The base of the flat triangle of the piriformis muscle lies in the sacrum, and the narrow peak is attached to the greater trochanter. On its way from the pelvis it passes through the sciatic foramen. They occupy only the central section of the opening. Small gaps remain in the upper and lower parts, which received their own names: supragiriform and subpiriform. pear-shaped opening. The canals serve for the passage of blood vessels and long branches extending from the sacral plexus.

Topographic anatomy of the supragiriform and infrapiriform foramina

Both canals are parts of the greater sciatic foramen. Its location is the lateral wall of the pelvic ring. Through the opening, the piriformis muscle, starting in the sacrum area, enters the buttocks area. She takes central part openings, leaving enough space for the passage of arteries, small blood vessels and nerve bundles. The size of the crevice formations can vary significantly depending on the individual characteristics of the person. The piriformis muscle can fill the entire space or be very thin, in some cases it is completely absent.

The anatomical formation is located in the deep layer of the pelvic muscles, superiorly and medially surrounded by the sheath of the gluteus maximus muscle. Through the slits, named after their location, the supragiriform and infrapiriform foramen, there is communication with the pelvic cavity. Characteristic feature the gluteal region, the topography of which includes the channels, is convex semicircular shape. Its appearance is due to the contour of the main muscular formation - the gluteus maximus muscle. On the outside there is a thick layer of skin penetrated by many sebaceous glands. The skin and internal fascia of the muscles are separated by reliable partitions made of connective tissue, dividing fiber into fat cells. IN subcutaneous tissue There are veins and arteries associated with the vessels of the lumbar region and the greater trochanter. Local muscles play a significant role in retention vertical position human torso, abduction, flexion, hip rotation.

Boundaries and structure

The suprapiriform foramen or foramen suprapiriforme has clear boundaries, the top of the canal is determined by the greater sciatic notch, and the bottom is the surface of the piriformis muscle. The upper bundle of vessels and nerves runs through a canal 4-5 cm long and about 1 cm wide. It is surrounded on all sides by fiber. The hole looks like a flattened tube directed from bottom to top. The beginning of the canal, facing the pelvis, has a round shape. Its triangular or oval-shaped end is directed into the space of the posterior pelvic region. The fascia of the muscles located here closes the canal.

The contents of the supragiriform foramina are the superior gluteal artery, vein and nerve. This structure has a medical designation - the superior gluteal neurovascular bundle. Its purpose is the transmission of reflex impulses and blood supply to the muscles. The artery is located directly on the bone, it is short vessel large diameter.

The infrapiriform foramen or foramen infirapiriforme is a slit-like interval, upper limit which is determined by the piriformis muscle, and the inferior sacrospinous ligament. On the side of the pelvis and buttocks it is covered by fascial sheets. The free gap remains in the middle part of the gap. It is densely filled with structures of the sacral plexus, blood vessels. The following nerves pass through the foramen infirapiriforme:

• sciatic - is in the extreme lateral position;
• genital or pudendal - located medially;
• lower gluteal - occupies an intermediate position;
• posterior cutaneous

Arteries located nearby:

• internal genitalia;
• inferior gluteal.

The inferior gluteal vein also passes through the canal. Coming out of the fissure, the arteries divide into several branches. They perform various functions: accompany the sciatic nerve, connect to the femoral artery, provide nutrition to the greater trochanter. Veins are located next to the arteries of the same name. The vessels form numerous anastomoses with the veins of the thigh. The pudendal (genital) neurovascular bundle is reliably covered by the sacrotuberous ligament. In order to get to its structures, if necessary, surgeons have to cut the ligament.

Functions of the nerves and arteries of the posterior pelvis

All arteries and nerve branches supplying the posterior part of the pelvis pass through the supragiriform and infrapiriform openings. Every anatomical structure has important function: vessels provide nutrition and oxygen, nerve bundles communicate with the central nervous system. Several structures are involved in the innervation of the pelvic muscles, but the main role belongs to the sciatic nerve (n. Ischiadicus). It is one of the longest branches of the sacral plexus. Having passed the infrapiriformis fissure, it lies on the gemellus and quadratus muscles. Its fibers are surrounded by a fascial sheath. The upper part of the protective formation, located at the sacral plexus, is wide and free. The case narrows at the bottom. Trunk n. Ischiadicus may divide into two parts, in which case two separate branches leave the pelvis: the tibial and peroneal nerves.

Other anatomical formations:

• The superior gluteal nerve is short in length and divides into three branches on the posterior surface of the pelvis. Transmits nerve impulses to the tensor fascia lata.
• Inferior gluteal nerve - fiber receptors are directed to the gluteus maximus muscle.
• Posterior cutaneous nerve - passes medial to n. Ischiadicus, placed in its own vagina, connected to the walls of the adjacent muscles. Its long, thin fibers occupy the area midway between the greater trochanter and the ischial tuberosity. Having descended onto the thigh, it falls under the fascia lata and is divided into several branches. Some of them are directed to the perineum.

Blood supply to the posterior part of the pelvis is provided by:

• The superior gluteal artery (a. glutea superior) is a full-blooded vessel originating from the internal iliac artery. In the passage of the supragiriform canal it divides into two branches, one goes to the surface, the other goes deep into the pelvis. Large-caliber formations disperse through a network of smaller vessels.
• Inferior gluteal artery (a. glutea inferior) – inferior in diameter and fullness to a. glutea superior. The vessel also starts from the trunk of the iliac artery, but passes through the infrapiriform interval. Provides nutrition hip joint, skin in the pelvic area, quadratus, adductor and obturator muscles. The final section of the vessel is accompanied by the sciatic nerve for 7-9 cm. Branches of the lower and superior artery anastomose with each other.

Possible pathologies

Pathological changes in the piriformis muscle have a significant impact on the sciatic nerve, especially when the fibers pass through muscle bundles, which is observed in 10% of anatomical structures. In the infrapiriform space it is located lateral to other structures. When muscle fibers become inflamed, not only the sciatic nerve, but also other branches of the sacral plexus suffer from compression. Compression of the sensitive posterior cutaneous nerve causes pain in the thigh, popliteal fossa, and groin. There are symptoms of insufficient blood supply (numbness, convulsions) when exposed to arteries. This pathology called piriformis syndrome. Manual tests help to recognize the disease.

Doctors and nurses need to know the topography of the supragiriform and infrapiriform foramina. This area, filled with many vessels and nerves, should be excluded when performing intramuscular injections. To avoid complications associated with damage to innervating structures, injections are performed only in the upper-outer part of the buttocks.

1. Nasal cavity, cavitas nasi. Rice. A, V.
2. Bone septum of the nose, septum nasi osseum. Formed mainly by the vomer and the perpendicular plate of the ethmoid bone. Rice. IN.
3. Pear-shaped aperture (anterior nasal), apertura piriformis (nasalis anterior). The opening leading into the nasal cavity. Rice. A, B, G.
4. Upper nasal passage, meatus nasalis superior. Located above the middle turbinate. Rice. A.
5. Middle nasal passage, meatus nasalis medius. Located between the middle and inferior turbinates. Rice. A.
6. Lower nasal passage, meatus nasalis inferior. Located under the inferior nasal concha. Rice. A.
7. Nasolacrimal duct, canalis nasolacrimal. Contains the nasolacrimal duct, which opens under the inferior turbinate. Rice. IN.
8. Wedge-ethmoid recess, hecessus sphenoethmoidalis. The space located above the superior turbinate. Rice. A.
9. Nasopharyngeal passage, meatus nasopharyngeus. The posterior part of the nasal cavity, located between the posterior edge of the turbinates and the choanae. Rice. A.
10. Choanae, choanae. Openings leading from the nasal cavity to the nasopharynx. Rice. A.
11. Sphenopalatine foramen, foramen sphenopalatinum. Formed by the same palatine notch and the body of the sphenoid bone. Connects with each other top part pterygopalatine fossa and nasal cavity. Rice. A.
12. Eye socket, orbita. The bony cavity that contains the eyeball. Rice. V, G.
13. Entrance to the orbit, adit us orbitalis. Anterior opening (base) of the orbit. Rice. G.
14. Orbital margin, margo orbitalis.
15. Supraorbital margin, mar go supraorbitalis. The upper edge of the entrance to the orbit. Rice. IN.
16. Infraorbital margin, margo infraorbitalis. The lower edge of the entrance to the orbit. Rice. B. 16a Lateral edge, mar go lateralis. 166 Medial edge, mar go medialis.
17. Upper wall, paries superior. Roof of the eye socket. Rice. IN.
18. Bottom wall, paries inferior. Floor of the eye socket. Rice. IN.
19. Lateral wall, paries lateralis. Rice. IN.
20. Medial wall, paries medialis. Rice. IN.
21. Anterior ethmoidal opening, foramen ethmoidae anterius. Located on the medial wall of the orbit between the frontal and ethmoid bones. The anterior ethmoidal nerve and vessels pass through it. Rice. IN.
22. Posterior ethmoidal opening, foramen ethmoidale posterius. Located on the medial wall of the orbit posterior to the foramen ethmoidae anterius. Contains the posterior ethmoidal nerves and vessels. Rice. B. 22a Tear groove, sulcus lacrimalis. Located at the beginning of the nasolacrimal duct. Rice. B. Fossa of the lacrimal sac, fossa sacci lacrimalis. Rice. IN.
23. Upper orbital fissure, fissura orbitalis superior. Located in the posterior part of the lateral wall of the orbit between the greater and lesser wings of the sphenoid bone. Connects the cranial cavity with the orbit and contains the ophthalmic, oculomotor, trochlear and abducens nerves, as well as v.ophthalmica superior. Rice. IN.
24. Inferior orbital fissure, fissura orbitalis inferior. Located between the greater wing of the sphenoid bone and the orbital surface upper jaw. Contains zygomatic, infraorbital nerves and vessels. Rice. IN.
25. Occipital norm, norma occipitalis. Rear view of the skull. Rice. B. 25a Inion, Shop. Corresponds to the center of the external occipital protrusion.
26. Lambda, lambda. The junction of the lambdoid and sagittal sutures of the skull. Rice. B.
27. Fontanelles of the skull, fonticuli cranii. Unossified connective tissue spaces between the bones of the cranial vault in fetuses and children. Rice. G, D.
28. Anterior fontanel, fonticulus anterior. It is diamond-shaped and located between the two halves of the frontal and parietal bones. Overgrows in the second year of life. Rice. G, D.
29. Posterior fontanel, fonticulus posterior. Located between the parietal and occipital bones. Overgrows in children in the third month of life. Rice. G, D.
30. Wedge-shaped (anterolateral) fontanelle/olpsm/gm sphenoidalis (anterolateralis). Located on the lateral surface of the skull between the frontal, parietal, temporal and sphenoid bones. Corresponds to pterion. Rice. G.
31. Mastoid fontanel (posterolateral), fonticulus mastoideus (posterolateral). Located between the parietal, occipital and temporal bones. Corresponds to asterion. Rice. G.

SUPRAPIRIFORMAL HOLE(foramen suprapiriforme) - a slit-shaped opening between the upper edge of the piriformis muscle and the greater sciatic notch. The superior gluteal vessels and nerve pass through it.

SUBPIRA-SHAPED HOLE(foramen infraperiforme) - a slit-like opening between the lower edge of the piriformis muscle and the sacrospinous ligament. The foramen passes through the sciatic nerve, the inferior gluteal vessels and nerve, the posterior cutaneous nerve of the thigh, the internal genital vessels and the pudendal nerve.

OBSTORATE CANAL(canalis obturatorius) is a bone-fibrous canal formed above by the obturator groove of the pubic bone, below by the obturator membrane and the external and internal obturator muscles. Contains vessels and nerve of the same name.

MUSCLE GAP(lacuna musculorum) - the outer part of the space under the inguinal ligament, limited anteriorly by the inguinal ligament, posteriorly and laterally ilium, medially – by the iliopectineal arch. Contains: iliopsoas muscle, femoral nerve and in some cases the lateral cutaneous nerve of the thigh.

iliopectineal arch(arcus iliopectineus) - a compacted area of ​​fascia covering the iliopsoas muscle, and passing from the inguinal ligament to the iliopubic eminence of the pelvic bone.

VASCULAR GAP(lacuna vasorum) - the internal part of the space between the inguinal ligament and the pelvic bone. It is bounded anteriorly by the inguinal ligament, posteriorly by the pectineal ligament (tendon of the pectineus muscle, attached to the upper surface of the superior branch of the pubic bone), laterally by the iliopectineal arch, medially by the lacunar (gimbernate) ligament (the fibers of the inguinal ligament are wrapped downwards). Contains: femoral artery and vein, femoral branch of the femoral-genital nerve, fiber, Rosenmuller-Pirogov lymph node. Exit site for typical femoral hernias.

FEMORAL TRIANGLE(trigonum femorale, Scarpa's triangle) - part of the anterior region of the thigh, bounded above by the inguinal ligament, laterally by the inner edge of the sartorius muscle, medially by the outer edge of the adductor longus muscle. The bottom of the triangle is the iliopsoas muscle, pectineus muscle, longus and adductor magnus muscles.

iliopectineal groove(sulcus iliopectineus) is an intermuscular groove in the upper part of the femoral triangle, limited on the medial side by the pectineus muscle, on the lateral side by the iliopsoas muscle. Contains the femoral artery and vein.

ANTERIOR FEMORAL GROOVE(sulcus femoralis anterior) - continuation of the iliopectineal groove in the lower part of the femoral triangle. It is limited on the medial side by the long and large adductors, on the lateral side by the vastus medialis muscle. Contains the femoral artery and vein and the saphenous nerve.

FEMORAL CHANNEL(canalis femoralis) is a narrow triangular interfascial gap in the superomedial part of the femoral triangle. The walls of the canal are: in front - the upper horn of the crescent-shaped edge of the superficial leaf of the proper fascia of the thigh, behind - the pectineal fascia, laterally - the fascial sheath of the femoral vein. The canal has an internal opening (femoral ring) and an external one ( subcutaneous ring). In healthy individuals, it is filled with fiber and lymphatic vessels. Anatomical route of exit of a femoral hernia.

FEMOR RING(annulus femoralis) – internal opening femoral canal occupies the most medial section vascular lacuna. Its boundaries: in front - inguinal ligament, posteriorly – pectineal ligament, lateral-fascial sheath of the femoral vein, medially – lacunar ligament. When a femoral hernia forms, it is its hernial orifice.

SUBCUTANEOUS RING(hiatus saphenus PNA, fossa ovalis BNA; sinus oval fossa) - the external opening of the femoral canal, limited laterally by the falciform edge, above and below, respectively, by the upper and lower horns of the falciform edge, medial pectineal fascia.

DRIVING CHANNEL(canalis adductorius, Gunter's canal, syn. femoral-popliteal canal) - an interfascial space connecting the anterior region of the thigh and the popliteal fossa. It has three walls (medial, lateral and anterior) and three openings (superior, inferior and anterior). The medial wall is formed by the adductor magnus muscle, the lateral wall by the vastus medialis muscle, the anterior wall by the fibrous lamina vastoadductoria, which spreads between these muscles. The superior foramen enters the femoral artery and saphenous nerve and exits femoral vein. The popliteal vein enters the inferior opening and exits femoral artery. From the anterior opening in the lamina vastoadductoria, the saphenous nerve and the descending artery of the knee emerge from the canal, and the descending vein of the knee enters.

POPELLETIUM FOSSA(fossa poplitea) - a diamond-shaped depression in the posterior region of the knee filled with fiber and bounded above and laterally by the biceps femoris muscle, above and medially by the semitendinosus and semimembranosus muscles, below laterally and medially by the heads calf muscle. Contains popliteal lymph nodes, tibial nerve (lies most superficially), popliteal vein and artery (lies most deeply) (“NEVA”). The bottom of the fossa forms the posterior surface of the distal epiphysis of the femur, capsule knee joint, popliteus muscle.

Ankle-popliteal canal(canalis cruropopliteus, Gruber's canal) is an intermuscular canal in the posterior region of the leg, originating in the lower corner of the popliteal fossa and ending at the medial edge of the soleus muscle at the origin of its tendon (lower third of the leg). Bounded: anteriorly by the tibialis posterior muscle, posteriorly by the deep layer of the fascia of the leg and soleus muscle, laterally by the flexor hallucis longus muscle, medially by the flexor digitorum longus muscle. Contains the posterior tibial artery and veins, the tibial nerve. Through the anterior opening in the interosseous membrane of the leg, the canal leaves the anterior tibial artery.

LOWER MUSCULORFIBULAR CANAL(canalis musculoperoneus inferior) – a branch of the ankle-popliteal canal, limited fibula and flexor hallucis longus. Contains the peroneal artery and vein.

SUPERIOR MUSCULORFIBULAR CANAL(canalis musculoperoneus superior) is an independent muscle-bone canal in the lateral osteo-fibrous bed of the leg, limited by the neck of the fibula and the peroneus longus muscle. The common peroneal nerve passes through the canal, which is also divided into the superficial and deep peroneal nerves.

MEDIAL PLANTAR GURROUS(sulcus plantaris medialis) - intermuscular groove limited by the short flexor of the fingers and the abductor big toe muscle. Contains the medial plantar artery and vein, medial plantar nerve.

LATERAL PLANTAR GROOVE(sulcus plantaris lateralis) is an intermuscular groove bounded by the flexor digitorum brevis and the abductor of the little finger muscle. Contains the lateral plantar artery and vein, the lateral plantar nerve.

SPLANCHNOLOGY

Skull as a whole

The internal base of the skull (basis cranii interna; Fig. 60) serves as a support for the base of the brain and takes on its relief. The inner base of the skull is divided into three cranial fossae.

The anterior cranial fossa is bounded in front and laterally by the frontal scales, and posteriorly it is separated from the middle cranial fossa by the posterior edge of the small wings of the sphenoid bone. It is formed by the frontal bone (orbital parts), the ethmoid bone (the cribriform plate) and the sphenoid bone (lesser wings). In the anterior cranial fossa are frontal lobes cerebral hemispheres.

The middle cranial fossa is formed by the sphenoid and temporal bones. It is separated from the posterior cranial fossa by the upper edge of the pyramid of the temporal bone and the dorsum of the sella turcica. The fossa is deepened and contains the temporal lobes of the cerebral hemispheres. At the top of the pyramid of the temporal bone there is a lacerated foramen. In the central part of the middle cranial fossa, in the pituitary fossa, is the lower appendage of the brain - the pituitary gland. Nerves and blood vessels pass through the superior orbital fissure and the openings in the greater wings of the sphenoid bone.

The posterior cranial fossa is formed mainly by the occipital bone, the posterior surface of the pyramid of the temporal bone, the body of the sphenoid and the posteroinferior angle of the parietal. In the central parts of the fossa, anterior to the foramen magnum, is the stem part of the brain, and on the sides are the cerebellar hemispheres. Through the foramen magnum, the cranial cavity connects to the spinal canal.

The outer base of the skull (basis cranii externa; Fig. 61) is formed by the bones of the brain and facial skull. On the front, facial, part of the outer base of the skull, a bony palate is visible, bounded in front and on the sides by the teeth of the upper jaws. Posterior to it are large openings - choanae, which serve to communicate the nasal cavity with the pharynx. Lateral to the choanae are the pterygoid processes of the sphenoid bone, posterior and lateral to which numerous formations of the lower surface of the pyramid of the temporal bone and large wings of the sphenoid bone (external foramen) are visible sleepy channel, mandibular fossa, styloid process, stylomastoid foramen, etc.). The posterior sections of the outer base of the skull are entirely composed of the occipital bone with the foramen magnum, occipital condyles, and a large surface of the occipital squama for muscle attachment.

The nasal cavity (cavitas nasi; Fig. 62) is located almost in the center of the facial skull. From above it borders with the cranial cavity, on the sides of it there are the orbits and maxillary sinuses, and below - the oral cavity. The nasal cavity is divided into anterior and posterior openings, a septum and four walls: upper, lower and two lateral.

The anterior (pyriform) opening is formed by the nasal notches of the upper jaws and the nasal bones. Through the posterior openings - choanae - the nasal cavity communicates with the pharynx. On the medial side, the choanae are separated from each other by a septum formed by the vomer. On the lateral side, each choana is limited by the medial plate of the pterygoid process, below by the horizontal plate of the palatine bone, and above by the body of the sphenoid bone.

The bony septum of the nasal cavity is formed from the vomer and the perpendicular plate of the ethmoid bone. The lower wall of the nasal cavity is the bony palate, which includes the palatine process of the upper jaw and the horizontal plate of the palatine bone. The upper wall of the nasal cavity is formed in front by the nasal bones, the nasal part of the frontal bone, the cribriform plate of the same bone and the body of the sphenoid bone.

The lateral wall of the nasal cavity is more complex. It consists of the nasal and lacrimal bones, the upper jaw, the labyrinth of the ethmoid bone, the inferior nasal concha, the perpendicular plate of the palatine bone and the medial plate of the pterygoid process of the sphenoid bone. Three nasal conchae hang from the lateral wall: the upper and middle are part of the ethmoid labyrinth, and the lower is an independent bone. The turbinates separate the lateral sections of the nasal cavity and the three nasal passages. The inferior nasal meatus is formed by the floor of the nasal cavity and the inferior turbinate. The nasolacrimal duct opens into it. Between the middle and inferior turbinates there is the middle meatus. The maxillary and frontal sinuses, the anterior and middle cells of the ethmoidal labyrinth open into it. The superior nasal meatus is located between the superior and middle turbinates. It communicates with the posterior cells of the ethmoidal labyrinth and with the sinus of the sphenoid bone.

The orbit (orbita; see Fig. 46) is a paired cavity in the shape of a four-sided pyramid, with its apex directed posteriorly and medially. The entrance to the orbit is limited from above by the supraorbital margin of the frontal bone, from below by the infraorbital margin of the maxilla and zygomatic bone, the medial frontal process of the maxilla and the frontal bone, and laterally by zygomatic bone and the zygomatic process of the frontal bone.

There are four walls in the orbit. The upper wall is formed by the orbital part of the frontal bone and the lesser wings of the sphenoid. Most of the lower wall consists of the orbital surface of the upper jaw, closer anteriorly - the zygomatic bone and almost at the apex - the orbital process of the palatine bone. The lateral wall is represented by the orbital surface of the greater wings of the sphenoid bone and the zygomatic bone. The medial wall is the most complex. From front to back it is formed by the frontal process of the upper jaw, the lacrimal bone, the orbital plate of the ethmoid bone and the body of the sphenoid bone, and in the upper sections the medial wall is supplemented by the orbital part of the frontal bone.

In the anterior part of the medial wall the fossa of the lacrimal sac is visible. The superolateral corner of the orbital pyramid is occupied in front by the fossa of the lacrimal gland, and in the back by the superior orbital fissure, through which the orbit communicates with the cranial cavity. Almost the entire inferolateral angle is occupied by the inferior orbital fissure, through which the orbit communicates with the pterygopalatine and infratemporal fossae. At the very top of the pyramid is the opening of the optic canal, through which the optic nerve passes.

The oral cavity (cavitas oris; see Fig. 46, 62) is limited from above by the bony palate, and in front and from the sides by the dentition and alveolar processes of the upper and alveolar parts of the lower jaws. On the bony palate in front you can see the incisive foramen connecting the oral cavity with the nasal cavity, and in the posterior parts there is a large palatine foramen through which blood vessels and nerves pass.

The temporal fossa (fossa temporalis; see Fig. 46) is formed by the large wings of the sphenoid bone, the parietal bone, the frontal squama and the scaly part of the temporal bone. The fossa is bounded above and behind by the superior temporal line, below by the zygomatic arch, and in front by the zygomatic bone. The temporalis muscle is located in the fossa.

The infratemporal fossa (fossa infratemporalis; see Fig. 61) is bounded above by the greater wing of the sphenoid bone, in front by the infratemporal surface of the upper jaw and the zygomatic bone, the medial pterygoid process of the sphenoid bone and laterally by the ramus of the mandible. The hole is filled with muscles. It communicates with the orbit through the infraorbital fissure. Medially it passes into the pterygopalatine fossa (fossa pterygopalatina). The latter is located behind the tubercle of the lower jaw, posteriorly limited by the pterygoid process of the sphenoid bone, and medially by the perpendicular plate of the palatine bone. The fossa communicates with the cranial cavity, orbit, nasal cavity, oral cavity and the area of ​​the foramen lacerum. In the skull of a newborn, the dimensions of its parts in relation to the length and weight of the newborn’s body are much larger than in an adult (Fig. 63). The bones of the newborn's skull are separated. The wide spaces between them are occupied by layers of connective tissue or cartilage that has not yet ossified. The presence of fontanelles is characteristic. Anterior (large) fontanelle - at the junction parietal bones and frontal, overgrows by 2 years. Posterior (small) - between the parietal and occipital bones, overgrows in the 2nd - 3rd month after birth. Wedge-shaped and mastoid fontanelles are paired. The cerebral skull is noticeably predominant, and the facial skull is relatively small. The ratio of their volumes (facial skull to brain) in a newborn is on average 1:8, and in an adult - 1:2 or 1:2 1/2. Since the newborn does not yet have alveolar processes and erupted teeth, the upper and mandible separated from each other by a wide gap. On a macerated skull or on x-ray The skull of a newborn shows that the bones consist of separate, not yet fully fused parts.

Pyriform aperture - see Pyriform aperture....

The external aperture of the vestibule aqueduct (apertura externa aqueductus vestibuli, PNA, BNA; apertura interna canaliculi vestibuli, JNA) is an opening located on the posterior surface of the pyramid of the temporal bone below and lateral to the opening...

News about Pear-shaped hole

• Ph.D. Yu.A. Olyunin Institute of Rheumatology, Russian Academy of Medical Sciences, Moscow Pain in the spine is one of the most common clinical disorders. Changes that may cause pain syndrome, are very diverse. In most cases, it is possible to accurately identify the mechanism by which it arose.
• J.G. Heathcote and his colleagues from Dalhousie University, Halifax, Canada, encountered unusual case cancer. In a 48-year-old patient, giant carcinoma cells were found in the area of ​​the right pyriform cavity.

Discussion Pear-shaped hole

• Please write the full name of the operation performed in 2000 and indicate exactly why it was performed. I can’t write the exact name. That's exactly what it says in the statement. Performed in connection with the diagnosis. Interested in the latest blood test results for hormones: An
• Dear Dmitry, have you contacted a neurologist? Did you take an R X-ray of the hip joint or lumbar spine? The complaints you describe can occur in a number of conditions, but first of all it is necessary to exclude muscular-tonic syndrome of the piriformis muscle. This syndrome is often diagnosed incorrectly