“I dwell in darkness, Madam, and darkness is where I belong.” Claire has lost her breath and voice! Learn about both tomorrow – Anatomy Lesson #42, The Larynx!
A deeply grateful,
Outlander Anatomist
Anatomy Lesson #40 “Snap, Crackle, Pop! or How Bones Heal”
Welcome Outlander Anatomy readers! Our last lesson covered the human skeleton (Anatomy Lesson #39 “Dem Bones – The Human Skeleton”). Today’s Anatomy Lesson #40, “Snap, Crackle, Pop! or How Bones Heal” expands on bone anatomy but also addresses bone fractures and how they mend. As always, Starz Outlander images and quotes from Diana Gabaldon’s marvelous books are generously sprinkled throughout the lesson.
Last lesson began with spectacular images from Master Raymond’s hidden ossuary. This lesson, we start with images of a world famous ossuary located in Kutná Hora, Czech Republic. Known world-wide as the Bone Church, it is an ossuary (‘Kostnice’ in Czech) that houses the bones of an estimated 40,000 – 70,000 people (Image A).
Image A
Here, bones are imaginatively and artistically arranged throughout the edifice. One of the most famous displays is a chandelier, purportedly containing every bone of the adult human body (Image B).
During the thirty years’ war, aristocracy of Central Europe wished to be buried in the hallowed graveyard at this site. As the number of burials outgrew available space, remains were exhumed and stored in the chapel, then assembled into artistic presentations.
The ruffled collars beneath the candle-bearing skulls are hip bones! At the tip-top are inverted sacra (pl.). Dangling bones are humeri (pl.). Quite the room-lighter! Makes Master Raymond’s animal skulls seem almost quaint!
Image B
Surely, these images put us in the mood to learn more about bones, although this lesson covers bones of the living. Today’s lesson will review and present more bone anatomy and types of bone cells. Then, we will cover events that ensue when bones go snap, crackle, or pop, as well as mechanisms of healing. Let’s go!
Review of Long Bone Anatomy: Lesson #39 presented long bone anatomy, but let’s take a moment to review. Once again, the femur, is our model (Image C). The shaft of a long bone is the diaphysis. The ends that form joints with other bones are the epiphyses (pl.); these are covered with articular cartilage (ball-shaped epiphysis is head of femur). The flared region between diaphysis and epiphysis is the metaphysis. Cortical bone forms a hard outer rind enclosing the marrow (medullary) cavity. Spongy bone fills epiphyses and metaphyses and is also scattered in the marrow cavity. Depending on the bone and age of the individual, the marrow cavity is filled with either fat cells or hematopoietic (blood-forming) cells, neither of which are elements of bone. Think of them as tenants not owners!
Image C
Periosteum and Endosteum: Periosteum is a thick fibrous layer covering the diaphyseal surface (Image D). Endosteum is a thin connective tissue layer lining the bone marrow cavity and covering all exposed surfaces of spongy bone. Both layers contain blood vessels and several types of bone cells as discussed below.
Image D
Vascular Supply: As we learned in Anatomy Lesson #39 “Dem Bones – The Human Skeleton,” bone is living tissue and thus requires a constant blood supply such that the human skeleton receives 5-10% of the entire cardiac output (amount of blood the heart pumps per minute).
To meet this demand, large bones receive several arteries (Image E). Periosteal arteries supply periosteum and outer compact bone. Epiphyseal arteries supply blood to epiphyses (pl.). Nutrient arteries supply inner cortical bone, endosteum, and help supply epiphyses and metaphyses.
These arteries access a bone via foramina (channels) that traverse compact bone to reach their respective turfs, then break into capillary beds where oxygen and nutrients are exchanged for carbon dioxide and waste products. Corresponding veins form and blood flows back to the heart. Round and round and round it goes…..
Image E
Nerve Supply: You may be surprised to learn that mineralized bone (organic matrix plus inorganic minerals – see Lesson #39) does not have pain receptors. Hum…if this is true, then why does a broken bone hurt so badly? Because periosteum and endosteum as well as articular surfaces are richly supplied with pain receptors (nociceptors). If these structures are compromised as with a fracture, then pain is severe!
Image F nicely illustrates nerve and blood vessel distribution in cortical bone and margin of the marrow cavity. Anatomy typically color codes arteries red, veins blue, and nerves yellow. The tiny yellow lines indicate that nerves follow blood vessels through cortical bone to the endosteum. Although not shown in Image D, nerves also follow periosteal arteries to innervate the periosteum.
Image F
Bone Cells: As mentioned above, bone contains several cell types including osteogenic cells, osteoblasts, osteocytes, and osteoclasts (Image G). These cells are located in periosteum, endosteum, or within mineralized bone. Again, although hematopoietic cells or fat cells fill spaces between spongy bone and within marrow cavities, these are not bone cells.
Osteogenic cells are stem or parent cells giving rise to osteoblasts (Image G); they reside in periosteum and endosteum.
Osteoblasts: From Greek osteo- meaning bone + blastanō meaning to germinate, osteoblasts produce collagen and other proteins as part of the organic matrix. These proteins are released into the extra-cellular environment where minerals deposit around them. Together, the organic matrix provides tensile strength and inorganic minerals provide compressive strength. As to their bulk, organic proteins represent 10% of bone mass with the remaining 90% being inorganic mineral. Osteoblasts reside in periosteum and endosteum.
Osteocytes: In the course of production and secretion of organic matrix and its subsequent mineralization, osteoblasts become “imprisoned” within bone and are renamed osteocytes. Located in compact and spongy bone, osteocytes help maintain the mineralized bone. Further, the mineralized matrix with imprisoned osteocytes is organized into cylinders of bone known as osteons (Haversian systems). A bone such as the femur contains millions of osteons but details about these units must await a future lesson.
Osteoclasts: Giant, multi-nucleated cells, the osteoclasts, are formed by the fusion of macrophages (Anatomy Lesson # 37, “Outlander Owies Part 3 – Mars and Scars”). Found in endosteum, their duty is to dissolve bone.
Image G
As you might imagine, a good deal of coordination among the various bone cells is required to ensure homeostasis (balance) between bone production, maintenance, and resorption. For example, as a bone grows in circumference due to periosteal osteoblast activity, osteoclasts of the endosteum remove bone from the inside so the thickness remains fairly constant, a highly regulated process.
Image H shows in detail the distribution of bone cells in periosteum, endosteum and in compact bone.
Image H
Next, let’s do something really daring and look at a microscopic image of bone cells as viewed through a light microscope (Anatomy Lesson #34 – “The Amazing Saga of Human Anatomy”). Please understand that microscopic anatomy, better known as histology (Greek histo- meaning “tissue” + ology meaning “to know”), is a challenge for most students. Watch this fun video by Harvard medical students as they lament about studying “histo!”
https://www.instagram.com/p/BEYogsIuTPz/
Ha ha! Very clever, medical students! But, you readers might respond the same way looking at a magnified image of a shard of spongy bone (Image I). This image is of a very thin slice of bone that has been stained blue and pink with H&E (hematoxylin = blue + eosin = pink). The so-called H&E stain is the most commonly-used histo stain in the US.
So, what do we see in Image I? The dense pink vertical band is a spicule of ossified spongy bone. The oval cells with pale nuclei along the left border of the shard are osteoblasts laying down a pale layer of unmineralized organic matrix (osteoid). The right border of the spicule show two large multi-nucleated osteoclasts busily dissolving bone – one such interface is a distinct divot indicated by the black arrowheads. Such divots are termed Howship’s lacunae (named for John Howship, a British anatomist). Several irregularly-shaped nuclei are scattered within the bony spicule – these are osteocytes encased in ossified bone.
That’s pretty much it! Being competent at recognizing cells and extracellular substance is based on pattern recognition. Looking at many examples of a given tissue is very useful in obtaining said competence. If you think this is impossible, understand that anatomical pathologists make their living looking at and diagnosing diseases from thousands of such tissue slides.
Image I
Bone Fractures: Time for snap, crackle, and pop, and I dinna mean Rice Krispies! Compressive strength from mineral deposition and tensile strength from organic matrix give normal bones the ability to behave elastically. If trauma overcomes this elasticity, then bones fracture!
Bone fractures fall into two major categories: mechanical bone fractures caused by high force impact or stress, and pathological fractures caused by disease.
Pathological Fractures: Diana presents a fabulous case of fracture caused by disease in Colum. The Laird of clan MacKenzie is haunted by the aftermath of a pathologic fracture and accompanying deformities due to Toulouse-Lautrec syndrome (Starz episode 208, The Fox’s Lair).
Outlander book informs readers that at 18 y.o., Colum took a bad fall breaking the long bone (femur) of his thigh that subsequently mended poorly. Other skeletal anomalies quickly ensued. Diana explains in Dragonfly in Amber:
Legs crippled and twisted by a deforming disease, Colum no longer led his clan into battle…
…He glanced dispassionately down at the bowed and twisted legs. In a hundred years’ time, they would call this disease after its most famous sufferer—the Toulouse-Lautrec syndrome.
Read Anatomy Lesson #27, “Colum’s Legs and Other Things too!” for details about this rare syndrome (1.7 per million births). Of course, there are also many other diseases leading to pathological fractures. Nowadays, the most common in the US is osteoporosis.
Mechanical fractures: High force impact or stress cause bones to snap. Different types of bones (e.g. short vs. long) often exhibit characteristic fractures. This lesson will consider fractures of long bones using the femur again as our example. Fractures are generalized into six different categories:
- Closed fracture – bone is broken but overlying skin is unbroken
- Open fracture – better known as a compound fracture, broken bone pierces the skin
- Simple fracture – bone is broken but no other tissues damaged
- Complex fracture – sharp fracture edges damage surrounding soft tissues
- Complete fracture – bone breaks completely across the shaft
- Incomplete fracture – bone is partly broken but remains in one piece
Then, fractures are named according to features of the break (Image J).
- Normal – left image is the normal femur
- Transverse – break crosses the shaft horizontally
- Oblique – break crosses shaft at an angle
- Spiral – torque on the broken halves twists these in opposite directions
- Comminuated – bone is broken into four or more pieces (including main body of the bone)
- Avulsion – a piece of bone is torn away usually by pull of a muscle tendon
- Impacted – bone parts are driven together, also known as a buckle, or compression fracture
- Fissure – crack along one side of the shaft
- Greenstick – incomplete break through the shaft. Analogous to breaking a stick of green wood.
Image J
Fracture Healing: Fracture healing is the process by which the body repairs a broken bone and what a process it is! Several overlapping steps occur, different descriptors are used, and times may vary depending on the bone, but the general sequence is (Image K):
- Hematoma Formation (days 1-5): Bone fractures tear blood vessels, and periosteum and endosteum. Blood pours from the damaged vessels forming a hematoma (blood clot) between the fractured surfaces. Blood flow in intact vessels increases such that an army of white cells are delivered for defense and repair.
- Soft Callus Formation (days 3-40): Gradually, a bridge of cartilage and collagen replaces the hematoma and unites the broken ends. The cartilage bridge is made by chondroblasts (cartilage-generating cells) and is termed a soft callus.
- Hard Callus Formation (days 30-80): During this stage, cartilage of the soft callus is gradually replaced with new, woven bone (cartilage does not change into bone) and the site is renamed a hard callus. But, woven bone is immature and not as strong as mature compact bone. Mild exercise is often resumed during this phase.
- Bone Remodeling (days 80-100): If all goes well, the hard callus is gradually replaced with normal, mineralized compact bone that remodels to align with muscle pull and mechanical stress. Exercise promotes this process which is typically 80% complete within three months. But, depending on the bone and the fracture, step four can take up to 18 months.
Image K
Normal fracture healing requires the following:
- Adequate blood supply: Oxygen and nutrients must be delivered to the repair site and carbon dioxide and waste products removed; these processes require blood vessels. Thus, re-vascularization occurs at the fracture site.
- Fracture stabilization: Excessive movement of the fractured bones interrupts callus formation so fractures are immobilized with a variety of ingenious devices such as casts, rods, plates, screws, and external fixators.
- Adequate nutrition: On average, a fracture heals by 12 weeks. However, healing times depend on which bones are broken, severity of the breaks, age (younger folks usually heal faster), and nutrition. A vitamin sandwich (Image L) looks funny but animal and human studies show that fracture healing improves with supplements of Vitamins C, D, and E, as well as calcium and amino acids. Details of these experiments exceed our lesson goals, but understand that many average diets are marginal in these substances. So, be sure to consult with your physician about supplements while healing a bone fracture.
- Rehabilitation: Immobilization of a fracture contributes to muscle wasting. Physical therapy can provide critical support in re-building muscle and encouraging proper bone alignment. This includes weight-bearing on a fracture after it has mostly healed in order to build bone strength.
- No-No nicotine: Studies are pretty clear that nicotine in any form hinders the process of bone healing. Avoidance behavior!
Image L
Now for some real “fun.” With Starz images, let’s use applied anatomy to consider mechanical bone fractures and healing. Starz Outlander episodes offer two excellent examples of bone fractures, both are compound in type.
A workman is admitted to L’Hôpital des Anges in Paris (Starz episode 204, La Dame Blanche). He screams in agony because he has suffered a compound fracture of the right tibia (Anatomy Lesson #27, “Colum’s Legs and Other Things too!”). The skin is open and the upper part of the broken tibia is clearly visible at the red arrow.
This injury hurts like holy toothpicks because tears of periosteum and endosteum stimulate nociceptors (pain receptors). Then, muscles spasm as they attempt to stabilize bony fragments, upping the pain meter. And, adding insult to injury, a compound fracture rents the skin and we all ken how sensitive skin is to pain! All around, an agonizing situation.
So, what does a good hangman do to ease his patient’s discomfort? Why, he hammers a nail into the side of the poor fellow’s knee, of course! What else? Presumably a type of primitive acupuncture, it momentarily halts the patient’s agony; mayhap from PTSD?
A quote from Dragonfly in Amber:
Monsieur Forez was at work today. The patient, a young workman, lay white-faced and gasping on a pallet. …The leg, though, was something else… Sharp bone fragments protruded through the skin … “Here, ma soeur ,” he directed, taking hold of the patient’s ankle. “Grasp it tightly just behind the heel… Monsieur Forez brought the point of the brass pin to bear …he drove the pin straight into the leg with one blow. The leg twitched violently, then seemed to relax into limpness.
Monsieur Forez enlightens Claire regarding this startling exhibit of bedside manner (from Dragonfly in Amber):
“There is a large bundle of nerve endings there, Sister, what I have heard the anatomists call a plexus. If you are fortunate enough to pierce it directly, it numbs a great deal of the sensations in the lower extremity.”
Stop! I must pick at a wee bone: During the episode, Mr. Forez explains to Claire that anatomists describe a nerve at the inside of the knee which, if pierced, briefly anesthetizes the leg (Anatomy Lesson #27 – “Colum’s Legs and Other Things too!”). So, the human grease-guy whacks a 4” nail into the side of the workman’s knee for pain relief!
So this is what troubles me: the nail pierces skin near the saphenous nerve (a branch of the femoral) which, unfortunately, supplies only skin of the area and does nothing for bone pain. The correct nerve to pierce would be the tibial nerve, a branch of the sciatic; but, both of these nerves are in the back of the thigh! From the thigh, the tibial nerve sends fibers to the tibia in concert with its nutrient artery where it innervates endosteum and periosteum. Ergo, for this technique to work, the good Monsieur must pierce the tibial nerve in the back of the thigh.
I canna vouch for the efficacy of nail piercing, which seems a wee bit harsh, but I can question Forez’s anatomists and their data base. Soon after the shock of piercing subsides, the patient resumes screaming so I canna think it verra efficacious. Gah! Back to the dissection lab for those anatomists! But, I must say, the special effects are superb!
Next, we will consider another compound fracture, arguably the most infamous of the Starz series. The Wentworth Smack-Down delivered high force impact causing mechanical fractures of Jamie’s left hand bones (Starz episode 115, Wentworth Prison). Let’s do a walk through of these fractures.
Heading to Outlander book, Diana enlightens us with these quotes:
Luckily the thumb had suffered least; only a simple fracture of the first joint. That would heal clean. The second knuckle on the fourth finger was completely gone; I felt only a pulpy grating of bone chips when I rolled it gently between my own thumb and forefinger…
The compound fracture of the middle finger was the worst to contemplate. The finger would have to be pulled straight, drawing the protruding bone back through the torn flesh. I had seen this done before—under general anesthesia, with the guidance of X rays.
We can easily deduce from Diana’s description that, at a minimum, Jamie’s hand suffered:
- Simple fracture of the first phalanx of thumb.
- Communiated fracture of the ring finger (4th finger in English system; 3rd in US system – see Anatomy Lesson #22, “Jamie’s Hand – Symbol of Sacrifice”) – proximal and middle phalanges smashed into bony bits.
- Compound fracture of middle finger – appears to be middle phalanx of the middle finger.
Like any combat nurse worth her salt, Claire cleanses Jamie’s wounds. She has no modern isotonic fluids or antibiotics, so she cleans his compound fracture with (no doubt) sterile water, perhaps containing a wee dram of alcohol for sterilization?
Next, Claire ponders the damage and then re-aligns and resets the bony fragments (Starz episode 116, To Ransom a Man’s Soul). And again from Outlander book:
I began to lose myself in the concentration of the job… deciding how best to draw the smashed bones back into alignment.
Now, as we learned above, a compound fracture tears surrounding flesh and skin. So Claire carefully closes the wounds with sutures (Starz S.2, introductory image) to exclude pathogens and reduce blood loss.
Earlier in this lesson, we read that movement of a new fracture interferes with callus formation. So, various devices are used to immobilize fractures as they heal.
Ever resourceful Claire (or the monks?) devises an external fixator for Jamie’s smashed hand in the form if a very clever wire/leather, linen, and wood device! External fixation is a surgical treatment used to stabilize bone and soft tissues at a distance from the injury. So, check out the amazing invention (Starz episode 116, To Ransom A Man’s Soul) to immobilize Jamie’s hand! The middle finger is reset and stitched. The communiated and most severely wounded ring finger is stitched and splinted against the small finger. Brava, Madam Sassenach!
Jamie’s hand care is not yet complete! Claire provides physical therapy in the form a rag ball she made. Squeezing the ball helps Jamie regain hand mobility and strengthen the knitting bones as he and Murtagh plan how best to skewer BJR (Starz episode 203, Useful Occupations and Deceptions)!
In case you forgot from earlier in this lesson, exercising a repairing bony callus augments the ossification process, so Claire’s rehabilitation plan is spot on!
Two quotes from Diana’s Dragonfly in Amber:
It really wasn’t too bad; a couple of fingers set slightly askew, a thick scar down the length of the middle finger. The only major damage had been to the fourth finger, which stuck out stiffly, its second joint so badly crushed that the healing had fused two finger bones together. The hand had been broken in Wentworth Prison, less than four months ago, by Jack Randall.
He had regained an astounding degree of movement, I thought. He still carried the soft ball of rags I had made for him, squeezing it unobtrusively hundreds of times a day as he went about his business. And if the knitting bones hurt him, he never complained.
And, pithy quotes from Diana’s Dragonfly in Amber remind us that months later, Jamie’s hand is still not whole (Starz Season 2 opening images), so clever caring Claire applies her personal version of massage therapy… a task that she and he undoubtedly relish! Hee, hee.
I crawled in beside him and took up his right hand, resuming my slow massage of his fingers and palm. He gave a long sigh, almost a groan, as I rubbed a thumb in firm circles over the pads at the base of his fingers.
Thus ends Outlander compound fractures and healing. Whether bone breaks or skeletons, people are endlessly fascinated by bones and the stories they tell. Book readers will recognize this poignant commentary from Dragonfly in Amber as Jamie and Claire find the bony inhabitants of an unknown cave in France.
He turned again then to the two skeletons, entwined at our feet. He crouched over them, tracing the line of the bones with a gentle finger, careful not to touch the ivory surface. “See how they lie,” he said. “They didna fall here, and no one laid out their bodies. They lay down themselves.” His hand glided above the long arm bones of the larger skeleton, a dark shadow fluttering like a large moth as it crossed the jackstraw pile of ribs.
Now, I have my own bone story to share. The following is a true event underscoring the amazing capacity of bones to heal. During WW II, my father was a welder of Liberty Ships in California. When I was 18 months of age, neighborhood kids accidentally ran over me and the trauma snapped off the head (ball-shaped epiphysis) of my right femur. Local physicians were unable to help so they sent us to the Treasure Island Naval Base where many of the best US physicians were stationed to assist with the war effort.
Those docs had never set a child’s femoral head before, but they courageously reset my leg, placed me in a 3/4 body cast, and prepared my parents for the bad news: the blood supply to the femoral head was likely severed, the femoral head would become necrotic (die), and the hip would freeze into an immobile joint. I would not walk normally, if at all.
Well, the good news is that my femoral head did not perish! Somehow and somewhere, an arterial supply survived. Although my colleagues and I share theories about which vessel might have remained intact, no one knows for sure.
Image M was taken in 1944 at Stinson Beach, CA, six months after the injury (like the artery, my appetite clearly remained intact <G>). Observe that the right leg is slightly rotated outward (externally), a classic stance following a femoral head fracture.
Today, the only residual is my right leg is 3/8” shorter than the left. Otherwise, nada! I am able to exercise vigorously and with no noticeable deficit. Blessings to those unknown healers who helped the wee bairn of a common laborer!
Image M
Our lesson on how fractures heal has come to an end. After two lessons about the skeleton, there remains much more to be studied, so we may revisit this topic at a later date.
A few last thoughts: Remember, bone is a dynamic tissue which constantly remodels itself throughout life. Individual bones are organs that collectively constitute the skeleton, our internal support system. Bone cells create, maintain, and destroy bone tissue to our benefit.
Bones have been prodded, examined, healed, revered, saved, feared, embellished, and cherished. Not all of this lesson is about happy stuff, so let’s end with this slightly irreverent image from the bow of the Titanic.
Image N
Dem bones, dem bones!
A deeply grateful,
Outlander Anatomist.
Photo creds: Starz, Outlander Anatomy archives (Image M), www.anatomy-medicine.com (Image F), www.askabiologist.edu (Image J), www.apps.carleton.edu (Image B) www.boneandspine.com (Image C), www.geneticliteracyproject.org (Image L), www.medcell.med.yale.edu (Image I), www.reddit.com (Image A), www.en.wikipedia.org (Image E; Image H), www.everythingfunny.org (Image N), www.commons.wikimedia.org (Image G) ,www.studyblue.com (Image D), www.ippe2ools.blogspot.com (Image K)
Anatomy Lesson #38: “Outlander Tears” or “Why, oh Why, do We Cry?”
Greetings anatomy students! Flurry over the Outlander premier has abated and S.2 is well underway so it is time for another anatomy lesson. Yay! The bell has rung and class is in session! This anatomy lessons turns our attention to the poorly understood act of emotional crying.
As always, we’ll use Starz images to set the stage for our lesson. Beginning with S.2 opening theme, we are greeted with excellent images of emotional weeping. Claire’s tears flow as she desperately pleads with Jamie after his torture at the hands of the Bloody Blackguard (Starz episode 116, To Ransom a Man’s Soul)!
Her tears flow almost unabated through the first half of Starz episode 201, Through a Glass, Darkly. The episode begins with Claire separated from Jamie and her pain is palpable as she shrieks her rage to the heavens (Starz episode 201, Through a Glass, Darkly)!
Her fury is quickly followed with helpless tears of loss and grief as she collapses amid the towering stone monoliths capping Craigh na Dun!
Wandering the road to Inverness, Claire meets a kindly Scotsman. She collapses in desperate sobbing after he reveals, yes indeed, the British won the Battle of Culloden! We empaths shed tears along with our beautiful, courageous heroine!
This quote from Diana’s Dragonfly in Amber book adds depth to Claire’s desolation:
I woke three times in the dark predawn. First in sorrow, then in joy, and at the last, in solitude. The tears of a bone-deep loss woke me slowly, bathing my face like the comforting touch of a damp cloth in soothing hands. I turned my face to the wet pillow and sailed a salty river into the caverns of grief remembered, into the subterranean depths of sleep.
Time to start this tearfilled lesson (sob) with a brief anatomical overview. Unless one suffers from an unfortunate condition such as dry eyes (keratoconjunctivitis sicca), tears flow under three different conditions: base-line tear production, non-emotional tearing, and emotional weeping. Regardless of the cause, all three types involve lacrimation (Latin, lacrima, meaning tear), the production of tears. So, sharpen your scalpels and let’s dissect each type of tear, one-at-a-time.
Base-line Tears: We learned in Anatomy Lesson #30, “Aye, Eye – The Eyes, Part 2,” each eyeball is equipped with a lacrimal apparatus which produces and drains tears. That apparatus includes the following features.
In the upper outer corner of each bony orbit (Anatomy Lesson #30, “Aye, Eye – The Eyes, Part 2,”) lies the small but powerful lacrimal gland (Image A). Most of the gland lies inside the bony orbit but a small part projects into the upper eyelid. Small ducts (channels) pierce the conjunctiva (transparent membrane) and convey the secretion onto the eyeball surface.
The lacrimal gland is designed to continuously secrete (discharge) the aqueous (watery) part of the tear film which bathes the surfaces of cornea and conjunctiva (Anatomy Lesson #30, “Aye, Eye – The Eyes, Part 2,” and Anatomy Lesson #31, “Aye for an Eye – The Eye, Part 3”). Although their roles differ, fibers from both sympathetic and parasympathetic divisions of the autonomic nervous system (the part we don’t control) supply the gland (see Anatomy Lesson #32, “A Real Eye Opener – The Eye, Part 4“). Working together, parasympathetic fibers induce secretion and sympathetic fibers control blood flow.
The tri-laminar tear film (Image A) is composed of an inner mucous (adj.) layer produced by mucous cells of the conjunctiva, a middle aqueous layer produced by the lacrimal gland, and an outer oil layer produced by tarsal glands of the eyelids (Anatomy Lesson #29, “The Eyes Have It! – The Eyes, Part 1”). The tear film represents basal tearing and it is critical to the health of exposed eye surfaces.
Image A
The tear film is continuously renewed and then drained by the following structures. Closure of the eyelids moves the tear film toward two small openings, the lacrimal puncta (pl.), at the nasal end of each eyelid (Image B – lacrimal apparatus of right eye). Each punctum (find yours) drains into one of two lacrimal canaliculi, tiny channels which empty into a reservoir, the lacrimal sac. From the lacrimal sac, tears traverse the nasolacrimal duct and drain into the ipsilateral (same side) nasal cavity. Remember, each eye has its own lacrimal apparatus.
The tear film doesn’t just give Jamie his sparkling bonny blue orbs; rather, it serves three important purposes:
- Protects and lubricates exposed surfaces of the eyeball.
- Washes away foreign particles.
- Reduces the risk of eye infections (antibacterial).
Image B
Non-Emotional Tearing: Also known as reflex tearing, non-emotional tear production is a response to eye irritants. If the exposed eyeball is insulted, the lacrimal glands are stimulated to produce a flood of tears which overwhelms the lacrimal drainage system. Having no adequate outlet, they escape the eyelids and run down the face.
What are the causes of non-emotional tearing? Well, foreign bodies, objects that enter the eye from outside the body, are the most common cause. Although intuitively obvious, here are some important clues that a foreign body may have taken up residence in your eyeball:
- Pressure
- Discomfort or pain
- Sensation of something “in the eye”
- Extreme tearing (yes!)
- Photophobia (pain or discomfort with light exposure)
- Excessive blinking
- Redness or bloodshot conjunctiva (image C)
Image C
And just so you know, the following foreign objects are the most common causes of non-emotional tearing:
- eyelashes
- dried mucus
- sawdust
- dirt
- sand
- cosmetics
- contact lenses
- metal particles
- glass shards
Those who read Anatomy Lesson #29, “The Eyes Have It! – The Eyes, Part 1” may recall examples of the now-popular eyelash jewelry, including among other delights, crystals glued to the eyelashes! Who thought that was a good idea? Well, if one is not verra careful, these fake jewels can wreak havoc as foreign bodies! Case in point, crystals float on the tear film overlying conjunctiva and cornea (Image D). These were likely applied to the upper surface of the lower eyelashes. The glue failed and the crystalline escapees drifted onto the eyeball surface.
Understand that if the conjunctiva is intact, objects deposited on the front of the eyeball cannot get lost behind it (Anatomy Lesson #30, “Aye, Eye – The Eyes, Part 2“). They can, however, scratch the cornea and cause infection so foreign bodies in the eye should be resolved STAT!
Image D
Then, there are really dangerous foreign bodies such as metal shards (Image E) that pierce the transparent conjunctiva and embed in the sclera (Anatomy Lesson #32, “A Real Eye Opener – The Eye, Part 4“). Such objects can scratch the inner eyelids and cause infections. Och, I bet that hurts!
Protective eyewear can help prevent such injuries and should certainly be worn if working with:
- saws, hammers, grinders, lawn mowers, and other power tools
- dangerous or toxic chemicals
Image E
Non-emotional tearing also follows exposure to irritating substances such as the whiff of onions (Image F) or noxious agents such as insecticides, perfumes, detergents, smoke, dust, etc.
Image F
Well then, fair’s fair (Image G)! Too gruesome? If yes, why are ye watching/reading Outlander? Hee, hee.
Image G
Speaking of noxious substances, if an across-the-counter product splashes into the eye, you can immediately relieve discomfort and assist tear formation by washing the eyeball. Yes, you read it correctly! Every science laboratory worth its salt sports an eye wash station as part of its safety equipment. Since few homes have such an apparatus, you can use a sink faucet or garden hose. Run a stream of cool water (NOT hot!) from the tap or hose. Open the irritated eye and turn head so the affected eye is DOWN. Let the water run across the eyeball from the nose towards the ear (Image H). Do NOT run water from the ear towards nose! Why? Because the irritant will flow into the lacrimal drainage structures and nose. Voila, now the problem is compounded!
Flush the eye for 15 minutes! Yes your water bill will skyrocket, but the irritant must be thoroughly diluted. Depending on the substance (think acids, lye, etc.), hie to the nearest urgent care facility or call EMT/fire department. In the meantime, wash!
Image H
Finally, if something splashes into both eyes, use a garden hose or a faucet spray nozzle. Look down and widely opening both eyes, allow water to flush them simultaneously. Do not turn the head to either side.
The following is an informative and well-done Youtube video that includes images of how to deal with splashes involving both eyes. Note that although it starts with showing a one eye splash, later it demos both eyes involvement.
Emotional Tearing: Now, we get to the nitty-gritty! Also known as psychic tearing, this is the same as crying, the shedding of tears trigger by emotions. Crying synonyms include weeping, wailing, sobbing, whimpering, squalling, mewling, and bawling. Humans cry if we feel grief, stress, sadness, happy, overwhelmed, pleasure, anger, and suffering. But, the bottom line is, scientists understand very little about why emotions provoke human crying!
Again, Outlander S.2 comes to our rescue: Rage, grief, and despair fuel Claire’s tears in Starz episode 201, Through a Glass, Darkly. But, in the same episode, Frank shares with us fine examples of emotional tears!
Tears of gratitude – Claire has finally returned to him. He doesn’t care who she bedded during her Highland gad-about, nothing could ever change the way he feels about her! No way, Jose!
Tears of wonder – After Claire reveals that she has a “bun in the oven”, Jack, oops, I mean Frank, is thrilled and responds with more pop up tears. Oh, my, he is delighted, desperately happy and “over the moon”! Ah, erm…wait! How could such a miracle happen because his doctor told him that …
Tears of fury – What? That red-haired bastard (weil, son of a bastard) knocked up his beloved Claire? Who the hey does that guy think he is? And, presto, just like that, Franks’s tears of joy turn into rivulets of rage! So much for his “nothing you could ever do” speech.
Recall not-her-name Sally and her alley cat friends (Starz episode 108, Both sides Now)? Frank came very close to sharing the same black-jack knuckle sandwich with Claire! Fist of fury!
In rapid succession, Frank delivers a wallop of emotion-ladened tears just in time for this lesson. TY, Frank. Much obliged!
Back to our lesson: many of us ken that newborns wail without tears. Their nascent lacrimal glands produce just enough baseline tears to moisten their eyeballs. Somewhere between 1-3 months the lacrimal glands develop enough to shed tear droplets in response to physical discomfort (Image I).
Around puberty, tears from emotional pain usually overtake those from physical discomfort. Gradually, with age and experience, people add moral crying in response to acts of courage and self-sacrifice or to symbols such as the flag of one’s country or to the sound of bagpipes (my personal favorite)!
Image I
Now, scientists do have insights about how tears and emotions are linked. Emotional crying is a complex secretomotor phenomenon characterized by the shedding of tears sans ocular irritation. The lacrimal gland is linked to the limbic system (Image J), part of the brain that processes emotions. The limbic system (waaaay too complex for this lesson) is hard-wired into the autonomic nervous system/ANS (the part you cannot voluntarily control). With the proper emotional trigger, the limbic system stimulates the ANS to release the neurotransmitter, acetylcholine, a wee molecule which then stimulates the lacrimal gland to shed emotional tears. Ergo, emotions interpreted by the limbic system activate the ANS which releases acetylcholine which turns on the water taps! Voila, we sob with feeling! Pretty remarkable.
Image J
What we don’t understand is why do strong emotions cause us to cry? What is the purpose of emotional tears? Well, there are lots of ideas, one dating back more than 2,000 years.
Greek philosopher and scientist, Aristotle, posited that tears are waste products like urine and therefore, discarded by the body (Image K): “That they are of one nature is plain to the taste.”
Take comfort, Jamie! Claire isna the only healer to taste urine (deferred to a future lesson). Truth be told, dedicated physicians used to routinely taste their patient’s urine. Talk about the call of duty. Pitooey!
Image K
Here’s a good one…in the 1940s, American psychoanalyst and physician, Phyllis Greenacre, proposed that female weeping is a sign of penis envy and the way a woman can imitate a man urinating. A hypothesis to which I offer this scientific response: Snort!
Others have proposed that tears, like urine production, cleanse the blood. However, the average cry yields only about 20 tear droplets or the equivalent of 1 ml, a totally inadequate amount of fluid loss to alter blood composition.
Some suggest that crying purges the body of harmful chemicals produced under duress. Forty years ago, a biochemist found that emotional tears were richer in protein than non-emotional tears. Unfortunately, others failed to replicate his findings so they lost momentum. A basic tenet of scientific research is that independent laboratories must be able to replicate another’s results…. an excellent check and balance system.
However, later studies have shown that emotional tears contain elevated levels of prolactin (cuddle hormone), adrenocorticotropic hormone (induces adrenal cortex to release the stress hormone, cortisol), and leucine enkephalin (a natural painkiller). So, there may be merit to the idea of emotional purging. Verra complex, are our emotional tears!
Along a similar vein, Darwin proposed that in addition to lubricating the eyeballs, tears “serve as a relief to suffering,” and the idea that crying is cathartic remains viable but unproven. General wisdom suggests that emotional crying does make one feel better. But, why? Well, if misery is short lived, our mood may lighten by the time we finish a good cry. Or, in the midst of despair, something wonderful might happen to completely alter one’s mood such that eyes spout tears of joy!
Intriguingly, some researchers consider emotional crying as a social signal that a person needs nurturing; a sort of primal “shoutout” for help. One interesting study showed pictures of tearful faces to subjects. Within 50 milliseconds (.05 sec.) test subjects reported a boost in feelings of empathy and friendship towards people shown in such images. This very interesting hypothesis awaits further investigation.
Here’s some Outlander proof that social signals work: a mess of fans were ready, willing, and able to comfort that ginger-haired laddie as he wept at Wentworth Prison (Starz episode 115, Wentworth Prison)! Yep!
Here’s another fascinating aspect of emotional tearing. Boys and girls cry with equal frequency until puberty when something complex happens. In Western cultures, boys are conditioned to restrain tears such that women cry twice (one study says 5x) as frequently as men. Biology may also play a role as male puberty is marked by increased testosterone production and some studies hint that this male hormone helps suppress emotional tearing.
Even more interesting, in some social settings such as sports, male displays of feeling such as hugging, cheering, and crying are OK; perhaps because people expect emotions to run high at sporting events. Consider Mario Balotelli, a world class footballer (soccer in US) for team Italy. At the 2012 Euro final, Spain defeated Italy and Mario wept with deep regret (Image L). Apparently, this emotional display did nothing to hinder his career and may have helped it.
Finally, it seems that emotional crying in men can be downright desirable. Studies show that if powerful men display controlled weeping in response to sad or challenging situations, they are perceived as more competent than men who do not. Consider the lion-hearted WW II British PM, Winston Churchill, who has been dubbed the most tearful politician of all time!
Image L
Another consideration: scientists agree that animals shed tears to protect their eyes but also posit that humans are the only animals that cry based on feeling. Now, I ken that this supposition is bound to rouse some mighty powerful responses from readers who swear their pets display emotions (I’m pretty sure mine do)!
Charles Darwin wrote in The Expression of the Emotions in Man and Animals that keepers of Indian elephants at the London Zoo claim their charges shed tears of sorrow (Image M). And, social media is rife with anecdotal reports that, indeed, animals do demonstrate sadness.
However, science can barely evaluate human emotions much less interpret the emotional status of animals. Understand that this scientific position makes psychic weeping in animals neither true nor false, just not provable at this point in time.
Image M
As if this isn’t enough of teary stuff to contemplate, photographer Maurice Mikkers has recently photographed evaporated human tears and found that no two are alike in salt and mineral deposition (Image N)! ”Every tear is as unique as a snowflake,” writes Maurice. The significance of this fascinating finding awaits further studies.
Image N
So, one may safely surmise that the scientific jury is still out on why humans engage in emotional crying. Love it or despise it, crying appears to be a complex, multifactorial response which is crucial to our well-being! Emotional tears are potent symbols of who we are as individuals and as members of the collective whole (such as Outlander fans), celebrating our deepest connections to the world.
Sniff! Now that Outlander has returned to Starz, where is my box of tissues? Awaiting new episodes, but thus far, my favorite emotional tears are those shed by Jamie after Claire declares, “take me home to Lallybroch” (Starz episode 111, The Devil’s Mark). Wake up lad! She’s baaaaack!
Diana’s words from Outlander book!
He slept on his back, as he usually did, hands crossed on his stomach, mouth slightly open. The last rays of daylight from the window behind me limned his face like a metal mask; the silver tracks of dried tears glinted on golden skin, and the copper stubble of his beard gleamed dully…I kissed his cheek, damp and salty.
I close this lesson with an amateur’s haiku poem in honor of Jamie’s emotional weeping:
Ode to Jamie’s Tear
Single tear slips free
Silent, salty and serene…
Pledge of endless love
A deeply grateful,
Outlander Anatomist
Photo creds: Starz, Maurice Mikkers – photographer of human tears (Image N – 27 Feb. 2016, New Scientist), www.dailybhaskar.com (Image D), www.emedicine.medscape.com (Image E), www.en.wikipedia.org (lmage J), www.evolutionaryparenting.com (Image I), www.hubpages.com (Image C), www.huffingtonpost.com (Image M), www.huntingtoneyecare.com (Image A), www.pickchur.com (Image G), www.inthestands.co.uk (Image L), www.studyblue.com (Image B), www.thekoreanforeigner.blogspot.com (Image F), www.vikasacharya.wordpress.com (Image K), www.youtube.com (Image H)