THE RESPIRATORY SYSTEMChapter 23

Functions

Area of gas exchange between air and circulating blood

Producing sounds for communication

Components of the Respiratory System

Respiratory Defense System Goblet cells and mucous glands

produce a thick mucous to bathe exposed surfaces

This traps foreign particles Cilia “sweep” the mucous and

trapped debris to the pharynx where it will be swallowed, this is called the “mucous elevator”

Mucous production stimulated by exposure to vapors, allergens, pathogens….

Organization of the Respiratory System

2 major divisions Upper

Nose, nasal cavity, paranasal sinuses and pharynx

LowerLarynx, trachea, bronchi, bronchioles and alveoli of lungs

The Upper Respiratory System The Nose and Nasal Cavity Primary entrance for air Enters the external nares or nostrils which

opens up to the nasal cavity Hairs: trap large airborne particles and

prevent from entering the cavity Nasal Septum separates the nasal cavity

into Right/Left halves Superior, Middle, Inferior Nasal Concha

separate into meatuses which cleanse, warm and filter air

Nasopharynx is the junction between the nasal cavity and the Pharynx

The Upper Respiratory System Pharynx Chamber shared by digestive and respiratory

tracts 3 divisions

Nasopharynx Superior portion Connects nasal cavity to the pharynx

Oropharynx Boundary between Nasopharynx and

Oropharynx Laryngopharynx

Entrance of larynx and esophagus

The Lower Respiratory System Larynx

Air leaves the Pharynx and enters the Larynx through the glottis

Made of 3 large pieces of cartilage1. Thyroid Cartilage2. Cricoid Cartilage3. Epiglottis

The Lower Respiratory System Larynx Thyroid Cartilage

Largest Known as the “Adam’s apple”

Cricoid Cartilage Ring shaped Protect the entrance to the trachea

Epiglottis Forms a lid or flap over the glottis of the

Larynx Closes during swallowing prevents food

from entering the lungs

Sound produced at the vocal folds

Trachea

The Lower Respiratory System Laryngeal Problems:

Aspiration: weakening of the epiglottisChoking on foodCommon with elderly

The Lower Respiratory System Trachea

Aka windpipe Starts at the end of the Larynx and

ends at the branching to form the Right and Left Primary Bronchi

Has several tracheal cartilage ringsStiffens to protect airway from collapse or overexpansion

The Lower Respiratory System The Bronchial Tree Primary Bronchi

First branching towards right or left lungs Secondary Bronchi

Branching entering each lung Right lung= 3 Left lung = 2

Tertiary Bronchi 10 additional branching segments in each lung

Bronchioles Multiple passageways connect to alveolar ducts

The lower Respiratory System Alveoli are the structures in which

gas exchange occurs About 150 million per lung Covered with capillaries

Vessels carrying deoxygenated blood transport it to the capillaries found on the alveoli where CO2 is exchanged with O2

Right Lung—3 lobesLeft Lung—2 lobes

Day 2

Pulmonary Ventilation

Physical movement of air into and out of the respiratory tract.

Air moves in and out due to pressure changes

Respiratory Tract

Divided into a conducting portion and a respiratory portion

Conducting portion=from the entrance down to the terminal bronchioles

Respiratory portion=respiratory bronchioles and alveoli

Inhalation (Inspiration)

1. Diaphragm contracts1. Moves down

2. Rib cage relaxes1. Moves out

3. Pressure decreases

4. Air rushes in

Exhalation (Expiration)

1. Diaphragm relaxes1. Moves up

2. Rib cage contracts

1. Moves in

3. Pressure increases

4. Air pushed out

Day 3

http://www.youtube.com/watch?v=mhtArz6fl10&feature=related

Respiration rate

Number of breaths you take each minute

Normal adult resting=12-18 breaths/minute

Children=18-20 breaths/minute

Tidal Volume

Air moves from an area of high pressure lower pressure

1 Respiration cycle: inspiration and expiration Tidal Volume: amount of air moving into

or out of lungs during 1 cycle

Inspiratory Reserve Volume

• Amount of air you can voluntarily inhale after you have completed a normal respiration cycle

Inspiratory Reserve Volume (IRV)

Expiratory Reserve Volume (ERV)

Amount of air you can voluntarily expel after you have completed a normal respiration cycle

Residual Volume

Amount of air that remains in your lungs even after a maximal exhalation

Typical =1200mL in males, 1100mL in females

Vital Capacity

Maximum amount of air you can move into or out of your lungs in 1 single respiration cycle

Total Lung Capacity

Total volume of your lungs Sum of tidal and residual

Typically 6000mL in males, 4200mL in females

Regulation of Breathing

Acidity of your blood increases as the amount of CO2 increases

When you work out your body increases the breathing rates to decrease the amount of acidity

Asthma

http://www.youtube.com/watch?v=S04dci7NTPk&NR=1

Pneumonia

http://www.youtube.com/watch?v=cWQ14x1URXo&feature=related