Respiratory System

Disorders of Respiratory System

Organs of Respiratory system & location

Difference of Right & Left Bronchi & Lung

Breathing Mechanism

Definition of lung capacity terminology

Major Functions of the Respiratory System

Anatomy of the Respiratory Tract

Internal & External respiration

Function #1: Gas exchange between blood & external environment

Function #2: Passageways to lungs purify warm and humidify the incoming air

Pharynx

Trachea

Paranasal sinus

Larynx

Upper Respiratory tract

Lower Respiratory Tract

Nasal Cavity: the nasal cavity is inferior of the nose and divided by the nasal septum

  • olfactory receptors (sense of smell) located in mucosa on superior surface
  • rest lined w/ respiratory mucosa
    • Function: moistens air & traps incoming foreign particles
  • lateral walls have conchae
    • Function: Increase surface area & increase air turbulence w/in nasal cavity




Nose: air enters nose through external nares (nostrils)

Pharynx: ( throat) is the muscular passage from nasal cavity to larynx Passage of air only

  • Three regions
    • Nasopharynx: superior region behind nasal cavity
    • Oropharynx: middle region behind mouth
    • Laryngopharynx: inferior region attached to larynx
      • oropharynx and laryngopharynx are common passageways for air and food


Paranasal Sinuses : cavities w/in bones

  • frontal, sphenoid ethmoid, maxillary bone
  • lighten the skull
  • resonance chambers for speech
  • produce mucus

Primary Bronchi: formed by division of trachea and enters the lung

  • right bronchus is wider, shorter, & straighter than the left, due to the presence of the heart on the left side
  • bronchi subdivided into smaller & smaller branches

Lungs : occupy most of the thoracic cavity and apex is near clavicle (superior) , base rest on diaphragm ( inferior) & each lung is divided into lobes by fissure ( 2 on left & 3 on right)

Trachea : connects larynx with bronchi and fairly rigid because of the c-shaped rings made of hyaline cartilage to keep airway open at all times

  • lined with ciliated mucosa
    • beat continuously in opposite direction of incoming air
    • mucus loaded w/ dust & other debris away from lungs

right and left bronchi

right and left lung

Right: is wider, shorter, and straighter

Left : smaller and larger due to the presence of the heart on the left side

Right: contains three lobes

Left: cardiac notch, 10% smaller, 2 lobes

Internal Respiration: exchange of gases between blood capillaries & body cells

External Respiration: gas exchange between alveoli and blood capillaries

Inspiration : increase/ upward in size of thoracic cavity and downward/decrease pressure

  • Diaphragm: moves down
  • moves ribs up and sternum forward
  • Forced inhalation: scalenes muscles, sternocleidomastoid & pectoralis minor

Control of Respiration : respiratory center: several groups of neurons in medulla oblongata & pons; control rate & depth of breathing

  • Chemical Factors: increase CO2 & decrease respiration, acts directly on medulla oblongata
  • CO2 levels in blood s the main reg. chemical for respiration
  • decrease in O2 levels and increase in respiration
  • chemoreceptors in aorta & carotid artery
  • info sent to medulla oblongata
  • Physical Factors: increased body temp., exercise, talking, coughing, emotion

Pulmonary Ventilation: movement of air in lungs; depends in pressure gradient

  • before inspiration, pressure in lungs (Pl= pressure of atmosphere) & (PA= 760mm Hg)
  • Inspiration: flow of air into lung
  • Expiration: air leaving lung

Expiration: passive process, diaphragm and rib muscle relax

  • elastic recoil of starched elastic fibers of lungs decrease/downward lung volume and increase pressure forcing air out
  • forced expiration requires concentration of intercostal ribs muscles & abdominal muscles

Functional residual capacity: residual volume + expiratory reserve volume

Vital Capacity: inspiratory reserve volume + tidal volume+ expiratory reserve volume

Inspirational capacity: tidal volume + inspiratory reserve volume

Total lung capacity: sum of all volumes

Nasal Cavity

Primary bronchi

Nose

Respiration: entire process of exchanging gases between atmosphere and body cell

  • Breathing or ventilation : moving air in & out of the lungs
  • Cellular respiration occurs in the mitochondrion of the cell; oxygen carried as oxyhemoglobin in blood

Lungs

Larynx: voice-box, is the passageway in the head through which air flows.

  • contains tiny hairs, & is lined w/ sticky mucous membranes that trap dust, pollen, & other particles that enter the nose

Chronic Bronchitis : mucosa becomes inflamed, mucus production increases

  • Effects: pooled mucus impairs ventilation & gas exchange
  • risk of lung infection increases
  • pneumonia is common

Lung Cancer: 1/3 of all cancer deaths in US, associated w/ smoking

  • Three common types:
    • squamous cell carcinoma
    • adenocarcinoma
    • small cell carcinoma

Emphesyma: alveoli enlarge as adjacent chambers break through

  • Causes: chronic inflammation promotes lung fibrosis
    • airways collapses during expiration
    • patients use a large amount of energy to exhale
  • Effects: over inflation causes barrel chest
    • cyanosis ( blue skin due to lack of oxygen in blood & tissue) late in disease

Sudden Infant death Syndrome (SIDS): unexplained infant death

  • Causes: neural respiratory control center or abnormal heart rhythm

Chronic obstructive Pulmonary Disease (COPD): Patients almost always have a history of smoking

  • Effects: labored or difficulty breathing (dyspnea) becomes progressively more severe
    • Coughing & frequent pulmonary infections are common
    • Hypoxic ( insufficient O2 in tissues)
    • leads to respiratory failure
  • Major causes of death & disability in the US

Asthma: chronic inflamed hypersensitive bronchiole passages

  • response to irritants w/ dyspnea, coughing & wheezing

Birth Defects: cystic fibrosis, over section of thick mucus clogs the respiratory system

Aging Effects: elasticity of lungs decreases, vital capacity decreases; blood O2 levels decreases, stimulating effects of CO2 decrease

  • More risks of respiratory tract infection