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Pain, Pain -Go Away!

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You came with no warning and no invitation

You came with a single message of doom and gloom

I had no control

It was fate

It was no joke

I had to take you seriously

You seem to be endless and to be going nowhere

With the unintended intention to taunt and haunt me

You are the source of my suffering.

Since the dawn of man

You have accompanied us with a not so gentle reminder

That everything is not OK

Some say you are protective

But it is sometimes hard to understand

All I know is that I suffer

Nociceptors sense the feeling

They come in different forms

Transmitting pain from pressure, prick, or improper heat,

– or a severe lack of it

Quickly the sensation travels

On the A, delta, or C train-

 Impulses that run their course

From source to spinal cord

With sizzling hot news of my experience

Where they snap to a halt as they clap as a synapse

And get a second order of direction

At the gate of decision

Which waves them on to a new thoughtless action

On their way to master control.

And through and via the wire of the RAS

Which awakens an awareness of you;

And then to the thalamic relay

Where they get their new orders:

To whom they should turn

And what direction to take.

In the higher levels of limbic autonomic and homunculus centers

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The sense becomes real

And the feeling becomes severe

And after all the science

I know not what to do

But to increase my heart rate a little,

Contract a muscle and a gland or two

And perhaps let out a scream at the height –

And impugn your intrusive impudence that imposes on me.

pain, nociceptor, poem, prayer, sensory system, thalamus, A fiber, delta fiber, C fiber, Ashley Davidoff MD. The Common Vein, Art in Anatomy

 And then sometimes

We use the eyes and guise

Of X-ray Eyes

Or try a tincture of opiate

To extirpate the excruciate –

And then sometimes to no avail

Yet I could care less about your wonderful pathways of biology and science

I know that I hurt -but also in a different way

It is not only the pain that I feel

But the pain of fate as well

That was handed to me as a card in a bad deal of nature

And I have no choice but to deal with it …..

But it hurts!

person, old lady, emotional pain, aging, poverty, loneliness

 

 

See the BLOG about the Art and Science of Pain

The Common Vein Copyright 2017

Ashley Davidoff MD

Revised since publication as a Blog August 2016

 

 

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Pain – Art and Science

Pain

Pain is an unpleasant  sensation originating from our physical and or emotional environments.

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Faces of Pain

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Extreme Physical Pain

 

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Extreme Emotional Pain

Physical Pain

Pain is a symptom and as such reflects a derangement of either the external or internal environment.

All sensations start by stimulating a receptor of  a nerve that conducts the impulse to the spinal cord where low level control and discrimination occurs, and transfers  the stimulus to the brain, where higher centers process the stimulus and react to it.  The structures in the brain include the thalamus, somatosensory cortex, limbic system, and autonomic systems and they are involved in  perception, localization and integration.  They send out a stimulus with instructions of how to react which is executed by muscle contraction or tissue secretion.

Functionally, pain is protective. The physiology and pathophysiology relate to changing the mechanical stimulus into an electrical impulse, and then through a series of complex synapses the stimulus is transmitted with the intent of  protecting the person from further damage.

The causes of pain are innumerable and exist within the full spectrum of human diseases. Pain may result from pain receptors sensitive to pain, (pricking, cutting, tearing) extreme temperatures, pressure, or aberrant chemical environments. A myriad of processes then occur in response to tissue injury causing either irritation of a somatic nerve or distension and pressure on a visceral sensory nerve. Inflammation is one of the most common of these injurious processes that is classically and universally expressed with  pain – a concept first described by the second century philosopher Celsus.

The result of a pain impulse is usually withdrawal from the insulting stimulus, resting of the injured part, or seeking the help of a medical practitioner if the pain is unbearable and arises from an internal disorder.

Diagnosis of pain disorders should proceed with careful history taking and clinical examination, followed by appropriate laboratory tests, and imaging if necessary.

Pain is a very common symptom and most instances are treated with an analgesic or antiinflammatory agent.   For more serious pains, treatment is directed at the cause of the pain.

Classification

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The table explores the variety of ways of classifying pain.  The left hand column reveals the classification based on functionality, origin, mode of stimulation, pathological causes and relationship of pain to chronicity.  As for functionality it may be adaptive or nonadaptive.  The pain may originate from somatic or visceral nociceptors, may originate from damaged nerves in which case it is called neuropathic, or it may be psychogenic.  The causes are usually via the inflammatory process but may result from any of the disease listed.

Structural Basis of Pain

A pain impulse is initiated by sensory receptors called nociceptors which are located in almost all the tissues. A noxious stimulus say from a hand touching a hot stove is then transmitted by sensory nerves to the spinal cord where a direct spinal reflex causes immediate withdrawal from the source. Additionally the stimulus is modified in the spinal cord by a variety of influences from other sources and is then transmitted via the midbrain and reticular activating system to the cortex. Finally, the stimulus reaches the brain’s somatosensory area where it is perceived and localized with additional extension to other areas of the cortex for the provision of a variety of protective reactions to the stimulus.

We will now expand the detail of the structural pathway described above.

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Pain from the Joints

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Pain from Sinuses 

The Sensory Pain Receptors – Nociceptors

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Nociceptor

A pain impulse is initiated by sensory receptors called nociceptors which are located in almost all the tissues. They are tree like branching structures.

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Types of Receptors Subtending the A delta Fibers and C Fibers

The diagram shows sensory stimuli including sharp pressure, extreme heat and cold as well as chemical, stimulating the free nerve endings of the nociceptors  that are linked to the myelinated A delta fiber , and non myelinated C fiber.  The myelinated fiber will conduct the impulse between 3 and 15 times faster than the non myelinated fiber.

 These specialized receptors vary in structure and number throughout the tissue and viscera of the body. There are external nociceptors that are situated in the skin and cornea with higher concentrations in the coverings of the body including the skin, pleura, pericardium, peritoneum and periosteum. Internal nociceptors are found in muscles, joints, around blood vessels, and within the mucosa of some organs including the urinary bladder, genitourinary tract, and the gastrointestinal tract. There are nociceptors in varying concentrations in almost every organ in the body, but interestingly there are none in the brain substance itself .

First Order of Transmitting Sensory Fibers 

The first order of nerve fibers transport the stimulus from the nociceptor to the dorsal root ganglion

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The sensory receptors of the nociceptors are found in the tissues peripherally and are connected  by a long fiber that transmits the impulse to the ganglion cell that lies in the dorsal ganglion in the neural canal alongside the spinal cord. This diagram shows the three types of receptors and fibers that transmit impulses related directly and indirectly to pain . The upper fiber is called the C fiber and it is non myelinated, consists of the receptors in the top left hand corner that when stimulated transmit the impulse via a long afferent neuron to the cell body lying alongside the spinal column. This fiber is relatively thin, measuring between .4 to 1.2 micrometers, and conducts the impulse at about 2m/s. The second neuron is the A delta fiber and it responds to the pricking or sharp sensation that is first felt and reacted to. It is weakly myelinated and is about 2-6 micro meters thick, and conducts the stimulus with a velocity of between 15-30 meters per second. The last fiber is the A beta fiber and it is responsible for the pressure component which indirectly affects response to pain by affecting the gate mechanism of pain. It is greater than 10 microns thick due to heavier myelination and conducts impulses at 30-100 meters per second

The Dorsal Root Ganglia

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The Dorsal Root Ganglion of the Afferent Neurons

The dorsal root ganglion  is a focal accumulation of the first order nerve cells of the sensory component of the peripheral nerve. (orange)  It is situated  in the neural foramen of the vertebral body.  The central process emanates from the ganglion cell  and ends in the dorsal horn.

2nd  Order of Neurons

The second order sensory fibers are those fibers in the spinal cord.  They first cross to the contralateral side of the spinal cord and then connect to the thalamus via the spinothalamic tract. 

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Second Order Neurons  – Cross Over in the Spinal Cord and 3rd order are Found in the  Spinothalamic Tract 

The spinothalamic tract is the major sensory ascending pathway of 2nd order neurons and serves as the major pathway for pain, temperature, itch and crude touch. Within its construct, the spinothalamic tract has three merging bands of specialized fibers that conduct pain impulses. The anterior spinothalamic tract carries pain signals initiated by touch while the lateral spinothalamic tract carries slow and fast fibers for pain and temperature sensations. The anterolateral spinothalamic pathway, located in the anterolateral white column pathway in the anterior half of the lateral funiculus conducts a variety of somatic pain signals.

3rd  Order of Neurons – Connect the Thalamus with the Sensory Cortex

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The Three Orders of Neurons

Second Order Neurons From the Spinal Cord to the Brain and Perception of the Pain  The Three Orders of Neurons

 The stimulus is first converted into an electrical impulse which is taken by a first order sensory nerve (orange)  to the spinal cord (dorsal root ).  The second order neurons (blue) first transport the stimulus to the contralateral spinothalamic tract  which in turn transports the impulse  to the thalamus,.  The third order neurons (pink)  transport the impulse to the somatosensory cortex.

Role of the Thalamus

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Thalamus – Relay Station to the Cortex in the Pain Pathway
The thalamus (T) is the gateway to the cerebral cortex. It is a paired organ and represents the main part of the diencephalon and subserves both motor and sensory function. It is structurally and functionally situated between the cortex and the midbrain. The thalamus has specific nuclei with diffuse projections to and from multiple regions of cerebral cortex.  The thalamus functions as a translator for the cerebral cortex. It processes sensory and motor information and mediates the autonomic nervous system regulating sleep and arousal. The thalamus also contains reciprocal connections to the cortex that are involved in consciousness. It may also play a role in vestibular function.  The thalamus translates pain signals of the 2nd order neurons and gives rise to the third order neurons that extend to the cortex. Awareness and localization of the pain is then achieved at the level of the cortex. The thalamus however is not merely a relay station for nociception but also plays a role in processing the stimulus.  Axons terminating in the lateral thalamus mediate discriminative aspects of pain (somatosensory cortex) including the originating body part. The fibers ending in the medial thalamus mediate the motivational and affective aspects relating for example to the emotional and memory of pain. These third order neurons travel to the prefrontal cortex, insular and cingulate gyrus which contribute to the emotion and memorization of pain experiences. 

The Homunculus Man and Localization of the Pain 

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HOMUNCULUS MAN and Localization of Sensation in the Somatosensory Cortex of the Parietal Lobe

The homunculus man (literally the “little man”) is the distorted figure drawn to reflect the concept of size of organ paralleling the size of the sensory innervation. The diagram reflects the relative functional sensory space each body part occupies in the somatosensory cortex. Those structures with a high density of sensory receptors are represented by a larger size, while those with a lesser concentration of sensory apparatus are shown as being “smaller” in size. Hence the mouth lips, hands feet and genitalia have a relatively large representation. Nerve fibers from the spinothalamic tract in the spinal cord (blue line) are relayed to the thalamus (orange) which filters and then distributes the sensation to the somatosensory cortex.

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The Somatosensory Cortex in the Parietal Lobe – Home of the Sensory Homunculus

The somatosensory cortex in the parietal lobe  is the location of the the main sensory receptive area for all the senses including pain. It receives the stimuli from the thalamus and then integrates the information with other parts of the brain  that will modify the perception of the sensation

The function of the somatosensory cortex is that of a higher processing center for touch, temperature, pain, and proprioception serving to amplify awareness of the sensations enabled by the thalamus. Sensation from the left side of the body are processed in the right somatosensory cortex and similarly those from the right side are processed on the left. The higher function of the somatosensory cortex allows us to localize the pain to a specific site, perceive the character and intensity of the stimulus, and sometimes helps identify the shape of the originating object.

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The Higher Multicentric Levels of Pain Perception and Reaction

The somatosensory cortex relays impulses to other cerebral areas of perception that modulate the reaction to the pain  It forward the pain signals via the white matter to other centers in the cortex to enable integration with visual and auditory input, and with other higher cortical functions such as emotion and memory for example. The full experience is then “seen” by the brain enabling the consequent reaction to be as discriminating  and prudent relative to the nature and experience of the person. The difference between the reaction of an infant, child and an adult to the “shot at the doctors” speaks volumes about this latter function. 

Emotional Pain

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Pain of Poverty

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Pain of Addiction

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Pain of Loneliness

Pain .. Pain go away! – and please leave us alone!

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Anatomy of the Caribbean Heavens

The heavens are rich with artistry  creativity, and lessons to teach us

When viewed from a ship at sea they are even richer – and vacation provides the time and opportunity to explore and express this beauty.  The art is biased of course by the perspective of the observer.  AiA finds the shapes and character of “things” related to the body, biology, art and culture of primary interest.  The Caribbean heavens explored from a boat contains  a wealth of material.

As we started our journey….

I swear I saw  Prometheus running down from the heavens !

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and then I looked a little closer …

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and then put on my shades… and yes twas  a powerful athlete running down to earth from the skies and he was carrying something!  body, sky, heavens,clouds, athlete, running

 

Prometheus is a Greek mythological figure who brought fire to the earth that he stole from Mount Olympus.  He was punished by Zeus who chained him to the rocks of Mount Caucasus.  In addition an eagle (Zeus himself) punished Prometheus by daily feeds on his liver.  The ancients knew of the magical regenerative properties of the liver and the antiseptic qualities of bile.  The eagle (Zeus) is later slain by Heracles and Prometheus is given his freedom.  He gains strength due the the regenerative powers of the liver (also known by contemporary physicians in the world of hepatology and hepatic surgery).

Talking of animals of the sky?  And what about the Scottie dog?  What lessons does he have to teach us?

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Scottie of the Skye in the Sky

In this image a Scottie dog was found romping in the heavens.  The Scottie is an endearing name for the Scottish terrier – aka Aberdeen terrier.  It is part of the group of Skye terriers and therefore is fittingly suited for the theme of the wonderful sightings in the sky.   The Scottie is one of the terrier breeds that come from Scotland.  Other terriers in this group include the Skye, West Highland Terrier, Dandie Dinmont and the Cairn .  The Scottie has a characteristic compact and powerful body.  The torso and head are rectangular, ears are pointed , eyes are almond shaped, and the beard has  long and soft hair.  The legs are short but powerful allowing for agility and quick movement. The breed exemplifies “power in a small package” . The confident and independent nature has earned them the nickname “Diehard”.  It is extremely territorial.  Both President Franklin D Roosevelt and George W Bush owned Scotties. George, the fourth Earl of Dumbarton owned a pack of brave Scottish Terriers, that were named “Diehards”.  Dumbartons regiment in the The Royal Scots were fittingly named the “Dumbarton Diehards”  Scotty Cramp is a disease in Scottish Terriers that causes muscle spasms resulting in hyperflexion and hyperextension of the legs. It is an inherited recessive trait of the breed.  It is  caused by a deficiency in serotonin.

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1 Real Scottie, 1 in the Sky, and 2 in Dem Bones

In Radiology we look at the neck of the Scottie dog in a condition of the lumbar spine that causes back pain in athletes called spondylolysis.  The neck of the Scottie is overlaid in maroon in the image on  the right and represents the pars interarticularis which may undergo stress fracture in young athletes (spondylolysis) resulting in one lumbar vertebral body slipping forward on the other (spondylolisthesis).  It is one of the causes of back pain in young athletes. 

Rain – Good or Bad? –  

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“Anatomy of Rain in the Sky at Sunrise” 

In this image sunrise brings a shower of rain in the east.  The sun shining through the dark clouds illuminates other clouds and brings some hope.  In the context of the vacationer the rain is a disappointment and means an undesirable day indoors.   For the farmer and for mother earth it is a blessing!

The art piece is dominated by falling rain and a rising sun that shines through and illuminates the vista.

and what does that teach us – It all depends on context

Some quotes:

Predicting rain doesn’t count. Building arks does.  Warren Buffett

Let the rain kiss you. Let the rain beat upon your head with silver liquid drops. Let the rain sing you a lullaby.  Langston Hughes

 As the day continued – it got grayer and grayer

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Anatomy of Rain in the Sky

In this instance the gray skies of rain bring a gloom for some and yes … also a bloom .. of life for others.  It is an essential to all biology.  

The image shows rain romping  from the heavens.  

Some Quotes

The best thing one can do when it’s raining is to let it rain.  Henry Wadsworth Longfellow

Gray skies are just clouds passing over. Duke Ellington

The rain began again. It fell heavily, easily, with no meaning or intention but the fulfilment of its own nature, which was to fall and fall.  Helen Garner

but things change..time moves on..and 

“Time and Tide Wait for No Man”

And the following day – all had changed – the rain had passed and bright orange heavens illuminated the sky a moment before sunrise

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Anatomy of the Sky Before Sunrise

Moments before sunrise brings light to the darkness, just before the sun pokes its head from the blanket of the ocean.  The sun shining illuminates the sky with an orange optimism in the cloudless sky.

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Anatomy of the Sky at the Moment of Sunrise

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Anatomy of the Sky 1 Minute after Sunrise

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Anatomy of the Sky 3 minutes After Sunrise

Time passes quickly

Quotes

“You can’t stop the future, You can’t rewind the past, The only way to learn the secret…is to press play.” – Jay Asher

“Life is a series of natural and spontaneous changes. Don’t resist them; that only creates sorrow. Let reality be reality. Let things flow naturally forward in whatever way they like.” ― Lao Tzu

As the day progressed – Nirvana – a blue blue sky , and a blue blue ocean  – interrupted only by a ruffle of waving white

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Blue Sky, Blue Water, and A Ruffle of Waving White

and this also was not for long .. as time passed and ever changing cloud pattern passed before our eyes – containing all sorts of people

… and a surprise artist made his appearance –

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Chagall Blessing the Sky

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  Blessing in the Sky with Overlay

The artist spotted Chagall flying in typical fashion through the heavens of the Caribbean.  he had his arms outstretched as if to bless the sky

And by the end of the first day… the clouds rolled in to compete for kingdom of the earthly sky

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Anatomy of the Sky as the Sun Starts to Set

The kingdom of the earthly sky is shared by the sun with the clouds as each seeks to dominate.  For the sun this is a small battle since its kingdom stretches over the entire solar system.  For the clouds this is a major battle since they only rule over the earth.  They both play an essential role in preserving life on earth.  The sun is constant and dependable.  The clouds are transient and fickle. The setting sun descends through the blanket of the clouds, and gives the sky a mysterious, and magical  feel.

And the next day… the clouds and the sun shared the spotlight at sunrise

I took a nice cuppa tea, and sat on a chaise – longue to watch the spectacle.  To my surprise I saw my knee caps…

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Sunrise View of the Knee Caps

The art piece expresses a joint experience of my knees and the sun. As I sit on the chaise-longue sipping tea and watching the sunrise with X-ray vision, I share a gaze with the sun.  The sun looks at the sunrise view of my knees and I look at its sunrise in the sky.  In radiology we use the ‘sunrise view” to evaluate the joint space between the patella and the femur.

As the day progressed the clouds disappeared, and a day moon appeared.

 

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Day Moon

And nighttime came – not a cloud in the sky … blackness descended revealing the light of a crescent moon and its neighbour  Venus.

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The Moon and Venus in Conversation

and the heavens turned black – and I saw the overshadowed crescent moon talking to Venus… “What are people thinking?- Do they not realise life rules over death? Peace over terror? Why do the leaders of the people not declare this universal truth? It is so clear from where we stand, that there is something going wrong down there….Leaders must not remain silent! “

And after the moon rose my hand rose to tell the moon something…

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I Have a Bone to Pick with You .. I said

In this art piece the larger than life bones of the hand reach out into the sky in conversation. Tongue in cheek it wants to share the idea that it has a bone in its wrist that shares a common feature with the moon.  The lunate bone is is found in the  proximal row of metacarpal bones in the wrist, so named because of its shape. “Luna” is the Latin name for the moon.

and then two more hands with their scaphoids appeared to teach us the last lessons from the Caribbean

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Scaphoids That Pass Under the Lunar Night

The art piece shows a night time sky with the X-ray of three hands.  The hand on the left and right side of the image have the scaphoid bone of the wrist outlined in color.  The scaphoid is so named because of its ship like shape. “Skaphos” means  ship in Greek.  The middle hand dominates the trio of hands and unrealistically dominates the skyline.  The lunate bone is highlighted in the middle hand.  It is so named because it is moon shaped.   Artistically the scaphoid bone on the right is colored in Irish green since the ring finger carries a claddagh ring -an Irish ring that represents love, loyalty, and friendship.  The larger than life delicate  fingers of the middle hand reach out to the moon and  talks with the moon about their common shapes… small talk in the big picture

From a literary point of view the title “Scaphoids that Pass Under the Lunar Night” infers and  invokes the sentiment of Longfellow in “Tales of a Wayside Inn” about the “ships that pass in the night”

“Ships that pass in the night, and speak each other in passing,
Only a signal shown and a distant voice in the darkness;
So on the ocean of life we pass and speak one another,
Only a look and a voice, then darkness again and a silence.”

“Ships that pass in the night” speaks of chance meetings that are transitory that come and go and are just part of life that do not result  in a meaningful relationship – and in other contexts of two people who almost encounter each other – but do not.  In both cases, with a little effort of either party, a connection may have been life changing.

… and  these were just a few lessons taught by the Caribbean sky!