Organs Respiratory

R Frontal Sinus

The size and shape of the frontal sinus can vary from person to person. These spaces fill up with mucus, which then drain into the nose. The draining process can be hindered by blockages. If mucus accumulates, this can cause infections. Bacterial or viral infections are typically located in the frontal or paranasal sinus. Infections can lead to inflammation of the frontal sinus, called sinusitis. Source

R Ethmoid Air Cells 4

The ethmoidal air cells receive sensory fibers from the anterior and posterior ethmoidal nerves, and the orbital branches of the pterygopalatine ganglion, which carry the postganglionic parasympathetic nerve fibers for mucous secretion from the facial nerve. The groups of the ethmoidal cells are air cells: The posterior group (sometimes the posterior ethmoidal sinus) drains into the superior meatus above the middle nasal concha, sometimes one or more opens into the sphenoidal sinus. The middle group (sometimes the middle ethmoidal sinus) drains into the middle meatus of the nose on or above the bulla ethmoidalis. The anterior group (sometimes the anterior ethmoidal sinus) drains into the middle meatus of the nose by way of the infundibulum. Ethmoidal air cells of the ethmoid bone are one of the four paired paranasal sinuses. They are a variable in both size and number of small cavities in the lateral mass of each of the ethmoid bones and cannot be palpated during an extraoral examination. form one of the four pairs of paranasal sinuses. They are located within the single, midline ethmoid bone. They are present at birth, and they develop rapidly from 0-4-year-old, they further mature from 8-12-year-old during puberty. Source

R Ethmoid Air Cells 1

R Ethmoid Air Cells 3

R Ethmoid Air Cells 2

R Sphenoid Sinus

Sinuses are air-filled sacs (empty spaces) on either side of the nasal cavity that filter and clean the air breathed through the nose and lighten the bones of the skull. There are four paired sinuses in the head. The most posterior (farthest toward the back of the head) of these is the sphenoid sinus. Like the nasal cavity, the sinuses are all lined with mucus. The mucus secretions produced in the sinuses are continually being swept into the nose by the hair-like structures on the surface of the respiratory membrane (lung lining tissues). This serves to moisten the air we breathe through our noses. The hollow sinuses also act to lighten the bones of the skull and serve as resonating chambers for speech. Sphenoid sinuses are just behind the skull, above the nasopharynx and just below the pituitary gland. its contained within the body of the sphenoid. They vary in size and shape and owing to the lateral displacement of the intervening septum they are rarely symmetrical. They cannot be palpated during an extraoral examination. Source

R Eustachian Tube

The eustachian tube is a canal that connects the middle ear to the nasopharynx, which consists of the upper throat and the back of the nasal cavity. It controls the pressure within the middle ear, making it equal with the air pressure outside the body. Most of the time the eustachian tube is closed, opening only during activities such as yawning, swallowing, and chewing, to allow air through the passage between the middle ear and nasopharynx. When atmospheric pressure changes rapidly, causing a sudden feeling of blockage in the ear (such as during airplane travel), these activities can be done on purpose to open the tube and equalize the pressure within the middle ear. When the eustachian tube will not open enough to equalize pressure, symptoms such as discomfort, dizziness, or ringing in the ear may result. Visual examination of the eardrum with a lighted scope helps to determine if the cause is inflammation, swelling, or fluid in the ear. Conditions such as nasal congestion, infection of the ear or sinus, or allergies may cause these symptoms and lead to eustachian tube problems. These causes can often be treated with decongestant medication or antibiotics, but in severe cases, surgery may be necessary. Source

R Maxillary Sinus Duct

The pyramid-shaped maxillary sinus (or antrum of Highmore) is the largest of the paranasal sinuses, and drains into the middle meatus of the nose. It is the largest air sinus in the body. Found in the body of the maxilla, this sinus has three recesses: an alveolar recess pointed inferiorly, bounded by the alveolar process of the maxilla, a zygomatic recess pointed laterally, bounded by the zygomatic bone, and an infraorbital recess pointed superiorly, bounded by the inferior orbital surface of the maxilla. The medial wall is composed primarily of cartilage. The ostia for drainage are located high on the medial wall and open into the semilunar hiatus of the lateral nasal cavity, because of the position of the ostia, gravity cannot drain the maxillary sinus contents when the head is erect (see pathology).

R Maxillary Sinus

The pyramid-shaped maxillary sinus is the largest of the paranasal sinuses, and drains into the middle meatus of the nose. It is the largest air sinus in the body. Found in the body of the maxilla, this sinus has three recesses: an alveolar recess pointed inferiorly, bounded by the alveolar process of the maxilla, a zygomatic recess pointed laterally, bounded by the zygomatic bone, and an infraorbital recess pointed superiorly, bounded by the inferior orbital surface of the maxilla.

Nasopharynx

The nasopharynx is, by definition, the upper part of the throat behind the nose. It is a part of the pharynx, which comprises three separate segments: the nasopharynx, oropharynx, and the hypopharynx. The nasopharynx is 2 to 3 cm wide and 3 to 4 cm long and situated behind the nasal fossa inside the occipital bone. The nasopharynx is the space above the soft palate at the back of the nose and connects the nose to the mouth, which allows a person to breathe through the nose. The soft palate separates the nasopharynx from the oropharynx, which sits just below the soft palate. The nasopharynx remains open even when surrounding muscles flex so that the person can continue to carry on respiratory functions. The nasopharynx is surrounded by the salpingopharyngeal fold and tubal tonsils, which can become inflamed when infected. It contains adenoid tissue, which fights infection, and the openings to the Eustachian tubes, which lead to the ears. It provides a major drainage path for lymphatic fluids and generally drains into the throat, nose or ears. Source

Adenoids

Adenoids are a patch of tissue that is high up in the throat, just behind the nose. They, along with the tonsils, are part of the lymphatic system. The lymphatic system clears away infection and keeps body fluids in balance. The adenoids and tonsils work by trapping germs coming in through the mouth and nose. Source

Trachea

The trachea (or windpipe) is a wide, hollow tube that connects the larynx (or voice box) to the bronchi of the lungs. It is an integral part of the body’s airway and has the vital function of providing air flow to and from the lungs for respiration. The trachea begins at the inferior end of the larynx in the base of the neck. It is located along the body’s midline, anterior to the esophagus and just deep to the skin, so that it is possible to feel the larynx through the skin of the neck. From its origin at the larynx, the trachea extends inferiorly into the thorax posterior to the sternum. In the thorax, the trachea ends where it splits into the left and right bronchi, which continue onward toward the lungs. Viewed in cross section, the trachea is about one inch (2.6 cm) in diameter. It has a thin, membranous wall with C-shaped rings of cartilage embedded into it. Between sixteen and twenty cartilage rings are stacked along the length of the trachea, with narrow membranous regions spaced between the cartilage rings. The open ends of the cartilage rings face the posterior of the trachea near the esophagus.

Four layers of tissues make up the walls of the trachea: The mucosa is the innermost layer and consists of ciliated pseudostratified columnar epithelium with many goblet cells. Goblet cells produce sticky mucus to coat the inner lining of the trachea and catch any debris present in inhaled air before it reaches the lungs. On the surface of the columnar cells, long, hair-like cilia beat together to push mucous away from the lungs like a microscopic conveyor belt. Mucus from the trachea, along with any trapped contaminants, makes its way to the larynx, where it is either expelled during coughing or swallowed and digested in the stomach. Deep to the mucosa is the submucosa layer, which is made of areolar connective tissue containing blood vessels and nervous tissue. Many collagen, elastin and reticular protein fibers give soft support and elasticity to the wall of the trachea, while blood vessels and nerves support the other layers of the tracheal wall. Longitudinal smooth muscle fibers are present in the posterior trachea between the ends of the cartilage rings. This smooth muscle tissue allows the trachea to adjust its diameter as needed. Surrounding the submucosa is a layer of hyaline cartilage that forms the supportive rings of the trachea. Hyaline provides a strong, yet flexible structure that maintains an open airway and is resistant to external stresses. The outermost layer of the trachea is the adventitia, a layer of areolar connective tissue that loosely anchors the trachea to the surrounding soft tissues. While the trachea plays a vital role as a passive air passageway, it also performs several other important functions as well. The trachealis muscle in the posterior wall allows the trachea to contract and reduce its diameter, which makes coughs more forceful and productive. During the process of swallowing food, the esophagus expands into the space normally occupied by the trachea. The incomplete cartilage rings of the trachea allow it to narrow and permit the esophagus to expand into its space. Finally, the loose connection of the adventitia allows the trachea to move within the neck and thorax, aiding the lungs in their expansion and contraction during breathing.

R Bronchus

Bronchi are the main passageway into the lungs. When someone takes a breath through their nose or mouth, the air travels into the larynx. The next step is through the trachea, which carries the air to the left and right bronchus. The bronchi become smaller the closer they get to the lung tissue and are then considered bronchioles. These passageways then evolve into tiny air sacs called alveoli, which is the site of oxygen and carbon dioxide exchange in the respiratory system. Primary bronchi are located in the upper portion of the lungs, with secondary bronchi near the center of the lungs. Tertiary bronchi are located near the bottom of these organs, just above the bronchioles. No gas exchanges occur in any of the bronchi. When the bronchi become swollen due to irritants or infection, bronchitis results and makes breathing more difficult. Bronchitis sufferers also tend to have much more mucus and phlegm than someone without inflamed bronchi. Source

Bronchial Tree

Together, the trachea and the two primary bronchi are referred to as the bronchial tree. At the end of the bronchial tree lie the alveolar ducts, the alveolar sacs, and the alveoli. The tubes that make up the bronchial tree perform the same function as the trachea: they distribute air to the lungs. The alveoli are responsible for the primary function of the lungs, which is exchanging carbon dioxide and oxygen. A layer of protective mucus, called a mucus blanket, covers a large portion of the membrane lining the bronchial tree. The mucus is an important air purifier. The average adult produces about 125 milliliters of mucus daily, which is slightly more than half a cup. Microscopic, hair-like cilia move the cleansing mucus up to the pharynx—part of the throat between the mouth and esophagus—from the lower part of the bronchial tree. Cigarette smoke paralyzes the cilia, which allows mucus to accumulate and leads to what is called smoker’s cough. Source

R Lung

The human lungs are a pair of large, spongy organs optimized for gas exchange between our blood and the air. Our bodies require oxygen in order to survive. The lungs provide us with that vital oxygen while also removing carbon dioxide before it can reach hazardous levels. If the inner surface of the lungs could be stretched out flat, they would occupy an area of around 80 to 100 square meters — about the size of half of a tennis court! The lungs also provide us with the air we need in order to speak, laugh at jokes, and sing. The pleura are double-layered serous membranes that surround each lung. Attached to the wall of the thoracic cavity, the parietal pleura forms the outer layer of the membrane. The visceral pleura forms the inner layer of the membrane covering the outside surface of the lungs. Between the parietal and visceral pleura is the pleural cavity, which creates a hollow space for the lungs to expand into during inhalation. Serous fluid secreted by the pleural membranes lubricates the inside of the pleural cavity to prevent irritation to the lungs during breathing. Source

L Pleura

Therefore, in cases of pneumothorax, the other lung will still function normally unless there is a tension pneumothorax or simultaneous bilateral pneumothorax, which may collapse the contralateral parenchyma, blood vessels and bronchi. The visceral pleura receives its blood supply from the bronchial circulation, which also supplies the lungs. The parietal pleura receives its blood supply from the intercostal arteries, which also supply the overlying body wall. The pleural cavity, with its associated pleurae, aids optimal functioning of the lungs during breathing. The pleural cavity also contains pleural fluid, which acts as a lubricant and allows the pleurae to slide effortlessly against each other during respiratory movements. Sou rce

L Eustachian Tube

L Ethmoid Air Cells 4

L Ethmoid Air Cells 3

L Ethmoid Air Cells 2

L Ethmoid Air Cells 1

L Sphenoid Sinus

L Maxillary Sinus Duct

L Maxillary Sinus

L Frontal Sinus

Pharynx

The pharynx has roles in both the respiratory and digestive systems, and can be thought of as the point where these systems diverge. While food and liquids will follow the alimentary canal through the esophagus, the air we breathe in through that common entry point will enter the trachea and follow into the respiratory system.

The pharynx’s respiratory role is mainly to allow inhaled air entering the nasal cavity to make its way to the respiratory tract – which includes the larynx, the trachea or “windpipe” and finally the lungs’ bronchioles and alveoli where respiration takes place. This is made possible by the “isthmus” or structural common-space that connects the oral and nasal pharyngeal areas so that we are able to breathe through our mouths and noses. The pharynx has an equally big digestive role thanks to its muscles. The constrictive circular muscles of the pharynx’s outer layer play a big role in peristalsis. A series of contractions will help propel ingested food and drink down the intestinal tract safely. The inner layer’s longitudinal muscles, on the other hand, will widen the pharynx laterally and lift it upward, thus allowing the swallowing of ingested food and drink. An interesting role the pharynx also plays is in projecting speech. Sound is made possible by the passage of vibrations through air. The pharynx provides a nice enclosed space that will allow speech muscles to initiate sound and resonate it so that it projects even better. Source

L Bronchus

L Lung

L Pleura

The pleural cavity is the thin fluid-filled space between the two pulmonary pleurae (known as visceral and parietal) of each lung. A pleura is a serous membrane which folds back onto itself to form a two-layered membranous pleural sac. The outer pleura (parietal pleura) is attached to the chest wall, but is separated from it by the endothoracic fascia. The inner pleura (visceral pleura) covers the lungs and adjoining structures, including blood vessels, bronchi and nerves. The pleural cavity can be viewed as a potential space because the two pleurae adhere to each other (through the thin film of serous liquid) under all normal conditions. The pleura, pericardium and peritoneum are membranes that encapsulate major organs of the body. The pleura, the lungs, the pericardium the heart and the peritoneum the digestive organs. The Pleura are membranes of the thoracic cavity. There are two pleura, the parietal and the visceral. The parietal pleura lines the inner surface of the thoracic cavity and ribcage. The visceral pleura line the lungs. The pleura secrete a fluid that fills the pleural space between the lungs and ribcage to reduce the friction created by the movement of the lungs during inhalation and exhalation. In humans, there is no anatomical connection between the left and right pleural cavities. Therefore, in cases of pneumothorax, the other lung will still function normally unless there is a tension pneumothorax or simultaneous bilateral pneumothorax, which may collapse the contralateral parenchyma, blood vessels and bronchi. The visceral pleura receives its blood supply from the bronchial circulation, which also supplies the lungs. The parietal pleura receives its blood supply from the intercostal arteries, which also supply the overlying body wall. The pleural cavity, with its associated pleurae, aids optimal functioning of the lungs during breathing. The pleural cavity also contains pleural fluid, which acts as a lubricant and allows the pleurae to slide effortlessly against each other during respiratory movements. Sou rce