The Temporal Line: There's a Kansas City That Isn't In Kansas

Now that we've covered basic head anatomy in The Head: Part One of Oh My Gosh, Who Knows?, we're ready to observe the individual bones and landmarks of the skull. The first rule of thumb to establish is that bony landmarks of the head tend to be more prominent and visible in adult males. This is especially evident in the superciliary crest (a.k.a. brow ridge), the mental protuberance (a.k.a chin bump), the zygomatic arch (the bony ridge along the cheek) and the temporal line, which we'll look at more closely today.

The temporal line runs along the side of the head across two separate bones-- the frontal bone, which forms the forehead, and the parietal bone, which, with its bilateral twin on the other side, forms the "roof" of the head. 

The temporal line's name can be a little confusing for those first learning about skull anatomy, because we also have a temporal bone (shown in blue below). But, just to keep you on your toes, the temporal line is not on the temporal bone. The temporal bone, which is also bilateral, lies lower down on the side of the head. It's the bone on which the external ear rests, and in which the delicate inner ear structures lie. It's quite an elaborate cranial bone, so we'll take time to look at it and its many surface features later.

This whole situation was summed up nicely by one of my anatomy students last spring. Several students were quizzing one another in preparation for an upcoming skull test, and as they reviewed the temporal line, one said, "the temporal line is not on the temporal bone-- kind of like there's a Kansas City that isn't in Kansas." Indeed!

So let's take a look at the structures involved:

The temporal line (shown in red dashes) is a subtle ridge that runs across the frontal bone (shown in green) and the parietal bone (shown in peach). The temporal bone is shown in blue, but the temporal line does not run across the temporal bone.

Several anatomical structures in this area of the head have all or part of the word temporal in their names. The temporal line, the temporal bone, the temporal fossa (which is the shallow depression on the side of the cranium), the temporalis muscle (a muscle that rests in the temporal fossa), the temporal lobe of the brain (which is the part of the brain that lies on the sides of the head), and several temporal arteries and veins (blood vessels that run through this area). The only of these that we can observe directly on the surface, though, are the temporal line and the temporalis muscle (which we can sometimes see moving when an individual is chewing.)

The slightly sunken area on the lateral skull, just below the temporal line, is known as the temporal fossa.

The temporalis muscle rests in the temporal fossa, just below the temporal line (shown with a red dashed line). The movement of this muscles can sometime be observed when the figure is chewing.

As you can probably guess, most of the temporal line is obscured by hair (unless, of course, the individual in question is losing said hair). At its anterior end, though, it often shows up on the sides of the forehead, where hair would not get in the way. This is one of the skull landmarks that seems to be more prominent on older males-- particularly the bad guys in comic books. (Google Professor X to see what I mean.)

If you look around a little bit, you should have no trouble seeing examples of the temporal line. Even on an individual with a full head of hair, look for a ridge on either side of the forehead, positioned at the same degree laterally as the outer edges of the orbits.

What did I say about older males? Just take a look at Fred Thompson's temporal line. And really, next time you see your dad, take a close look at his forehead. There's a very good chance you'll see at least part of his temporal line. Perhaps all of it, if he's losing his hair!

Older males do not, however, hold a monopoly on the temporal line, as this photo of a bald Britney will demonstrate. She has quite a few prominent skull landmarks, so we'll revisit this image soon. And you thought her abs were defined!

Uncle Fester can join the fun, too. Not much hair blocking this one.

Hey, even individuals sewn together from spare parts can have a temporal line. Dr. Frankenstein was clearly meticulous in his attention to head detail.

The great Oz has spoken! His temporal line rules all! It's prominent as well as quite elaborate. Enough so to have haunted me as a child, anyway. Did anyone else worry that this guy was going to show up in their closet when they were trying to fall asleep?

And finally...

Here is one last shot of the temporal line, this time on my pal Tim. This is from my book, The Figure Artist's Book of Anatomical Landmarks, for which Tim was kind enough to pose. Tim is an accomplished a capella singer, so be sure to check out his group Chicago Voice Exhange!

Well, I think we've about exhausted this topic. Next time we'll either cover more head landmarks, or possibly to finish up one of the other several areas we've begun. Until then, go out and look for some temporal lines! They're everywhere! Even Kansas City.

Human Anatomy for the Artist at Chicago Comic Con

Just a quick post to let you know I'll be at table 3138 at the Chicago Comic Con this week, August 9 through August 12. I'm very happy to be sharing a table with Spiro's Greek Myths, a wonderful comic created by my friend Spiro Dousias.

Spiro will be selling his awesome comics about ancient Greek myths as well as his paintings and action figures of Greek gods and goddesses. I'll be selling my handy little anatomy book, The Figure Artists Book of Anatomical Landmarks. This is a good time to get yourself a copy without having to pay any pesky shipping fees! Also, bring your figure drawings by my table, and I'll be happy to check them out and answer any anatomy questions you might have.

I hope those of you planning to attend the Con will stop by and say hello. I'd love so much to meet you in person!

The Head: Part One of Oh My Gosh, Who Knows?

The human head is incredibly complex-- certainly too complex to try to write too much about it in one post. When I took gross anatomy in graduate school, we spent as much time dissecting the human head as we spent on the rest of the body. And for good reason. There's just a heck of a lot going on in there. On this blog, of course, we won't be discussing any of the deep structures, like the brain, the twelve cranial nerves, or the elaborate labrynth of cerebral blood vessels. But in this area of the body, even the surface landmarks are packed in. I would like very much to savor them one post at a time, but before we do this, we she should probably start with a head overview. 

The head differs a great deal from the rest of the body, even landmark-wise, because not much muscle shows here. There are muscles that obscure most of the skull, but they are very thin and flat and, as such, don't show much on the surface. Most of the facial muscles insert into the skin (as opposed to inserting on bone) because it's the skin that they move-- for the sake of facilitating facial expression. But most of the muscles themselves don't show up individually.

Sometimes we can see evidence of two cranial muscles, the temporalis muscle and the masseter muscle, because they contract a bit when we are chewing. The masseter, the thickest muscle on the skull, lies over a portion of the mandible, just anterior to the ear, and sometime even its striations can be seen during chewing. The wide temporalis muscle lies on the side of the head, just above the ear, and sometimes we can see it, too, flexing, when an individual is chewing or clenching. 

Movement of both the temporalis muscle and the masseter muscle can sometimes be seen when an individual is chewing. These are among the only muscles on the head that can be identified individually on the surface.

But other than these occasionally visible muscles, most of the head's prominent surface landmarks are bone. We'll cover each of these in future posts. But before we begin this, let's look at the basic structure of the skull.

The skull has two basic portions, the cranium and the facial region. These are good to keep in mind when drawing the head, because each has its own shape and the two together help define the form of the head. The cranium is the oval shaped, hollow portion of the skull that encases and protects the brain. It shaped somewhat like an egg and is tilted upward anteriorly. The facial region of the skull is the area on which the facial features (such as the eyes, nose, and mouth) rest. It's shaped like a mask and hangs off the front of the cranial egg shape. 

The image below shows a lateral view of the skull alone and with outlines of the cranial and facial regions. The cranium is shown in pink and the facial region is shown in blue.

The cranium is the egg shaped portion of the skull than encases and protects the brain. The cranial region of the skull is outlined in pink here. The facial region, outlined in blue, is the mask shaped portion of the skull. It's the area on which the facial features rest.

It's important to consider the shapes of both these regions when drawing the head. The region shapes may also be used to determine proper head proportions and to position the ear. When measuring any human head from its most anterior to its most posterior point, the halfway point almost always falls just behind the mandible and just in front of the ear. When drawing a head, placing a vertical line halfway back on it helps to properly position both the back edge of the mandible and the front edge the ear. This is demonstrated in the image below.

When divided in half from front to back, the halfway way point on the human head falls just posterior to the mandible and just anterior to the ear. This is helpful to know when placing an ear on a drawing of the head. The black lines here show the anterior and posterior halves of the head. The verticle strip of beige shows where tissue depth has been accounted for on the anterior side (since its greater here than on the posterior side.) The red line shows the placement of the ear behind the middle line.

In upcoming posts we will begin examining the individual bony landmarks of the skull more thoroughly. These include the superciliary crests, the zygomatic arch, the mental protuberance, the angle of the mandible, and the occipital protuberance, to name a few. This will take, well, who knows how long? But I don't mind! Do you? 

The Figure Artist's Book of Anatomical Landmarks: Here's the Order Form!

The Figure Artist's Book of Anatomical Landmarks has long been a reference guide for my anatomy students, but it's now available to all using the link below! The cost is $30 within the continental U.S. and can be paid with Venmo using this link or with Paypal using this link. Shipping and handling rates will be added to orders outside the continental U.S. Please email me at kristin@gm-studio.com for overseas shipping rates. More information about the book can be found below.

The Figure Artist's Book of Anatomical Landmarks is a quick reference guide to help the artist identify and understand the lumps, bumps, creases and depressions on the human body. Its clear, concise text and dozens of labeled photographs are organized by body region for handy reference. Its small size and soft cover make it convenient and portable, whether keeping it on your drawing table or taking it along to life drawing sessions. It is 7" x 7", 48 pages, black and white, with a soft cover. This book is best used in conjunction with more traditional anatomy books, as it is not a book of anatomical diagrams. It's consists primarily of figure photos with the anatomical surface landmarks labeled and accompanying descriptions of each, much like those seen on this blog. Here are two sample spreads, which are indicative of just about every page in the book.

 Thank you for your order! I am grateful and humbled by your support!

My New Baby! (Don't Call it Ugly.)

The first proof is in! It's small, it's one color, and some might even call it, um... ugly. But hey, it only had a three week gestation period. As its proud mother, I think it's beautiful, and I hope you will, too. (Or you could always lie to me.) In any case, it's packed with information, and I think it will be a very helpful resource to any figure artist exploring anatomical surface landmarks.

One thing I will admit, though, is that I'm going to have to spring for better quality paper. The stock I used for the proof just isn't working; it's super absorbent and the photos got so muddy. And the stock change will mean a change in layout as well. To make a long story short, the current book size won't allow for any other stock. So I have to do some rearranging. This means the book won't be printed quite as soon as I thought, but it should still be done by sometime in the next two weeks. I will post details as soon as possible!

I Hope Print Isn't Completely Dead Because I'm Making a Book!

A recent occurrence in the life of a friend (to be elaborated upon later) spurred an unexpected dive into a project I've been thinking about for years. Writing and diagramming for a blog is all fine and dandy, but despite my love of electronic media and its infinite educational possibilities, I still have a soft spot for print. So I've always dreamed of creating a book. A book with thick creamy pages that smells like a printing press. A book I can crack open for the first time and run my fingers over after hugging the UPS guy and dragging my eagerly awaited shipment box into the house. Until recently this dream has been next to impossible without an official publisher, but now that the printing process has evolved beyond the expensive and limiting, it's possible for us less-than-famous-or-well-known-or-prolific writers to get some of our own goofy little projects printed.

As such, I'm inhaling deeply and jumping into the world of print-- for a short time anyway. Yep, I'm making a little booklet of anatomical landmarks references for figure artists. It will include diagrammed photos, illustrations, and concise explanations of labeled structures. Its intended purpose is to function as a handy reference guide for figure artists who are stuck on any particular area of the body and would like some extra anatomical guidance.

The book will be organized by body regions, including head, neck, shoulders, anterior, lateral, and posterior torso, upper arm, forearm, hand, hip, thigh, lower leg, and foot. Heck, I may even throw in an ear and eye page is there is enough space. Each area will be shown from a variety of angles and everything will be labeled clearly and thoroughly.

Below is a sample photo from the book, showing the axilla and medial upper arm. It also shows one of my cabinets and some dishes in it because, yeah, I'm not a professional photographer. No matter, we can see lots of anatomical structures, right? Not sure if this specific image will make it into the final cut (I'm still shooting and slashing and re-shooting and editing) but we'll see. Regardless, why don't we take a little time now to talk about what we're seeing here?

OK, first a word about the weird numbering. In this image, I used the same numbers as in another photo on the page (in which they are in order.) Ah, it'll make sense when it's in print. I hope!

The axilla (the anatomical term for the armpit) is formed by two muscles-- the pectoralis major (10) anteriorly, and the latissimus dorsi (11) posteriorly. Up inside the axilla, we can see a short muscle called coracobrachialis (12.) It is given this name because it runs from the coracoid process on the antero-superior scapula down to the humerus bone in the upper arm. (The Latin root brachio- refers to the upper arm.)

Just before coracobrachialis inserts on the humerus, it tucks under biceps brachii (4), the most obvious superficial muscle on the anterior upper arm. Just deep to biceps brachii at its distal end is the brachialis muscle (13) which can be seen peeking out on either side of biceps brachii (although its borders are not very obvious here.) We can also see the long (8) and medial head of the triceps on the medial upper arm. The only bony landmark we see on the medial upper arm is the medial epicondyle at the distal end of the humerus. Another visible structure in the area is the deltoid muscle (3) that covers the top of the shoulder.

Just posterior to the coracobrachialis (12) we can see another soft lump of tissue labeled with an F. This is not a muscle, but a small mass of fat tissue that cushions and protects a few structures that course through the underarm, including the basilic vein, the median and ulnar nerves, the brachial artery, and some lymph nodes, which feel like lumpy little jelly beans in the armpit.

There are also a few structures in the image that, while unrelated to the upper arm, warranted acknowledgment for their clarity. Those are the clavicle (C) and the sternocleidomastoid (SCM) muscle on the anterior neck.

The book should be printed and on sale by sometime in June! I will post more information then. See you next time!

Vestigial Traits: You May Not Need Us, But We're Still Here

Short post today. I have a side project in the works, the details of which are soon to come! Until then, how about a short post about human vestigial traits! 

Because my anatomy course is for art students, its content is designed almost entirely around the human body's superficial structures-- mostly muscles and bony landmarks-- that dictate the external human form. But occasionally (well, OK, often) we go off on random tangents during which students asks about other anatomical structures or physiological processes. And I have to admit, these random questions are one of my favorite parts of the class.

One subject that comes up often is that of human vestigial anatomical structures. Vestigial structures are those that had a purpose in earlier evolutionary forms of ourselves, but now have little or no function. As evolution allows us, as a species, to slowly adapt to our environment and our circumstances, certain structures become unnecessary. With each generation these structures become slightly less prominent, until they are slowly phased out altogether. Our vestigial structures (and reflexes, for that matter) are those which still remain in some form but no longer serve much of a purpose. One example is our coccyx bone, which is the remains of what use to be caudal vertebrae, or bones of a tail.

Here is a nice summary of ten vestigial traits that still occur in humans today. Enjoy, and I will be back soon with a new posterior torso post as well as more news about my new project!