Page 4 - class-XI-ch.8-Lesson notes

SAI INTERNATIONAL SCHOOL

CLASS – XI

SUBJECT: PHYSICAL EDUCATION

CHAPTER – 8,

Fundamentals of Anatomy,

Physiology and Kinesiology in Sports

Lession Notes

STRUCTURE AND FUNCUNCTIONS OF RESPIRATORY SYSTEM AND CIRCULATORY SYSTEM:

Structure of Respiratory System:
Respiration is the process of obtaining and using oxygen, while eliminating carbon dioxide. It is the process by which
human Nasal cavity beings take in oxygen from their environment Nostril and give out carbon dioxide that is produced
Epiglottis Pharynx as a result of some chemical changes within the cells. The requirement of oxygen is Larynx Trachea
indispensable for the human body. So, our body needs a continuous supply of oxygen. Some chemical changes take
place in tissue cells. The main product of these chemical changes is CO2. A continuous elimination of C02 is essential. In
fact, respiration is a two- fold process. One is called internal respiration and other is external respiration.

The inhalation of oxygen is followed by some chemical changes in which, waste products are formed. Then exhalation of
waste products takes place. The process of inhalation of 02 and exhalation of CO2 +H20 is called respiratory process.
There are various organs of respiratory system, which play a vital role in respiration. These are mentioned below.

1. Nose 2. Pharynx
3. Larynx 4. Trachea
5. Bronchi 6. Diaphragm
7. Lungs
Nose:

The nose is a special organ of smell and it has a significant role in respiration. It consists of two parts—the external
feature, and the internal cavities.
(a) External Feature: It is composed of a triangular framework of bone and cartilage, covered by skin. On the inner side
of the nose, there are two oval-shaped openings, called nostrils.
(b) Internal or Nasal Cavities: These two cavities are separated by a partition or septum. At the entrance, each cavity or
vestibule has numerous coarse hairs. These hairs of the cavities serve as the filters to remove particles that may be taken
in with the inhaled air.
Pharynx:
Pharynx lies behind the nose. It is a muscular tube which extends from the base of the skull to its junction with the
oesophagus at the level of the cricoid cartilage.

Larynx
After pharynx the air passes through larynx or voice box. It is mainly composed of cartilage.

It consists of two Pairs of membranes. Air causes the vocal cords to vibrate, thus producing sound.

Trachea