Respiratory System 2 PDF

Lecture 2 Respiratory System By Prof. A. / Fatma A. Madkour  Nasal Sinuses  General Definition: Are air filled spaces within NC, lined with respiratory epithelium Types of Nasal Sinuses I-Conchal sinuses (sinuses of nasal conchae...

Lecture 2 Respiratory System By Prof. A. / Fatma A. Madkour  Nasal Sinuses  General Definition: Are air filled spaces within NC, lined with respiratory epithelium Types of Nasal Sinuses I-Conchal sinuses (sinuses of nasal conchae) -Definition -They are 3 conchal sinuses -Comparative II-Paranasal Sinuses (sinuses of skull)  Definition: -Irregular air filled spaces, excavate some bones of skull. -Lie between external and internal laminae of individual bone. -Lined by respiratory mucous membrane resembles that of NC but with some differences. - Connected with the nasal cavity. -Vary in number, size and form according to species.   Development During embryonic life At birth After birth 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 (act as a buffer against head trauma).  Enlarge the skull area for muscle attachment without increasing weight.  Lighten the skull.  Humidifying and Warming Air: They help to moisten and warm the air that is inhaled.  Affect the resonance of voice.  Mucus Production: The lining of the sinuses produces mucus, which helps trap dust, pathogens, and other particles, preventing them from entering L. respiratory tract.  Immune Function: The mucous membranes lining the sinuses contain immune cells that help defend against infections.  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 (maxillary) septum into: 1-Rostral maxillary sinus. 2-Caudal maxillary sinus, subdivided by boy crest 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 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.) In ox: It opens into middle nasal meatus through the maxillary sinus.  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.)