Chapter 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  Lower  Larynx, trachea, bronchi, bronchioles and alveoli of lungs

The Upper Respiratory System  The Nose and Nasal Cavity  Primary entrance for air external nares or nostrils  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 cartilage 1.Thyroid Cartilage 2.Cricoid Cartilage 3.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 epiglottis  Choking on food  Common 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 rings  Stiffens 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 lobes Left 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 contracts 1. Moves down 2. Rib cage relaxes 1. Moves out 3. Pressure decreases 4. Air rushes in

Exhalation (Expiration) 1. Diaphragm relaxes 1. Moves up 2. Rib cage contracts 1. Moves in 3. Pressure increases 4. Air pushed out

Day 3

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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  TPk&NR=1 TPk&NR=1  Pneumonia  URXo&feature=related