Respiratory System

Anatomy
1. Clear, open pathway from extrenal surroundings to lungs for Air
2. Stretchy Structures and organs = air movement and distribution
3. Large surface area = rapid diffusion to blood
4. Trauma to one lung may not affect the other
5. Apex of lung is superior to the rest of the lung and extends past the clavicles
6. The concave base of the lungs rests of the diaphragm
7. Lung has 2 or 3 lobes and these are dicided by fissures
8. Pleural membrane
  1. Visceral Pleura covers lung
  2. Parietal Pleura lines thoracic cavity wall
  3. Serous fluid in Pleural cavity
    1. Reduce friction during breathing
    2. membranes to adhere each other
  4. Mechanical coupling = both layers move together when breathing
Function
1. Gas exchange in lings between Alveoli and blood
2. Ph Regulation - CO2 concentration
3. Sense of Smell
4. Voice Production
5. Helps Venous blood and Lymph back to heart
Structure
1. Upper Respiratory Tract
  1. Nose
    1. Bone
    2. Cartilage
    3. Nostril - Bounded laterally by flared alae
  2. Nasal Cavity
    1. Mucous Membrane lined
    2. Ciliated cells
    3. Sensory nerve endings present = Sneezing
    4. Blood capillaries and thin walled veins
    5. Nasal cavity dicided by septum = part bone and part cartilage
    6. Nasal conchae from lateral wall
      1. Increase surface area
      2. generate turbulence = warm and moisten inspired air
  3. Phranyx
    1. Nasopharynx
      1. Pharyngeal tonsils (adenoids)
        destroy/trap pathogens
      2. Auditory tube
        Drains the middle ear
        middle ear pressure = atmospheric pressure
    2. Orthopharynx
      1. palatine tonsils
      2. lingual tonsil
      3. posterior to oral cavity
    3. Laryngopharynx
      1. opens to larynx anteriorly
      2. open to oesophagus posteriorly
2. Lower Respiratory tract
  1. Larynx
    1. Passageway - connects Larynchpharynx to Trachea
    2. Thyroid Cartilage (adams apple)
    3. Epiglottis
      1. Anchored by anterior rim of thryoid cartliage
      2. Mucous Membrane coverage
      3. Guards entrance of Glottis
      4. Breathing = held open anteriorly
      5. Swallow = pulled back to close off glottic opening
    4. Glottis
      1. Vocal cords that vibrate produce sound is here
    5. Passage for air
    6. Vocal cords = sound
    7. initiate cough reflex
    8. switching mechanism = swallowing and breathing opening
  2. Trachea
    1. passage for air
    2. From Larynx and divides into 2 main brochi in lungs
    3. Cilia = propel debris-laden mucous towards external
      1. smoking damages cilia
    4. Elastic tissue = flexible
    5. sub-mucousal layer
    6. Cshaped cartilage rings
    7. Leads to Carina = sensitive = coughing if foreign objects makes contact
  3. Primary Bronchi
    1. Rings of C shaped cartilage
      1. Does not collapse
    2. Right is more wider and short and more vertical
      1. risk of foregin object being inhaled and stuck is higher
  4. Bronchioles
    1. Connects to Tertairy bronchi and Alveoli
    2. Cartliage replaced by smooth muscles
      1. controlled by autonomic nervous system
    3. Mucous producing cells and cilia sparse
    4. airflow can be heard at posterior or anterior chest = make it easier to hear adventitious sound
    5. Simple cuboidal epithelium replaces cili cells = diffusion of gases to blood and vice versa
  5. Alveoli
    1. Pulmonary Lobules
      1. Wrapped in elastic tissue
      2. around alveolus
      3. lymphatic vessel
      4. an arteriole
      5. a venule
      6. a Terminal Bronchiole
      7. Alveolar sac
    2. Large surface are for gas to exchange with blood
    3. Lined with simple squamous epithelium for effiecient diffusion
    4. Rich supply of blood capiliaries and fluid around each alveolus (pulmonary lobules)
    5. Moist = contains surfactant to lower surface tension
    6. Surfactant prevents alveolar collapse
    7. Macrophages remove particles from alveoli
  6. Secondary Bronchi
    1. Supply all 3 lobes in the RIGHT lung
    2. Supply all 2 lobes in the LEFT lung
    3. Rings of cartilage replaced by strips of cartilage
  7. Tertiary Bronchi
    1. Supply lobes of each lung
    2. Strips of cartilage
3. CN I = Olfactory Neurons
  1. Sense of smell
  2. Stimulated by odour
  3. axons travel up through bones in the bones superior to nasal cavity
Physiology
1. Pressure Gradient = air flow
2. Filter and humidifies air particles = prevention of microbes into Lungs
3. O2 and CO2 effieciently exchanged between atmosphere and blood
Imbalance of Homeostasis
1. Viral and Bacterial infections cause inflammation of mucous membrane (nasal cavity)
  1. excess mucus production
  2. Nasal Congestion
  3. Postnasal Drip
  4. Upper Resp tract infections
2. Sinusitis = infections may spread to paranasal sinuses
  1. infectious material block passageway
  2. air absorbed = vacuum
  3. causes sinus headaches over inflammed area
3. Laryngitis
  1. Inflammation of vocal cords
  2. Vocal cords swell = disturbing vibration
    1. Produce hoarse sounds
    2. whisper
  3. Infection
  4. Overuse of voice
  5. Irritants e.g smoke/cigarette
Cell Respiration
1. Aerobic respiration
  1. Uses Glucose and O2
  2. Produces CO2 , heat and many ATP
2. Anaerobic respiration
  1. Uses Glucose
  2. Produce minimal ATP and Pyruvic Acid
  3. Production of Lactic Acid
Ageing
1. Airways, tissues = less elastic, more rigid.
2. Reduce Vital capacity
3. Reduce O2 and its level. unable to excercise vigourously

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Respiratory System

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	Created by Addeana over 10 years ago