In describing the regulations for the proper performance of the Passover Seder, the Talmud concludes that the celebrant must recline while drinking each of the Four Cups of wine.Then comes this discussion of how, exactly, one reclines:
פסחים קח, א
פְּרַקְדָּן לָא שְׁמֵיהּ הֲסִיבָּה. הֲסִיבַּת יָמִין לָא שְׁמַהּ הֲסִיבָּה. וְלֹא עוֹד, אֶלָּא שֶׁמָּא יַקְדִּים קָנֶה לְוֶושֶׁט, וְיָבֹא לִידֵי סַכָּנָה
Lying on one’s back is not called reclining. Reclining to the right is not called reclining [as free people do not recline in this manner. People prefer to recline on their left and use their right hand to eat, whereas they find it more difficult to eat the other way]. And not only that, perhaps the windpipe will precede the esophagus. [The food will enter the windpipe, and one will come into danger of choking].
Rashi, the great medieval commentator explains that the last comment “perhaps the windpipe will precede the esophagus” refers to lying flat on ones’s back:
רש׳י פסחים קח, א
שמא יקדים - אפרקדן קאי שמתוך שצוארו שוחה לאחריו שיפוי כובע הסותם את פי הקנה נפתח ומתקפל למעלה והקנה פושט למעלה והמאכל נכנס לתוכו ונחנק
This refers to lying on the back. For then the neck is stretched backwards, and the covering that blocks the trachea is open and the trachea is thrust upwards. Food can enter and cause choking.
However Rashi had a prodigious grandson called Shmuel, who also wrote a commentary on this passage. Rabbi Shmuel ben Meir (c.1085-1158) or Rashbam, as he is known, disagreed with the explanation of his grandfather, and offered this instead:
רשב׳ם פסחים קח,א
שמא יקדים - … וקשיא לי אמאי לא סמכיה להאי ולא אהסיבת ימין ורבותי פירשו שמא יקדים קנה לושט דושט הוי על (דרך) ימין ונפתח הכובע שעל פי הקנה מאיליו כשהוא מטה כלפי ימין ואם יכנס בו המאכל הרי סכנה שאין אוכלין ומשקין נכנסין אלא דרך הושט ולכך נראה בעיני דאהסיבת ימין קאי מדסמכיה לדידיה
Anatomy of the upper airway. The esophagus (or oesophagus, as it is written in the UK) lies behind the trachea, and not to its right.
Rashi’s explanation is difficult to understand. Why did he not explain that [the danger] is when you lean to the right [while drinking]? My teachers explained that “perhaps the windpipe will precede the esophagus” refers to leaning, because the esophagus is on the right side. The covering that covers the trachea will open when he leans to the right, and if food gets into the trachea there is a danger [of choking], because food and drink should usually only be found in the esophagus. This is why I believe the Talmud is referring to the [danger of] leaning to the right…
The Rashbam’s Anatomy is incorrect
The anatomy described by the Rashbam is wrong. The trachea lies directly in front of the esophagus; one is not to the right of the other. If you reach up and put your fingers around your trachea now (go on, do it) you will not feel the esophagus because it is lying behind the trachea (and because it is essentially a long fleshy tube with no internal rings for support). This is true in us, and it is true in animals like cows, sheep and chickens, which are kosher and which, presumably, the Rashbam could have used as a model to figure this out. Had he taken a look at freshly slaughtered chicken, he would have seen this.
From Yaakov Dovid Lach, Chullin Illuminated. Brooklyn New York. Hamesivta Publications 5771(2011). p35.
The trachea clearly lies directly in front of the esophagus, though in the image the latter is slightly off center because of the pressure of the thumb.
What happens when we swallow?
The Rashbam did not have access to YouTube, which is a shame, because there are many great videos that explain the process. Here is one, for example. The key bits are at 1:44.
So the epiglottis acts as a trapdoor, closing off the entrance to the trachea each and every time you swallow. Of course when you talk and try to swallow your food, you are forcing air down into the into your larynx while at the same time hoping that no food gets in. When it does, you will cough at best, and choke at worst. Which is why we were always taught never to talk with our mouths full. It’s good advice.
When you choke, a piece of food is stuck around the epiglottis or top of the trachea. This stimulates our coughing reflex, in an attempt to use the force of air to dislodge the food and expel it up and out. If food gets past this sensitive area and enters the lungs, there is no more choking. It is too late for that.
But does leaning to one side or another increase the likelihood of choking on food? Not at all. First, because if you listen to your mother’s advice and don’t try and talk while swallowing, you won’t choke. And second, because the trachea, the esophagus and the epiglottis are all midline structures. Leaning to one side makes you no more or less likely to choke than does leaning to the other.
But what about the Right Main Bronchus?
The Steinsaltz (Koren) English Talmud has a nice diagram of the upper trachea and esophagus, but unfortunately it fails to label the all important epiglottis, and nor does it address the issue of the mistaken anatomy of the Rashbam. The Schottenstein (ArtScroll) English Talmud goes into a little more detail. It notes that “actually the esophagus is directly behind the windpipe…which makes it unclear what Rashbam means when he writes that the esophagus is ‘on the right side.’” So far, so good. But then comes this:
There are, though, anatomical differences between the left side and and the right side (e.g the right bronchus branches off the windpipe into the right lung at a far more gradual angle than the left one does into the left lung) that might account for why leaning on the right side presents a choking hazard whereas leaning on the left side does not.
Here is what the ArtScroll explanation is getting at:
From here.
As you can see, the trachea ends at a sort of T-junction with the right and left main bronchi. And if you pay attention to the diagram, you will see that the right main bronchus comes off at a more gentle angle than does the left. Here is another diagram, this time just of the trachea and bronchi, where you can see this a little more clearly:
From here.
Do you see how, when compared to the left, that right main bronchus comes off at a more gentle angle? Now, if you were a piece of bread, or better yet, a piece of matzah that had snuck past the epiglottis and you were making your way down into the lungs, which direction would you be more likely to go, all things being equal, when you reached that junction with the right and left main bronchi? You would be more likely to continue in a straight line, rather than take a sharp left turn. And so you would be more likely to end up in the right main bronchus. Which is exactly what happens when people aspirate food into their lungs: it generally ends up in the right lung rather than the left. And, by the way you now know the answer to a common question thrown at medical students on the first day of their pulmonary rotations. You are welcome.
But what does this have to do with leaning to the right, as noted in the ArtScroll commentary? In a word, nothing. In two words, absolutely nothing. Leaning to one side or another might theoretically change the side into which the food might lodge of you are unlucky enough to aspirate it, but food in the right lung is as undesirable as food aspirated on the left. Neither is good for you, and if left untreated will lead to aspiration pneumonia and its complications, none of which are good. It’s an easy fix for ArtScroll to make to its excellent product. Could you please let them know?
What about a left-handed person?
When the Talmud addresses issues to do with sides, it assumes that the person is right-handed, since this is true of the majority. But there are differences for left-handed people. For example, a left-handed person puts tefillin on the right arm, while right-handers do so on the left. Might there be a difference for left-handers when it comes to this business of leaning on the Seder night?
Rabbi David ben Solomon ibn Zimra (1479-1573, known by his acronym Radbaz, was one of the leading rabbinic leaders of his generation. In one of his three thousand (!) responsa he addressed the question of whether a person who is left-handed should recline on his right side. In his answer he wrote that he too failed to understand the anatomy described by the Rashbam.
תשובות רדב׳ז ג: 1012
ועוד ראיתי כי הסימנים שוכבין זה על זה ולא ידעתי אם סימני אדם נשתנה
Furthermore, I have seen that the trachea and the esophagus lie one behind the other (although I do not know if this is the same as in people)
Radvaz wrote that for a left-handed person, leaning to the left would be uncomfortable, and since the entire point of the act of leaning is to replicate a feeling of freedom, for a left-handed person this cannot be the correct thing to do:
ועוד הרי תקנו הסיבה זכר לחירות ואם הוא מסב על ימינו ואוכל בשמאלו מצטער הוא ואין זה דרך חירות
Therefore, he concluded that a left-handed person should lean rightwards, though not because of anything to do with a danger of choking, which, as we have seen, does not depend on leaning one way or the other. (Bonus content - for more on left-handedness in the Talmud see here.)
A Yiddish Bonus
Dr Avi Rockoff of Newton, Massachusetts is a longtime friend and Talmudology reader. He noted a fascinating linguistic twist to today’s daf. “When I was a kid and choked on something,” he told me via email, “my mother would clap me on the back, commiserate, and tell me that I had to take care so food wouldn't enter die linke keyli [lit. the left vessel].” And then he added this:
Yiddish has its fair share of Talmudic references, part of traditional cultural knowledge of even unlearned Jews. This one is more than a quotation--it's a bit of lomdus [learning], referring to a dispute between Rashbam, whose view prevailed over even that of his famous zeyde, and seems to have made it into Yiddish anatomical folklore.
How to save a choking person
According to the National Safety Council, about 5,000 people die in the US each year from choking. About half are over 74, and food is often responsible. This is why each of us should know how to perform abdominal thrusts, also known as the Heimlich maneuver:
Stand behind the person. Place one foot slightly in front of the other for balance. Wrap your arms around the waist. Tip the person forward slightly. If a child is choking, kneel down behind the child.
Make a fist with one hand. Position it slightly above the person's navel.
Grasp the fist with the other hand. Press hard into the abdomen with a quick, upward thrust — as if trying to lift the person up.
Perform between six and 10 abdominal thrusts until the blockage is dislodged.
And here is a useful video of how to save a choking person. So go on, watch the 2 minutes and 19 second video. Who knows? You might save a life on Seder night.
