Nose, nasal cavity and pharynx
(Head and digestive models)
- Nostril - either of two external openings of the nasal cavity that admit air into the nasal cavity
- Nasal cavity - the space inside the nose; superior to the palate and anterior to nasopharynx; air enters the nasal cavity through the nostrils and exits via the internal nares to enter the pharynx; separated into left and right cavities (aka fossae) by the nasal septum; each lateral wall of the cavity has three conchae; filters, warms and humidifies the air; also contain special cells that are involved in the sense of smell.
- Nasal septum - cartilaginous and bony structure that separates the nasal cavity into left and right nasal fossae
- Concha - elongated seashell-shaped bony projection; on lateral walls of nasal cavity; increase the surface area and disrupt the flow of air as it enters the nose, causing air to bounce along the epithelium, where it is cleaned and warmed.
- Hard palate - bony plate that forms the roof of the mouth and floor of the nasal cavity; separates the oral and nasal cavities
- Soft palate - composed mainly of skeletal muscle; posterior to the hard palate, has a fleshy hanging extension called the uvula
- Frontal sinus - an air-filled space in the frontal bone; located just above the eyebrows; warms/humidifies air, resonates voice and lightens the weight of the skull
- Sphenoid sinus - an air-filled space in the body of the sphenoid bone, just anterior and inferior to the sella turcica; the most posterior of the paranasal sinuses; produces mucus and lightens the weight of the skull
- Nasopharynx - most superior portion of the pharynx; posterior to nasal cavity; passageway for air only; houses the pharyngeal tonsils
- Oropharynx - middle portion of the pharynx; is bordered superiorly by the nasopharynx, anteriorly by the oral cavity, and inferiorly by the laryngopharynx; passageway for both air and food; contains the palatine and lingual tonsils
- Laryngopharynx - inferior to the oropharynx and posterior to the larynx; continues the route for ingested material and air until its inferior end, where the digestive and respiratory systems diverge
Larynx
(Head, respiratory and digestive models)
- Hyoid bone - small U-shaped bone located in the upper neck near the level of the inferior mandible; attachment structure for the tongue and for muscles in the floor of the oral cavity.
- Thyroid cartilage - single hyaline cartilage; largest cartilage of the larynx; has the “Adam’s apple” also known as the laryngeal prominence
- Epiglottis - single elastic cartilage; covers the opening of the trachea and prevents food from entering the trachea
- Cricoid cartilage - single hyaline cartilage; forms a ring, with a wide posterior region and a thinner anterior region
- Vocal cords - folds of smooth muscle tissue; vibrate as air passes through them to produce the sound of the voice; tend to be larger in males than in females, which create a deeper voice
Trachea
(Head, respiratory and digestive models)
-
Tracheal cartilages - C-shaped hyaline cartilage that prevent collapse of trachea; open posteriorly and are completed by the trachealis muscle
Bronchial tree and lungs
(Respiratory model)
- Primary bronchus (right and left) - arise from the trachea; one per lung; part of the bronchial tree; mucous membranes within the bronchi traps debris and pathogen
- Secondary bronchi - first subdivision of the main bronchi; two on the left and three on the right; part of the bronchial tree; mucous membranes within the bronchi traps debris and pathogens
- Lung (right and left) - pyramid-shaped, paired organs in the thoracic cavity; have a narrower superior apex and wider inferior base
- Oblique fissure - deep groove in both lungs; divides lungs into superior and inferior lobes
- Horizontal fissure - deep groove in the right lung that separates the right middle lobe from the right upper lobe.
- Diaphragm - dome-shaped muscle; separates thoracic cavity from abdominal cavity; major muscle of respiration
- External intercostal muscles - superficial muscles of the thoracic wall; found between the ribs; assist in the expansion of the lungs during inspiration