week 10 respiritory Flashcards
Upper respiratory tract consists of:
Nose, nasal cavity, paranasal sinuses and pharynx
Lower respiratory tract consists of:
Larynx, trachea, bronchi, bronchioles and alveoli
what are the 2 anatomical divisions of respiratory organs
upper and lower respiratory tract
what are the 2 functional divisions of the respiratory system
conducting and respiratory zones:
Conducting zone
All structures in the respiratory tract from the nose down to the terminal bronchioles
Only for passage of air WITHOUT any gas exchange
Respiratory zone
Respiratory bronchioles, alveolar ducts, and alveoli
These are the parts where gas exchange takes place
The nasal cavity
Our nostrils lead into a nasal cavity housing three turbinate bones (nasal conchae) and nasal meatuses.. The conchae increase the surface area and produce a turbulent airflow to delay it for warming, humidifying and cleaning the air to protect the lungs. The vestibule is continuous with the skin outside and so, lined with keratinised stratified squamous epithelium to withstand mechanical insults like scratching and abrasion. The roof of the nasal cavity is lined with sensory cells of the olfactory mucosa to help with smell sensation. the paranasal sinuses are hollow cavities in the facial bones, continuous with the nasal cavity. They warm, humidify, and filter air, lighten the skull and enhance voice resonance.
what are the 3 parts of the pharynx
Nasopharynx, Oropharynx, Laryngopharynx
Nasopharynx
It is lined with respiratory epithelium and help with warming, humidifying, and filtering air.
Oropharynx
Lying posterior to the oral cavity, the common path for food and air. It is lined with non-keratinised stratified squamous epithelium.
Laryngopharynx
extending from the epiglottis to the oesophagus. It opens into the larynx anteriorly and oesophagus posteriorly. So, it is the common path for food and air. The stratified squamous epithelium changes to non-keratinised in this region.
The larynx (Voice Box)
The larynx is supported by cartilages, ligaments and muscles. The thyroid cartilage enlarges into Adam’s apple after puberty in males. It is made of smooth Hyaline cartilage.
Epiglottis
leaf-like elastic cartilage. It covers the opening of the larynx (glottis) during swallowing, so that food and drinks cannot enter the airways.
cricoid cartilage
found below the thyroid cartilage and the two are linked by a membrane. This membrane is the one cut open during emergency if airways are obstructed. The procedure is known as Cricothyroidotomy.
Vocal cords (folds)
are membranous tissue arising from the sides of the larynx and forming a slit-like opening called glottis. The movement of air through the glottis vibrates the vocal cords and produce sound/speech.
what is the respiratory tree from superior to inferior
larynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchiole
trachea
a 10–12 cm long and 2 cm wide hollow tube passing through the mediastinum
supported and kept open always by incomplete C-shaped hyaline cartilage rings. An elastic connective tissue and smooth muscle (trachealis muscle) completes the ring at the back. These soft tissues protect the oesophagus posterior to the trachea and allow it to expand during swallowing.
Where the trachea branches into the two primary bronchi, we find the Carina, the last tracheal cartilage ring covered with mucous membrane and a large number of sensory receptors. Irritation of these receptors triggers a violent cough reflex, preventing entry of unwanted particles into the lungs.
respiratory bronchioles
diameter smaller than 0.5 mm start the respiratory zone and branches into two or more alveolar ducts leading into alveoli (air sacs) looking like a bunch of grapes.
alveoli
made of thin simple squamous epithelia to facilitate easy diffusion of gases.