Anatomy Respiratory System Videos

Question 1

What is the laryngeal prominence?

Answer 1

The Adams Apple

This is formed by the fusion of the two thyroid cartilage.

Question 2

What is the cricoid cartilage?

Answer 2

Inferior to the laryngeal prominence.

The cricoid cartilage is a ring of cartilage that surrounds the trachea, or windpipe. It is located near the middle and center of the neck.

Question 3

What is the carina?

Answer 3

The v-shaped section of the trachea where it splits into the primary bronchi.

Question 4

How does the right main bronchus differ from the left?

Answer 4

it is broader

Question 5

What is the hiluem of the lung?

Answer 5

The hilum of the lung is where a number of structures enter into the lung. The right and left bronchi enter into the lungs. The pulmonary artery, most superiorly, enter and the pulmonary vein.

Question 6

Where is the apex of the lung located?

Answer 6

The apex of the lungs projects, 2 to 3 cm superior to the clavicle bone.

Question 7

What is the lingual?

Answer 7

The left lung, unlike the right does not have a middle lobe. However the term lingula is used to denote a projection of the upper lobe of the left lung that serves as the homologue.

Question 8

What is the root of the lung?

Answer 8

This is found just above the middle of the mediastinal surface and behind the cardiac impression of the lung. The root of the lung is where the structures enter and leave the mediastinum. The hilum is where structures enter and leave the lung itself.

Question 9

What is the pulmonary ligament?

Answer 9

There is an extension following to the end of the hilum, known as the pulmonary ligament and is a reflection of the pleura. This resides at the inferior aspect of the hilum of the lung. Some of the large structures such as the aorta, leave impressions on the lung.

Question 10

What is the costodiaphragmatic recess?

Answer 10

The pleura cavity is enlarged between the diaphragm and the lung, there is a potential space known as a costodiaphragmatic recess. This means the lung can expand further during forced inspiration. There is also a mediastinal recess.

Question 11

Why is the first rib not palpable?

Answer 11

It lies just inferior to the clavicle bone.

Question 12

How do the ribs articulate with the vertebrae?

Answer 12

The tubercle of the rib articulates with the facet located on the transverse process of the same numbered vertebrae (costal facets).

The head of the rib fits into small depressions located on the centrum of the adjacent vertebrae known as demifacets through their articular facets. The tubercle articulates with the costal facet, located on the transverse process of the more posterior vertebra, and the ribs angle posteriorly at the point of articulation.

Question 13

What is the pectoralis major?

Answer 13

The pectoralis major is the first muscle after you remove the skin on the anterior wall. The pectoralis major articulates with the humorous, the clavicle and the sternum. There is a sternal part if the pectoralis major and a clavicular head.

Question 14

What is the pectoralis minor?

Answer 14

The pectoralis minor is a thin, flat muscle found immediately underneath the pectoralis major. This is the smaller of the two pectoral muscles. It is bound to the scapula and the ribs.

Question 15

What is the serrates anteior?

Answer 15

A muscle that attaches to the lateral edges of the ribs.

Question 16

What are accessory muscles?

Answer 16

Muscles not usually involved in respiration. The primary function of the serrates anterior, pectoralis minor and pectoralis major is upper limb action. During respiratory distress, the muscles contract to elevate the thoracic cage during inspiration.

Question 17

Which muscle lies in a different configuration within the intercostal muscule?

Answer 17

The exterior intercostal muscle.

Question 18

Which plane does the external intercostal muscles lie?

Answer 18

Lies infero-medially.

Question 19

Where does the external intercostal muscle become the external intercostal membrane?

Answer 19

The costal cartilage

Question 20

Where does the intercostal veins drain into?

Answer 20

The azygous system which will eventually drain into the superior vena cava.

Question 21

Which vessel supplies the internal thoracic artery?

Answer 21

The subclavian artery

Question 22

Which vessel gives rise to the posterior intercostal artery?

Answer 22

The aorta

Question 23

Which vessel gives rise to the anterior intercostal artery?

Answer 23

The internal intercostal artery. This artery is found on the anterior aspect lateral to the sternum.

Question 24

What is found inferior to the nasal cavity?

Answer 24

The hard and soft palette.

Question 25

What is the function of the Eustachian tube?

Answer 25

This is an opening of our auditory tube. This runs from the pharynx to the eardrum and means the pressure in the eardrum can be equalised across the tympanic membrane.

Question 26

What are the aryepiglottic folds?

Answer 26

The aryepiglottic fold forms a part of the laryngeal inlet.
TheAryepiglottic foldsare triangularfoldsof mucous membrane enclosing ligamentous and muscular fibres. They are located at the entrance of the larynx, extending from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name ‘aryepiglottic’.

Question 27

Where is resistance to airflow greatest in the lungs?

Answer 27

In the larger airways. This is as in the smaller airways, the cross-sectional area increases as many of the smaller airways are in parallel and so resistance decreases.

Question 28

What causes inspiration?

Answer 28

During normal, quiet respiration, the diaphragm contracts and moves downwards in inspiration and the diaphragmatic parietal pleura descends. This movement pulls down the visceral pleura so that the airways and alveoli expand and air is sucked in. The diaphragm relaxes in expiration and the recoil of the elastic tissues in the lung expels air from the alveoli and airways. Movement of the ribcage also contributes to respiration by increasing the diameter of the chest, thereby increasing the thoracic volume and making the negative pressure in the lungs more ‘negative’, allowing air to be sucked in. The joints between the posterior ends of the ribs and the transverse processes of the vertebrae enable the lower ribs to swivel upwards and outwards to increase the lateral diameter of the chest, while the anterior ends of the ribs move up and out to increase the anteroposterior diameter. The diaphragmatic movement contributes about 75% and movement of the ribcage contributes 25% to the increase in thoracic volume.

Question 29

What is Pulmonary diffusion capacity?

Answer 29

Pulmonary diffusion capacity is the ability of the lungs to transfer a gas, usually oxygen (O2), or carbon dioxide (CO2), across the alveolar-capillary membrane.

Question 30

What are normal values for pulmonary diffusion capacity at rest and after exercise?

Answer 30

Ø The diffusing capacity for both oxygen (DLO2) and carbon dioxide (DLCO2) is difficult to measure, and therefore not often used clinically.
Ø The single breath carbon monoxide (CO) diffusion test is the more usual test of pulmonary diffusion capacity.
Ø Interpretation of DLCO needs to be in the context of other clinical and physiological findings.
Ø Values for oxygen diffusion capacity at rest vary between 15 mL/min/mmHg and 35 mL/min/mmHg. The average is about 20 mL/min/mmHg.
Ø Diffusion capacity is increased in exercise, to values of 65 mL/min/mmHg or more, presumably due to dilatation of the capillaries and opening up of the closed capillary bed in the lung apex.
Ø In disease, diffusion capacity is reduced. Thickening of the alveolar-capillary interface can occur in scleroderma, asbestosis, pulmonary fibrosis, pulmonary oedema and sarcoidosis. Reduction of the area of the alveolar-capillary interface may occur through emphysema or surgery.

Question 31

What is Bronchiectasis?

Answer 31

Bronchiectasis is the condition of permanently dilated bronchi with chronic infection. It is most commonly caused by severe respiratory infection (often in childhood) leading to permanently dilated bronchi, although it can also be caused by congenital abnormalities of the cilia which reduce the removal of mucus from the lungs.

Question 32

What is atelectasis?

Answer 32

Atelectasis is a failure of the lungs to expand. This is most commonly caused, whether acutely by foreign bodies or chronically by tumours, when complete obstruction of the airways prevents air inflating the alveoli. Air in this distal region is absorbed and the alveoli collapse. Secretions then accumulate and may become infected. If the lung remains collapsed, irreversible fibrosis occurs. Atelectasis may also be caused when compression, for example due to pleural effusion or pneumothorax, opposes inflation.

Question 33

How do accessory muscles assist ventilation?

Answer 33

The external intercostal muscles move the ribcage upwards and outwards to increase the lateral and antero-posterior diameter of the thorax. The neck muscles pull the ribcage upwards; the sternocleidomastoids will elevate the sternum while the scalenes major and minor muscles will elevate both the first two ribs and the sternum. The oblique, transversus and rectus abdominis muscles will pull the ribcage downwards. By fixing the shoulder girdle, the pectoralis major and latissimus doors muscles will pull the ribcage outwards. These muscles can be seen hard at work in patients with respiratory distress as in acute asthma, and in athletes at the end of a hard race.

Question 34

What is the difference between intrinsic and extrinsic pulmonary disease?

Answer 34

ntrinsic lung disease, when lung tissue (parenchyma) is destroyed, which reduces lung volume. In acute situations, the air spaces become filled with inflammatory exudates and debris. Chronic inflammation with scarring and fibrosis (interstitial fibrosis) destroys air spaces, thereby reducing lung volume. Large parts of the lung parenchyma cannot function for gaseous exchange.
Ø Extrinsic disorders of the muscles of respiration, the chest walls, connective tissue, pleura or the nerve supply that impair movement during inspiration. The inability of the chest to expand for whatever reason mechanically restricts ventilation, and respiratory failure ensues.

Question 35

How does the position of the diaphragm vary with posture? What is the significance of this?

Answer 35

The position of the diaphragm varies with body posture. In an upright posture, the abdominal contents sink under gravity as does the diaphragm. The diaphragm also flattens out, increasing its cross-sectional area. Thus, in the upright posture, the diaphragmatic movement required to achieve expansion of the thoracic cavity is smaller than that required to achieve the same expansion in the supine posture, when the diaphragm is more dome-shaped. This explains why patients with respiratory diseases, particularly those involving respiratory muscle fatigue, prefer an upright posture.

Question 36

What are triggers to Bronchospasm?

Answer 36

Typically, all asthma patients with active disease have hyper-responsive (hyper-reactive) airways. Bronchomotor tone is mainly under control of the parasympathetic system. Bronchial constriction is mediated by efferents from the vagus to ganglia in the walls of the small bronchi, from which short postganglionic fibres lead to nerve endings which release acetylcholine to act on muscarinic receptors in the bronchial smooth muscle, causing bronchoconstriction. Many different triggers can cause bronchospasm. Stimulants include:
Ø Noxious substances such as cigarette smoke, atmospheric pollution, some occupational sensitizers and chemicals, particles (including nebulised water), cold air and exercise
Ø Histamine, released from mast cells, which affects the parasympathetic system and has a direct action on airway smooth muscle
Ø Non-adrenergic non-cholinergic fibres that pass to bronchial smooth muscle can also cause constriction by releasing vasoactive intestinal polypeptide.
Ø Some classes of drugs, such as non-steroidal anti-inflammatory drugs (notably aspirin) and β-adrenoceptor blocking drugs.
Many inflammatory mediators are found in the airway secretions of patients with asthma, causing mucus secretion, bronchoconstriction and gaps in the capillary endothelium. Leakage of protein into the interstitium leads to submucosal oedema, which narrows the lumen, increasing airway resistance, and contributes to bronchial hyper-responsiveness. Inflammatory mediators are released from mast cells, neutrophils and eosinophils.

Question 37

How does the pressure of liquids change when they vaporise? What is the significance of water?

Answer 37

When liquids vaporise they also contribute to the total pressure. But the vapours of liquids, for example water, exert partial pressures at different temperatures. Water vapour complicates the situation as its pressure is independent of barometric pressure, but dependent on temperature. So the partial pressure of gaseous components of humidified air must be reduced so that the total will equal barometric pressure less water vapour pressure. The vapour pressure of fully saturated air at 37 °C is 47 mmHg. In moist air at normal body temperature oxygen has a partial pressure of 0.21 × (760 - 47) or about 100 mmHg. Expired air is normally fully saturated with water at 37 °C. Inspired air may not be fully saturated and the pressure it exerts will be less than at full saturation. The saturation of inhaled air depends on humidity, which is in turn dependent on climatic conditions. Expired air also contains more carbon dioxide and less oxygen, the levels of which depend on alveolar ventilation.

Question 38

How do intrapleural and intrapulmonary pressure change with inspiration and expiration?

Answer 38

With expansion of the chest and the accompanying inflation of the lung, pressure within the alveoli of the lungs, the intrapulmonary pressure, falls to about 3 mmHg below the atmospheric pressure. As the lungs fill, this gradient decreases, and by the end of inspiration the intrapulmonary pressure equals atmospheric pressure. During expiration, intrapulmonary pressures become positive relative to atmospheric (+3 mmHg) but return to atmospheric pressure once expiration is complete. Intrapleural pressure refers to pressures within the pleural space, i.e. between the visceral and parietal pleural layers. These are normally subatmospheric (-4 mmHg) because of the elastic recoil of the lungs continually trying to separate the two layers. During normal breathing and movement of the diaphragm and ribcage, intrapleural pressures will fall or rise by about 5 mmHg relative to this subatmospheric pressure. A deep inspiration can drop the intrapleural pressures by as much as 30 mmHg below atmospheric. Intrapleural pressures can be measured by inserting the tip of a needle connected to a manometer into the pleural cavity. Less invasively, changes in intrapleural pressure can be measured by a balloon catheter in the oesophagus at the level of the mediastinum.

Question 39

What is physiological dead space?

Answer 39

Dead space is the volume of the respiratory tract not involved in gas exchange. The anatomical dead space lies between the mouth/nose entrance and the respiratory bronchioles where the tissue walls are too thick and blood vessels too few to allow diffusion of gases into the blood. Some air may also enter parts of the lungs where gaseous exchange is not fully efficient because these parts of the lungs are either relatively poorly perfused or relatively overventilated. The total volume of air not involved in oxygenation of blood is termed the physiological dead space and encompasses this and the anatomical dead space. In healthy people, the physiological dead space is identical to the anatomical dead space.

Question 40

How does flow-related collapse work?

Answer 40

Air may be trapped behind a collapsed conducting airway during expiration.
Ø Airways beyond generation 11 in the tracheobronchial tree have no cartilage and hence no structural rigidity and rely on the elastic recoil of the surrounding tissue to prevent collapse.
Ø When making a forced, rapid expiration, intrathoracic pressure must be raised well above atmospheric to generate the required flow rate.
Ø As air flows from the alveoli to the mouth, the pressure in the airway will drop due to airway resistance.
Ø Thus, at some point along the airway the forces maintaining airway patency matches the intrathoracic pressure, and the pressure across the airway wall (the transmural pressure) is zero.
Ø Further downstream, i.e. towards the mouth in expiration, the transmural pressure gradient is reversed and the airway collapses.
Ø This collapse is temporary, because the occlusion of the airway will increase the pressure behind it (i.e. upstream), raising the intra-airway pressure to open the airway again and restore airflow.
Ø This flow-related collapse during a forced expiration accounts for the brassy sound which is occasionally heard.
Ø A similar mechanism narrows large airways during coughing to increase the velocity and the scouring action by the rapidly moving exhaled air on the airway walls.

Question 41

What is a Chylothorax? How is this caused?

Answer 41

A chylothorax is lymph in the pleural cavity. It is caused when the thoracic duct ruptures. The thoracic duct is a duct that drains lymph from the lower half of the body and drains it into the area at which the subclavian and jugular vein merge to form the brachiocephalic vein.

Question 42

What structure compresses the oesophagus?

Answer 42

The left primary bronchus

Question 43

What is the azygous vein?

Answer 43

The azygous vein drains the posterior intercostal veins and empties them into the superior vena cava.

Question 44

What is the moderator band?

Answer 44

When there is an impulse from the SAN, AVD, Bundle of His and Purkinje fibres, just before the ventricles and ventricular systole, there are purkinje fibres in the moderator band that project to the papillary muscles. This happens milliseconds before ventricular systole. This is to cause the papillary muscles to contract and keep the tendinous chords taunt and keep the valve in place during ventricular systole.

Question 45

How many papillary muscles are in each ventricle?

Answer 45

There are three cusps in the tricuspid valves and so three papillary muscles. The same is true for the mitral valve in which there is only two papillary muscles.

Question 46

What is the aortic sinus>

Answer 46

At the aortic valves, there is the origin of the coronary valves known as the aortic sinus. This sinus is a gap between the aortic valve and the aortic wall. From two of the aortic sinus, there is the origins of the right and left coronary sinus.