sassynach – Page 2 – Outlander Anatomy

September 29, 2015September 29, 2015

“Aye, Eye – The Eyes – Part 2!”

Greetings faithful anatomy students! Today we continue our studies of the complex and elegant eye in Anatomy Lesson #30, The Eyes – Part 2. Anatomy Lesson #29 covered anatomy and function of eyelids, eyebrows and eyelashes. Today, we will discuss other structures that are designed to aid the eye in the vision it provides: bony orbit, orbital fat (yes indeed!), conjunctiva, lacrimal apparatus, and extraocular muscles.

And just to set the mood, eyes are extremely important in the English language. A quick glance (ha ha) yields more than 200 eye idioms: catch one’s eye, apple of one’s eye, in the blink of an eye, more than meets the eye, in a pig’s eye, all eyes and ears, a bird’s eye view, a sight for sore eyes, easy on the eyes, bedroom eyes (we know who has THOSE! ?), can’t take eyes off of, eye for an eye, catch one’s eye. Well, you get the idea…references to the eye makes English more colorful! Blink. Blink. Wink. Wink.

SPOILER ALERT: early in this lesson a wee spoiler appears from Diana’s eighth book of the Outlander series: no names, no dates, and no places. A warning will surface beforehand. Look for this (heehee…this is going to be fun!) obnoxious, glaring, flashing sign so you can skip and not whinge about something you would rather not read. Don’t say I didn’t warn ye!

Let’s begin this lesson by considering the bony home for the eye. Each eyeball dwells in a cave known as the bony orbit (Photo A – dashed black line). Each orbit is composed of skull bones, some of which are so thin they readily transmit light (Photo A – black arrow). It isn’t even Halloween yet – Boo! ?

Photo A

A whopping seven skull bones form each bony orbit. These are difficult to distinguish in the adult skull where the bones are fused, but easily discerned using a color coded image (Photo B – right bony orbit):

Blue = fontal bone

Orange = zygomatic bone

Green = maxillary bone

Violet = lacrimal bone

Grey = ethmoid bone

Pink = palatine bone

Gold = sphenoid bone

The bony orbits protect and support the eyeballs and provide attachment for several accessory structures. Although difficult to appreciate in a two-dimensional figure, each orbit is shaped like a cone: the apex (point) lies at the back and the base, or orbital rim, faces front (Photo B – dashed black line). Each apex has holes which serve as access ports for nerves and blood vessels to enter and leave the bony orbit (Photo B – red stars). The orbital rim, roof and temporal (side) walls are thick and strong but the nasal (medial) wall and part of the floor are thin and delicate (Photo B – black arrows). In fact, each medial wall is so thin it is known as the lamina papyracea (Latin meaning paper layer)!

Photo B

Indeed, a direct blow to the bony rim can break any of walls but the medial wall and floor are most commonly disrupted. Known as a “blowout” fracture, this injury appears in one of Diana’s prolific writings!

SORTA SPOILER ALERT: The following quote describes this type of injury. If you don’t want to read it skip the next two quotes and images and head straight for the furry mammal with the big eyes. NO! Not Rupert! It has orange eyes and Rupert doesn’t.

Herself correctly describes the consequences of a blowout fracture suffered by a character in her 8^th book, Written in My Own Heart’s Blood, a.k.a. Moby. Claire relates:

A split lip and badly swollen eye seemed to be the chief injuries… The eye was swollen half shut …the underlying flesh a lurid palette of green, purple, and ghastly yellow. The eye itself was red as a flannel petticoat … I couldn’t move the globe of the eyeball upward at all…

Clinical Correlation #1: Photo C shows the appearance of a right eye (on your left) with a classic blowout fracture juxtaposed with a normal left eye. The left eye has a white sclera, normal skin of eyelids and cheek and, when tested, the patient can elevate (lift) the normal eye. The right eye is patently abnormal: the sclera is red due to hemorrhage and the eyelids and cheek are bruised and swollen also due to hemorrhage. The right eyeball cannot be raised in tandem with the left eye; it is frozen with the gaze directed forward. Failure to elevate the right eye occurs because a small muscle of the eyeball (inferior rectus – see below) is trapped within the fracture, anchoring the globe and preventing its lift.

Photo C:

And, continuing the quote from Moby – again, Dr. Sassynach is our observer:

It was almost certainly what was called a “blowout” fracture, which had cracked the delicate bone of the orbital floor and forced a displaced bit of it—along with part of the inferior rectus muscle—down into the maxillary sinus. The edge of the muscle was caught in the crack, thus immobilizing the eyeball.”

YOU CAN LOOK NOW!

See, I told ye it wasna Rupert!

Photo D is a vertical CT scan through the skull. The paired ghoulish-looking white rings are the bony orbits. The patient’s left orbit (on your right) is normal; the black triangular space below it is the normal left maxillary sinus. These are separated by a thin white line, the orbital floor (Photo D – green arrow). The patient’s right eye shows a blowout fracture. The red arrow points to the white, broken and dangling bony bit of the orbital floor. The right maxillary sinus is grey because it is filled with displaced orbital tissues: the light grey material is prolapsed orbital fat (see below) and the aforementioned inferior rectus muscle (Photo D – blue arrow) which is trapped in the fracture anchoring the eyeball so it cannot be elevated. Very interesting stuff!

$Blowout-fracture-KLS-edited$

Photo D

Now, structures other than eyeballs inhabit the bony orbits, including extraocular muscles, blood vessels, nerves and orbital fat. However, the eyeballs do not touch the bones of the orbit. Rather, they rest-in-a-nest of orbital fat that fills all the nooks and crannies not otherwise occupied. Orbital fat acts like a shock absorber cushioning the eyeball against trauma; it also serves as a socket in which each orb glides, slides and rotates. Photo E shows a horizontal section through the right eyeball and bony orbit; the cone shape of the bony orbit is easily appreciated from this birds-eye view (Photo E – black dashed lines). For orientation, the cornea and superior tarsus are labelled (Anatomy Lesson #29). See the yellow globs of “stuff” surrounding the eyeball? This is orbital fat and it is surprisingly abundant! Periorbital fat is also present but it lies superficial to the bony orbit being confined to eyelid margins and overlying orbital rim and cheek bone/zygomatic arch (Anatomy Lesson #8).

Try this: Close one eye and gently tap the soft tissues around the eyelids and overlying the orbital rim and zygomatic arch. Feel the springy and spongy nature of the soft tissues? This is periorbital fat. Orbital fat lies deep in the bony orbit and cannot be readily palpated.

Photo E

Most of the exposed eye is covered with the conjunctiva, a transparent, vascular mucous membrane. Bulbar conjunctiva overlies the sclera (white part) of the eyeball but it stops at the corneal rim and hence, does not cover the cornea. Palpebral conjunctiva lines upper and lower eyelids (Photo F).

Photo F

This design is possible because the conjunctiva reflects (turns) from the sclera onto the insides of upper and lower eyelids (Anatomy Lesson #29). This reflection creates a blind pocket or fornix where the sheet of conjunctiva turns from one surface onto another (Photo G – vertical section through eyeball and lids of eye). Thus, objects trapped on the exposed surface of the eyeball (e.g. contact lens) cannot move into the deep recesses of the bony orbit unless the conjunctival fornix is torn. The conjunctiva secretes mucus and contributes to the tear film (see below); it also produces immune cells that help protect the eyeball from microbes.

Photo G

Now, it is time to consider the lacrimal apparatus (Latin meaning tears), an uppity name for the system which produces and drains tears. The lacrimal apparatus for each eye includes a lacrimal gland, lacrimal canaliculi, lacrimal sac and nasolacrimal duct.

The lacrimal gland is roughly the size and shape of a large almond. Most of it lies inside the bony orbit but a smallish part sits in the outer upper eyelid (Photo H). The purpose of the gland is to secrete (discharge) the aqueous part of the tear film. Several small ducts (tubes) pierce the conjunctiva and empty the secretion onto the surface of the eyeball.

Photo H

As the palpebral parts of orbicularis oculi (Anatomy Lesson #29) close the eyelids, the tear film sweeps across the exposed surface of the eyeball. To understand where it goes next, please see Photo I. Near the nasal ends of upper and lower eyelids, the eyelashes (Anatomy Lesson #29) disappear and small elevations appear on the lids; these are superior and inferior lacrimal papillae (pl.). Each papilla bears a small opening, the lacrimal punctum.

Try this: Face a mirror and gently pull down on the lower eyelid. See the small bump near the medial canthus (Anatomy Lesson #29)? This is the inferior lacrimal papilla. Find its tiny opening, the inferior lacrimal punctum. Repeat with the upper lid.

Photo I

As the eyelids close, the tear film is swept toward the lacrimal puncta (pl.). Tears then enter the puncta and drain through the next group of lacrimal structures: lacrimal canaliculi (pl.), lacrimal sac and nasolacrimal duct. The paired lacrimal canaliculi are tiny ducts, each leading from its respective punctum to the lacrimal sac, an enlargement at the side of each nasal cavity. Tears then drain into the longer nasolacrimal duct.

Photo J

The nasolacrimal duct opens into the outer wall of each nasal cavity (Photo K – outer wall of right nasal cavity) under shelter of the inferior concha (Anatomy Lesson #28). After collecting in the nose, we blow out or swallow our tear film.

Hard to believe, but the thin tear film (40 µm or .0016 in) has three layers: 1) a deep mucous layer made by specialized conjunctival cells; 2) a middle aqueous film produced by the lacrimal glands; 3) an outermost lipid sheet released by tarsal glands (Anatomy Lesson #29).

Excessive tearing caused by pain or intense emotion, floods the lacrimal system, spills over the cheeks and fills the nasal cavity; this is why our nose “runs” when we weep.

Photo K

Can we see lacrimation (flow of tears) at work in Starz episodes? Oh, aye! Claire is a strong 20^th century woman but I count at least six season one episodes where she weeps. This is my favorite: the lass is touchingly, tenderly tearful while confronting her beloved hubby about his intent to end it all (Starz episode 116, To Ransom a Man’s Soul). Intense emotions have her lacrimal system in full flush!

Speaking of crying, Jamie presents us with a gut-wrenching, Emmy-worthy (AHEM!) performance as a single tear overflows his lid and slips down his face. Bound by his word, he stays absolutely still as the wicked wolverine (oops, Wolverton) of Wentworth messes with his scars (Starz, episode 115, Wentworth Prison). Ugh! Puir lad!

In addition to the above structures, each eyeball is moved by six extraocular muscles (intraocular muscles are inside the eyeball). These are all voluntary, strap-like muscles: four are recti (pl., Latin meaning straight) and two are oblique. The four recti muscles arise at the apex of the bony orbit, pass directly forward and attach to the eyeball like the hours on a clock face. In a left eyeball (Photo L – left eye) superior rectus inserts at the 12:00 position, inferior rectus at 6:00, lateral rectus at 3:00, and medial rectus at 9:00. Understand that the positions of medial and lateral recti are reversed in a right eyeball: medial rectus inserts at 3:00 and lateral rectus at 9:00. Superior oblique and inferior oblique are so named because they approach and insert into the eyeball at oblique angles.

Figure L

Movements of the head provide coarse adjustments to eye position but the extraocular muscles produce fine movements of the eyes. The four recti move each eye in linear directions: up (elevate), down (depress), toward the nose (adduct) and toward the ears (abduct). Oblique muscles roll each eye inward toward the nose (intorsion) or outward toward the ears (extorsion). The table below shows the main movements attributed to each of the six extraocular muscles. Each of these movements is aided by other extraocular muscles but these combos are beyond the scope of this lesson. Extraocular muscle movements are complex and require activation by three pairs of cranial nerves (from the brain) and several brain centers (too complex for our lesson).

Superior rectus	Inferior rectus	Medial rectus	Lateral rectus	Superior oblique	Inferior oblique
elevates	depresses	adducts	abducts	intorsion	extorsion

Each extraocular muscle has a yoke muscle that operates in concert to coordinate the gaze. For example, when we gaze to the right, the left medial rectus adducts the left eyeball and the right lateral rectus abducts the right eyeball. When we gaze to the left, the opposite muscle actions occur. Ditto for the obliques: as we roll our eyes to the right, the right inferior oblique contracts in tandem with the left superior oblique. The opposite muscles engage as our eyes roll to the left.

NOTE: both medial recti muscles adduct our eyes as we examine near objects but we will revisit this issue in the next eye lesson. Personally, I have never known a person who could simultaneously contract both lateral rectus muscles to abduct the eyes (eyeballs point toward the ears) although in an 1837 article from The London Medical Gazette, the author states that some men (?) can perform this maneuver. What about those lassies?

Speaking of maneuvers…get a keek of this! Och! All those lovely eye muscles working in tandem give us that gaze! Gah!

A simplistic description of the extraocular muscles at work can be seen at this link https://www.youtube.com/watch?v=f4RxYRpIqLs!

Or, for an interactive and sophisticated version, try this link. It’s a bit involved but here’s how it works: go to the site http://www.bmc.med.utoronto.ca/anatomia/intro.swf, select orbit, then select structure & function, and lastly, select extraocular muscles. On the right is a giant H with a four-arrow circle. Capture the circle with your mouse and move it along the H to activate and view the six extraocular muscles at work. Very cool!

Hey, here’s a novel idea, let’s use more Starz episodes to help us understand eye movements! Time for Claire to hop onto the dissection table: here she contracts both superior recti to elevate her eyes (Starz, episode 103, The Way Out). She’s had, oh, um, roughly one hogshead of Colum’s finest rhenish wine – she canna really recall but enough to drop Angus under the table. Even Jamie is waaay impressed! Claire’s eyes also demonstrate an interesting Eye Rule #1: lift the eyes – lift the lids meaning levator palpebrae superioris (Anatomy Lesson #29) and superior recti muscles contract together.

Try this: close both eyelids. Now attempt to elevate the eyes while keeping the eyelids closed. You’ll find it is difficult to almost impossible because of Eye Rule #1: lift the eyes – lift the lids. If you can lift your eyes while keeping the lids closed, then per Rudyard Kipling (the (wo) is my addition):

By the livin’ Gawd that made you,

You’re a better (wo)man than I am, Gunga Din!

Claire is still in the dissection lab as both inferior rectus muscles contract to depress her eyes (Starz, episode 109, The Reckoning). Note that her upper eyelids are also lowered. She’s totally pissed at Jamie ‘cause his sword belt gave her a licking (Not the only lickin’ she gets. Snort)! Now, I could be wrong, but isna she wrapping her hair with an elastic band in prep for beddy bye sans Big Red One? Har har. Don’t think those bands were invented for another century or so. Eye Rule #2: lower the eyes – lower the lids; as the eyes depress (look down), the eyelids lower; inferior recti and palpebral part of orbicularis oculi contracting together. Yes! Bravo!

Try this: With eyelids widely open, try depressing your eyes. It is possible but verra difficult.

Ooooh! If looks could kill, Claire would be six feet under right here, right now! Casting the evil eye, wee wily LegHair (dissing the character not the awesome actress!) glares at Claire and Jamie as they share wine, words, gazes and body heat (Starz, episode 103, The Way Out)! Yoked together, her right lateral rectus abducts the right eye and her left medial rectus adducts the left eye. Her eyes are slightly elevated because her head is tilted to the right. Got it? Super-duper!

Now, LogHare isna the only character who can coordinate eye movements: fury and fear curdle Jamie’s wame as he watches Black-Jack-Rat run a dagger tip along Claire’s linea alba (Anatomy Lesson #16). He’s so friggin’ mad and scairt he can scarcely contain himself (Starz episode 109, The Reckoning). Yoked together, the right medial rectus adducts his right eye and the left lateral rectus abducts his left eye. Both eyes are also slightly elevated because his chin is tilted down. This keeps his gaze focused on the “object” of interest – rat man. Ye ken? Grand!

Let’s finish this lesson with some interesting tidbits about leeches (Hirudo medicinalis). Ahhh… What do leeches have to do with eyes? Well, hang on and let’s find out! Leeches have a long shared history with humankind. A mural from an 18^th dynasty tomb in Thebes shows that leeches were used for medical purposes as early as 1300 B.C. Later, Latin and Greek writers Plautus, Cicero and Horace wrote of medicinal leeches using the names of bdella, sanguisuga or hirudo. The English word leech is from the Old English word “laece,” meaning doctor! Yikes! Today, many modern medical centers employ leeches in plastic surgery and trauma medicine especially to relieve venous congestion (Photo M). Mother Nature at her verra best!

Photo M

In the 18^th century, medical practitioners transported leeches in special containers. Talk about fancy pet carriers! These beasties were not only placed on the skin but in some pretty hard to reach areas such as mouth, conjunctiva, rectum and vagina (Photo N – 18^th & 19^th century leech carriers). The clear tube at the bottom of this pic was used for placement in hard-to-reach places!

Photo N

And, when not being transported, leeches were kept in some verra purty jars. Nice housing, guys!

Photo O

Herself writes about leeches and healing in Outlander book. After Rupert beats Jamie in the great hall, Mrs. Fitz places leeches on his swollen face. Claire describes the event:

“That eye, now, lad, let’s have a look at that.”… “Still bleedin’ under the skin. Leeches will help, then.” She lifted the cover from the bowl, revealing several small dark sluglike objects, an inch or two long, covered with a disagreeable-looking liquid. Scooping out two of them, she pressed one to the flesh just under the brow bone and the other just below the eye… she explained to me, “once a bruise is set, like, leeches do ye no good. But where ye ha’ a swellin’ like this, as is still comin’ up, that means the blood is flowin’ under the skin, and leeches can pull it out… When ye use ’em on an old bruise, they just take healthy blood, and it does the bruise no good.”

The fabulous leech scene was filmed but edited from the aired version (Starz episode 102, Castle Leoch). So, here’s a wee bit of the deleted footage where Mrs. Fitz works leech magic (purported to be black licorice) on Jamie’s red and swollen left eye and cheek (see gif). Rupert’s eye punch broke blood vessels that hemorrhaged into extraorbital fat and loose connective tissue of eyelids, brow and cheek. Had the punch directly hit the bony orbit and eye, Jamie could have suffered a blowout fracture!

Claire de-claires (ha ha) that the leech-leach induces remarkable improvement, but she also uses this as a chance to cradle Jamie’s face. Yep! This lass just wants to pet that lad’s epidermis! Hang on, Claire – more skin touching is, erm, coming!

Eyes are endlessly amazing and today, we learned more about their accessory structures. Next lesson, we will study the eyeballs! For now, let’s end today’s fascinating topic with a quote about the oblique muscle action from funnyman Jim Carrey:

“Behind every great man is a woman rolling her eyes.”

A deeply grateful,

Outlander Anatomist

photo creds: Starz, www.sussexvt.k12.de.us (warning gif), Medicine: Perspectives in History and Art by R. E. Greenspan, 2006 (Photo O – 19^th century leech jars), Netter’s Atlas of Human Anatomy, 4^th ed. (Photos B – L), www.aapos.org (image of blowout fracture), www.collectmedicalantiques.com (Photo N – image of leech carriers), www.leeches-medicinalis.com/the-leeches/biology (Photo M – image of leech), www.radiopaedia.org (CT image of blowout fracture), http://funny-pics-fun.com (lemur)

August 25, 2015August 31, 2015

Fun Fact – Borborygmi

Learn more about borborygmi in Anatomy Lesson #16: Jamie’s Belly or Scottish Six-Pack!

And from Outlander book:

I wasn’t at all thirsty, but the faint scent of honey reminded me that I was starving, and had been for some time. My stomach gave an embarrassingly loud growl, protesting my neglect. “Hey, then, Jamie-lad! Hungry, are ye? Or have ye a set of bagpipes with ye?” shouted Rupert, mistaking the source of the noise. “Hungry enough to eat a set of pipes, I reckon,” called Jamie, gallantly assuming the blame. A moment later, a hand with a flask came around in front of me again. “Better have a wee nip,” he whispered to me. “It willna fill your belly, but it will make ye forget you’re hungry.”

See Jamie stave off Claire’s borborygmi in Outlander, Starz, episode 101: Sassenach!

The deeply grateful,

Outlander Anatomist

August 18, 2015August 19, 2015

“The Savvy Sniffer – Claire’s Nose Knows!”

Welcome, students to Anatomy Lesson #28 – The Nose! Oh, you don’t think the nose sounds very interesting? Well, please read on because this lesson contains surprising, startling and shocking info about the human proboscis.

Is the nose important to society? You bet! There is a mess of English idioms about the nose including: as plain as the nose on your face, nose to the grind stone, turn nose up, brown nose, follow one’s nose, cut one’s nose off to spite one’s face, count noses, nose for gossip, win by a nose, keep nose out of business, no skin off one’s nose, nose about, nose to the ground, look down one’s nose at, nose around, and nose-to-nose. Clearly, the nose is a clever conduit to convey important social messages.

Oh, and let us not forget the nose-out-of-joint idiom! Claire and Jamie are clearly in that realm going at it “Down by the Riverside.” Pretty simple really: Jamie expects an apology and Claire isna giving one (Starz episode 109, The Reckoning)! He told her to STAY PUT but she doesna have to do what he says! She’s his wife and she doesna like that one bit! Whew, their passionate noses are fully engaged in this battle of wills!

Those who read Diana’s books know that Claire is endowed with a very keen sniffer. Her nose catalogues a staggering array of smells including but certainly not limited to: alcohol, bat guano, bitter almonds, blood, clover, feces, grass, herbs, honey, hops, ink, laundry starch, opium, pickled herring, pine needles, pine tar, pitch, pus, raw sewage, resin, road dust, seasickness, soap, sulfur, wine, wood smoke, yeast and last but not least, male sweat! Jamie, Himself offers a fine flattering appraisal of Claire’s nose (Voyager book)!

“’You smell of ink.’” He smiled slightly, stepping back and running his hand through his hair. ‘You’ve a nose as keen as a truffle pig’s, Sassenach.’ ‘Why thank you, what a graceful compliment,’ I said.

At the base of Craigh na Dun we see more proof of her superb sniffing skills. Claire’s knowing nose encounters Frank dressed in 18^th century soldier garb (Starz episode 101, Sassenach). Oops, it isn’t Frank, but his six-time great grand paternoster: Jonathan Randall, Esquire, Captain of his Majesty’s Eighth Goons, er, Dragoons! Ugh, he’s too close for comfort as Claire analyzes his personal plethora of peculiar odors:

“My captor, whoever he was, seemed not much taller than I…. I smelled a faint flowery scent, as of lavender water, and something more spicy, mingled with the sharper reek of male perspiration.”

His miasma of lavender and male sweat doesna appeal to Mistress Claire; her nose knows a real stinker when it sniffs one. But, dinna despair lassie, a braw and bonny laddie is coming your way pronto! Ye will like the whiff of him. No problema!

Anatomy of the human nose is fascinating so let’s get started! Nose and chin are typically the most projecting parts of the face. In anatomy, the nose is divided into external nose, the visible projecting part, and internal nose, the part deep to the surface. In anatomy, the nose belongs to the respiratory system because it serves as a passageway for air flow during respiration: nitrogen, oxygen, carbon dioxide, and argon, along with trace elements and other particles move through the nose on their way into and out of the lungs.

The external nose has a root that is continuous with the forehead (Photo A – red arrow). The tip of the nose is its apex. The paired nostrils are the nares. The bridge is formed of bone and cartilage and the alae (pl. – Latin meaning wings) are the nasal flaps. Nasal skin is typically thin (Anatomy Lesson #5 and Anatomy Lesson #6) and adheres tightly over the alae but elsewhere is quite moveable.

Photo A

The skeleton of the external nose is composed of bone, cartilage and fibro-fatty tissue that mimics the external shape. The bridge includes a pair of small nasal bones (Photo B) that form non-movable joints between themselves and with frontal (forehead) bone and nasal cartilages. Nasal cartilages include a septal cartilage most of which is internal and alar cartilages that form sides and tip of the nose as well as much of the nares. Finally, the nasal flaps are made of fibro-fatty tissue – mostly collagen fibers interspersed with fat cells. There are some small accessory nasal cartilages also, but we won’t concern ourselves with these.

Try this: Grip the upper bridge of your nose and wiggle your fingers. Normally, it won’t budge because the nasal bones are firmly-anchored. Slide fingers toward the apex and wiggle it; this part moves easily because it is formed of flexible cartilage. Now, find the juncture between hard and flexible areas; this is where nasal bones meet nasal cartilages.

Photo B

Clinical Correlation #1: ever seen a broken nose? Not a pretty sight. One may look a bit like wee, wild Willie’s nose after the tavern brawl (Starz episode 5, Rent). It was his first time on the road, but being a true Highlander, the lad held his own. The bloody jagged line across the bridge of his nose lies near the juncture between nasal bones and cartilages, a common site to suffer a broken nose.

As you might imagine, nasal fractures range from mild to severe and symptoms include: pain and swelling that persists after 3 days, crooked nose, difficulty breathing through the nose even after swelling decreases, fever and recurrent nosebleeds. If clear fluid starts leaking from an injured nose, get to an emergency room pronto as this could be CSF (cerebrospinal fluid)!

The external nose also has two muscles (Photo C): nasalis (Latin meaning pertaining to the nose) and depressor septi nasi (Latin meaning pull down nasal septum). The alar part of nasalis lifts and flares the nasal alae to open the nares. A transverse part of nasalis compresses the alae to close the nares. Depressor septi nasi aid the transverse nasalis muscles by drawing down the septum.

Photo C

Do we see examples of the nasalis muscles at work in Starz episodes? Aye we do! Jamie’s grand, garrulous (ha) godfather offers a terrific example for our viewing pleasure. Here, dour Murtagh glares at Claire as they scour Scotland for their beloved Lallybroch Laird (Starz episode 114, The Search)! It’s easy to tell if the nasalia (pl.) muscles are contracted because the alae flare deepening the furrow between them and the sides of the nose.

The internal nose consists of two slit-like nasal cavities separated by a midline nasal septum. Nasal cavities begin at the nares as right and left vestibules, each lined with thin skin and coarse hairs that trap unwanted particles (Photo D – left septum). The nasal cavities extend posteriorly ending at the choanae, a pair of openings on either side of the septum that are continuous with the nasopharynx or back of the throat (Photo D).

Each nasal cavity has floor, roof, septal wall and lateral wall. The floor is made of bony palate that separates nasal and oral cavities (Photo D – blue arrow). The septal wall or nasal septum is flat, smooth and divides the paired nasal cavities (Photo D – left side of nasal septum). A whopping seven cranial bones plus the septal cartilage form the nasal septum but these will not be covered in this lesson. When we are young, the septum is typically straight but trauma, disease or age can create a deviated septum, a condition which may interfere with air flow on the narrowed side.

Photo D

Unlike the septal walls, the lateral walls are complex; each is convoluted into three chonchae or turbinates that project like drooping shelves into their respective nasal cavity (Photo E). Humans also have four sets of paranasal sinuses with openings that drain into the lateral walls but these will be covered in a later lesson. The roof of each nasal cavity is described below.

Photo E

Excepting the vestibule, all surfaces of the nasal cavities are covered with mucous membrane (red surfaces in Photos D and E) so named because all cells of the surface layer are living as opposed to skin wherein the topmost cells are dead. The mucous membrane of floor and septal and lateral walls include a surface layer called respiratory epithelium. Deep to the nasal respiratory epithelium are glands which release mucus and watery fluids forming a surface coat that hydrates and moistens the entire mucous membrane (Note: mucous is adj. form and mucus is a noun – these are not misspellings).

Nasal respiratory epithelium includes six types of cells but we will cover only the ciliated cell because it is really special. Photo F isn’t an image of heather covering a Scottish Munro; it is a scanning electron micrograph (SEM) of nasal respiratory epithelium. We have seen SEM images before in skin (# 5 and #6) and inner ear (#25) anatomy lessons. SEM micrographs are 3-D images showing highly magnified surface details. Thus, in Photo F, the pinkish shag carpet is actually cilia, motile “hairs” projecting from the surfaces of ciliated cells. Cilia of the front of the nasal cavities beat toward the nares to kick out mucus and unwanted debris; cilia toward the back of the nasal cavities beat toward the pharynx where debris and mucus can be swallowed or coughed out. Cool, huh?

Photo F | Photo credit: Steve Gschmeissner

Now, let’s return to the scroll-like lateral walls of the nasal cavities. Why the complex shape? First, the shelves increase surface area of mucous membrane to help warm and humidify inspired air before it reaches the delicate lungs (Photo G). Second, air is tumbled as it flows over the chonchae trapping air-borne particles in the mucous film so cilia can move this stuff toward the nares or the pharynx. An ingenious design indeed!

Clinical Correlation #2: Cigarette smoking (are you weary of this topic?) causes respiratory epithelium to be replaced with a more durable type such as lines the mouth. Unfortunately, the replacement epithelium lacks cilia so particles and mucus cannot be properly removed. Further, these changes are not limited to nasal respiratory epithelium but occur throughout the airways even into the lungs and are the basis for smoker’s cough. And, in case you are wondering, yes, routine marijuana smoking causes similar changes to respiratory epithelium. As for e-cigarettes, the jury is still out on this practice because it is new. However, early results indicate that it is also deleterious to respiratory epithelium. Don’t mean to preach… just sayin’! It’s my job, ye ken?

Photo G

Now, a moment for something truly fascinating: deep in the nasal mucous membranes are structures known as swell bodies. It’s true! Would I lie to you? Here’s what they look like. Och, sorry students, wrong image! These are swell bodies but not the swell bodies of nasal mucous membrane (Starz, episode 107, The Wedding)!

Lost me train of thought…Oh, there it is! The mucous membranes of both nasal cavities contain an extensive plexus of vessels labelled “network of veins” in Photo H, a LM (light micrograph) taken of a thin section of nasal mucous membrane after staining with pink and blue dyes.

This extensive plexus of veins constitutes swell bodies of nasal mucosa (in each nasal cavity), a type of erectile tissue like that of male and female phalli (pl.). During sexual arousal, the venous spaces of the phallus fill with blood causing the organ to become turgid and erect. Well, something very similar occurs to the swell bodies of the nasal cavities. YES, it does! Regulated by the brain (hypothalamus), the swell bodies of one nasal cavity fill with blood while those of the opposing side drain. Known as the nasal cycle, every so often the sides flip such that swell bodies of the opposing side engorge with blood while the former full side empties. How long is the interval? Well, it varies from about 30 minutes to a few hours. Normally, we are unaware of the nasal cycle because overall airflow remains constant. Why do we have a nasal cycle? Well, air flow is reduced through the engorged side allowing it to rest and rehydrate. Then the sides flip so the other nasal cavity can recuperate. Isn’t this wondrous? It boggles the mind!

Try this: Slowly inhale and exhale. Can you feel air moving more freely through one nasal cavity? This is the side with empty swell bodies whereas swell bodies are filled with blood on the closed side. Wait an hour or so and see if the sides flip. Note: if you have a deviated septum, active allergies or a cold this phenomenon will be difficult to demonstrate.

Photo H

Lastly, we must consider the roof of the nasal cavities. The roof is endowed not with respiratory epithelium but with olfactory epithelium (Photo I – blue area). Taste buds of the oral cavity detect five distinct qualities of taste, but our noses distinguish hundreds of substances even in minute quantities. Being more diversified, olfaction (smell) also aids our sense of taste. And to further refine the issue, we detect odors during inhalation but the taste boost occurs during exhalation.

Photo I

Olfactory epithelium is composed of numerous olfactory neurons (nerve cells) which collectively form the olfactory nerve or Cranial Nerve I (Photo J). Airborne molecules bind to the surface of the olfactory neurons causing them to depolarize. This electrical response travels along the olfactory bulb (Photo J) before distributing to olfactory areas of the brain where smell is perceived and interpreted.

Lastly you should know that our ability to detect odors decreases with age, a change usually more pronounced in men than in women. People often do not recognize the loss unless they also experience a decreased sense of taste.

Photo J

Clinical Correlation #3: Neurons are terminal cells meaning early in life they cease to divide and proliferate. Olfactory epithelium is exceptional because these neurons retain the amazing ability to divide and replace themselves throughout life.

You all ken that major spinal cord injuries do not repair because surviving neurons cannot divide to replace damaged or dead neurons. Well, recently, Polish doctors transplanted olfactory neurons (his own) into the spinal cord of a man paralyzed from the chest down in the world’s first attempt to reverse paralysis using this technique. The hope is that olfactory neurons transplanted to the spinal cord will proliferate, connect with and stimulate his paralyzed muscles. You can follow his progress at Spinal Cord Injury Zone. Let’s send him and his health care team our best wishes for success!

Now, for more fun stuff: let’s peruse Starz images and book quotes for more about splendid noses; there are many!

After being whacked on the heid by Murtagh’s dirk, Claire awakens astride a horse and immediately analyzes his fine fecund funk (Starz episode 101, Outlander):

“I knew it wasn’t a dream. My erstwhile savoir fairly reeked of odors too foul for any dream I might conjure up.”

Claire meets Jamie in a stone cottage and a whole lot of “playing doctor” ensues enabling Jamie to erm, mount a steed. Snort! Dougal jerks puir Claire around and then hoists her up on Jamie’s horsie (Starz episode 101, Sassenach and Outlander book)!

“With a slight grunt, he boosted me into the saddle in front of Jamie, who gathered me in closely with his good arm… He smelt strongly of woodsmoke, blood, and unwashed male, but the night chill bit through my thin dress and I was happy enough to lean back against him.”

Next, Claire uses her knowing nose after Dougal and his merry men lay waste to a raft of redcoats at Cocknamon Rock (Starz, episode 101, Sassenach and Outlander book).

“Someone passed a flask to Jamie, and I could smell the hot, burnt-smelling liquor as he drank. I wasn’t at all thirsty, but the faint scent of honey reminded me that I was starving…”

Fast forward to swell bodies! Going nose-to-nose with her young gallant on their wedding night, Claire considers Jamie’s splendid nose (Starz episode 107, The Wedding)! Herself writes in Outlander book:

“’My mother was a MacKenzie, though. Ye’ll know that Dougal and Colum are my uncles?’ I nodded. The resemblance was clear enough, despite the difference in coloring. The broad cheekbones and long, straight, knife-edged nose were plainly a MacKenzie inheritance.

Now, here’s Jamie’s 18^th century colorful counsel about sharing one’s armpit aura with another creature (Starz episode 107, The Wedding and Outlander book):

“He raised one arm, displaying a soft tuft of cinnamon-colored hair. ‘You rub your oxter over the beast’s nose a few times, to give him your scent and get him accustomed to you, so he won’t be nervous of ye.’ …’That’s what you should have done wi’ me, Sassenach’….’Then I wouldn’t have been skittish.’”

Snort!

A skittish Scottish Scot? Har, har! Ready for something truly amazing! Experiments show that mice chose genetically diverse mates based on smell. Fine and dandy, but what about humans? Have you heard of the “sweaty T-shirt” experiment? In 1995, a Swiss zoologist devised an experiment to determine if women prefer the odor of some men over others. Male volunteers wore clean T-shirts and female volunteers blindly smelled shirt odor to evaluate it for intensity, pleasantness and sexiness. Overall, the women preferred the smell of men whose MHC genes differed from their own. Whaaat? What is MHC? MCH (major histocompatibility complex) genes generate molecules that enable our immune system to recognize and destroy invaders; the more diverse the parental MHC genes the stronger the immune system of their offspring, an advantage in destroying pathogens. The study results suggest that evolution has provided humans with a transmitter (odor/pheromone) and receiver (olfactory epithelium) of genetic information that could influence mate choice. Wow!

Now, you might think Claire is just resting her face against Jamie’s back to recuperate after hiking around this braw Scottish mountain (Starz episode 107, The Wedding)! But, she was clearly sniffing to detect his MHC. Her nose knows he is the King of Men! Yup, he’s a keeper! Herself explains (Outlander book):

“His pleasant musky smell mingled with the harsh scent of linen. “Take off your shirt,” I said … He smelled faintly of soap and wine…”

And he did! Take off his shirt, I mean. Yerp!

Hey, hey, come back! In summary, the external nose adds contour and expression to our faces while the internal nose cleanses and humidifies the air we breathe as well as provides us with the ability to smell a broad and fascinating array of molecules. Do you appreciate your sniffer? Is it as keen as Claire’s? Let’s be grateful to the sense of olfaction for the richness and joy it adds to our lives!

Be Glad Your Nose is on Your Face

Jack Prelutsky, 1940

Be glad your nose is on your face,
not pasted on some other place,
for if it were where it is not,
you might dislike your nose a lot.

Imagine if your precious nose
were sandwiched in between your toes,
that clearly would not be a treat,
for you’d be forced to smell your feet.

Your nose would be a source of dread
were it attached atop your head,
it soon would drive you to despair,
forever tickled by your hair.

Within your ear, your nose would be
an absolute catastrophe,
for when you were obliged to sneeze,
your brain would rattle from the breeze.

Your nose, instead, through thick and thin,
remains between your eyes and chin,
not pasted on some other place–
be glad your nose is on your face!

A Deeply Grateful,

Outlander Anatomist

photo creds: Netter’s Atlas of Human Anatomy, 4^th ed., Sony Pictures, Starz, www.rci.rutgers.edu (schematic of olfactory epithelium), www.sciencephotolibrary.tumblr.com (SEM of respiratory epithelium)