Kit Library / Science / Human Physiology
⚡ Topic Learning KitShared by a Veda learner · Generated with Veda AI
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💡 Key Idea
Blood is more than a red liquid.
Blood is a connective tissue with a fluid matrix called plasma and formed elements: RBCs, WBCs, and platelets. Plasma carries nutrients, wastes, and hormones.
↳ Blood = plasma + cells, a transport system for nutrients, wastes, and hormones.
⭐ Important Fact
Gases dissolve in plasma too.
Plasma carries small amounts of oxygen and carbon dioxide in dissolved form. Most oxygen is in RBCs, but about 1.5% is dissolved in plasma. About 5-7% of CO₂ is dissolved, mostly as bicarbonate ions.
↳ Plasma carries ~1.5% O₂ and 5-7% CO₂, mostly as bicarbonate.
📖 Definition
Biconcave oxygen carriers.
RBCs are biconcave, disc-shaped cells with a central depression. They contain haemoglobin, which binds oxygen and gives blood its red color. They transport oxygen and a little CO₂.
↳ RBCs are biconcave cells packed with haemoglobin for gas transport.
⭐ Important Fact
Millions of RBCs per drop.
Normal RBC count is 4 to 5.5 million per mm³ of blood. Before and immediately after birth, RBCs form in liver and spleen. In adults, they form in red bone marrow of short bones like sternum, ribs, and vertebrae.
↳ RBCs are made in liver/spleen early, then red bone marrow in adults.
⚙️ Process
RBCs live about 120 days.
↳ RBCs lose nucleus, live ~120 days, then are destroyed in spleen/liver.
⭐ Important Fact
2 million RBCs replaced every second.
The body has more than 30 trillion RBCs. About 2 million RBCs die and are replaced every second to maintain steady supply.
↳ RBC production and destruction are continuous and rapid.
📖 Definition
Colorless defenders of the body.
WBCs are colorless and have irregular shapes. They are formed in red bone marrow, and some mature in lymph nodes, tonsils, thymus, or spleen. They defend against diseases.
↳ WBCs are irregular, colorless cells that protect against infections.
⚖️ Comparison
Key differences at a glance.
↳ RBCs are numerous, red, and carry gases; WBCs are fewer, colorless, and defend.
⭐ Important Fact
About 7000 WBCs per mm³.
Normal adult WBC count is about 7000 per mm³. Their lifespan depends on the body's needs—some live hours, others days or longer. There are several types of WBCs.
↳ WBC count is ~7000/mm³, and lifespan varies with immune demand.
🧠 Memory Trick
Millions vs thousands.
Think: RBC = Rich in count (millions), WBC = Warriors (fewer, but fight). RBC count ~4-5.5 million, WBC ~7000.
↳ RBCs are in millions, WBCs in thousands.
🎯 Exam Tip
Liver/spleen vs bone marrow.
Remember the shift: Before/after birth → liver and spleen; adults → red bone marrow of sternum, ribs, vertebrae. This is a common exam point.
↳ RBC formation site changes from liver/spleen to bone marrow with age.
❓ Did You Know
No nucleus, more space for oxygen.
During formation, RBCs break down their nucleus and organelles. This leaves more room for haemoglobin, maximizing oxygen-carrying capacity.
↳ RBCs sacrifice nucleus to pack more haemoglobin.
Blood is a connective tissue composed of plasma and formed elements. Plasma carries nutrients, wastes, hormones, and dissolved gases. RBCs are biconcave, haemoglobin-filled cells that transport oxygen, while WBCs are col…
Full explanation, worked examples & memory tricks in the app
All 16 questions, laddered from warm-up to topper-level, each with its answer and the reasoning behind it.
Q1. Which of the following is NOT a component of plasma?
BeginnerD · Haemoglobin
Plasma carries nutrients like glucose and amino acids, hormones, and wastes, but haemoglobin is contained in red blood cells, not in plasma.
Q2. Which blood cells are biconcave and contain haemoglobin?
BeginnerC · Erythrocytes
Red blood cells (erythrocytes) are described as disc-shaped (biconcave) and contain haemoglobin.
Q3. What is the average life span of a red blood cell?
BeginnerA · 120 days
The average life span of an RBC is about 120 days, after which they are removed by the spleen and liver.
Q4. The normal range of WBCs in adult blood is approximately:
BeginnerD · 7000 per mm³
An average of 7000 WBCs per mm³ of blood is present within the normal range for adults.
Q5. Which of the following is carried by plasma?
BeginnerD · All of the above
Plasma carries nutrients (glucose, lipids, amino acids), wastes produced by cells, and hormones secreted by endocrine glands.
Q6. Which blood component is primarily responsible for defending the body against diseases?
BeginnerB · White blood cells
White blood cells (leukocytes) defend the body against diseases.
Q7. Which of the following is true about the colour change of haemoglobin?
BeginnerD · It turns bright red in the presence of oxygen and dark red when deoxygenated.
Haemoglobin turns bright red in the presence of oxygen and dark red when deoxygenated.
Q8. The average life span of a red blood cell is about 120 days.
BeginnerA · True
The source states that the average life span of an RBC is about 120 days.
Q9. White blood cells are more numerous than red blood cells in the blood.
BeginnerB · False
WBCs are less in number than RBCs; the average count is 7000 per mm³ compared to millions of RBCs per mm³.
Q10. Approximately what percentage of oxygen is transported dissolved in plasma?
IntermediateA · 1.5%
About 1.5% of oxygen is dissolved in plasma; the majority is carried by haemoglobin in RBCs.
Q11. In adults, red blood cells are formed in the:
IntermediateD · Red bone marrow of short bones
Before and immediately after birth, RBCs are formed in liver and spleen, but in adults they are formed in the red bone marrow of short bones like sternum, ribs, and vertebrae.
Q12. Which of the following statements about white blood cells is correct?
IntermediateD · They are colourless and have irregular shapes.
WBCs are colourless, irregular in shape, larger in size, and fewer in number than RBCs. They do not contain haemoglobin.
Q13. Which of the following is NOT a site where some WBCs mature?
IntermediateC · Liver
Some WBCs mature in lymph nodes, tonsils, thymus, or spleen, but not in the liver. The liver is involved in RBC formation before birth and removal of aged RBCs.
Q14. What happens to the nucleus and organelles during RBC formation?
IntermediateC · They are broken down.
During the formation of an RBC, its nucleus and organelles are broken down, which allows more space for haemoglobin.
Q15. The total number of RBCs in the entire body is approximately:
IntermediateB · 30 trillion
There are more than 30 trillion RBCs throughout the body, while 4-5.5 million is the count per mm³ of blood.
Q16. Which of the following is NOT a function of blood plasma?
IntermediateB · Carrying oxygen
Oxygen is mainly carried by RBCs; plasma carries only a small dissolved amount (about 1.5%). The primary function of plasma is to transport nutrients, wastes, and hormones.
18 flashcards in this kit — the app reviews them with spaced repetition so the right card returns on the right day.
Every game is built from this kit's own content — scores feed your mastery, so playing counts as studying.
Word Match
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True False
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Memory Match
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Flashcard Battle
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Speed Quiz
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Sequence Builder
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Revision Battle
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