Survey of Anatomy & Physiology Chap 13
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Transcript of Survey of Anatomy & Physiology Chap 13
The Respiratory System: It's a Gas
13
Respiratory SystemRespiratory System
Respiratory system's primary function: to transport oxygen from atmosphere to bloodstream to be utilized by cells, tissues, organs for process of cellular respiration, which is necessary to sustain life
Respiratory SystemRespiratory System
Respiratory system moves 12,000 quarts of air per day in and out of lungs
Respiratory system removes waste gas—carbon dioxide—so it doesn't build up in toxic levels
Cellular Respiration Cellular Respiration Needs OxygenNeeds Oxygen
Cellular respiration depends on continuous supply of oxygen, found in abundance in air we breathe
Using oxygen produces carbon dioxide, which would become toxic if allowed to build in bloodstream; must be removed
Cardiopulmonary SystemCardiopulmonary System
Respiratory system closely related to heart and circulatory system; they are sometimes grouped together as cardiopulmonary system
Anatomy of Respiratory Anatomy of Respiratory SystemSystem
Components of respiratory system:
Two lungs that serve as vital organs
Upper and lower airways that conduct gas in and out of the system
Terminal air sacs called alveoli surrounded by network of capillaries that provide for gas exchange
Anatomy of Respiratory Anatomy of Respiratory SystemSystem
Components of respiratory system:
Thoracic cage that houses, protects, facilitates function for the system
Muscles of breathing that include the main muscle, the diaphragm, and accessory muscles
Figure 13-1Figure 13-1The various components of The various components of the respiratory systemthe respiratory system
http://www.youtube.com/watch?v=hc1YtXc_84A
Watch Video on “Respiratory
System”
Ventilation versus Ventilation versus RespirationRespiration
Ventilation versus Ventilation versus RespirationRespiration
Ventilation: bulk movement of air into and out of lungs where gas exchange takes
place
Ventilation versus Ventilation versus RespirationRespiration
Respiration: process of gas
exchange, where oxygen added to blood and carbon dioxide removed
External Respiration External Respiration versus Internal versus Internal RespirationRespiration
External Respiration External Respiration versus Internal versus Internal RespirationRespiration
External respiration: gas exchange in lungs
occurs between blood and air in the
external atmosphere
External Respiration External Respiration versus Internal versus Internal RespirationRespiration
Internal respiration:
oxygenated blood transported
internally via cardiovascular
system to cells and tissues; oxygen
moves into cells as carbon dioxide
removed
Table 13-1Table 13-1 Gases in the Gases in the AtmosphereAtmosphere
Air contains many gases,
predominantly nitrogen, which is a support gas that keeps lungs open with its constant volume and pressure
Table 13-1Table 13-1 Gases in the Gases in the AtmosphereAtmosphere
Next highest concentration found in air is oxygen, essential to life; carbon dioxide is
found in very small
concentrations
Figure 13-2Figure 13-2Contrast of ventilation and Contrast of ventilation and
external and internal external and internal respirationrespiration
We have reserve of
oxygen to last 4 to 6
minutes; after that we will die if we
don't get more oxygen
The Airways and LungsThe Airways and Lungs
Respiratory system is series of branching tubes called bronchi and bronchioles
The Airways and LungsThe Airways and Lungs
Airways transport atmospheric gas deep within lungs to small air sacs called alveoli, which represent terminal end of respiratory system
The Airways and LungsThe Airways and Lungs
Each alveolus is surrounded by capillaries; combination called alveolar-capillary membrane; represents connection between respiratory and cardiovascular systems
Structures of Upper Structures of Upper AirwayAirway
Function of Upper Airway Function of Upper Airway StructuresStructures
Mouth
Nose
Larynx
Pharynx
Figure 13-3The upper airway and vocal
cords
Upper Airways of Upper Airways of Respiratory TractRespiratory Tract
While some people breathe through their mouths, we are meant to breathe through our noses
Rigid structure made of cartilage and bone
Upper Airways of Upper Airways of Respiratory TractRespiratory Tract
Nasal cavity: behind nose, divided into three main regions
Vestibular
Olfactory
Respiratory
Figure 13-4Figure 13-4The nasal regionsThe nasal regions
Regions of the NoseRegions of the Nose
Three Main Regions
Vestibular Region of Vestibular Region of NoseNose
Vestibular region: located inside nostrils and contains coarse nasal hairs that act as first line of defense for respiratory system
These hairs (vibrissae) covered with sebum, greasy substance secreted by sebaceous glands of nose
Sebum helps trap particles; keeps hairs soft and pliable
Olfactory Region of Olfactory Region of NoseNose
Olfactory region: located on roof of nasal cavity, allowing air to be held there so it can be sampled
Respiratory Region of Respiratory Region of NoseNose
Respiratory region
Air warmed to body temperature and moistened in this region inside nasal cavity, which is lined with mucous membranes and richly supplied with blood
There are three scroll-like bones (turbinates) that split incoming air into three channels, providing more surface area
Respiratory Region of Respiratory Region of NoseNose
Respiratory region
Turbinates serve to make incoming air current more turbulent, bringing more air in contact with mucous membranes for warming and moisture, adding 650 to 1,000mLs of water each day to moisten air to 80% relative humidity
Mucociliary ElevatorMucociliary Elevator
Cells in epithelial lining of airways of respiratory system are called pseudostratified ciliated columnar cells
Consists of single layer of tall columnlike cells that have nuclei at different heights, giving appearance of two or more layers
Each columnar cell has 200 to 250 cilia on its surface
Mucociliary ElevatorMucociliary Elevator
Goblet cells and submucosal glands are interspersed.
Mucus resides as two layers:
Cilia reside in sol layer; contains thin, watery fluid that allows them to beat freely
Top layer is gel layer that is more viscous and sticky, trapping small particles
Mucociliary ElevatorMucociliary Elevator
Cilia act as tiny "oars" resting in
watery sol layer and beat 1,000 to 1,500 times per minute and propel gel layer and its trapped debris
onward and upward about one inch per minute to
be expelled
Mucociliary ElevatorMucociliary Elevator
In nose, debris-laden secretions pushed toward front of nasal cavity to be expelled through nose
Pseudostratified ciliated columnar epithelium propels gel layer toward oral cavity to be expectorated with cough or swallowed into stomach
The SinusesThe Sinuses
Skull contains air-filled cavities called sinuses that connect to nasal cavity via small passageways
Located around nose and sometimes referred to as paranasal sinuses
Cavities help prolong and intensify sound produced with our voice and helps to lighten weight of head
The SinusesThe Sinuses
Three different sinuses: Frontal, Ethmoid and Maxillary
Sinuses do not exist at birth
Develop as we grow; facial features changes influenced by sinuses as we mature
Sinuses also help to warm and moisturize air
Pharynx: Three PartsPharynx: Three Parts
Pharynx, or throat, is hollow muscular structure beginning behind nasal cavity, lined with epithelial tissue
Pharynx can be divided into three sections
Nasopharynx
Oropharynx
Laryngopharynx
Figure 13-7Figure 13-7The nasopharynx, oropharynx, and The nasopharynx, oropharynx, and
laryngopharynx and related laryngopharynx and related structuresstructures
First Part: First Part: NasopharynxNasopharynx
Nasopharynx is uppermost section, beginning behind nasal cavity
Section contains lymphatic tissue called adenoids; passageways into middle ear called Eustachian tubes
Air from nasal cavity passes through nasopharynx
Second Part: Second Part: OropharynxOropharynx
Oropharynx is located behind oral, or buccal, cavity
Conducts not only atmospheric gas but also food and liquid
Air breathed through both nose and mouth passes through here, and anything that is swallowed
Second Part: Second Part: OropharynxOropharynx
Tonsils are part of lymph system
Palatine tonsils are located in oropharynx, as are lingual tonsils located at back of tongue
During swallowing, uvula and soft palate move in posterior and superior position to protect nasopharynx and nasal cavity from entry of food or liquid; can be overcome by forceful laughing
Third Part: Third Part: LaryngopharynxLaryngopharynx
Laryngopharynx is lowermost portion of pharynx
Air breathed and/or swallowed passes through laryngopharynx
Swallowed materials pass through esophagus to get to stomach
Air travels through larynx and trachea on its way to lungs
The LarynxThe Larynx
Semi rigid structure composed of cartilage connected by muscles and ligaments that provide movement of vocal cords to control speech
“Adam's apple” (thyroid cartilage) is largest of cartilages found in larynx
The Larynx and The Larynx and GlottisGlottis
Cricoid cartilage lies beneath it, providing structure and support for airways so they do not collapse
Glottis is opening that leads into larynx and eventually lungs
The EpiglottisThe Epiglottis
Leaf-shaped flap like fibrocartilage
Closes over opening to larynx when you swallow; opens up when you breathe, as part of swallowing reflex (glottic or sphincter mechanism)
Seals so food does not enter lungs
Figure 13-8The upper airway and related
infections
Vocal Cords as Vocal Cords as Dividing LineDividing Line
Vocal cords act as dividing line between upper and lower airways
Lower airway starts below vocal cords
Upper airway ends at vocal cords
Respiratory DiseasesRespiratory Diseases
Complete the RespiratoryDiseases Worksheet
Due Thursday Nov 12, 2013
Also due: Take home quiz on Anatomy of the Heart
The Lower Respiratory The Lower Respiratory TractTract
Resembles upside-down tree, sometimes called tracheobronchial tree
From vocal cords, air enters trachea, or windpipe, 4½˝ long tube lined with ciliated mucous membrane
The Trachea and EsophagusThe Trachea and Esophagus
C-shaped cartilage found in anterior portion of trachea provide rigidity and protection for exposed airway in neck
Esophagus lies in area where C opens up posteriorly; room for esophagus to expand when you swallow larger chunks of food
Trachea and Mainstem Trachea and Mainstem BronchiBronchi
Trachea is largest pipe; can be thought of as trunk of tree
Trachea begins branching (bifurcating) at center of chest into left and right mainstem bronchi (bronchus is singular form)
Trachea and Mainstem Trachea and Mainstem BronchiBronchi
Site of bifurcation is called carina
Next bronchi must branch into five lobular bronchi; correspond to five lobes of lungs
carina
Bronchi of the Bronchi of the LungLung
Each lung lobe further divided into specific segments; next branching of bronchi called segmental bronchi
At point from trachea down to segmental bronchi, tissue layers of bronchi are all the same, only smaller, as they branch downward
Figure 13-10Three Tissue layers in the
bronchi
• Epithelial layer contains mucociliary escalator
• Middle is lamina propria layer which contains smooth muscle, lymph, and nerve tracts
• Third layer is protective and supportive cartilaginous layer
Bronchi in Lung SegmentsBronchi in Lung Segments
Branching continues to tiny subsegmental bronchi that branch deep within each lung segment
Cartilaginous rings become more irregular and eventually fade away
Closer to gas exchange regions, airways simplify to make it easier for gas molecules to pass through
Bronchi Lead to Bronchi Lead to BronchiolesBronchioles
Bronchioles average 1 mm in diameter
Cilia, goblet cells, and submucosal glands are almost all gone
There is no gas exchange yet
Terminal BronchiolesTerminal Bronchioles
Terminal bronchioles mark border between conducting and respiratory zones
Respiratory BronchioleRespiratory Bronchiole
Next airways beyond terminal bronchioles are respiratory bronchioles, because some gas exchange occurs here
Alveolar Ducts to Alveolar Ducts to AlveoliAlveoli
Alveolar ducts originate from respiratory bronchioles,
These give way to alveoli
Figure 13-11Conduction and gas exchange structures and functions
Alveoli and Pulmonary Alveoli and Pulmonary CapillariesCapillaries
Alveoli are terminal air sacs, surrounded by numerous pulmonary capillaries
Together capillaries and alveoli make up functional unit of lung known as alveolar capillary membrane
Adults have 300–600 million alveoli, with total of 80 square meters (m2) surface area for oxygen molecule to diffuse across into capillaries
Pulmonary CirculationPulmonary Circulation
Blood from right heart entering pulmonary capillaries is high in carbon dioxide and low in oxygen
Gas Exchange at Alveolar Gas Exchange at Alveolar Capillary MembraneCapillary Membrane
http://www.youtube.com/watch?v=AyUtdqiOgCA
Gas exchange takes place and
pulmonary capillary
increases in oxygen
concentration before traveling to left heart to be pumped around
to tissues
Gas Exchange at Alveolar Gas Exchange at Alveolar Capillary MembraneCapillary Membrane
1. The pressure of oxygen in the alveolus is higher than in the capillary and by SIMPLE DIFFUSION, the oxygen enters the circulatory
system
Gas Exchange at Alveolar Gas Exchange at Alveolar Capillary MembraneCapillary Membrane
2. The pressure of carbon dioxide in the capillary is higher than in the alveolus and
by SIMPLE DIFFUSION, the CO2 enters the respiratory system and is exhaled
Gas Exchange at Cellular Gas Exchange at Cellular MembraneMembrane
3.At the tissue level, the pressure of oxygen in the capillary is higher than in the tissue and by SIMPLE DIFFUSION, the
oxygen enters the cell.
Gas Exchange at Cellular Gas Exchange at Cellular MembraneMembrane
4.The pressure of carbon dioxide in the cell is higher than in the venule and by SIMPLE DIFFUSION, the carbon dioxide enters the
circulatory system
Housing of the LungsHousing of the Lungsand Related Structuresand Related Structures
Lungs reside in thoracic cavity and are separated by region called mediastinum, which contains esophagus, heart, great vessels, and trachea
Breathing in and out causes lungs to move within thoracic cavity
Pleura of the LungsPleura of the Lungs
To prevent irritation of lungs moving against thorax, each lung wrapped in sac or serous membrane called visceral pleura
Pleura of the LungsPleura of the Lungs
Thoracic cavity and upper side of diaphragm lined with continuation of membrane called parietal pleura
Pleural Space with Pleural Space with FluidFluid
Between these two pleural layers is pleural space (intrapleural space), which contains slippery liquid called pleural fluid that reduces friction as individual breathes
The LungsThe Lungs Conical-shaped with rounded peaks (apex) extending 1 to 2 inches above clavicle
Base of lungs rest on right and left hemi diaphragm with right lung base a bit higher to accommodate liver
Cardiac impression
Medial surface of lung has deep, concave cavity that holds heart, called cardiac impression, and is deeper on left side
Hilum of The LungsHilum of The Lungs
Hilum is area where root of each lung is attached, containing main stem bronchus, pulmonary artery and vein, nerve tracts, and lymph vessels
The Lobes of the LungsThe Lobes of the Lungs
Right lung has three lobes: upper, middle, lower lobes; divided by horizontal and oblique fissures
Left lung has one fissure, oblique fissure, and therefore has only two lobes: upper and lower lobes
Lingula is area of left lung that corresponds with right middle lobe
The Lobes of the LungsThe Lobes of the Lungs
Left lung has only two lobes because largest part of heart is located in left lung area
Right lung is larger, with 60% of gas exchange occurring here
Figure 13-15Structures of the thoracic
cavity
The Protective Bony The Protective Bony ThoraxThorax
Bony and cartilaginous frame providing freedom of movement
Protects organs of chest
Includes rib cage, sternum, and thoracic vertebrae to which each rib attaches
Sternum, or breastbone, is centrally located; comprised of manubrium, body, and xiphoid process
The Protective Bony The Protective Bony ThoraxThorax
True ribs (pairs 1–7): called vertebro sternal; connect to sternum and vertebrae
Pairs 8–10: called false ribs or vertebro costal; connect to costal cartilage of superior rib and to thoracic vertebrae
Figure 13-17The thoracic cage
How We BreatheHow We Breathe
Respiratory control center is in medulla oblongata
which is part of the brain stem and is continuous with the
spinal cord
How We BreatheHow We BreatheInspiration: active process
in which diaphragm is
sent signal via phrenic nerve, causing it to contract and
flatten downward, increasing
thoracic cavity space
How We BreatheHow We Breathe
Increase in thoracic cavity
volume decreases pressure,
creating lower pressure in lungs than outside,
allowing air to rush into lungs
Figure 13-18Figure 13-18How we breatheHow we breathe
Ease of ventilation is called compliance
•High compliance: little effort required to expand lungs•Low compliance: more difficult to expand lungs
How We BreatheHow We Breathe
Exhalation: passive act;
diaphragm relaxes, which decreases
amount of space in thoracic cavity; pressure in lungs becomes greater than atmospheric pressure; air is pushed out of
lungs
How We BreatheHow We Breathe
While we can consciously influence
breathing rate,
Our breathing rate is normally controlled by level of carbon dioxide in blood
How We BreatheHow We Breathe
If carbon dioxide levels rise, it means that not enough CO2 is being ventilated
When this occurs, chemoreceptors in medulla oblongata send signals to respiratory muscles to increase rate and depth of breathing
Factors Affecting Breathing Factors Affecting Breathing RateRate
How We BreatheHow We Breathe Accessory Muscles include:
Scalene muscles in neck
Sternocleido mastoid
Pectoralis major
Pectoralis minor
Figure 13-19Figure 13-19The accessory muscles of The accessory muscles of
exhalationexhalation
Accessory muscles of exhalation assist in more forceful and active exhalation by increasing
abdominal pressure
How We BreatheHow We Breathe
Main accessory muscles of
exhalation are abdominal muscles
that push up diaphragm or the back muscles that
pull down and compress thoracic
cage
EmphysemaEmphysemaAffects lung compliance:
Bronchioles become damaged and wider, allowing air into lungs, increasing compliance but making it much more difficult to breathe out Breathing then requires the use of more accessory muscles
Damage to the LungsDamage to the Lungs
Figure 13-14Figure 13-14Asthma and emphysemaAsthma and emphysema
Figure 13-20Figure 13-20Classes of drugs used to Classes of drugs used to
treat respiratory disorderstreat respiratory disorders
GAS EXCHANGEGAS EXCHANGE
Complete the GAS EXCHANGE
WORKSHEET IN CLASS
Use a RED pencil to represent the direction of
the oxygen movement and BLUE for the direction of
the carbon dioxide movement