lab hand outs respiratory system

RAK COLLEGE OF MEDICAL SCIENCESDEPARTMENT OF ANATOMYGROSS ANATOMY DISSECTION LAB HAND OUTS- RESPIRATORY SYSTEM

1. PARTS OF NOSE

2. STRUCTURES ON LATERAL WALL OF NOSE

The nasal cavity• = the internal portion of the nasal region• Opens into the nasopharynx via the internal nares• Drains mucus from the Para nasal sinuses and tears from the nasolacrimal

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Ducts• Is divided in half midsagittally by the nasal septum, which is made up ofCartilage and bones (the perpendicular plate of the ethmoid and theVomer)• Its walls have 3 pairs of nasal conchae (superior, middle, and inferior).

3. NASOPHARYNX

The pharynx (throat)• = a common passageway for air and Food• Extends from the internal nares to the Junction of the esophagus and larynx• Has 3 regions:– 1. The nasopharynx (respiratory only) – from the internal nares to the uvula of the soft palate• It’s lined with PCCE

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• It contains the pharyngeal tonsil (adenoid) and the openings of the auditory (Eustachian) tubes– 2. The oropharynx (respiratory and digestive) – from the uvula of the soft palate to the base of the tongue (or tip of the epiglottis)• It’s lined with stratified squamous epithelium• It contains the palatine and lingual tonsils– 3. The laryngopharynx (respiratory and digestive) –from the base of the tongue (or tip of the epiglottis) to the junction of the esophagus and larynx.

The larynx (“voice box”)• Connects the laryngopharynx with the trachea• Is formed by 9 pieces of cartilage and some connecting ligaments and muscles• The vocal folds and above are covered with stratified squamous epithelium• Inferior to the vocal folds is covered with respiratory epithelium (PCCE)• Epiglottis = an elastic cartilage plate that closes off the glottis (= the superior opening of the larynx) during swallowing.

• The vestibular folds close off the glottis during breath holding, lifting heavy objects, etc.• The vocal folds = the vocal cords,– Contain elastic fibers– Vibrate to produce speech sounds– Are attached anteriorly to the thyroid cartilage– Are attached posteriorly to the arytenoid cartilages.

The trachea (“windpipe”)= a short (4-5”) tube that carries air between the larynx and the junction of the primary bronchi.

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The trachea divides at the sternal angle/T 4 vertebra into two primary bronchi, which enters the hilum of lungs and further divides into secondary bronchi or lobar bronchi. Each lobar bronchus further divides in to tertiary bronchi/bronchopulmonary segmental bronchi. There are ten BP SEGMENTS in both lungs.

Left Lung

Superior (upper) lobe:

1. Apical 2. Posterior

3. Anterior .

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4. Superior lingular

5. Inferior lingular

Inferior (lower) lobe:

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6. Superior (apical) …………

7. Medial basal ………. .

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8. Anterior basal ……

9. Lateral basal …. .

10. Posterior basal ……

Right Lung

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Superior (upper) lobe:

1. Apical 2. Posterior 3. Anterior

Middle lobe

4. Lateral 5. Medial

Inferior (lower) lobe:

6. Superior (apical) 7. Medial basal 8. Anterior basal 9. Lateral basal 10. Posterior basal

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The pleura• Each lung is surrounded by the pleura (= a double-layered serous membrane):– 1. The parietal pleura lines the inside of the thoracic cavity– 2. The visceral pleura cover the surface of the lungs• The ultra-thin pleural cavity is between the two layers and contains pleural fluid, which…– Reduces the friction between layers during the movements of ventilation– Causes the layers to adhere to one another, preventing the collapse of the lung.

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RESPIRATORY MUSCLES

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Each lung has an apex, base, and hilum (hilus)

The Apex of the Lung

The rounded, tapered superior end or apex of the lung extends through the superior thoracic aperture into the root of the neck. It lies in close contact to the dome or the copula of the pleura. The apex of the lung is crossed by the subclavian artery, which produces a groove in the mediastinal surface. The artery, however, is separated from the copula by the suprapleural membrane.

The Base of the Lung

This is the concave diaphragmatic surface of the lung, which is related to the dome of the diaphragm. The base of the right lung is deeper because the right dome rises to a more superior level. Its inferior border is thin and sharp where it enters the cost diaphragmatic recess.

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The Root of the Lung

The root serves as the attachment of the lung and is the "highway" for the transmission of the structures entering and leaving the lung at the hilum. It connects the medial surface of the lung to the heart and trachea and is surrounded by the reflection of parietal to visceral pleura.

The Hilum of the Lung

This is the where the root is attached to the lung. It contains the main bronchus, pulmonary vessels (one artery and two veins), bronchial vessels, lymph vessels, and nerves entering and leaving the lung.

The Main Differences between the Right and Left Lungs

1. The right lung has 3 lobes while the left has 2 lobes. 2. The right lung is larger and heavier than the left lung, but is shorter and wider because the

right dome of the diaphragm is higher and the heart and pericardium bulge more to the left.

3. The anterior margin of the right lung is straight, whereas the margin of the left lung has a deep cardiac notch.

4. The right main bronchus is wider, shorter and more vertical (significant in inhaled obstructions) than the left one.

Lobes and Fissures of the Lungs

The Left Lung

This is divided into superior (upper) and inferior (lower) lobes by a long deep oblique fissure. This extends from its costal to its medial surface. The superior lobe has a large cardiac notch on its anterior border, where the lung is deficient owing to the bulge of the heart. The anteroinferior part of the superior lobe has a small tongue-like projection called the lingula. The inferior lobe of the left lung is larger than the superior lobe and lies inferoposterior to the oblique fissure.

The Right Lung

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This is divided into superior (upper), middle, and inferior (lower) lobes by horizontal and oblique fissures. The horizontal fissure separates the superior and middle lobes. The oblique fissure separates the inferior lobe from the superior and middle lobes. The superior lobe is smaller than in the left lung, and the middle lobe is wedge-shaped.

Surfaces of the Lung

The Costal Surface of the Lung

This surface is large, smooth, and convex. It is related to the costal pleura, which separates it from the ribs, their costal cartilages, and the innermost intercostal muscles. The posterior part of this surface is related to the thoracic vertebrae.

The Mediastinal Surface

This medial surface is concave because it is related to the middle mediastinum. Because 2/3 of the heart is to the left, the pericardial concavity is deeper in the left lung. The mediastinal surface of the embalmed lung shows a cardiac impression produced by the heart and the great vessels. This surface also contains the root of the lung, around which the pleura forms a "sleeve" or covering. The pulmonary ligament hangs inferiorly from the pleural sleeve around the root of the lung.

The Diaphragmatic Surface

This is a deeply concave surface, often referred to as the base of the lung. It rests on the convex dome of the diaphragm. The concavity is deeper in the right lung because of the higher position of the dome. Laterally and posteriorly, the diaphragmatic surface is bound by a thin sharp margin that projects into the cost diaphragmatic recess.

Borders of the Lungs

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The Anterior Border of the Lung

This border is thin and sharp and overlaps the pericardium. There is an indentation in the anterior border of the left lung (cardiac notch). In each lung, the anterior border separates the costal surface from the mediastinal surface. During deep inspiration, the lung projects into the costomediastinal recess of the pleura.

The Posterior Border of the Lung

This border is broad and rounded and lies in the deep concavity at the side of the thoracic region of the vertebral column, called the paravertebral gutter.

The Inferior Border of the Lung

This border circumscribes the diaphragmatic surface from the costal surface. It is thin and sharp where it projects into the costodiaphragmatic recess. It is, however, blunt and rounded medially, where it separates the diaphragmatic surface from the mediastinal surface.

Surface Markings of the Lungs

Apex of the Lung

This is represented by a line drawn superolaterally from the sternoclavicular joint to a point 2.5 cm superior to the medial 1/3 of the clavicle and then inferolaterally to the junction of the middle and lateral thirds of the clavicle.

Anterior Border of the Right Lung

This corresponds to the anterior border of the right pleura. Between the level of the 2nd and 4th cartilages, its anterior border is near the median plane. Inferior to the 4th costal cartilage, the surface of the right lung gradually diverges from this plane and leaves the sternum posterior to the 6th costal cartilage.

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The Anterior Border of the Left Lung

This corresponds to the anterior border of the left pleura as far as the level of the 4th costal cartilage. Here, the anterior border deviates laterally to a point about 2.5 cm lateral to the left edge of the sternum to form the cardiac notch. It then turns inferiorly and slightly medially to the 6th costal cartilage.

The Inferior Borders of the Lungs

These are indicated by a line drawn from the inferior end of the line representing the anterior border that crosses the 6th rib at the midclavicular line, the 8th rib in the midaxillary line and the 10th rib in the midscapular line. These borders end about 2.5 cm lateral to the spinous process of T10 vertebra. They lie two ribs superior to the pleura on each of three vertical lines just mentioned.

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lab hand outs respiratory system

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