Frontal Bone

00:02 Now let's take a closer look at the bones of the skull.

00:05 Starting with the frontal bone.

00:09 Here we have a little area that's going to participate in the orbit.

00:13 So this is the orbital part of the frontal bone.

00:18 Similarly, this portion in the midline is going to participate in the nasal formation.

00:24 So we call this the nasal part of the frontal bone.

00:29 The flatter parts are called the squamous part.

00:32 Squamous means scale like so whenever you see that term, it usually means something flat.

00:38 We also have the portion that's going to interact with the zygomatic bone.

00:42 So that's the zygomatic process.

00:46 There are some big bumps on the squamous portion that we call the frontal tubers.

00:53 And then where we have these arches above the orbit.

00:56 We call them the superciliary arches.

01:00 There's a little spot or depression in between the two.

01:03 That is a landmark called the glabella.

01:07 And then we call the edge of the upper portion of the orbit.

01:11 The supra-orbital margin.

01:15 In this area, the supra-orbital margin there are a couple landmarks that are pretty important because of what passes through them.

01:22 So we have a supraorbital foramen.

01:25 Through which the supraorbital nerves and vessels pass.

01:29 There's also a frontal notch through which the supratrochlear artery passes.

01:34 And trochlear is a term that has to do with eye movements and eye muscles that we'll talk about in later sections.

01:43 For the squamous part.

01:45 We have borders with the zygomatic bone.

01:47 Borders with the parietal bone.

01:50 Borders with the sphenoid bone.

01:53 We also have borders with the nasal part.

01:57 And there are actually a lot of bones in this area that are pretty small.

02:01 For example, the nasal bone lacrimal bones, part of the maxilla.

02:05 And part of this deep bone called the ethmoid bone.

02:09 That has a plate that runs perpendicularly.

02:13 The frontal bone has a little gap on the medial aspect called the ethmoidal notch.

02:20 And that's going to be the location of the ethmoid bone.

02:25 We also have little depressions if we were to look upward from below, on the lateral aspects of the orbital area.

02:34 And those are fossa or depressions for the lacrimal glands.

02:38 Lacrimal means tears and these are the glands that are going to produce tear fluid.

02:45 We also have a shallow depression here called the trochlear fovea.

02:49 Which is a spot for the trochlea or a little pulley.

02:53 That interacts with one of the muscles of extra ocular movement.

02:59 Here we see that little trochlea or pulley and it's a fibrocartilaginous sling through which the muscle called the superior oblique passes through.