Respiratory System

Chapter 13

Upper Respiratory Tract

Lower Respiratory Tract

Nose

Air enters the nose by passing through the external nares or nostrils

The interior of the nose consists of the nasal cavity, divided by a midline nasal septum

Nose

Mucus lines the interior of the respiratory tract Moistens the air Traps incoming bacteria and other debris Consists of water, salts, and glycoprotein (mucin)

Cilia helps move the contaminated mucus towards the pharynx (throat) to be swallowed and digested by stomach juices

Hair prevents some debris from entering the trachea

Nose

Cold temperatures cause cilia to become sluggish, allowing mucus to accumulate in the nasal cavity and to dribble outward through the nostrils

Nose

Conchae – the three uneven mucosa covered lobes that consist of the nasal cavity

Superior

Nose

The conchae traps and prevent inhaled particles from reaching the lungs

Blood vessels in the nasal cavity warms the surrounding air

Superior

Nose

Palate – the structure that separates the nasal cavity from the oral cavity Hard palate – supported by bone Soft palate – not supported by bone; posterior

part

Nose

Paranasal sinuses Lighten the skull Act as resonance chambers (amplifies sound) for speech Produce mucus which drains into the nasal cavities

Four sinuses Frontal Ethmoid Sphenoid Maxillary

Nose

The suctioning effect created by nose blowing helps to drain the sinuses

The nasolacrimal ducts, which drain tears from the eyes, also empty into the nasal cavities

The Boy Who Cries Blood http://abcnews.go.com/GMA/video?id=8460654

Pharynx

The pharynx (throat) is a passageway for food and air

The pharynx is divided into three regions Nasopharynx - the passage that connects the

nasal cavity to the top of the throat Oropharynx –the part of the pharynx between the

soft palate and the epiglottis Larynopharynx –the lowest portion of the pharynx;

near the larynx

Pharynx

Tonsils – trap and remove any bacteria or other pathogens entering the throat

Tonsillitis – a condition when tonsils become congested with bacteria and become red, swollen, and sore

Tonsil stones

Pharynx

Three types of tonsils Pharyngeal tonsils (adenoids) – located

high in the nasopharynx Palatine tonsils – located in the oropharynx

at the end of the soft palate Lingual tonsils – located at the base of the

tongue

Pharyngeal tonsil

Palatine tonsil

Lingual tonsil

Larynx

Larynx – voice box Thyroid cartilage – the

largest of the hyaline cartilage (Adam’s apple)

One theory of “Adam’s apple”: Adam ate a piece of the forbidden fruit that got stuck in his throat

Larynx

Epiglottis – protects the superior opening of the larynx When food is swallowed, the larynx is pulled

upward and the epiglottis blocks the larynx Food enters the esophagus and not the larynx

Breathing stops when swallowing occurs

Larynx

Larynx

Vocal cords (or vocal folds) – part of the mucous membrane of the larynx forms a pair of folds

Glottis – the slit-like passageway between the vocal cords

Glottis

Larynx

Laryngeal Video·stro·bos·co·py Endoscopy performed with an intermittent

(occurring at irregular intervals) light at a frequency that approximates the frequency of movement of the object visualized so that it appears to be motionless; useful in analyzing vocal fold structure and motion.

Trachea

Trachea – (windpipe) Lined with cilia The cilia propel contaminated mucus away from

the lungs to the throat where it can be swallowed or spat out

The trachea is rigid because its walls are reinforced with C-shaped rings of hyaline cartilage The unprotected area of the trachea is adjacent to

the esophagus

Trachea

Smoking inhibits ciliary activity and destroys the cilia

Without these cilia, coughing is the only means of preventing mucus from accumulating in the lungs

Non-smoker Smoker (10+ years)

Heimlich maneuver Should ask for

permission before performing on an individual…

Primary Bronchi

Primary bronchi – formed by the division of the trachea

The right primary bronchus is wider, shorter, and straighter than the left

The air is warm, cleansed of most impurities, and well humidified when it reaches the bronchi

Lungs

Composition of lungs Primary bronchus Secondary bronchus Tertiary bronchus Bronchiole Terminal bronchiole Alveoli Alveolus – air sac; gas exchange occurs here

Oxygen and carbon dioxide undergo diffusion The exterior of alveoli are covered with capillaries

Lungs

Right lung Superior lobe Middle lobe Inferior lobe

The right side is larger than the left side

Left lung Superior lobe Inferior lobe

Cardiac notch - a depression where the heart sits

Apex – the narrow portion of the lung

Base – the broad portion of the lung

Apex

Base

Cardiac notch

Lungs

Visceral pleura – the membrane that lies against the lungs

Parietal pleura – the membrane that lines the walls of the thoracic cavity

The membranes secrete pleural fluid which reduces friction of the lungs and the thorax wall during breathing

Mechanics of Breathing

Ventilation Mechanical process of pulling air in and out using

muscles and pressure Respiration

Chemical inflation & deflation of lungs and cellular respiration in each cell

Mechanics of Breathing

Inspiration (or inhalation) – air flows into the lungs The diaphragm contracts (moves down) allowing

air to enter the lungs Expiration (or exhalation) – air leaves the

lungs The diaphragm relaxes (moves up) forcing air out

of the lungs