Ch 22 Respiratory System Sec 22 1 Adaptations

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Ch 22: Respiratory System Sec 22 -1: Adaptations for Gas Exchange

Ch 22: Respiratory System Sec 22 -1: Adaptations for Gas Exchange

Diffusion Gas exchange in all organisms relies on diffusion… - Passive movement of molecules

Diffusion Gas exchange in all organisms relies on diffusion… - Passive movement of molecules from high to low concentration C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O Cellular respiration - Depletes oxygen - Increases carbon dioxide - Creates concentration gradients that favor diffusion of CO 2 out of cells & O 2 into cells

General Features of Respiration All respiratory systems share 3 features that facilitate diffusion: 1)

General Features of Respiration All respiratory systems share 3 features that facilitate diffusion: 1) Respiratory surface must remain wet - 2) 3) O 2/CO 2 must dissolve in water before they can diffuse Cells lining surfaces must be very thin Must have large surface area in contact w/ environment - Allows for adequate gas exchange

General Features of Respiration General Stages of Gas Exchange: (all organisms) 1) Pulmonary ventilation

General Features of Respiration General Stages of Gas Exchange: (all organisms) 1) Pulmonary ventilation - Air (or water) high in O 2 & low in CO 2 is moved past respiratory surface…usually by muscular movements 2) External respiration - O 2 & CO 2 are exchanged through respiratory surface by diffusion…O 2 diffuses into capillaries, CO 2 back out

General Features of Respiration General Stages of Gas Exchange: (all organisms) 3) Respiratory gas

General Features of Respiration General Stages of Gas Exchange: (all organisms) 3) Respiratory gas transport - O 2 & CO 2 transported from respiratory system to body tissues as blood is pumped through body 4) Internal respiration - O 2 & CO 2 exchanged between blood supply & body tissues 5) Carbon dioxide output - CO 2 returned to respiratory system from body tissues & exchanged w/ O 2 in lungs

Ch 22: Respiratory System Sec 22 -2: How the Human Respiratory System Works

Ch 22: Respiratory System Sec 22 -2: How the Human Respiratory System Works

Organs of the Respiratory System Respiratory system divided into two main parts: 1) Conducting

Organs of the Respiratory System Respiratory system divided into two main parts: 1) Conducting portion - Series of passageways that carry air in/out of lungs 2) Gas-exchange portion - Where gases are exchanged between air & blood

Organs of the Respiratory System Respiratory system includes: 1) 2) 3) 4) 5) 6)

Organs of the Respiratory System Respiratory system includes: 1) 2) 3) 4) 5) 6) 7) Nose Pharynx Larynx Trachea Bronchi Lungs Alveoli

Functions of the Respiratory System Special functions of respiratory system: 1) Oversee gas exchange

Functions of the Respiratory System Special functions of respiratory system: 1) Oversee gas exchange between blood & external environment 2) Purify, warm, & humidify incoming air 3) Aids in temperature control

Upper Respiratory Tract

Upper Respiratory Tract

Anatomy of the Respiratory System Nasal Cavity - Olfactory receptors located in lining of

Anatomy of the Respiratory System Nasal Cavity - Olfactory receptors located in lining of the superior surface…provide sense of smell - Rest of cavity lined w/ tissue that moistens incoming air & traps foreign particles

Anatomy of the Respiratory System Paranasal Sinuses - Cavities within bones surrounding nasal cavity

Anatomy of the Respiratory System Paranasal Sinuses - Cavities within bones surrounding nasal cavity - Functions: 1) Lighten the skull 2) Act as resonance chambers for speech 3) Produce mucus that drains into nasal cavity

Anatomy of the Respiratory System Pharynx - Separates food/water into esophagus & air into

Anatomy of the Respiratory System Pharynx - Separates food/water into esophagus & air into the larynx Larynx (voice box) - Opening to trachea - Plays role in speech…vocal cords found here - Thyroid cartilage (anterior portion) forms Adam’s Apple

Anatomy of the Respiratory System Trachea - Commonly known as the “windpipe” - Lined

Anatomy of the Respiratory System Trachea - Commonly known as the “windpipe” - Lined with ciliated cells *Cilia expel mucus loaded w/ dust & other debris away from lungs - Walls reinforced w/ C-shaped hyaline cartilage

Anatomy of the Respiratory System Primary Bronchi - Division of the base of the

Anatomy of the Respiratory System Primary Bronchi - Division of the base of the trachea - Branches off into left & right sides…lead to lungs - Right bronchus wider, shorter, & straighter than left - Once in lungs, they subdivide into smaller & smaller branches

Anatomy of the Respiratory System Lungs

Anatomy of the Respiratory System Lungs

Anatomy of the Respiratory System Lungs - Occupy most of thoracic cavity - Each

Anatomy of the Respiratory System Lungs - Occupy most of thoracic cavity - Each lung divided into lobes 1) Left lung = 2 lobes 2) Right lung = 3 lobes

Anatomy of the Respiratory System Bronchioles - Smallest branches of bronchi - End in

Anatomy of the Respiratory System Bronchioles - Smallest branches of bronchi - End in alveoli Alveoli - Sites for actual gas exchange

Anatomy of the Respiratory System Alveoli (“Air-Blood Barrier”) - Each alveolus is wrapped in

Anatomy of the Respiratory System Alveoli (“Air-Blood Barrier”) - Each alveolus is wrapped in capillaries for maximum O 2/CO 2 exchange - Capillaries are only 1 cell thick & coated in a thin layer of fluid - Fluid allows gases to dissolve & diffuse into blood stream easily

Mechanics of Breathing Pulmonary Ventilation - Completely mechanical process - Depends on volume changes

Mechanics of Breathing Pulmonary Ventilation - Completely mechanical process - Depends on volume changes in thoracic cavity - Volume changes lead to pressure changes which ultimately leads to flow of gases to equalize pressure

Mechanics of Breathing Two Phases 1) Inspiration - Air flowing INTO lungs 2) Expiration

Mechanics of Breathing Two Phases 1) Inspiration - Air flowing INTO lungs 2) Expiration - Air flowing OUT of lungs

Mechanics of Breathing Inspiration - Requires energy - Diaphragm & external intercostal muscles (between

Mechanics of Breathing Inspiration - Requires energy - Diaphragm & external intercostal muscles (between ribs) contract - Size/volume of thoracic cavity increases - External air pulled into lungs due to increased volume (*Don’t forget your Gas Laws from Chem!!)

Mechanics of Breathing

Mechanics of Breathing

Mechanics of Breathing Expiration - Fairly passive process - Depends on natural elasticity of

Mechanics of Breathing Expiration - Fairly passive process - Depends on natural elasticity of lung - As muscles relax, air is pushed out of lungs - Can be forced by contracting abdominal muscles & internal intercostals (which contract rib cage)

Mechanics of Breathing

Mechanics of Breathing

Non-respiratory Air Movements Air movements that have nothing to do with gas exchange: Cough/sneeze

Non-respiratory Air Movements Air movements that have nothing to do with gas exchange: Cough/sneeze (clearing lungs of debris) Laughing Crying Yawn Hiccup *Caused by reflexes or involuntary actions.

O 2 & CO 2 Transport Mechanisms O 2 & CO 2 are transported

O 2 & CO 2 Transport Mechanisms O 2 & CO 2 are transported using different mechanisms: 1) Oxygen - Binds loosely & reversibly to hemoglobin on RBCs - Each hemoglobin holds 4 O 2 molecules (8 oxygen atoms) - Nearly all O 2 carried by blood is on hemoglobin molecules

O 2 & CO 2 Transport Mechanisms O 2 & CO 2 are transported

O 2 & CO 2 Transport Mechanisms O 2 & CO 2 are transported using different mechanisms: 2) Carbon Dioxide - Transported in three different ways: a) 70% of CO 2 reacts w/ H 2 O to form bicarbonate ions that then diffuse into the plasma b) 20% binds to hemoglobin as it returns to the lungs c) Remaining 10% is dissolved in plasma & not removed

Respiratory Volumes & Capacities Spirometer - Instrument used to measure respiratory capacities

Respiratory Volumes & Capacities Spirometer - Instrument used to measure respiratory capacities

Respiratory Volumes & Capacities Total Lung Capacity (TLC) - Approximately 6 liters of air

Respiratory Volumes & Capacities Total Lung Capacity (TLC) - Approximately 6 liters of air Tidal Volume (TV) - Amount of air moved by a normal breath - Usually about 500 m. L of air Residual Volume (RV) - Amount of air left in lungs after maximum exhalation - About 1. 2 L

Respiratory Volumes & Capacities Dead Space Volume (DSV) - Air that remains in conducting

Respiratory Volumes & Capacities Dead Space Volume (DSV) - Air that remains in conducting zone - Approximately 150 m. L never reaches alveoli Factors that affect respiratory capacities: Person’s size Age Gender Physical condition

Respiratory Control Breathing Rate - Controlled by the medulla oblongata - Changes with the

Respiratory Control Breathing Rate - Controlled by the medulla oblongata - Changes with the concentration of CO 2 in the blood *Increased CO 2 = Increased BR *Decreased CO 2 = Decreased BR (An increase in CO 2 of just 0. 3% will cause BR to double!)

Respiratory Control Factors influencing respiratory rate: 1) Physical factors - Increased body temp Exercise

Respiratory Control Factors influencing respiratory rate: 1) Physical factors - Increased body temp Exercise Talking Coughing 2) Volition - Conscious control 3) Emotional factors

Respiratory Control Factors influencing respiratory rate: 4) Chemical factors a) Carbon dioxide levels -

Respiratory Control Factors influencing respiratory rate: 4) Chemical factors a) Carbon dioxide levels - Main regulatory mechanism - Various sensors located in blood vessels throughout body b) Oxygen levels - Only influence respiration if O 2 levels drop drastically - Sensors found in aorta & carotid arteries

Ch 22: Respiratory System Sec 22 -3: Homeostatic Imbalances

Ch 22: Respiratory System Sec 22 -3: Homeostatic Imbalances

Carbon Monoxide Poisoning Carbon Monoxide - Toxic gas produced by combustion of fossil fuels

Carbon Monoxide Poisoning Carbon Monoxide - Toxic gas produced by combustion of fossil fuels - Can be deadly at concentrations as low as 0. 1% - Binds to hemoglobin 200 times easier than O 2 does… blocks O 2 from binding & leads to asphyxiation. How can you tell difference between someone who dies of regular asphyxiation & someone who dies of CO asphyxiation?

Respiratory Disorders Chronic Obstructive Pulmonary Disease (COPD) - Major cause of death/disability in U.

Respiratory Disorders Chronic Obstructive Pulmonary Disease (COPD) - Major cause of death/disability in U. S. - Features of COPD: 1) Patients almost always have history of smoking 2) Dyspnea (short of breath) becomes progressively worse 3) Coughing & frequent pulmonary infections are common 4) Most victims have difficulty clearing out CO 2 5) Those afflicted ultimately develop respiratory failure - Two major categories: 1) Chronic bronchitis 2) Emphysema

Respiratory Disorders Chronic bronchitis - Lining of lower respiratory passages becomes severely inflamed -

Respiratory Disorders Chronic bronchitis - Lining of lower respiratory passages becomes severely inflamed - Causes increased mucus production - Mucus pools in base of lungs impairing ventilation & gas exchange - Increased risk of lung infection & pneumonia

Respiratory Disorders Emphysema - Alveoli become enlarged & break adjacent alveoli - Chronic inflammation

Respiratory Disorders Emphysema - Alveoli become enlarged & break adjacent alveoli - Chronic inflammation leads to lung fibrosis - Airways collapse during expiration requiring large amounts of energy to exhale **Warning!! GRAPHIC PICTURES AHEAD!!**

Respiratory Disorders

Respiratory Disorders

Respiratory Disorders Lung Cancer - Accounts for 1/3 of all cancer deaths in U.

Respiratory Disorders Lung Cancer - Accounts for 1/3 of all cancer deaths in U. S. - Smoking & air pollution increases risks - Three common types

Respiratory Disorders Sudden Infant Death Syndrome (SIDS) - Apparently healthy infant stops breathing &

Respiratory Disorders Sudden Infant Death Syndrome (SIDS) - Apparently healthy infant stops breathing & dies while sleeping - Some cases are thought to involve poorly functioning respiratory control center in brain - 1/3 of cases appear to be due to heart rhythm abnormalities

Respiratory Disorders Asthma - Chronically inflamed, hypersensitive bronchioles - Response to environmental irritants includes

Respiratory Disorders Asthma - Chronically inflamed, hypersensitive bronchioles - Response to environmental irritants includes dyspnea (shortness of breath), coughing, & wheezing http: //www. bing. com/videos/watch/video/asthma-pediatric/bdj 1 yf 0 e

Respiratory Disorders Cystic Fibrosis (CF) - Over-secretion of thick, sticky mucus in the airways

Respiratory Disorders Cystic Fibrosis (CF) - Over-secretion of thick, sticky mucus in the airways - Causes clogs to develop & poor gas exchange - Result of a genetic mutation before birth - One of the most chronic respiratory diseases in children & young adults - Often leads to premature death

Respiratory Disorders Effects of Aging: - Elasticity of lungs decreases - Blood oxygen levels

Respiratory Disorders Effects of Aging: - Elasticity of lungs decreases - Blood oxygen levels decrease - Response to high CO 2 levels decreases - More risk of respiratory tract infection