or other environmental substances during his time in the garden. Alternatively, Shreyas, if already an asthma patient, could be facing exacerbated symptoms due to the wintry climate. (2) When a person is allergic to … Read more

Smita was working in a garage with the doors closed and automobiles engine running. After some time she felt breathless and fainted. What would be the reason? How can she be treated?

1. Working with the car engine running in a closed garage suggests that Smita might be experiencing carbon monoxide poisoning. 2. Carbon monoxide (CO) is a dangerous gas formed when fuels burn incompletely in automobile engines. 3. Due to haemoglobin’s strong attraction to carbon monoxide, it forms a stable compound called carboxyhaemoglobin. This reduces available … Read more