ELAINE N. MARIEB EIGHTH EDITION 13 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Respiratory System

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Respiratory System  Gas exchange between the blood and external environment  Passageways to the lungs purify, warm, and humidify the incoming air

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Only externally visible part  Air enters external nares (nostrils) The Nose

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Nasal Cavity  Divided by nasal septum  Olfactory receptors in the mucosa on the superior surface (  Respiratory mucosa  Moistens air  Traps incoming foreign particles

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Nasal Cavity  Conchae- Projections on lateral walls  Increases:  surface area  air turbulence (why?)  Nasal and oral cavity separated by the palate  Anterior hard palate (bone)  Posterior soft palate (muscle)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Paranasal Sinuses  Cavities within bones (near nasal cavity)  Frontal, Sphenoid, Ethmoid, Maxillary  Functions  Lighten skull  Role in speech  Produce mucus (drains into the nasal cavity)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pharynx (Throat)  Muscular passage from nasal cavity to larynx  Three regions  Nasopharynx – superior region behind nasal cavity  Oropharynx – middle region behind mouth  Laryngopharynx – inferior region attached to larynx  (Which two would also be passages for food?)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Pharynx  Auditory tubes enter the nasopharynx  Tonsils  Pharyngeal (adenoids)-nasopharynx  Palatine- oropharynx  Lingual-base of the tongue  Tonsils and adenoids are the body’s first line of defense—our immune system.  (They “sample” bacteria and viruses that enter the body through the mouth or nose at the risk of their own infection. )

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Larynx (Voice Box)  Routes air and food into proper channels  Role in speech  8 rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Larynx  Thyroid cartilage  hyaline cartilage  Protrudes anteriorly (Adam’s apple)  Epiglottis  Superior opening of the larynx  Routes food to esophagus and air toward the larynx

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Larynx  Vocal cords (vocal folds)  Vibrate with expelled air to create sound (speech)  Glottis – opening between vocal cords

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

 Nasal Endoscopy with Vocal Folds Nasal Endoscopy with Vocal Folds  Incredible Human Machine- Steven Tyler Vocals Incredible Human Machine- Steven Tyler Vocals

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea (Windpipe)  Connects larynx with bronchi  Lined with ciliated mucosa  Goblet cells- produce mucus  Beat continuously in the opposite direction of incoming air (WHY?)  Expel mucus loaded with dust and other debris away from lungs  Walls= C-shaped hyaline cartilage

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Primary Bronchus  Formed by division of the trachea  Right bronchus is wider, shorter, and straighter than left (why?)  Bronchi subdivide into smaller and smaller branches

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Bronchi Figure 13.5a  Passageways off primary bronchi  All but the smallest branches have reinforcing cartilage

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bronchioles  Bronchi get smaller as they branch off Figure 13.5a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bronchi/Bronchioles  Terminal bronchi end in alveoli Figure 13.5a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Alveoli  At birth= 30 million  At age 8= 300 million  100,000/day increase  Constant after that

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Alveoli  Tiny interconnected bubbles:  Diameter= 0.2 mm  Walls= 0.4 micrometers thick  Exterior is covered by capillaries

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Zone  Site of gas exchange  Structures involved:  Respiratory bronchi  Alveolar duct  Alveoli

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Question  Describe the path of air flow from the blood to the external environment.  Include important structures and components.  Ex: Tonsils in pharnyx, vocal folds in larynx etc

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

ELAINE N. MARIEB EIGHTH EDITION 13 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Human Lung

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Lungs  Exchange of 0 2 and C0 2  Keeps the bodies pH constant  Moisturizes the air  (Evidence for this?)  Heat exchange  Voice production (power of 1mW)  Air for yawning, sighing, laughing, sniffing

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lungs  Occupy most of the thoracic cavity  Apex -base rests on the diaphragm (inferior portion)  Each lung is divided into lobes by fissures  Left lung – two lobes  Right lung – three lobes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Coverings of the Lungs  Pulmonary (visceral) pleura- cover the lung surface  Parietal pleura- lines the walls of the thoracic cavity  Pleural fluid between layers of pleura allows gliding

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Needs/Byproducts Needs:  Each cells needs glucose and oxygen  (Lungs are the supplier of oxygen) Byproducts:  Carbon Dioxide=Main byproduct of glucose  (released from blood through lungs)  C0 2 drives the breathing rate – not oxygen

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Completely mechanical process  Depends on volume changes in the thoracic cavity  Volume change  pressure change  flow of gases (air) equalizes pressure  Gases will flow from High  low pressure Pulmonary Ventilation (Breathing)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Inspiration  Diaphragm and intercostal muscles contract  The size of the thoracic cavity increases  Process: 1.Diaphragm causes lungs to expand (lowers interior pressure) 2.air rushes in to equalize pressure

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Expiration  Passive process that depends on natural lung elasticity  As diaphragm relaxes, lungs naturally shrink (raising interior pressure) and air is pushed out of the lungs  Forced expiration- contracting internal intercostal muscles to depress the rib cage

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What We Breath In and Out INSPIRATIONEXPIRATION 80%Nitrogen80% Less than 20%Oxygen16% Much less than 1%Carbon Dioxide4%

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Surface Area of Lungs  The lungs have a large surface area  The convoluted surfaces have a surface area of 80m 2  This is at least ½ the size of a tennis court

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The lungs have a greater exposure to the environment than any other part of the body – including the skin.  The air we breathe contains dust, smoke, bacteria, noxious gases  All come in contact with the blood.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Respiratory Membrane (Air-Blood Barrier)  Thin squamous epithelial layer lining alveolar walls  Pulmonary capillaries cover external surfaces of alveoli

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Each alveolus is surrounded by blood so that 0 2 and C0 2 can exchange through diffusion.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gas Exchange  Gas crosses the respiratory membrane by diffusion  O 2 enters blood/CO 2 enters alveoli  Macrophages add protection  Surfactant coats alveolar surfaces  helps to prevent the alveoli from collapsing  (alveoli too small for cartilage support)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Events of Respiration  Pulmonary ventilation – moving air in and out of the lungs  Internal respiration – gas exchange between pulmonary blood and alveoli

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nonrespiratory Air Movements  Can be caused by reflexes or voluntary actions  Examples  Cough and sneeze – clears lungs of debris  Laughing  Crying  Yawn  Hiccup

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The airways must be able to remove particles.  The body does this in two ways: 1.Coughing removes large particles

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 2.Small particles are carried upward by millions of small hairs called cilia.  1000 vibrations/minute  Mucous moves 1 – 2 cm/minute  Takes 30 minutes to be cleared.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Effects of Aging  Elasticity of lungs decreases  Vital capacity decreases  Blood oxygen levels decrease  Stimulating effects of carbon dioxide decreases  More risks of respiratory tract infection

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings HW  Explain the two parts to pulmonary ventilation.