72 - Squamous suture aka Squamosal suture

Like any suture of the skull which joins two bones, this squamous suture; sometimes also called as the squamosal suture joins the parietal bone to the temporal bone (the temporal bone has two parts - the petrosal part and the squamous part - this suture joins the squamous part of the temporal bone to the parietal bone).

                                             It is oriented horizontally and extends posteriorly from the pterion (Pterion is the region as indicated in the figure above, that is the meeting point of the frontal, parietal, temporal and sphenoid bones). The suture continues posteriorly as the petromastoid suture.

                                                       Some consider the posterior part the squamous suture as a separate suture called additamentum posterius suturae squamosae because of its serrated appearances in most of the humans. 

60 - Inion

The inion is the most prominent projection of the occipital bone at the posterioinferior (lower rear) part of the skull. The ligamentum nuchae and trapezius muscle attach to it.

The term external occipital protuberance (protuberantia occipitalis externa) is sometimes used as a synonym, but more precisely the term "inion" refers to the highest point of the external occipital protuberance.

The word "inion" is the Greek word for the occipital bone.

An Anatolian bump is a protuberance on the back of the skull said to be related to East and Central Asian ancestry, especially Turkic tribes.It is an unusually large external occipital protuberance.

37 - Skull Foramina

1. Anterior Palatine Foramen
2. Palatine Process of Maxilla
3. Palatine
4. Greater Palatine Foramen
5. Lesser Palatine Foramen
6. Pterygoid Processes of Sphenoid
7. Zygomatic Process
8. Squamous Part of Temporal Bone
9. Mandibular Fossa
10. Styloid Process
11. Stylomastoid Foramen
12. Mastoid Process
13. Mastoid Foramen
14. Superior Nuchal Line
15. External Occipital Protruberance
16. Median Nuchal Line
17. Inferior Nuchal Line
18. Foramen Magnum
19. Condyloid Canal
20. Occipital Condyle
21. Hypoglossal Canal
22. Jugular Foramen
23. Carotid Canal
24. Foramen Spinosum
25. Foramen Ovale
26. Foramen Lacerum
27. Vomer
28. Transverse Palatine Suture
29. Median Palatine Suture

View this page to read about the structures that pass through each of these foramina. 

17 - diploic veins and diploic bones

Recently a question was asked in the DNB june 2008 exam about the diploic bones , which was like this :

q. which of the following is a diploic bone ?

a.zygomatic

b.ethmoid

c. maxilla

d. frontal

answer : d . frontal bone.

The diploic veins are found in the skull, and drain the diploic space. This is found in the bones of the vault of the skull, and is the marrow-containing area of cancellous bone between the inner and outer layers of compact bone.

The diploic veins drain this area to the outside of the skull.

Specific diploic veins

They are usually four in number: one frontal, two parietal, and one occipital. These bones are also called the diploic bones.

• (1) the frontal, which opens into the supraorbital vein and the superior sagittal sinus.

• (2) the anterior temporal, which is confined chiefly to the frontal bone, and opens into the sphenoparietal sinus and into one of the deep temporal veins, through an aperture in the great wing of the sphenoid.

• (3) the posterior temporal, which is situated in the parietal bone, and ends in the transverse sinus, through an aperture at the mastoid angle of the parietal bone or through the mastoid foramen.

• (4) the occipital, the largest of the four, which is confined to the occipital bone, and opens either externally into the occipital vein, or internally into the transverse sinus or into the confluence of the sinuses (torcular Herophili).