System: Respiratory

Corniculate Cartilage

Corniculate Cartilage The structure indicated is the corniculate cartilage of the larynx. The corniculate cartilages are also known as the cartilages of Santorini. The larynx consists of several cartilages, as well as lots of small muscles and a fibroelastic membrane. There are three pairs of small cartilages, and three large unpaired cartilages. The large unpaired cartilages include the cricoid cartilage, the thyroid cartilage and the epiglottis. The small paired cartilages include the arytenoid, the corniculate and the cuneiform cartilages. The corniculate cartilages are small cone shaped cartilages which sit on the apices of the arytenoid cartilages. Learn more about the …

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Corniculate Cartilage

Central Tendon of Diaphragm

Central Tendon of Diaphragm The structure indicated is the central tendon of the diaphragm. The diaphragm is a musculotendinous structure which seals the inferior thoracic aperture and separates the abdominal cavity from the thoracic cavity. When it contracts, it flattens, increasing the intrathoracic volume and thereby allowing air to enter the lungs. The central tendon is an aponeurosis which forms the top of the dome-shaped diaphragm. It blends with the fibrous pericardium above, helping to maintain it in place. The inferior vena cava passes through the central tendon at the level of the 8th vertebra.

Central Tendon of Diaphragm

Major alar cartilage

Major alar cartilage The structure indicated is the major alar cartilage (greater alar cartilage). The lateral walls of the external nose are comprised from three cartilages: Lateral process of septal cartilage Major alar cartilage Minor alar cartilage The major alar cartilage is located directly below the lateral process of the septal cartilage. It is structured such that it is bent in on itself to form both the medial and lateral walls of the nose. The crus laterale forms the lateral wall, whereas the crus mediale forms the medial wall.

Major Alar Cartilage

Internal Intercostal Muscle

Internal Intercostal Muscle The structure indicated is the internal intercostal muscle. The intercostal muscles are a set of three flat muscles which are located in each intercostal space. The three intercostal muscles, from superficial to deep are: External intercostal Internal intercostal Innermost intercostal Origin: Lateral edge of costal groove of rib directly above Insertion: Superiorly on rib directly below Innervation: Intercostal nerves (T1 – T11) Action: Forced expiration, movement of ribs inferiorly The muscle fibres of the internal intercostal muscles pass obliquely in the opposite direction to the external intercostal muscles, whose fibres pass anteroinferiorly (when the thoracic wall is viewed …

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Internal Intercostal

Right Main Bronchus

Right Main Bronchus The structure indicated is the right main bronchus. The trachea divides into two main bronchi – the right main bronchus and the left main bronchus (also referred to as primary bronchi). The trachea divides at the level of the sternal angle and the point at which it bifurcates is known as the carina – a cartilaginous ridge which runs between the left and right main bronchi. The main bronchi then divide into smaller and smaller airways in the following sequence: Lobar bronchi (secondary bronchi) Segmental bronchi (tertiary bronchi) Bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar sacs …

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Right Main Bronchus

Arytenoid Cartilage

Arytenoid Cartilage The cartilage highlighted in yellow is the arytenoid cartilage of the larynx. The larynx consists of several cartilages, as well as lots of small muscles and a fibroelastic membrane. There are three pairs of small cartilages, and three large unpaired cartilages. The large unpaired cartilages include the cricoid cartilage, the thyroid cartilage and the epiglottis. The small paired cartilages include the arytenoid, the corniculate and the cuneiform cartilages. The arytenoid cartilages are shaped like little pyramids and consist of three surfaces: Posterior surface Antero-lateral surface Medial surface The arytenoid cartilage has a broad base which articulates with the …

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Arytenoid Cartilage

Middle Lobe of Right Lung

Middle Lobe of Right Lung The right lung consists of three lobes: superior lobe inferior lobe middle lobe. These lobes are separated by two fissures, known as the oblique fissure and the horizontal fissure. The oblique fissure separates the middle and inferior lobes, whereas the horizontal fissure separates the superior and middle lobes. Pictured here is the middle lobe of the right lung. The left lung, on the other hand only has two lobes separated by one fissure. The superior lobe is separated from the inferior lobe by the oblique fissure. Learn more about the respiratory system in this tutorial.

Middle lobe of right lung