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Jessica Velazquez Period 3 The Respiratory System - Coggle Diagram
Jessica Velazquez Period 3
The Respiratory System
Major functions
Gas Exchange:
Supplies the body with oxygen (O2) for cellular respiration and disposes of carbon dioxide (CO2), a waste product
Coupling with Circulatory System:
Works closely with the circulatory system; failure of either leads to oxygen starvation and cell death
Olfaction:
Houses receptors for the sense of smell
Speech
: Serves as a resonating chamber and provides the air necessary for sound production
Four Processes of Respiration:
Pulmonary Ventilation:
Movement of air in and out of the lungs
External Respiration:
O2 and CO2 exchange between lungs and blood
Transport of Gases:
Circulatory system moving gases in the blood
Internal Respiration:
O2 and CO2 exchange between systemic blood vessels and tissues
Upper respiratory structures and functions
Nose and Nasal Cavity:
External Nose:
Includes the root, bridge, dorsum nasi, and apex
Nasal Cavity:
Divided by the nasal septum; contains the nasal vestibule with vibrissae (hairs) to filter particles
Nasal Conchae:
Scroll-like projections that increase mucosal surface area and enhance air turbulence to filter, heat, and moisten air
Paranasal Sinuses:
Found in frontal, sphenoid, ethmoid, and maxillary bones; they lighten the skull, secrete mucus, and help warm/moisten air
Pharynx (Throat)
: A muscular tube connecting the nasal cavity to the larynx
Nasopharynx:
Air-only passageway; closed by the soft palate/uvula during swallowing
Oropharynx:
Passageway for both food and air
Laryngopharynx
: Passageway for food and air; continuous with the esophagus
Lower respiratory structures and functions
Larynx (Voice Box):
Routes air and food into proper channels via the epiglottis and houses vocal folds for voice production
Trachea (Windpipe):
A flexible tube kept open by C-shaped hyaline cartilage rings; lined with ciliated mucosa that sweeps mucus toward the throat
Bronchial Tree:
Conducting Zone:
Trachea branches into main (primary) bronchi, then lobar (secondary), and segmental (tertiary) bronchi, eventually leading to bronchioles and terminal bronchioles
Respiratory Zone:
Where gas exchange occurs; begins at respiratory bronchioles, leading to alveolar ducts and alveolar sacs
Alveoli:
Microscopic chambers that are the main sites of gas exchange; the respiratory membrane (blood-air barrier) allows for simple diffusion
Lungs:
Paired organs; the left lung has two lobes and a cardiac notch for the heart, while the right lung has three lobes
Layers of the pleurae
Parietal Pleura:
The outer membrane that lines the thoracic wall and the superior face of the diaphragm
Visceral Pleura:
The inner membrane that directly covers the external lung surface
Pleural Cavity:
The slit-like space between the layers filled with pleural fluid, which provides lubrication and surface tension to assist in lung expansion
Mechanism of inspiration and expiration
Inspiration (Inhalation):
Active Process:
Requires muscle contraction
Primary Muscles:
Diaphragm (contracts and flattens) and external intercostals (lift the rib cage)
Accessory Muscles (Forced):
Scalenes, sternocleidomastoid, and pectoralis minor further increase thoracic volume
Result:
Thoracic volume increases, intrapulmonary pressure drops below atmospheric pressure, and air flows into the lungs
Expiration (Exhalation):
Passive Process (Quiet):
Muscles relax, and the natural elasticity of the lungs causes them to recoil
Active Process (Forced):
Uses abdominal muscles (obliques, transversus) and internal intercostals to depress the ribs and push the diaphragm up
Result:
Thoracic volume decreases, intrapulmonary pressure rises above atmospheric pressure, and air flows out
Volume and Pressure relationships in thoracic cavity
Boyle’s Law:
States that the pressure of a gas varies inversely with its volume (P1V1=P2V2)
Atmospheric Pressure (P atm):
Pressure of air surrounding the body (760 mm Hg)
Intrapulmonary Pressure (P pul)
: Pressure inside the alveoli; it fluctuates but always equalizes with P atm
Intrapleural Pressure (P ip):
Pressure in the pleural cavity; it is always negative relative to P pul to prevent lung collapse
Transpulmonary Pressure:
The difference between P pul and P ip ; it keeps the air spaces in the lungs open
Respiratory volumes and capacities
Volumes
:
Tidal Volume (TV):
Air moved per normal breath (~500 ml)
Inspiratory Reserve Volume (IRV):
Air inspired forcibly beyond TV (2100–3200 ml)
Expiratory Reserve Volume (ERV):
Air expelled forcibly beyond TV (1000–1200 ml)
Residual Volume (RV):
Air always remaining in lungs to keep alveoli open
Capacities:
Vital Capacity (VC):
Maximum amount of air that can be expired after maximum inspiration (TV+IRV+ERV)
Total Lung Capacity (TLC):
Sum of all lung volumes
Dead Space:
Air in passageways that does not contribute to gas exchange (anatomical dead space) or air in nonfunctional alveoli (alveolar dead space)
Internal vs. external respiration
External Respiration (Pulmonary Gas Exchange):
Exchange of O2 and CO2 between the lungs (alveoli) and the blood. It is driven by a steep partial pressure gradient (Alveolar PO2 =104 mm Hg vs. Venous PO2 =40 mm Hg)
Internal Respiration (Capillary Gas Exchange):
Exchange of O2 and CO2 between the systemic blood vessels and the body tissues
Disorders of the respiratory system
COPD:
Chronic obstructive pulmonary disease, including chronic bronchitis, emphysema, and asthma
Tuberculosis (TB):
An infectious disease caused by the bacterium Mycobacterium tuberculosis
Pneumonia
: A bacterial or viral infection that causes inflammation and fluid in the lungs
Lung Cancer:
Uncontrolled cell growth in the lungs; main types include Non-Small Cell (NSCLC) and Small Cell (SCLC)
Seasonal Flu
: A rapidly changing viral infection of the respiratory tract
Homeostatic Imbalances:
Laryngitis:
Inflammation of the vocal folds
Pleurisy:
Inflammation of the pleurae, often causing stabbing pain
Atelectasis:
Lung collapse due to plugged bronchioles or pneumothorax (air in the pleural cavity)