anaphy

RESPIRATIORY SYSTEM
-supplies the body with oxygen and removes carbon dioxide

Function:

·         Ventilation – bring air into the body(movement of air in and out in the lungs)

·         Filters, humidifies and warms inspired air

·         Respiration – O2 and CO2 gas exchange between the external environment and the blood

·         maintains pH homeostasis by removing CO2

·         Production of sound

·         01 factory sensation

RESPIRATORY FUNCTIONAL DIVISIONS

·         Conducting Zone – transfers air to and from the lungs

Ø  nose, pharynx, larynx, trachea, bronchi, terminal bronchiole

·         Respiratory Zone – site of gas exchange

Ø  respiratory bronchioles, alveolar ducts, alveoli

RESPIRATORY ANATOMICAL DIVISIONS
1. Upper Respiratory Tract
Nasal Cavity, Pharynx, Larynx
2. Lower Respiratory Tract
Trachea, Bronchi, Lungs

RESPIRATORY MUCOSA

·         The Upper Respiratory Tract is lined by respiratory mucosa-pseudostratified ciliated colummar epithelium (PSCCE) with goblet cells

·         Filters, moistens and warms air

o   Mucus - traps bacteria and foreign debris and moisten airs

o   Cilia - sweeps mucus towards the throat

o   Network of veins warms passing air

·         Smokers cough smoking paralyzes, damages cilia leading to increased particles in the airways, risk of infection

PULMONARY DEFENSE MECHANISMS

·         The respiratory system is open to the air and needs protection from contaminants (debris, bacteria)

·         Upper and Lower Airways:

o   Mucus traps and remove

o   Nasal hairs and nasal conchae (turbinates): trap and remove

o   Cilia: sweeping motion moves debris out of airway

o   Irritant receptors: trigger sneeze, cough reflexes to propel substances out

-     Nostrils, trachea, large airways (bronchi)

·         Air sacs (Alveoli)

o   Alveolar macrophages: ingest and remove debris and bacteria

o   Surfactant: enhance phagocytosis by macrophages, down-regulate inflammation

NASAL CAVITY

·         External and internal nares openings to nasal cavity

·         Nasal septum divides cavity into right and left sides

·         Nasal conchae (turbinates) - increases turbulence of inspired air and exposure to respiratory mucosa

o   Meatus groove under the nasal conchae

·         Hard and soft palate floor of nasal cavity, roof of mouth

PARANASAL SINUSES

·         Paranasal sinuses lighten the skull, produce mucus and resonate sound

Frontal sinuses, Maxillary sinuses, Sphenoid sinuses, Ethmoid sinuses

PHARYNX (THROAT)

·         Nasopharynx superior to the soft palate

o   Pharyngeal tonsil on posterior wall

o   Auditory tube drains into nasopharynx

·         Oropharynx passageway for food and air

o   Non-keratinized stratified squamous epithelium

o   Palatine tonsils on the lateral walls

o   Lingual tonsil, base of the tongue

·         Laryngopharynx hyoid bone to the larynx

o   Splits into esophagus (posterior) and larynx

LARYNX (VOICE BOX)

·         Larynx- produces sound and prevents food from entering the trachea

·         Muscles that move the larynx, control vocal cords, contribute to swallowing and respiration, prevent aspiration into trachea

·         Cartilage structures protects and prevent collapse of the airway:

o   Epiglottis

o   Thyroid cartilage

o   Cricoid cartilage

o   Arytenoid cartilage (2)

o   Corniculate cartilage (2)

o   Cuneiform cartilage (2)

EPIGLOTTIS

·         Epiglottis spoon shaped elastic cartilage flap that projects from the anterior aspect of the larynx over the glottis

·         The epiglottis keeps food out of the larynx, moved downward to form a lid over the glottis when swallowing

VOCAL CORDS

·         found within the larynx

o   Vestibular folds (false vocal cords) mucosal folds superior to true vocal cords

-     Sensitive to touch and will provoke coughing reflex to eject anything that enters the larynx

o   True vocal cords elastic ligaments attached to the arytenoid and thyroid cartilages

-     Vibrate and produce sound as air is expelled from the lungs

·         Glottis opening between vocal cords

TRACHEA (WINDPIPE)

·         Anterior to the esophagus

·         Extends from the larynx to T5

·         Divides the carina into the right and left primary bronchi

o   Irritant receptors, stimulates cough reflex and airway narrowing to expel irritants

·         Lined with respiratory mucosa

·         C-shaped hyaline cartilage rings prevent trachea from collapsing (16-20 cartilage rings)

o   Incomplete posteriorly to allow the esophagus to expand anteriorly during swallowing (Trachealis muscle)

THORACIC CAVITY AND PLEURAL CAVITIES

THORACIC CAVITY:

·         Bound by the rib cage, sternum, thoracic vertebrae

·         Separated from the abdominal cavity by the diaphragm

·         Right and left pleural cavities for right and left lung

    ■ Right and left pleura

·         Mediastinum for heart, esophagus. trachea, great vessels
    ■ pericardium

LOCATION OF LUNGS
Lungs:
Anterior

·         Apex

o   Anterior about 2-3 cm above inner 1/3 of clavicle

·         Base

o   Anterior 6th rib mid-clavicular line to 8th rib midaxillary line

-     Posterior: T10 spinous process

-     Descends with diaphragm on inspiration

·         Oblique fissures
■ T3 spinous process to 6th rib mid clavicular

·         Right lung horizontal fissures
■ 4th rib anteriorly to 5th rib mid-axillary line

PLEURA

·         Lungs are surrounded by pleura: double layered serous membranes

o   Parietal pleura lines the walls of thoracic cavity

o   Pleural fluid fills the area between layers to allow gliding and resist separation
  ■ 18ml, thin layer of fluid
  ■ Lubricates surfaces to prevent friction
  ■Creates surface tension that prevents separation of layers

o   Visceral pleura covers the lung surface

SENSORY INNERVATION OF PLEURA

·         Parietal pleura has sensation of pain in response to injury or inflammation

o   Mediastinal and diaphragmatic part innervates by phrenic nerve
     ■ Refers pain to (C3, 4, 5)

o   Intercostal nerves

·         Visceral pleura & lung tissue have visceral sensory reflexes, but no pain sensation

o   Parasympathetic fibers from the vagus nerve (CNX), visceral fibers of (CNX)

o   Sympathetic fibers from the sympathetic trunks

o   NO pain or general sensory fibers. Visceral fibers here are responsible for visceral reflexes, such as cough and stretch stimulus

LOBES OF THE LUNGS

·         Each lung is divided into lobes by fissures

·         Right lung-three lobes; superior, middle, and inferior: has horizontal and oblique fissures

·         Left lung - two lobes; superior and inferior, separated by the oblique fissure

LUNG HILUS & BRONCHI

·         Bronchi enter the right and left lung at the hilus (root, medial depression)

·         Left primary bronchus: curved, broad 45degree angle

·         Right primary bronchus: steep, wide, 20-30 degree angle

o   Most likely to be site of foreign bodies inhaled, aspiration

BRONCHI

·         Bronchi - mucosa, smooth muscle, cartilage

o   Primary bronchi first branch from trachea

o   Secondary (lobar) bronchi one per lobe

o   Tertiary (segmental) bronchi - each supplies a bronchopulmonary segment

BRONCHIAL TREE: BRONCHIOLES

·         Bronchioles - mucosa, smooth muscle, connective tissue (no cartilage)

o   Terminal bronchioles non- ciliated simple cuboidal

o   Respiratory bronchioles - last branch, alveoli begin

·         Cilia, goblet cells become more sparse and smooth muscle and connective tissue gets thinner as airways get smaller

ALVEOLI

·         tiny air sacs that are the sites of gas exchange between the lungs and the blood

·         The respiratory zone of the lungs begins when the first alveoli appear on respiratory bronchioles

o   Ventilation: bring air into the lungs

o   Respiration: gas exchange

ALVEOLAR WALL

·         Type I Alveolar Cells simple squamous epithelium supported by elastic basement membrane

-     pneumocytes lining or wall of alveoli

·         Type II Alveolar Cells surfactant secrete

o   Surfactant: lipoproteins

o   Coats the alveoli reduces surface tension to prevent collapse of alveoli

o   Binds to pathogens, cells and contributes to control of inflammation and immunity

·         Alveolar macrophages (a.k.a dust cells, mononuclear phagocytes) engulf debris and prepare it for removal via lymph nodes

Cardiac notch – where the heart rest