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Alanna Garcia period 5. Respiratory System - Coggle Diagram
Alanna Garcia period 5. Respiratory System
Major functions of the respiratory system:
supply body w/ O2 for cellular respiration & dispose of CO2, a waste product of cellular respiration
also functions in olfaction & speech
pulmonary ventilation (breathing): movement of air into & out of lungs
external respiration: exchange of O2 and CO2 between lungs and blood
Volume and Pressure relationships in thoracic cavity:
Atmospheric Pressure (Patm):
-pressure exerted by air surrounding the body
-760 mm Hg at sea level = 1 atmosphere
Transpulmonary pressure (Ppul-Pip):
-pressure that keeps lung spaces open
-keeps lungs from collapsing
Intrapleural pressure (Pip):
-pressure in pleural cavity
-fluctuates w/ breathing
-always negative pressure (<Patm & < Ppul)
Intrapulmonary Pressure (Ppul):
-pressure in alveoli
-fluctuates w/ breathing
-always eventually equalizes w/ Patm
Layers of the pleurae:
parietal pleura; membrane on thoracic wall, superior face of diaphragm, around heart, & between lungs
visceral pleura: membrane on external lung surface
pleurae:thin, double-layered serosal membrane that divides thoracic cavity into 2 pleural compartments & mediastinum
pleural fluid: fills slitlike pleural cavity between two pleurae; provides lubrication & surface tension that assists in expansion & recoil of lungs
Internal vs. external respiration:
Internal respiration: diffusion of gases between blood and tissues
-(pulmonary gas exchange) involves the exchange of O2 and CO2 across respiratory membranes
External respiration: diffusion of gases between blood and lungs
-involves capillary gas exchange in body tissues
Respiratory volumes and capacities:
Respiratory volumes:
Expiratory reserve volume (ERV): amount of air that can be forcefully exhaled after a normal tidal volume expiration (1000-1200 ml)
Inspiratory reserve volume (IRV): amount of air that can be forcefully inhaled after a normal tidal volume inspiration (2100-3200ml)
Residual volume (RV): amount of air remaining in the lungs after a forced expiration (needed to keep alveoli open)
Tidal volume (TV): amount of air inhaled or exhaled w/ each breath under resting conditions (Average ~500ml)
Respiratory capacities:
Vital capacity (VC): maximum amount of air that can be expired after a maximum inspiratory effort (VC= TV+IRV+ERV)
Inspiratory capacity (IC): maximum amount of air that can be inspired after a normal tidal volume expiration (IC= TV+IRV)
Total lung capacity (TLC): maximum amount of air contained in lungs after a maximum inspiratory effort (TLC= TV+IRV+ERV+RV)
Functional residual capacity (FRC): volume of air remaining in the lungs after a normal tidal volume expiration (FRC= ERV+RV)
Upper respiratory structures and functions:
Paranasal sinuses:
structure: Mucosa-lined, air-filled cavities and cranial bone surrounding nasal cavity
function: Lighten skull; may also warm, moisten, and filter incoming air
Pharynx:
structure: -Passageway connecting nasal cavity to larynx and oral cavity to esophagus. Three subdivisions: nasopharynx, oropharynx, and laryngopharynx
-Houses tonsils (lymphoid tissue masses involved in protection against pathogens).
function: -Passageway for air and food
-Facilitates exposure of immune system to inhaled antigens
Nose & nasal cavity:
structure: -Jutting external portion is supported by bone and cartilage. Internal nasal cavity is divided by midline nasal septum and lined with mucosa.
-Roof of nasal cavity contains olfactory epithelium.
functions: -Produces mucus; filters, warms, and moistens, incoming air; resonance chamber for speech
-Receptors for sense of smell
Lower respiratory structures and functions:
Trachea:
structure: - Flexible tube running from larynx and dividing inferiorly into two main bronchi. Walls contain C-shaped cartilages that are incomplete posteriorly where connected by trachealis
functions: - Air passageway; cleans, warms, and moistens incoming air
Bronchi & branches:
structure: - Consists of right and left main bronchi, which subdivide within the lungs to form lobar and segmental bronchi and bronchioles. Bronchiolar walls lack cartilage but contain complete layer of smooth muscle. Constriction of this muscle impedes expiration.
functions: - Air passageways connecting trachea with alveoli; cleans, warms, and moisten incoming are
Larynx:
structure: -connect pharynx to trachea. Has framework of cartilage and dense connective tissue. Opening (glottis) can be closed by epiglottis or vocal folds.
-Houses vocal folds (true vocal cords)
functions: - Air passageway; prevents food from entering lower respiratory tract
-Voice production
Alveoli:
structure: - Microscopic chambers at termini of bronchial tree. Walls of simple squamous epithelium overlie thin basement membrane. External surfaces are intimately associated with pulmonary capillaries.
-Special alveolar cells produce surfactant
functions: -Main sites of gas exchange
-Surfactant reduces surface tension; helps prevent lung collapse
Lungs:
structure: - Paired composite organs that flank mediastinum in thorax. Composed primarily of alveoli and respiratory passageways. Stroma is elastic connective tissue, allowing lungs to recoil passively during expiration.
functions: Houses respiratory passages smaller than the main bronchi
Disorders of the respiratory system:
Pneumonia: bacterial or viral infection of the lungs
symptom: fever, chills, chest pain
treatment: oxygen therapy, meds
cause: aspiration, viral infection
Lung Cancer: uncontrolled cell growth & development of tumors in the lungs
symptom: weight loss, chest pain
treatment: chemotherapy, radiation, surgical removal
cause: radon gas, genetics
Tuberculosis: bacterial infection on the respiratory system cause by myobacterium tuberculosis
symptom: chest pain, fever or fatigue
treatment: surgery, long-term antibiotics
cause: weakened immune system, contagious (inhaled)
Seasonal Flu: A viral infection; there are many variations of this virus & it changes year to year which changes the severity of the symptoms
cause: pregnancy, age, occupation
symptom: chills, fever, fatigue
treatment: vaccination, rest & hydration, meds
COPD: chronic obstructive pulmonary disorder; includes chronic bronchitis emphysema, & asthina
treatment: broncidaltors, meds
symptom: chronic cough, heart disease
cause: air pollution, age
Compare and contrast the mechanism of inspiration and expiration:
Inspiration:
-Active process involving inspiratory muscles diaphragm & external intercostals
-when dome-shaped diaphragm contracts, it moves inferiorly & flattens out: results in increase in thoracic volume
-when external intercostals contract, rib cage is lifted up & out, much like when handle on a bucket is raised; results in increase in thoracic volume
-causes intrapulmonary pressure to drop allowing air to flow into lungs
-accessory muscles activated: scalenes, sternocleidomastoid, & pectoralis minor
Expiration:
-passive process
-inspiratory muscles relax, thoracic cavity volume decreases, & lungs recoil
-volume decrease causes intrapulmonary pressure (Ppul) to increase
-uses oblique & transverse abdominal muscles, as well as internal intercostal muscles