Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Heart is a hollow, muscular organ located in the chest cavity, slightly tilted towards the left. It is roughly the size of a closed fist.
The heart is divided into four chambers: two upper chambers called the and , and two lower chambers called the and .
A thick muscular wall called the separates the left side of the heart from the right side to prevent the mixing of oxygenated and deoxygenated blood.
The of the heart receives deoxygenated blood from the body and pumps it to the lungs for oxygenation.
The of the heart receives oxygen-rich (oxygenated) blood from the lungs and pumps it to the rest of the body.
are present between the chambers to ensure that blood flows in only one direction and does not flow backward.
The rhythmic contraction and relaxation of the heart muscles is called a . A normal human heart beats about times per minute.
📐Formulae
💡Examples
Problem 1:
During a physical education class, Ravi counted his pulse and found it to be beats in minutes. Calculate his heart rate per minute.
Solution:
The heart rate is beats per minute.
Explanation:
Using the formula , we get beats per minute.
Problem 2:
Identify which chamber of the heart has the thickest muscular walls and explain why.
Solution:
The has the thickest walls.
Explanation:
The must pump oxygenated blood to the entire body, which requires a much higher pressure than pumping blood just to the lungs (done by the ). Therefore, it has thicker muscular walls to generate that force.