chapter17 - respiratory system

Copyright © 2012 F.A. Davis Company

Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Chapter 17

The Respiratory The Respiratory SystemSystem



Upper respiratorytract

Lower respiratorytract



Nose and nasal cavitiesNose and nasal cavities

Conchae

Branches of olfactory nerve

Sphenoid sinus



PharynxPharynx

Nasopharynx

Oropharynx

Laryngopharynx



LarynxLarynx

Thyroid cartilage

Vestibular folds



Which is a function of the nasopharynx?

A.Filter dustB.Warm and moisten inspired airC.Provide openings for eustachian tubesD.Contain olfactory receptors for sense of smell



Correct answer: C

Rationale: Filter dust, warm and moisten inspired air, and contain olfactory receptors are all functions of the nasal cavity.



Lower respiratory tractLower respiratory tract

Consists of the trachea, bronchi, and lungs



Trachea

Carina



AlveoliAlveoli



LungsLungs

Horizontal fissure

Oblique fissure

Oblique fissure



PleuraPleura

Visceral pleura

Parietal pleura

Pleural cavity



Inhaled food or foreign objects are most likely to lodge in which part of the respiratory system?

A.PharynxB.Right bronchusC.Left bronchusD.Bronchioles



Correct answer: B

Rationale: The right bronchus is slightly wider and more vertical than the left, making it the most likely location for aspirated objects to lodge.



Pulmonary ventilationPulmonary ventilation Inspiration and expiration Both depend on:

Respiratory muscles Difference between air pressure within

the lungs and outside the body



Respiratory musclesRespiratory muscles

External intercostals

Internal intercostals

Diaphragm



Neural control of breathingNeural control of breathing Inspiratory centerInspiratory center: Primary

respiratory center Apneustic centerApneustic center: Increases length

and depth of inspiration Pneumotaxic centerPneumotaxic center: Prevents lung

overinflation Expiratory centerExpiratory center: Used for forceful

exhalations



Factors that influence Factors that influence breathingbreathing

Oxygen levels Hydrogen ions (pH) Stretch Pain and emotion Irritants



What is the main muscle responsible for pulmonary ventilation?

A.AbdominalsB.External intercostalsC.DiaphragmD.Internal intercostals



Correct answer: C

Rationale:Whereas the intercostals are used in the respiratory process, the diaphragm is the main muscle for pulmonary ventilation. The abdominal muscles are accessory muscles of ventilation.



Pressure and airflowPressure and airflow Atmospheric pressure Atmospheric pressure drives

respiration. When pressure within lungs drops lowerlower

than atmospheric pressure, air flows inin. When pressure within lungs rises aboveabove

atmospheric pressure, air flows out out.



InspirationInspiration



ExpirationExpiration

View animation on respiratory cycle



When pressure in the lungs drops lower than atmospheric pressure, what occurs?

A.Air flows out of the lungs.B.Air flows into the lungs.C.A pneumothorax forms.D.The bronchioles constrict.



Correct answer: B

Rationale:Air flows from an area of higher to lower pressure; therefore, air flows out of the lungs when pressure in the lungs is higher than atmospheric pressure.



Factors that affect airflowFactors that affect airflow Pulmonary compliance Alveolar surface tension



Measurements of ventilationMeasurements of ventilation Tidal volume Inspiratory reserve volume Expiratory reserve volume Residual volume Vital capacity Total lung capacity



Gas exchangeGas exchange Exchange depends on differences in

pressure. Gas diffuses from higher to lower

pressure until pressures are equalized.



Transport of oxygenTransport of oxygen Forms oxyhemoglobin in the lungs. Oxyhemoglobin travels to the cells. Difference in pH between venous and

arterial blood breaks bond with hemoglobin.

Oxygen is released to the tissues.



Transport of carbon dioxideTransport of carbon dioxide

1. 10% dissolved in plasma2. 20% bound to hemoglobin3. 70% carried as bicarbonate ions

Occurs in three ways: Occurs in three ways:



The primary way oxygen is transported in the blood is:

A.in the form of bicarbonate.B.in the form of carbaminohemoglobin.C.in the form of oxyhemoglobin.D.dissolved in plasma.



Correct answer: C

Rationale:Carbaminohemoglobin and bicarbonate are two forms used to transport carbon dioxide. Only 1.5% of oxygen is dissolved in plasma; 98.5% circulates in the form of oxyhemoglobin.

chapter17 - respiratory system

Health & Medicine

understanding anatomy

interactive approachcorrect answer

interactive approachcopyright 2012

air flows

physiologya visual

olfactory receptors

pressure

oxygen