Human Lungs – Important Points

 Human Lungs  Lungs are the primary organ of the respiratory system, located in the thoracic cavity. Humans have two lungs: Right lung (3 lobes) and Left lung (2 lobes) — left is smaller to accommodate the heart. Covered by a double-layered membrane called Pleura (visceral & parietal), with pleural fluid reducing friction. Main function: Gas exchange – oxygen intake and carbon dioxide removal. Air pathway: Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli. Alveoli are tiny air sacs (~300 million) where actual gas exchange occurs via diffusion. Alveolar walls are lined with a single layer of squamous epithelium for fast diffusion. Surfactant (produced by Type II alveolar cells) reduces surface tension, preventing alveolar collapse. Lungs are not muscular; breathing is driven by diaphragm and intercostal muscles. Diaphragm contraction → lung volume increases → inhalation (negative pressure). Diaphragm relaxation → lung volume decreases → exhalation. Right l...

About Us

Welcome to JK StudyPulse
JK StudyPulse is an educational plateform dedicated to providing reliable and easy to understand content related to Health, Science, and Competitive exams preparation.
Our goal is to make learning simple, interesting and accessible for students, aspirants and knowledge seekers. We regularly share educational articles, science facts, biology notes, MCQs.

Popular posts from this blog

Nursing MCQs: 50 Most Important Questions

FATTY LIVER – INTERESTING FACTS

50 Nursing Exam MCQs — Complete Practice Set for All Competitive Nursing Exams