user143: "There are in this body head-hairs, body-hairs, nails, teeth, skin, flesh, sinews, bones, marrow, kidneys, heart, liver, pleura, spleen, lungs, intestines, intestinal tract, stomach, feces, bile, phlegm, pus, blood, sweat, fat, tears, grease, saliva, nasal mucus, synovium (oil lubricating the joints), urine, and brain in the skull." source
This seems like a pretty comprehensive list, but semen and menses are noticeably missing; although if they were included, there would obviously have to be separate male and female versions of this contemplation. 
Do we know why they are missing? Are other body parts missing? It seems unusual given how direct the Buddha's teachings normally are; so I imagine there is a reason. Thank you! 

user2207: The author of the Sutra wasn't a biologist and may not have intended this list to be biologically complete or even all that accurate. The issue here isn't the completeness of the list, but the purpose of working with those items.
So why the overly specific number of 32?  Some have suggested mnemonics; perhaps -- Buddhism has made heavy use of numbered lists after all.
But maybe it's because the Sutras used the concepts and imagery of a time and place far removed from our own?  So maybe there is some significance to this list that we're missing?  Since we aren't in the same historical context, many of the Sutras could seem jarring or confusing to modern ears. Fortunately this is not a problem, because the real message of the Sutras is timeless; we just need to look beyond the surface "message".
I think this is the real issue here.  Why does this question matter?  Are we perhaps getting side-tracked by the least important part of the Sutra?  Will our practice really be affected because of a missing body fluid or so?  For that matter, do body fluids matter, or is the exercise more about overcoming attachment to the body by a mental deconstruction of it?

user254: 
Do we know why they are missing?

I don't. Could it be because semen is not being produced/created?

Are other body parts missing?

It's a good list.
For completeness, there is also cartilage (e.g. the trachea), pancreas, a gallbladder apparently, glands (salivary, thyroid, etc.), all the gender-specific reproductive organs, blood vessels (including arteries and veins) except heart, sensory and motor nerves (including spinal cord) except brain, sense-organs (eyes, ears) could be given a special mention, tongue, the lymphatic system, bladder.
"Flesh" can be a catch-all though.

user5154: IMHO, - Upaya (skilful means) - the purpose of the Buddha's teaching is liken to a raft to take us across the ocean of samsara to the island of exquisite bliss.
Hence 32 parts of the body is adequate enough to accommodate various human tendencies to the attachment of the body. Whereas the classification of the the aggregates to only 5 is sufficient to lead one to see dukkha, anicca, anatta.
There are some who think the Buddha taught realities, physical & mental.
When ask what does your teacher teach? ",,there is suffering (or stress), the cause of suffering (or stress), that there is an end to suffering (or stress), and the path to the end of suffering (or stress).

user111: You could probably contemplate on it as blood. Women entered the Sangha somewhat later. So I would presume this meditation was taught to monks before that happened. You might have also noticed that seminal fluid is missing from the list.
Women having to contemplate on that might actually arouse their lust. Maybe it's the same case with men having to contemplate on women's period.

143: <p>"There are in this body head-hairs, body-hairs, nails, teeth, skin, flesh, sinews, bones, marrow, kidneys, heart, liver, pleura, spleen, lungs, intestines, intestinal tract, stomach, feces, bile, phlegm, pus, blood, sweat, fat, tears, grease, saliva, nasal mucus, synovium (oil lubricating the joints), urine, and brain in the skull." <a href="http://www.accesstoinsight.org/tipitaka/kn/khp/khp.1-9x.piya.html" rel="nofollow">source</a></p>

<p>This seems like a pretty comprehensive list, but semen and menses are noticeably missing; although if they were included, there would obviously have to be separate male and female versions of this contemplation. </p>

<p>Do we know why they are missing? Are other body parts missing? It seems unusual given how direct the Buddha's teachings normally are; so I imagine there is a reason. Thank you! </p>
 2207: <p>The author of the Sutra wasn't a biologist and may not have intended this list to be biologically complete or even all that accurate. The issue here isn't the completeness of the list, but the purpose of working with those items.</p>

<p>So why the overly specific number of 32?  Some have suggested mnemonics; perhaps -- Buddhism has made heavy use of numbered lists after all.</p>

<p>But maybe it's because the Sutras used the concepts and imagery of a time and place far removed from our own?  So maybe there is some significance to this list that we're missing?  Since we aren't in the same historical context, many of the Sutras could seem jarring or confusing to modern ears. Fortunately this is not a problem, because the real message of the Sutras is timeless; we just need to look beyond the surface "message".</p>

<p>I think this is the real issue here.  Why does this question matter?  Are we perhaps getting side-tracked by the least important part of the Sutra?  Will our practice really be affected because of a missing body fluid or so?  For that matter, do body fluids matter, or is the exercise more about overcoming attachment to the body by a mental deconstruction of it?</p>
 254: <blockquote>
  <p>Do we know why they are missing?</p>
</blockquote>

<p>I don't. Could it be because semen is not being produced/created?</p>

<blockquote>
  <p>Are other body parts missing?</p>
</blockquote>

<p>It's a good list.</p>

<p>For completeness, there is also cartilage (e.g. the trachea), pancreas, a gallbladder apparently, glands (salivary, thyroid, etc.), all the gender-specific reproductive organs, blood vessels (including arteries and veins) except heart, sensory and motor nerves (including spinal cord) except brain, sense-organs (eyes, ears) could be given a special mention, tongue, the lymphatic system, bladder.</p>

<p>"Flesh" can be a catch-all though.</p>
 5154: <p>IMHO, - Upaya (skilful means) - the purpose of the Buddha's teaching is liken to a raft to take us across the ocean of samsara to the <a href="http://www.arrowriver.ca/dhamma/nibbana.html" rel="nofollow">island of exquisite bliss</a>.</p>

<p>Hence 32 parts of the body is adequate enough to accommodate various human tendencies to the attachment of the body. Whereas the classification of the the aggregates to only 5 is sufficient to lead one to see dukkha, anicca, anatta.</p>

<p>There are some who think the Buddha taught realities, physical &amp; mental.</p>

<p>When ask what does your teacher teach? ",,there is suffering (or stress), the cause of suffering (or stress), that there is an end to suffering (or stress), and the path to the end of suffering (or stress).</p>
 111: <p>You could probably contemplate on it as blood. Women entered the Sangha somewhat later. So I would presume this meditation was taught to monks before that happened. You might have also noticed that seminal fluid is missing from the list.
Women having to contemplate on that might actually arouse their lust. Maybe it's the same case with men having to contemplate on women's period.</p>
