The Vertebrate Skeleton

Name: The Vertebrate Skeleton
Author: Reynolds, Sidney H. (Sidney Hugh)

Reynolds, Sidney H. (Sidney Hugh)

Skeleton

The =parietal segment= consists of both cartilage and membrane bones.
It is formed of five bones, which are in contact with those of the
occipital segment on the dorsal and ventral surfaces, while laterally
they are separated by the interposition of the auditory bones, and to
some extent of the squamosal. The =basisphenoid= (fig. 75, 6), an
unpaired bone forming the ventral member of this segment, is the
direct continuation of the basi-occipital. It tapers anteriorly, but
is rather deep vertically, its upper or dorsal surface bearing a
depression, the =sella turcica=, which lodges the pituitary body of
the brain. From the sides of the basisphenoid arise the =alisphenoids=
(fig. 75, 11) a pair of bones of irregular shape generally described
as wing-like; each gives off from its lower surface a =pterygoid
plate=, which is united in front with the palatine, and below with the
pterygoid. The alisphenoids are united above with a pair of large
nearly square bones, the _parietals_ (fig. 73, 2), which meet one
another in the mid-dorsal line. The line of junction is frequently
drawn out into a strong ridge, which forms the anterior part of the
=sagittal crest=.

[Illustration FIG. 72. VERTICAL LONGITUDINAL SECTION TAKEN A LITTLE TO
THE LEFT OF THE MIDDLE LINE THROUGH THE SKULL OF A DOG (_Canis
familiaris_) × 3/5. (Camb. Mus.)

    1. supra-occipital.
    2. interparietal.
    3. parietal.
    4. frontal.
    5. cribriform plate.
    6. nasal.
    7. mesethmoid.
    8. maxillae.
    9. vomer.
    10. ethmo-turbinal.
    11. maxillo-turbinal.
    12. premaxillae.
    13. occipital condyle.
    14. basi-occipital.
    15. tympanic bulla.
    16. basisphenoid.
    17. pterygoid.
    18. palatine.
    19. alisphenoid.
    20. internal auditory meatus.
    21. tentorium.
    22. foramen lacerum posterius.
    23. floccular fossa.
    24. coronoid process.
    25. condyle.
    26. angle.
    27. mandibular symphysis.
    28. inferior dental foramen.
    29. stylo-hyal.
    30. epi-hyal.
    31. cerato-hyal.
    32. basi-hyal.
    33. thyro-hyal.
    XII. condylar foramen.]

The =frontal segment=, which surrounds the anterior part of the brain,
is closely connected along almost its whole posterior border with the
parietal segment.

Public-domain text, read in full here on John Shaqi.

Opening the text

The Vertebrate SkeletonReynolds, Sidney H. (Sidney Hugh)

Science

The Vertebrate Skeleton

Reynolds, Sidney H. (Sidney Hugh)

Skeleton

The =parietal segment= consists of both cartilage and membrane bones.
It is formed of five bones, which are in contact with those of the
occipital segment on the dorsal and ventral surfaces, while laterally
they are separated by the interposition of the auditory bones, and to
some extent of the squamosal. The =basisphenoid= (fig. 75, 6), an
unpaired bone forming the ventral member of this segment, is the
direct continuation of the basi-occipital. It tapers anteriorly, but
is rather deep vertically, its upper or dorsal surface bearing a
depression, the =sella turcica=, which lodges the pituitary body of
the brain. From the sides of the basisphenoid arise the =alisphenoids=
(fig. 75, 11) a pair of bones of irregular shape generally described
as wing-like; each gives off from its lower surface a =pterygoid
plate=, which is united in front with the palatine, and below with the
pterygoid. The alisphenoids are united above with a pair of large
nearly square bones, the _parietals_ (fig. 73, 2), which meet one
another in the mid-dorsal line. The line of junction is frequently
drawn out into a strong ridge, which forms the anterior part of the
=sagittal crest=.

[Illustration FIG. 72. VERTICAL LONGITUDINAL SECTION TAKEN A LITTLE TO
THE LEFT OF THE MIDDLE LINE THROUGH THE SKULL OF A DOG (_Canis
familiaris_) × 3/5. (Camb. Mus.)

    1. supra-occipital.
    2. interparietal.
    3. parietal.
    4. frontal.
    5. cribriform plate.
    6. nasal.
    7. mesethmoid.
    8. maxillae.
    9. vomer.
    10. ethmo-turbinal.
    11. maxillo-turbinal.
    12. premaxillae.
    13. occipital condyle.
    14. basi-occipital.
    15. tympanic bulla.
    16. basisphenoid.
    17. pterygoid.
    18. palatine.
    19. alisphenoid.
    20. internal auditory meatus.
    21. tentorium.
    22. foramen lacerum posterius.
    23. floccular fossa.
    24. coronoid process.
    25. condyle.
    26. angle.
    27. mandibular symphysis.
    28. inferior dental foramen.
    29. stylo-hyal.
    30. epi-hyal.
    31. cerato-hyal.
    32. basi-hyal.
    33. thyro-hyal.
    XII. condylar foramen.]

The =frontal segment=, which surrounds the anterior part of the brain,
is closely connected along almost its whole posterior border with the
parietal segment.

Public-domain text, read in full here on John Shaqi.

The Vertebrate Skeleton

The Vertebrate Skeleton

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