The anatomy and physiology of the respiratory system Flashcards
How the respiratory system is divided (locations)
Upper respiratory tract:
-nose, pharynx
Lower respiratory tract:
-larynx, trachea, bronchi and lungs
How the respiratory system is divided (function)
Conducting zone
-involved in bringing air to the site of external respiration
-nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles
Respiratory zone
-main site of gas exchange
-bronchioles, alveoli,
Path air takes through respiratory system
-nasal cavity
-pharynx
-larynx
-trachea
-primary bronchi
-secondary bronchi
-tertiary bronchi
-bronchioles
Nose, structures
-external visible on face
-internal, large cavity beyond nasal vestibule
-internal nasal cavity divided by nasal septum into right and left nares
Conchae/ turbinates
-3 nasal conchae
-tucked under each nasal conchae is a meatus for a duct that drains sinuses of nose
-receptors in the olfactory epithelium pierce the bone of the cribriform plate
The olfactory area
Ethmoid- cribriform plate (sieve), very delicate so susceptible to trauma
Olfactory bulb and tract which contains a nerve connected to the brain
Olfactory epithelium- below the cribriform plate
Function of nose
-filters, warms and humidifies air
-warms air bc the nose is very vascular= lots of veins near the surface
-olfactory site- sense of smell
-modifies the voice
-tear ducts drain into the nose
Clinical points in terms of nasal cavity
-deviation of nasal septum
-nasal injury can cause massive
blood loss
-nasal airway is well tolerated but can’t be used if skull fractured
-CSF may leak if damage to cribriform plate= straw coloured fluid
-intubation bypasses the nose
Epistaxis=
nose bleed
Trauma to upper airway
Potential for obstruction if injured via:
-bones from airway
-blood, teeth, vomit
-tongue which is attached to mandible anteriorly
-lots of blood loss common
Pharynx
-structure, location, function
-is a fibromuscular tube
-extends from behind nasal cavity as far as cricoid cartilage behind larynx
-muscles of pharynx are involved with swallowing
Nasopharynx (above soft palate), oropharynx, hypopharynx- structures within the pharynx from superior to inferior
-eustachian tube= lateral walls that equalise pressure
-passage for air, food, water
Fauces
the narrow passage from the mouth to the pharynx situated between the soft palate and the base of the tongue.
-tonsils between fauces
Larynx structure
-9 pieces cartilage which connects laryngopharynx to trachea
-thyroid cartilage= adam’s apple
-cricoid cartilage- landmark for making emergency airway (cricothyroidotomy)
-level of C4-C6, carotid arteries lateral
3 single cartilages make up larynx:
-thyroid, epiglottis, cricoid
3 paired cartilages:
-Arytenoid, cuneiform and corniculate
Epiglottis
-flap of elastic cartilage covered in a mucus membrane
-attached to root of tongue
-guards entrance to the glottis
-when breathing it is held anteriorly
-pulled backward during swallowing
Swallowing
-oral, nasal and laryngeal openings into pharynx are closed
-epiglottis tuck over larynx, deflects food
-opens eustachian tube
-vocal cords shut
-larynx lifted and pulled forwards
-respiration pauses
-food pushed down oesophagus by wave of contraction
Clinical points of larynx
-haematoma, tumour
-damage cartilage
-blockage eg. tongue
-foreign body
-irritation- laryngospasm= vocal cords spasm
-laryngeal trauma
-autonomic nerve supply- laryngeal stimulation can cause bradycardia as it can stimulate the vagus nerve
Cilia
-upper respiratory tract move mucous down toward pharynx
-lower respiratory tract, move mucous up toward larynx
-beat 15x per second
Upper respiratory tract structures
-nasal cavity
-pharynx
Lower respiratory tract structures
-larynx
-trachea
-primary, secondary, tertiary bronchi
-bronchioles
-alveoli
Trachea
-semi rigid pipe, made semi circular cartilage rings
-anterior to oesophagus
-12cm long
-cartilage incomplete facing oesophagus
Carina
bottom of trachea where it divides into bronchus
Lungs
Location, lobes, disease
-occupy hemithorax from apex to diaphragm
-left 2 lobes- room for heart (left lung 10% smaller than right)
-right 3 lobes
-disease can be limited to one lung, lobe or segment
-apex lung superior to clavicles (collar bone)
-base of lung rests diaphragm
-separated by the heart and other structures in mediastinum
-pleural/visceral membrane surrounds each lung
-pleural fluid that reduces friction
-parietal lines thoracic cavity
Primary bronchi
-divide and subdivides
-cartilaginous rings in proximal bronchi
What the primary secondary and tertiary bronchi supply
-primary supply lungs
-secondary supply lobes
-tertiary supply segments
What happens to cartilage down the lower respiratory tract
-cartilage decreases
-turns into smooth muscle which is controlled by ANS
What ANS controls ad what it causes
-sympathetic stimulation, causes airway dilation
-parasympathetic stimulation causes airway constriction
Pulmonary lobe
-what it contains
-lymphatic vessel
-arteriole
-venule
-terminal bronchiole
Inside alveoli
-Types of cells
-Membrane
Type 1 alveolar cells- allow for exchange of gases with pulmonary capillaries
Type 2 alveolar cells- allow for surfactant, prevent collapse during exhalation
Alveolar-capillary membrane= AC membrane
-alveoli macrophages engulf microscopic debris
