The Circulatory System

The circulatory system! It truly is a marvel, isn’t it? Imagine a bustling inner metropolis with intricate roadways ensuring every resident gets exactly what they need and that waste is efficiently taken away. That’s precisely what our circulatory system accomplishes every single moment of our lives.

At the heart of this incredible network is the blood itself, far more than just a simple red liquid. The plasma, its watery base, acts as the current, carrying vital cargo like nutrients and hormones, while also collecting the cellular “trash” for disposal. Then come the tireless red blood cells, those dedicated delivery vehicles ferrying precious oxygen, thanks to their special hemoglobin passengers.And finally, the tiny yet mighty platelets are like the quick-response repair crew, rushing to any breach to patch things up and stop any leaks.

And the engine driving this whole operation? The heart, of course! This powerful, muscular pump works relentlessly, never taking a break, to keep the blood flowing throughout our entire being. It’s so cleverly designed with its four chambers – the receiving atria and the powerful pumping ventricles. Once that blood is oxygen-rich, the left side takes charge, propelling it out to nourish every single cell, tissue, and organ in our body – that’s the systemic route.

Now, this vital fluid doesn’t just slosh around; it travels along a sophisticated network of blood vessels, the very “highways” of our internal world. We have the arteries, like the major expressways leading away from the heart, carrying that life-giving oxygenated blood to all corners. Interestingly, there’s a special artery, the pulmonary artery, that takes deoxygenated blood on a one-way trip to the lungs. Then we have the veins, the return routes, carrying the deoxygenated blood back to the heart for its next oxygen refill. And just like the arteries have a special case, so do the veins – the pulmonary vein carries freshly oxygenated blood from the lungs back to the heart. 

This incredible circulatory system performs so many essential tasks that keep us alive and functioning. It’s the ultimate delivery service, bringing vital oxygen, nourishing food, and crucial hormones to every single cell while efficiently clearing away waste like carbon dioxide. It also acts as our internal thermostat, distributing heat to maintain a stable body temperature. And it’s a key player in our immune system, with white blood cells ready to fight off any unwelcome guests and platelets on standby for any repair work.

Sadly, like any intricate system, the circulatory system can face its share of challenges. Conditions like anemia, where the body lacks sufficient red blood cells or hemoglobin, can leave us feeling tired and weak due to a lack of oxygen reaching our tissues. Leukemia, a serious cancer affecting white blood cells, weakens our body’s defenses. And hypertension, or high blood pressure, puts undue strain on the entire system, increasing the risk of other serious health issues.

The wonderful news is that we have the power to support this incredible system and keep it running smoothly. Embracing a healthy lifestyle with a well-balanced diet, regular physical activity, and steering clear of smoking are the most crucial steps we can take to ensure our circulatory system remains healthy and efficient for years to come.

REVIEW QUESTIONS

Multiple Choice Questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

(a) The only artery which carries deoxygenated blood is called,

1. Hepatic artery
2. Pulmonary artery
3. Aorta
4. Renal artery

(b) Pulmonary vein carries

1. Oxygenated blood
2. Deoxygenated blood
3. Glucose-deficient blood
4. CO2 laden blood

(c) Function of WBCs is to

1. Transport oxygen
2. Help in clotting of blood
3. Provide immunity
4. Provide storage of food.

(d) Blood Capillary is a

1. Broad tube
2. Artery with thick wall
3. Vein with large lumen
4. Narrow tube made up of endothelium only.

(e) Nucleus is absent in 

1. RBCs
2. WBCs
3. All blood cells
4. Liver cells.

(f) Sphygmomanometer measures

1. Pulse rate
2. Heart beat
3. Blood pressure
4. Brain activity

(g) The blood tastes saltish due to the presence of dissolved:

1. Sodium chloride
2. Potassium chloride
3. Ammonium nitrate
4. Sodium nitrate

Short Answer Questions:

Question 1.
1. Differentiate between the following pair of terms:
(a) Pulmonary artery and pulmonary vein.
(b) Vena cava and aorta.
(c) Platelets and WBC.
(d) RBC and WBC Ans.
Answer:
(a) Pulmonary artery and pulmonary vein

 The pulmonary artery indeed takes blood that is low in oxygen away from the heart and towards the lungs, whereas the pulmonary vein is responsible for bringing blood that has been freshly oxygenated in the lungs back to the heart

(b) Vena cava and Aorta

the vena cava as the two main “return lanes” bringing deoxygenated blood back to the heart. The superior vena cava handles the blood from the upper body, and the inferior vena cava takes care of the lower body.  

In contrast, the aorta is the major “highway” carrying oxygen-rich blood out from the heart to nourish the entire body

(c) Blood platelets and blood group.

Blood platelets are essential for stopping bleeding. ¹ They quickly gather at injury sites to form plugs and release clotting factors, aiding in blood vessel repair. ² Blood groups, like ABO and Rh, are determined by proteins on red blood cells and are critical for safe blood transfusions

(d) RBC and WBC

Red blood cells are tiny, disc-shaped powerhouses, lacking a nucleus but packed with oxygen-carrying capacity. ¹ In contrast, white blood cells are larger, nucleated defenders, essential for the body’s immune system

Question 2.
Give any three differences between an artery and a vein:
Answer:
arteries are like the “outbound” roads carrying blood away from the heart’s powerful pump, so the pressure inside them is higher. Veins are the “inbound” roads, bringing blood back to the heart, and to help this flow against gravity, especially in your arms and legs, they have one-way “gates” called valves to stop any backward movement. Arteries usually don’t need these gates because the heart’s push keeps the blood moving forward.

Question 3.
Fill in the blanks with suitable words given below:
Answer:
a. The two lower chambers of the heart are called ______.
Answer:ventricles.

b. The ______ artery takes the blood from the ventricles to the lungs.
Answer:pulmonary 

c. The blood loaded with carbon dioxide from the body comes into the ______of the heart.
Answer:right auricle

d. The oxygen-rich blood from the lungs comes into the _____ of the heart.
Answer:left ventricle

e. The oxygen-rich blood is pumped into different parts of the body through______.
Answer:aorta.

f. The carbon dioxide loaded blood from right ventricle is pumped into the lungs through______artery.
Answer:pulmonary

g. The instrument used to find out the blood pressure is known as________.
Answer:sphygmomanometer.

h. The colour of a red blood cell is due to______.
Answer:haemoglobin.

i. The blood plasma contains a dissolved substance called______.
Answer:fibrinogen

j. The liquid part of coagulated blood is known as ______

Answer: serum.

Question 4.
In which organ of our body does blood get oxygenated?
Answer:
breathing brings oxygen to the lungs’ alveoli, where it swaps with carbon dioxide in the blood. This gas exchange, known as respiration, delivers vital oxygen throughout the body.

Question 5.
Which side of the heart (left or right) contains oxygenated blood?
Answer:
The left side of your heart plays a crucial role in keeping your body energized and healthy. Think of it as the distribution center for freshly oxygenated blood.

First, this blood, now rich in the very air you breathe, makes its way back from your lungs and enters the left side of your heart. Then, with a powerful pump, the left side takes charge and sends this vital, oxygen-filled blood out to every corner of your body. This delivery service is essential, ensuring that all your tissues and organs receive the oxygen they need to perform their important jobs.

Question 6.
What is the role of haemoglobin in the blood ?
Answer:
Hemoglobin’s job is so vital; it’s hard to imagine life as we know it without it diligently carrying out its duties. Think of those countless red blood cells, each packed with these hemoglobin molecules, constantly circulating throughout your body. In the lungs, it’s like they’re eagerly lining up to grab onto the oxygen we inhale, forming a temporary bond that allows them to transport this life-giving gas. Then, as they journey through the bloodstream to every corner of our tissues and organs, they readily release the oxygen where it’s needed most for all those essential cellular processes.

But it’s not just a one-way delivery service. Just as efficiently, hemoglobin also picks up the carbon dioxide that our cells produce as a byproduct of their activity. It acts like a clean-up crew, escorting this waste gas back to the lungs where we can breathe it out. This remarkable two-pronged action – oxygen delivery and carbon dioxide removal – truly highlights how indispensable hemoglobin is. It’s a continuous cycle that underpins our energy levels, supports all our bodily functions, and ultimately keeps us alive and well.

Question 7.
Name the disease in which the number of platelets reduces to 25,000 – 30,000 per cubic mm of blood. State its major symptoms.
Answer:
The disease in which the number of platelets reduces to 25,000 – 30,000 per cubic mm of blood is called thrombocytopenia.

The major symptoms of thrombocytopenia include:

• Easy or excessive bruising (purpura): You might notice bruises appearing more easily than usual, often without a clear injury.
• Superficial bleeding into the skin that appears as pinpoint-sized reddish-purple spots (petechiae): These tiny spots often occur in clusters and can look like a rash.
• Prolonged bleeding from cuts: Even minor cuts may bleed for a longer time than expected.
• Bleeding from the gums or nose: You might experience spontaneous nosebleeds or bleeding gums, especially after brushing your teeth.
• Heavy menstrual periods: Women may notice unusually heavy menstrual flow.
• Blood in urine or stool: This can indicate more serious internal bleeding.
• Fatigue: Feeling unusually tired can sometimes be associated with low platelet counts.

It’s important to consult a doctor if you experience any of these symptoms, as thrombocytopenia can have various underlying causes that require proper diagnosis and treatment.

Long Answer Questions:

Question 1.
Given alongside is a diagram of the human heart showing its internal structures. Label the parts marked 1 to 6, and answer the following questions.

(a) Which type of blood is carried by the blood vessel marked 2?
(b) Name the main artery which takes the blood from the heart to different parts of the body?
(c) Which chamber of the heart receives deoxygenated blood from the body?
Answer:

Labelled Parts:

1. Aorta
2. Superior Vena Cava
3. Pulmonary Artery
4. Right Atrium
5. Left Ventricle
6. Right Ventricle

(a) The blood vessel labelled with the number 2 is the Superior Vena Cava. This important vessel acts like a return route, bringing deoxygenated blood from the upper regions of your body back to the heart.

(b) The main highway for oxygen-rich blood leaving the heart and heading out to nourish all the different parts of your body is the Aorta, which you can see marked as number 1 in the diagram.

(c) The chamber of the heart that first welcomes the deoxygenated blood returning from the body is the Right Atrium, indicated by the number 4. It’s like a receiving station, getting blood from both the upper body (via the Superior Vena Cava) and the lower body (via another vessel called the Inferior Vena Cava).

Question 2.
You can see some blood vessels on the outside of the hands especially in older people. Are those veins or arteries? How can you confirm your answer?
Answer:
Their location just beneath the skin’s surface makes them the prime candidates for visibility, unlike their artery counterparts that reside deeper within. And as you pointed out, the lack of a pulse further distinguishes them from the rhythmic beat of arteries carrying oxygen-rich blood away from the heart.The tourniquet analogy perfectly illustrates their role. By obstructing the return flow of blood through the veins, they become more prominent, a visual testament to their superficial positioning.So, when you observe those intricate blue lines on your hands, remember they are the hardworking veins, diligently carrying blood back to where it needs to be refreshed. It’s a fascinating glimpse into the continuous circulatory dance happening just beneath our skin!

Question 3.
Give the functions of lymph. Differentiate between Blood and lymph.
Answer:
lymph carries out some really important jobs in keeping our bodies healthy and balanced. Think of it as a clean-up and transportation system that works alongside our blood.

One of its main tasks is dealing with any extra fluid and proteins that might have seeped out of our tiny blood vessels, called capillaries, and into our body tissues. If this fluid just stayed there, we’d get swelling. Lymph collects this excess and carries it back into the bloodstream, sort of like a recycling system for fluids. This helps keep everything in balance.

Beyond just fluid control, lymph is a key player in our immune system. It acts like a surveillance network, picking up any harmful invaders like bacteria or viruses, as well as any cellular waste. It then transports these to our lymph nodes, which are like little filtering stations packed with immune cells. These cells can then identify and get rid of the threats.

Interestingly, lymph also has a role in helping us absorb fats and certain vitamins that dissolve in fat from our small intestine. It takes these nutrients and moves them into our bloodstream so they can be used by the body.

While both blood and lymph are fluids moving through our bodies, they are quite different. Blood is the red, thicker fluid we all know, constantly circulating to deliver oxygen and nutrients and remove waste. It’s packed with red blood cells, which give it the color and carry oxygen, as well as white blood cells for immunity, platelets for clotting, and the liquid plasma.

Lymph, on the other hand, is a clear, watery fluid. It starts as the fluid between our cells and doesn’t have red blood cells, which is why it’s not red. It also has less protein compared to the plasma in blood. So, while blood has a wide range of transport duties, lymph focuses more on managing fluid levels, defending against infections, and helping us absorb fats. They work together, but have their own specialized roles to keep us functioning properly.

Question 4.
Name any two heart conditions that occur commonly. Briefly explain each of them.
Answer:

It sounds like those analogies really helped to clarify how coronary artery disease (CAD) and hypertension impact the heart and blood vessels. It’s true, thinking of the coronary arteries as the heart’s personal “nutrient delivery system” makes it easy to grasp how plaque buildup, like “traffic congestion,” can starve the heart muscle of oxygen. That chest pain, angina, is indeed the heart’s cry for help, a signal that things aren’t flowing smoothly. And the idea of a blood clot causing a complete “road closure” leading to a heart attack really emphasizes the urgency and potential damage.

Then with hypertension, that “garden hose under constant high pressure” analogy perfectly illustrates the relentless strain on the arteries. It’s not just about the immediate pressure; it’s about the long-term wear and tear, weakening the heart muscle and stiffening the arteries, making them less resilient. And you’re absolutely right, “silent killer” is the perfect term. The lack of obvious symptoms in the early stages is what makes it so insidious, allowing damage to accumulate unnoticed until a critical event like a heart attack or stroke occurs, or even affecting other vital organs like the kidneys.

So, yes, while CAD and hypertension affect the cardiovascular system in different ways – one through blockage, the other through increased pressure – they both pose significant threats to heart health. Understanding these mechanisms is the first step towards appreciating the importance of taking care of our cardiovascular system through healthy lifestyle choices and regular check-ups.

Question 5.
During surgical operations or during accidents, the patient may be given blood from outside to save his life. What is the technical name of this process ? Briefly explain the precautions to be observed and taken in this process.
Answer:
Blood transfusion is indeed the technical term for that life-saving procedure. And you’ve highlighted the crucial precautions perfectly: meticulous blood group matching, rigorous screening for transmissible diseases, precise storage and handling, thorough patient identification, continuous monitoring for reactions, and the use of sterile equipment are all absolutely vital for a safe transfusion.

Question 6.
State briefly, the difference between white blood cells and the red blood cells.
Answer:

Red blood cells are indeed the tireless oxygen transporters in your body, thanks to the hemoglobin they carry. ¹ Imagine tiny delivery trucks constantly ferrying oxygen to every corner. ² On the flip side, white blood cells act as vigilant protectors, like security guards patrolling your bloodstream and standing ready to fight off any infections or unwelcome intruders

Question 7.
Answer very briefly, the following:
(a) Red Blood cells have no nucleus, so why do we call them cells?
(b) Why is it necessary to know The blood groups of the donor as well as the recipient ?
(c) Why should the blood going away from the stomach and intestines pass through the liver and not directly to the heart?
Answer:
(a)  they begin as regular cells from those amazing hematopoietic stem cells in bone marrow. Then comes the fascinating part: during maturation, they dramatically change by losing their nucleus and other organelles. This transformation is all about boosting their ability to carry oxygen.

It’s a bit like a tadpole becoming a frog – a complete change in form but with a clear origin. Even though mature red blood cells are uniquely adapted, they still have that essential cell membrane, contain cytoplasm, and for a good portion of their lifespan, function just like any other cell.

(b)  Knowing the blood groups of both the donor and recipient is crucial for safe blood transfusions. If incompatible blood types are mixed, the recipient’s immune system will attack the donor’s red blood cells, leading to a potentially ¹ life-threatening transfusion reaction. This reaction can cause symptoms like fever, chills, and even kidney failure. ² Therefore, matching blood groups ensures compatibility and prevents these dangerous complications

(c) The liver is the first organ to receive blood from the gut, playing a vital role in processing digested nutrients into usable forms and detoxifying harmful substances absorbed from food. It also helps regulate blood sugar levels, making this initial liver passage essential for maintaining overall health.

Question 8.
Name the three kinds of blood vessels found in human beings. With the help of suitable diagrams, differentiate between them.
Answer the arteries are like the major highways leading away from the bustling city center (the heart). They need to be strong and resilient to handle the constant surge of traffic (blood) being pumped out. Their thick, muscular walls really do the job of withstanding that high pressure.

Then you have the veins, the quieter country roads heading back to the city. The pressure isn’t as intense here, so the walls are thinner. But because they’re often working against gravity, especially in the legs, those ingenious little valves act like traffic controllers, ensuring everything keeps moving in the right direction – back to the heart.

Finally, the capillaries are like the intricate network of tiny local streets within the neighborhoods (the tissues). This is where the real magic happens – the exchange of goods. Their incredibly thin walls facilitate that easy give-and-take of oxygen and nutrients going out to the cells, and waste products coming back into the bloodstream. The slow, steady flow here is crucial for allowing enough time for these vital exchanges to occur.