Respiratory System PDF

Respiratory System By Prof. A. / Fatma A. Madkour  Respiratory system Functions of respiratory system: 1. Exchange of gases. 2. Improves and regulates the air. 3. Olfaction 4. Production of voice Respiratory system is formed of: 1-Air conducting part which i...

Respiratory System By Prof. A. / Fatma A. Madkour  Respiratory system Functions of respiratory system: 1. Exchange of gases. 2. Improves and regulates the air. 3. Olfaction 4. Production of voice Respiratory system is formed of: 1-Air conducting part which includes: Nose (Nostril and Nasal cavity) Nasopharynx Larynx Trachea conducting part of bronchial tree. 2-Respiratory part which includes: Respiratory part of bronchial tree. Alveoli. 3-Pumping apparatus which includes: Two pleural sacs. Skeleton and muscles of the thorax Diaphragm.  Nose -The nose in domestic animals does not project from the face as in human, but in dog and pig it protrudes to some extent from the face. The nostrils: Two openings in the apex of the nose lead to the nasal cavity. The nasal septum: is a partition between the nostrils dividing the nasal cavity into right and left halves. NS Its rostral portion is cartilaginous but its caudal portion is osseous. The nose of cat The wall of the nose consists of: 1. Skin externally. F 2. Supporting layer in the middle (cartilages rostrally and bones caudally). L N Z 3. Mucous membrane internally. M The bony support of the nose are: nasal, maxilla, incisive, frontal, lacrimal, zygomatic and prependricular part of palatine bone. I - Nasal muscles associated with bones and cartilages F N L Z M I  Nasal cartilages The most rostral part of the nasal cavity and nostrils are supported by nasal cartilages which include: 1- Dorsal and ventral lateral nasal cartilages: The rostral part of the nasal septum widens along its dorsal and ventral margins to form the dorsal and ventral lateral nasal cartilages. In the carnivores, pig, and ruminants : the two cartilages come together lateral to the nostril. In the horse : the dorsal cartilage does not project very far laterally, and the narrow ventral cartilage or may be absent. 2- Lateral accessory nasal cartilage: According to the species it is either connected to the dorsal lateral cartilage (ruminants) or to the ventral lateral cartilage (carnivores) or to the rostral bone (pig). It is absent in horse. 3- Medial accessory nasal cartilage: It lies inside the alar fold. It is small in all species except in horse it forms a large S-shaped structure. 4- Alar nasal cartilage: It is present only in equine. It attaches to the rostral border of the nasal septum, and supports the nostril dorsally, medially and ventrally. It consists of lamina dorsally and cornu ventrally.  Nostrils (rostral nares)  They are the external orifices of the nasal cavity.  The nostril has two commissures (dorsal & ventral) and two borders (medial and lateral).  It varies in form, size and position in domestic animals.  Nostril is surrounded by an area of modified skin which varies according to the species : In carnivores and small ruminants: the modified skin is confined to the nostrils and forms planum nasale. In pig and ox: this area fuses centrally with upper lip and forms in pig planum rostrale (part of snout or rostrum) and upper lip in ox planum nasolabialis (muzzle). In horse: this area is normal skin covered with a coat of short hairs interspersed with tactile hair. N.B.:- This area of modified skin is divided by fine grooves into small polygonal areas which remain unchanged throughout life and is species specific. In the horse: The alar fold which ends in the dorsal part of nostril forms a horizontal shelf which divides the nostril into dorsal and ventral passages. The dorsal passage leads to a blind cutaneous pouch, the nasal diverticulum (false nostril), while the ventral passage leads into the nasal cavity proper.(during sever exercise, added skin of pouch opens up to expanded nostril, intake air)  Nasal Cavity  It is divided into right and left halves by the nasal septum.  Each nasal cavity opens externally by the nostrils (rostral nares) and communicates caudoventrally with the nasopharynx through the choanae (caudal nares).  It also communicates with paranasal sinuses.  Boundaries of nasal cavity: 1. Dorsal boundary (roof): by frontal and nasal bones. 2. Ventral boundary (floor): by palatine process of incisive and maxillary bones. It separates nasal cavity from oral cavity. 3. Lateral boundaries: by nasal surface of maxilla and incisive bone. 4. Medial boundary: by nasal septum and bony part of vomer and ethmoid which support this septum. F.B N.B P.P H.P  Divisions of nasal cavity: The nasal cavity is divided rostrocaudally into: 1-The nasal vestibule: - It is the rostral part of the nasal cavity. - It is lined with a cutaneous mucous membrane. 2-The nasal cavity proper (respiratory part): - It is the middle and largest part. - It is characterized by presence of nasal conchae. - It is lined with respiratory mucous membrane. 3-Nasal fundus (olfactory part): - It is the caudal part, occupied dorsally by ethmoidal conchae and ventrally communicated with the nasopharynx through caudal nares. - It is lined with olfactory mucous membrane.(Ol.S.N, B, S, Br. cells)  Nasal Conchae Definition: The nasal concha is thin osseous scrolls (called turbinate bone) covered on both sides with respiratory mucous membrane. Formation: = Each concha consists of: A- Basal lamella: - It is attached to the lateral wall of the nasal cavity. - It projects medially like a shelf. - It is continued by one, two or rarely more spiral lamellae which roll up on themselves and form the scrolls. B- The spiral lamella: =It has one or all the followings: 1- It rolls on itself termed recess. 2- Its free border forms a closed round elevation termed bulla. 3- It may fuse with the basal lamella or with the bones of the skull forming conchal sinus which communicates with the nasal cavity.  There are four nasal conchae: 1- Dorsal nasal concha: - It longest, occupies the dorsal part of nasal cavity. - It is attached to the dorsal turbinate crest of nasal bone. - It is continued rostrally with straight fold. 2- The ventral nasal concha: - It occupies the ventral part of nasal cavity. - It is attached to the maxilloturbinates crest of the maxilla. -It is continued rostrally with alar fold. 3- Middle nasal concha: -It is a small concha situated in the nasal fundus. 4- Ethmoidal conchae: -They are small conchae occupied nasal fundus. Supported by ethmoturbinates  D.N.C M.N.C V.N.C E.N.C  ENC DNC S.F A.F VNC B.F S.P  Nasal Meatuses Definition: The nasal conchae divide the nasal cavity into a number of passages termed nasal meatuses. They comprise the following: 1- Dorsal nasal meatus: - It lies between dorsal nasal concha and roof of the nasal cavity. - It transmits air to the caudal part of nasal cavity (olfactory region) and so it is called (olfactory meatus). 2- Middle nasal meatus: - It lies between dorsal and ventral nasal conchae. - The paranasal sinuses open into this meatus and hence it is called sinus meatus. 3- Ventral nasal meatus: - It largest, lies between the ventral nasal concha and the floor of nasal cavity. - It transmits the air to the nasopharynx through the caudal nares so it is called respiratory meatus. 3- Ventral nasal meatus: - It lies between the ventral nasal concha and the floor of nasal cavity. - It transmits the air to the nasopharynx through the caudal nares so it is called respiratory meatus. 4- Common nasal meatus: - It lies in the paramedian part of the nasal cavity. - It is bounded by the nasal septum medially, nasal conchae laterally, roof of nasal cavity dorsally and the floor ventrally. - It communicates with the other meatuses. 5-Ethmoidal nasal meatus - Narrow spaces lodged between nasal conchae  D.N.M D.N.C M.N.M M.N.C V.N.C E.N.C Incisive duct (nasopalatine duct): It is formed of pair of mucous tubes in the floor of the nasal cavity. It directed rostroventrally, connect the nasal cavity with the oral cavity, so it has two orifices (nasal and oral). Nasal orifice at VNM at level of canine teeth. Oral orifice of the duct is on the incisive papilla. (In horse don’t open in O.C end blindly under oral epith). Vomeronasal organs (organs of Jacobson): - It consists of a pair of blind tubes present in the floor of the nasal cavity on each side of the nasal septum. - They begin blindly in the nasal cavity and extend rostroventrally to open in the incisive papilla with incisive duct. - It may serve as smell organ (accessory olfactory organ) to determinate the flavour of food in the mouth. Lateral Nasal Glands: - The glands are found in all animals except bovine. - Its position varies according to the species. It lies mainly at the entrance of the maxillary sinus. - Except in horse, the secretion of the gland passes through the incisive duct into the oral cavity, this secretion helps in moisten the inhaled air.  LNG N.O Or.O  1 4 Conchal sinus  Paranasal Sinuses  Definition: -Irregular air filled spaces. -Excavate some bones of skull. -Lie between external and internal laminae of individual bone. -Lined by respiratory mucous membrane. - Connected with the nasal cavity. -Vary in number, size and form according to species.  Development Resp.Epp sinus NC Spongy bone sinus Resp.Ep internal lamina of compact bone  Functions of paranasal sinuses: Protect the orbits, nasal and cranial cavities. Enlarge the skull area for muscle attachment without increasing weight. Affect the resonance of voice. Lighten the skull.  Paranasal sinuses are: = Frontal sinus. = Maxillary sinus. = Palatine sinus. = Sphenoid sinus. = Lacrimal sinus. AnimaL F M P S L Number Dog + - - - 1 Recess Pig + + - + + 4 S.R + + + - + 4 L.R + + + + + 5 Horse + + + + - 4  Connection with the nasal cavity: There are two ways of connection: 1-The sinuses that communicate collectively with the middle nasal meatus (direct or indirect) through nasomaxillary opening. 2-The sinuses that communicate independently with ethmoidal meatuses.  Summary  N.B: In horse, all paranasal sinuses open in middle nasal meatus =Maxillary and palatine sinuses open in middle nasal meatus (direct or indirect) = Frontal, sphenoid, and Lacrimal sinuses open in ethmoidal meatuses except Lacrimal sinus in ox opens in middle nasal meatus (indirect through maxillary sinus). AnimaL M.N. Ethmoidal meatus meatuses Dog M F Pig M F, S, L S.R M, P F, L L.R M, P, L F, S Horse M, F, S, P _  Frontal sinus - It presents in all domestic animals. -The right and left sinuses are separated by a median septum. -It opens separately into ethmoidal meatuses, except in horse it opens via caudal maxillary sinus in middle nasal meatus. Position: =In dog, small ruminants and horse: It occipies frontal bone ( dorsal part of skull) between nasal cavity, cranial cavity and the orbits. =In the pig and ox: it occipies frontal bone and extends caudally also into parietal, interparietal, occipital and temporal bones and thus surround the cranial cavity dorsally, laterally and caudally. N.B: The cornual process of horned ruminants is excavated by the frontal sinus. L.R  Maxillary sinus - It presents in all domestic animals. - It opens into middle nasal meatus via nasomaxillary aperature. =In carnivores -It is not considered to be a true sinus, since it does not lie between the internal and external laminae of individual bones. Its proper name is maxillary recess. -It is divided into rostral and caudal parts. -It opens into the middle nasal meatus via wide nasomaxillary opening. =In pig -it is divided into rostral and caudal parts. -It opens into middle nasal meatus via nasomaxillary opening.. =In ruminants -The maxillary sinuses communicate with palatine sinus across infraorbital canal. They have common nasomaxillary opening leads to middle nasal meatus -N.B:- Not divided into rostral &caudal parts as other animals =In horse -it is divided by an osseous septum into: 1-Rostral maxillary sinus. 2-Caudal maxillary sinus, subdivided into: a-Large ventrolateral part communicates caudally with sphenopalatine sinus. b-Small dorsomedial part communicates dorsally with conchofrontal sinus. -The rostral and caudal maxillary sinuses communicate with middle nasal meatus.  Sphenoid sinus -It is absent in dog and small ruminants. It may be absent in ox and horse. -The sphenoid sinus is relatively small but relatively large in pig -It excavates sphenoid bone. =In pig and in ox, It opens in ethmoidal meatuses. =In horse, It communicates with palatine sinus forming sphenopalatine sinus which communicates with caudal maxillary sinus. -Its part which occupies presphenoid bone is closely related to optic nerve and optic chiasma, so that inflammation of the sinus may affect the vision.  Palatine sinus It is absent in carnivores and pig. =In ruminants -It excavates the palatine process of maxilla and the horizontal part of palatine bone. -It has incomplete bony roof, therefore it is separated from the nasal cavity by double layer of mucosa. (CLinical importance) -The palatine and maxillary sinuses communicate across infraorbital canal. They have common nasomaxillary opening leads to middle nasal meatus =In horse -It excavates perpendicular part of palatine bone. -It opens rostrally into caudal maxillary sinus and continues caudally with sphenoid sinus thus it is called sphenopalatine sinus. Soft palate Lacrimal sinus: -It is absent in carnivores and horse. -It excavates the lacrimal and zygomatic bones. In ox: It opens into middle nasal meatus through the maxillary sinus. In pig & small ruminants: -It opens into the ethmoidal meatuses. -It may be connected with frontal sinus (pig) , or may be a lateral recess of lateral frontal sinus (S.Rum.)  Lacrimal sinus -It is absent in carnivores 8 and horse. -It excavates the lacrimal and zygomatic bones. 5 1 2 3 =In ox It opens into middle nasal meatus through the 4 maxillary sinus. 6 7 =In pig & small ruminants -It opens into the ethmoidal meatuses. -It may be connected with frontal sinus (pig) , or may be a lateral recess of lateral frontal sinus (S.Rum.) Sinusitis Flush