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Body Fluids and Circulation

Body Fluids and CirculationNEET Zoology · Class 11 · NCERT Chapter 15

OverviewNotesNEET QuestionsInteractive Learning

3 interactive concept widgets for Body Fluids and Circulation. Drag any slider, change any number, and watch the formula and the answer update live. Built so you understand how each NEET problem actually works, not just the final number.

On this page

4-chambered heart: chambers, valves, vena cavae, aorta, pulmonary vessels
Plasma + RBC + WBC types + platelets with NEET-tested percentages
Cycle phases + ECG waves + valve states + heart sounds, scrubbable

Labelled heart anatomy

Click any chamber, valve or vessel on the four-chambered heart diagram to learn what it does, what blood it carries and the NEET fact tested about it.

Heart structure

Heart anatomy: click any chamber, valve or vessel

A labelled four-chambered human heart. Click any pin in the diagram or any chip in the list to see what each part does, whether it carries oxygenated or deoxygenated blood, and the NEET fact tested about it.

Superior Vena Cava
Inferior Vena Cava
Right Atrium
Tricuspid Valve
Right Ventricle
Pulmonary Semilunar Valve
Pulmonary Artery
Pulmonary Veins
Left Atrium
Bicuspid (Mitral) Valve
Left Ventricle
Aortic Semilunar Valve
Aorta

Right Atrium

Deoxygenated

Receives deoxygenated blood from both vena cavae. Passes it down to the right ventricle through the tricuspid valve.

NEET fact

The pacemaker (SAN) lies in the wall of the right atrium.

Try this

  • Find the pulmonary artery. Why is it the only artery with deoxygenated blood?
  • Compare the left and right ventricles. Which one has the thicker wall, and why?
  • Look at both atrioventricular valves. How many cusps each, and on which side of the heart?

Blood composition explorer

Three views: overview (plasma vs formed elements), WBC breakdown by percentage, and plasma protein breakdown.

Blood

Blood composition explorer

Three pie charts in one widget. Overview (plasma 55% vs formed elements 45%). White blood cell breakdown by percentage. Plasma protein breakdown.

Overview
White blood cells
Plasma proteins
Plasma 55%Formed 45%

Blood at a glance

  • Plasma (55%): water + plasma proteins + small molecules. Click the yellow slice to drill into plasma proteins.
  • Formed elements (45%):
    • RBCs: 4 to 6 million per mm3, biconcave, no nucleus, 120-day lifespan.
    • WBCs: 5,000 to 11,000 per mm3. Click the red slice to drill into WBC types.
    • Platelets: 1.5 to 3.5 lakh per mm3. Trigger clotting.

Try this

  • In the WBC view, click each slice. Lock down the order from most to least common (NEET asks this).
  • In the plasma view, which protein is most abundant, and what does it actually do for the blood?
  • After exploring, ask yourself: where do the platelets and RBCs fit in? (Hint: they are in the "formed elements" 45%.)

Cardiac cycle and ECG explorer

Scrub a slider through one 800 ms cardiac cycle. See the P, QRS and T waves on a live ECG curve, plus what every chamber, valve and heart sound is doing at each moment.

Cardiac cycle

Cardiac cycle and ECG explorer

Drag the time slider through one 800 ms cardiac cycle. See where the P wave, QRS complex and T wave fall on the ECG, what the atria and ventricles are doing, which valves are open and when the heart sounds happen.

Scrub through one cardiac cycle

150 ms

Ventricular ejection
0100200400600800PQRST

Atrium

Relaxed.

Ventricle

Ejects blood at high pressure into the aorta (left) and pulmonary artery (right).

AV valves

Closed

Semilunar valves

Open (pulmonary and aortic)

ECG event

After QRS, during S-T segment

Try this

  • Move the slider to about 140 ms. You are inside QRS. What is happening to the ventricles, and which heart sound has just started?
  • Move to about 450 ms. You are at the second heart sound "dubb". Which valves just closed?
  • Find where joint diastole begins. Notice this is when the ventricles fill passively, before the next atrial systole tops them up.

Next chapter interactive widgets

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Previous chapter
Class 11 · Ch 5

Breathing and Exchange of Gases

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Class 11 · Ch 7

Excretory Products and Their Elimination

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