Lesson 1: Upper Respiratory Tract

Question 1

Respiratory System: Structure
and Function

Answer 1

The human respiratory system is divided
into two parts;

The upper respiratory tract

The lower respiratory tract

Question 2

The Upper Respiratory
Tract

Answer 2

Air first enters the nostrils which conduct air
into the hollow nasal passages.

Thin bones called turbinates, hang suspended
from the nasal chambers and have several
functions;

Turbinates are covered in a thin
membrane which secretes mucous to
moisten the air.

The epithelial lining of the turbinates is
well supplies with capillaries to warm
the air and increase humidity.

The air passes to the pharynx next. The pharynx is part of the
gastrointestinal tract that connects the oral and nasal cavities to
the larynx.

The air now enters the glottis. The glottis is the opening of the
trachea and is protected by the epiglottis.
The air is now in the larynx (voice box).
The larynx houses the vocal cords.

When you breath normally there is
a large gap between the two flaps
of the vocal cords.

When you prepare to speak,
muscles around the larynx contract
bringing the cords closer together.
The passage of air through this
narrower space causes the cords
to vibrate producing sound.After passing the larynx, air goes down a
flexible tube called the trachea. The trachea is
supported by semicircular cartilage rings which
prevent the trachea from collapsing.

The nasal and other passages of the upper
respiratory tract are lined with ciliated cells
that secrete mucous.

This mucous traps foreign particles such as
dust and bacteria. The continual beating of
the cilia propel this material back into the
nose and throat where it can be expelled
through coughing or sneezing.