00:02 Here's an inferior view so we can look at the occipital bone. 00:06 And the occipital bone has a basilar part anteriorly. 00:11 Then lateral parts. 00:12 And then most posteriorly we have the squamous or flat parts. 00:17 And this is where we find the foramen magnum. 00:20 The opening through which the brainstem becomes the spinal cord. 00:26 If we look internally. 00:28 We see there's this flat portion of the basilar part called the clivus. 00:33 And there's a groove for another sinus here called the inferior petrosal sinus. 00:38 And we flip around to the external surface. 00:41 We see a tubercle for some pharyngeal muscles to attach called the pharyngeal tubercle. 00:48 There's also a little groove here for the sigmoid sinus. 00:53 And externally we have bumps for the attachment to the atlas called the occipital condyles. 00:59 Again this is the part that's going to rest on the vertebral column. 01:03 We also have a condylar canal. 01:06 And a hypoglossal canal for structures to pass through. 01:12 Internally, we have this cruciform eminence where these vertically and horizontally oriented bumps meet. 01:22 And this is we're going to have little fossa for the cerebrum on either side left or right. 01:28 We also more inferiorly of fossa for the cerebellum, which is the smaller portion of the brain. 01:36 And again, we have groups for dural venous sinuses in this case we have the superior sagittal sinus here. 01:41 And running transversely the group for the transverse sinuses. 01:47 On the internal surface where these two groups meet is a bump called the internal occipital protuberance. 01:55 And then the crest that runs from that is called the internal occipital crest. 02:02 We swim around to the external surface. 02:04 We have the corresponding external occipital protuberance. 02:09 So that's a bumped you can feel on the outer surface of the occipital bone. 02:14 And similarly, running from that is the external occipital crest. 02:19 The flat part above that is the occipital plane. 02:23 And then running laterally from the midline we have the inferior nuclear line. 02:27 Which is this attachment point for a lot of muscles. 02:31 We also have superior nuclear line. 02:32 And supreme nuclear line doing similar things.
The lecture Occipital Bone by Darren Salmi, MD, MS is from the course Skull.
Which of the following is NOT a part of the occipital bone?
What divides the concave internal surface of the occipital bone?
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