Diane
28-03-2006, 11:08 PM
I'm sort of sad this forum doesn't have the name "deep model" anymore, but that's ok.
This morning I got quite transfixed with looking at the diagram of a transverse section of a 10.5 mm embryo's hindbrain, being someone who sees everything through the goggles of evolution. See the thumbnail attached below. Here is another view (http://isc.temple.edu/neuroanatomy/lab/embryo_new/cc/index.html) with labels that light up. I have added the accompanying text (http://isc.temple.edu/neuroanatomy/lab/embryo_new/cc/detail.html) into my own thoughts.
I thought I'd bring part of the post I made on this, here, instead of letting it stay on the much less accessed or read embryology forum. To me, this hindbrain is the crux of the matter, the alpha and the omega of the whole system. This is the part of the nervous system we are trying to (or should be trying to..), impress, with our efforts.
The whole thing looks a bit like an insect with a row of big dots along its body. It is comprised of two joined "bumps", the first processes incoming data and the second processes outgoing data.
The top bit that looks like an antenna flipped backwards is the roof plate. It defines the dorsal limit of the hind brain.
1. The first dot from the roof plate represents the "special somatic afferent column." That means, incoming from special senses. A neuron is depicted coming into it from a structure called the otocyst, which will become the part of the inner ear that contains the otoliths. Why does that column need to be first? It's easy if you think evolutionarily. Obviously we are building a creature that needs to have its wits about it if it is to a) find food, and; b) escape predation. These two capacities will help it to c) live long enough to reproduce, and inherently, find someone with whom to reproduce. We could call the imperative of the first column, advanced warning, or awareness. Hear a noise, and the eyes look, the head turns.. Balance is important when you are a moving creature.Special somatic afferents (SSA) are found only in supraspinal locations and are represented by the laterally-lying vestibular and auditory nuclei in the medulla and pons. They develop from branchial arch structures.
Cranial nerves I and II serve vision (SSA) and olfaction (SVA). However, these are not true nerves. Rather they develop as evaginations of the telencephalon (olfactory nerve) and the diencephalon (optic nerve).
2. Next, we have a dot representing something called "general somatic afferent column", with a neuron coming into it from something called "skin." What? Why is skin next? Think about it: Skin is practically a special sense, it gives the organism information that it is being predated (attacked by another who sees it as their next meal), or that it is touching its own next meal, or that it is touching its beloved (mate or offspring), or that it is fighting off a rival or something that could potentially hurt the kids (former mate perhaps). Together with info incoming from special senses (the first dot), it can 'choose' how to react appropriately. Or rather, this part of the brain can choose a behavior, based on what level of threat exists or doesn't exist. Interaction is a word that could sum up this nucleus/column.
The continuous GSA cell column of the spinal cord dorsal gray horn which handles pain, temperature and touch sensations is continued without interruption into the medulla, pons and midbrain. In these locations it is variably known as the spinal nucleus of V, principal sensory nucleus of (of CN V) and the mesencephalic nucleus (of CN V). Any CN carrying GSA information will terminate in these trigeminal nuclei, derived from the alar plate.
Proprioceptive GSA information destined for the cerebellum from the lower extremity terminated in the nucleus dorsalis of the cord. Similar proprioceptive information from the upper extremity passes to the analagous rostral representation called the accessory cuneate nucleus in the low medulla.
3. Third in line is a dot called, "special visceral afferent column". If you're like me you'll immediately think viscera, organs.. but wait, there's a neuron coming into it from a taste bud. Ha. The whole point of existence (from a Sagan/Schneider, Into the Cool point of view) is to eat and transform energy from one form to another, striving to reduce the energy gradients in nature and reach eventual entropy. Of course taste is important.. if you eat something you weren't outfitted to break down, it could kill you. Taste buds will tell you if something has that potential. If it tastes "bad", spit out, if "good", then proceed. More "nonconscious" choice. Eat.Special visceral (branchial) afferents (SVA) are fibers from taste buds and are carried by CNs VII, IX and X. Upon entering the brainstem, they travel with the GVAs, in the tractus solitarius to the most rostral end of its nucleus (in the pons) where it is called the gustatory portion of the solitary nucleus.
4. Fourth dot in the big first bulge of our insect-shaped embryonic hind brain is a column called "general visceral afferent column." Aha. Here's were we have a neuron depicted as coming up from visceral epithelium. This is how grand central station is going to know/get feedback on how digestion is proceeding. We've found the food with our special senses, we touched it and made sure it didn't touch back, we tasted it to make sure it was the right sort of food, then we ate it. Now we are tracking its progress along the food tube. Moniter digestion. The discontinuous GVA cell column of the spinal cord dorsal gray horn is recognized throughout the medulla when it resumes as the nucleus of the tractus solitarius. Any CN carrying GVA information will terminate in this cell column.
B. Efferents:
5. Now we are into outgoing data management. The fifth dot is "general visceral efferent." A neuron is going out to visceral non-striated muscle. OK. Why, if the enteric nervous system handles all the motor digesting on its own, do we need any efferents going out to the gut from the brain? The answer, again from an evolutionary POV, is this: What if you're out there on the savannah minding your own business, having a snooze even, and digesting away, when out of the corner of your eye you spot a predator. Furthermore, you note that the predator spotted you first! Incoming through the special senses. The message goes shooting through the hindbrain, though the efferents to the gut. The message goes through the sympathetics, which set immediately into motion a whole chain of events designed to get you out of the danger, one of which is to shift blood flow from the viscera to your somatic body so that you feel fear! So that you can run! or fight! The message to the gut is to tell it to stop rather than to tell it to continue. It is inhibitory for the most part. The organism doesn't want to have to do two things at the same time, have its attention and energy divided into two activities, when immediate survival has just become the greater imperative rather than longer-term survival. When all is well and the organism is in parasympathetic mode, the rest and digest mode, these efferents do practically zilch in the viscera. They work harder in situations of stop digestion, we have a situation. Furthermore, blood flow is governed by smooth muscle constriction.The discontinuous GVE cell column of the spinal cord ventral gray horn resumes in the medulla as the dorsal motor nucleus of the vagus and the slightly more rostral inferior salivatory nucleus (of CN IX). In the caudal pons this discontinuous cell column is represented by the superior salivatory nucleus (of CN VII). In the midbrain, this interrupted cell column appears again as the nucleus of Edinger-Westphal (of CN III) at the level of the superior colliculus.
6. Next dot is "branchial efferent column". This dot has a neuron going to branchial striated muscle. Branchial muscle is in the throat, the swallowing reflex, breathing, coughing, vocalizing etc. The branchial striated muscle is interesting, and can be used either consciously or unconsciously. It has to be able to work non-consciously, because a newborn has to instinctively know how to take in nutrition and swallow it. Nutrition includes oxygen, breathing is included here. The lungs come from buds off the gut tube. Diaphragm was originally in the neck. So was heart. This part has to work properly from day one, or the infant will die. It warrents its own nucleus. Swallow/breathe or perish.Special visceral (branchial) efferents (SVE) are represented in the brainstem by an interrupted cell column that has no equivalent in the cord. These neurons innervate skeletal muscle that developed from the mesoderm of the branchial arches e.g., larynx, pharynx, facial muscles, muscles of mastication. In the medulla it is represented by nucleus ambiguus (CN IX and X) while in the pons it is represented by the motor nuclei of CN VII and V.
7. The last dot, the very last one, is the "somatic efferent column." This one regulates outflow to somatic striated muscle. This one gets the critter running before it realizes consciously what it's doing. Its imperative could be termed move or die! The continuous GSE cell column of the spinal cord ventral gray horn is represented throughout the brainstem by an interrupted cell column of neurons supplying skeletal muscle of head somite origin. In the medulla there is the motor nucleus of CN XII, in the pons there is the motor nucleus of CN VI, in the midbrain it is represented by the the nearly continuous cell column of CNs III and IV.I see that specifically this is for head muscles, muscles that twist the ears like radar dishes, turn the head toward sounds, turn the eyes toward glimpses. Not so much the soma striated/legs; however, they will go anyway.
This is command central, the war room, if you will, of the brain. This is the old part, the part that is awfully hardwired, integrated, specific, survivalist. Even though it's old (remember amphioxus with a spinal cord, a vertebrate but headless; i.e. we vertebrates likely didn't even havea head to begin with) - it's considered to be an add-on, something that fish invented.
This is the part that will get us out of danger and the part we can trust to get us out of pain, if we let it. As manual therapists, if we understand this part, and take it into account, we will get much further in our careers with a lot less effort, because we will understand our patients better, as organisms that are also human. This is the part that the patients are bringing us that (usually) isn't working quite right, or at least doesn't feel to them that it's working right; they don't feel integrated with their own bodies. If we take care not to alarm them, give them no reason to run, not cause them any nocioception, help them move easily again, their nervous systems will right themselves without any fuss, provided they are intact. I think a whole treatment manual could be written on just this little diagram.
1.First, make sure there are no nocebos. Environment non-threatening, pleasant smell, friendly colors, therapist clean with good breath/good boundaries.
2. Next, pleasant skin input. No rough handling, soft warm confident hands, no nocioception, warm blanket. (Maybe some soft fleece blankets with color choice.. I like to offer patients a choice. Takes care of the first two nuclei at the same time.)
3. The taste buds, viscera afferents and efferents have to wait, or can be refreshed with ample clean water from the cooler. Encourage slow deep abdominal breathing to improve feedback into this system.
4. The throat musculature? Let the patient tell you their fears and hopes, their own way, in their own time. Treat the throat area on all the neck patients. Soothe it. Treat inside the mouth on TMJ patients. Handle heads. Handle handle handle tissue/skin of the head and neck and throat. Soothe it. Learn ways to handle skin over clavicles and sternums. Soothe it.
5. The body? Help it find ways to move that reduce stress/pain in the system. Ideomotor movement works awfully, awfully well.
This morning I got quite transfixed with looking at the diagram of a transverse section of a 10.5 mm embryo's hindbrain, being someone who sees everything through the goggles of evolution. See the thumbnail attached below. Here is another view (http://isc.temple.edu/neuroanatomy/lab/embryo_new/cc/index.html) with labels that light up. I have added the accompanying text (http://isc.temple.edu/neuroanatomy/lab/embryo_new/cc/detail.html) into my own thoughts.
I thought I'd bring part of the post I made on this, here, instead of letting it stay on the much less accessed or read embryology forum. To me, this hindbrain is the crux of the matter, the alpha and the omega of the whole system. This is the part of the nervous system we are trying to (or should be trying to..), impress, with our efforts.
The whole thing looks a bit like an insect with a row of big dots along its body. It is comprised of two joined "bumps", the first processes incoming data and the second processes outgoing data.
The top bit that looks like an antenna flipped backwards is the roof plate. It defines the dorsal limit of the hind brain.
1. The first dot from the roof plate represents the "special somatic afferent column." That means, incoming from special senses. A neuron is depicted coming into it from a structure called the otocyst, which will become the part of the inner ear that contains the otoliths. Why does that column need to be first? It's easy if you think evolutionarily. Obviously we are building a creature that needs to have its wits about it if it is to a) find food, and; b) escape predation. These two capacities will help it to c) live long enough to reproduce, and inherently, find someone with whom to reproduce. We could call the imperative of the first column, advanced warning, or awareness. Hear a noise, and the eyes look, the head turns.. Balance is important when you are a moving creature.Special somatic afferents (SSA) are found only in supraspinal locations and are represented by the laterally-lying vestibular and auditory nuclei in the medulla and pons. They develop from branchial arch structures.
Cranial nerves I and II serve vision (SSA) and olfaction (SVA). However, these are not true nerves. Rather they develop as evaginations of the telencephalon (olfactory nerve) and the diencephalon (optic nerve).
2. Next, we have a dot representing something called "general somatic afferent column", with a neuron coming into it from something called "skin." What? Why is skin next? Think about it: Skin is practically a special sense, it gives the organism information that it is being predated (attacked by another who sees it as their next meal), or that it is touching its own next meal, or that it is touching its beloved (mate or offspring), or that it is fighting off a rival or something that could potentially hurt the kids (former mate perhaps). Together with info incoming from special senses (the first dot), it can 'choose' how to react appropriately. Or rather, this part of the brain can choose a behavior, based on what level of threat exists or doesn't exist. Interaction is a word that could sum up this nucleus/column.
The continuous GSA cell column of the spinal cord dorsal gray horn which handles pain, temperature and touch sensations is continued without interruption into the medulla, pons and midbrain. In these locations it is variably known as the spinal nucleus of V, principal sensory nucleus of (of CN V) and the mesencephalic nucleus (of CN V). Any CN carrying GSA information will terminate in these trigeminal nuclei, derived from the alar plate.
Proprioceptive GSA information destined for the cerebellum from the lower extremity terminated in the nucleus dorsalis of the cord. Similar proprioceptive information from the upper extremity passes to the analagous rostral representation called the accessory cuneate nucleus in the low medulla.
3. Third in line is a dot called, "special visceral afferent column". If you're like me you'll immediately think viscera, organs.. but wait, there's a neuron coming into it from a taste bud. Ha. The whole point of existence (from a Sagan/Schneider, Into the Cool point of view) is to eat and transform energy from one form to another, striving to reduce the energy gradients in nature and reach eventual entropy. Of course taste is important.. if you eat something you weren't outfitted to break down, it could kill you. Taste buds will tell you if something has that potential. If it tastes "bad", spit out, if "good", then proceed. More "nonconscious" choice. Eat.Special visceral (branchial) afferents (SVA) are fibers from taste buds and are carried by CNs VII, IX and X. Upon entering the brainstem, they travel with the GVAs, in the tractus solitarius to the most rostral end of its nucleus (in the pons) where it is called the gustatory portion of the solitary nucleus.
4. Fourth dot in the big first bulge of our insect-shaped embryonic hind brain is a column called "general visceral afferent column." Aha. Here's were we have a neuron depicted as coming up from visceral epithelium. This is how grand central station is going to know/get feedback on how digestion is proceeding. We've found the food with our special senses, we touched it and made sure it didn't touch back, we tasted it to make sure it was the right sort of food, then we ate it. Now we are tracking its progress along the food tube. Moniter digestion. The discontinuous GVA cell column of the spinal cord dorsal gray horn is recognized throughout the medulla when it resumes as the nucleus of the tractus solitarius. Any CN carrying GVA information will terminate in this cell column.
B. Efferents:
5. Now we are into outgoing data management. The fifth dot is "general visceral efferent." A neuron is going out to visceral non-striated muscle. OK. Why, if the enteric nervous system handles all the motor digesting on its own, do we need any efferents going out to the gut from the brain? The answer, again from an evolutionary POV, is this: What if you're out there on the savannah minding your own business, having a snooze even, and digesting away, when out of the corner of your eye you spot a predator. Furthermore, you note that the predator spotted you first! Incoming through the special senses. The message goes shooting through the hindbrain, though the efferents to the gut. The message goes through the sympathetics, which set immediately into motion a whole chain of events designed to get you out of the danger, one of which is to shift blood flow from the viscera to your somatic body so that you feel fear! So that you can run! or fight! The message to the gut is to tell it to stop rather than to tell it to continue. It is inhibitory for the most part. The organism doesn't want to have to do two things at the same time, have its attention and energy divided into two activities, when immediate survival has just become the greater imperative rather than longer-term survival. When all is well and the organism is in parasympathetic mode, the rest and digest mode, these efferents do practically zilch in the viscera. They work harder in situations of stop digestion, we have a situation. Furthermore, blood flow is governed by smooth muscle constriction.The discontinuous GVE cell column of the spinal cord ventral gray horn resumes in the medulla as the dorsal motor nucleus of the vagus and the slightly more rostral inferior salivatory nucleus (of CN IX). In the caudal pons this discontinuous cell column is represented by the superior salivatory nucleus (of CN VII). In the midbrain, this interrupted cell column appears again as the nucleus of Edinger-Westphal (of CN III) at the level of the superior colliculus.
6. Next dot is "branchial efferent column". This dot has a neuron going to branchial striated muscle. Branchial muscle is in the throat, the swallowing reflex, breathing, coughing, vocalizing etc. The branchial striated muscle is interesting, and can be used either consciously or unconsciously. It has to be able to work non-consciously, because a newborn has to instinctively know how to take in nutrition and swallow it. Nutrition includes oxygen, breathing is included here. The lungs come from buds off the gut tube. Diaphragm was originally in the neck. So was heart. This part has to work properly from day one, or the infant will die. It warrents its own nucleus. Swallow/breathe or perish.Special visceral (branchial) efferents (SVE) are represented in the brainstem by an interrupted cell column that has no equivalent in the cord. These neurons innervate skeletal muscle that developed from the mesoderm of the branchial arches e.g., larynx, pharynx, facial muscles, muscles of mastication. In the medulla it is represented by nucleus ambiguus (CN IX and X) while in the pons it is represented by the motor nuclei of CN VII and V.
7. The last dot, the very last one, is the "somatic efferent column." This one regulates outflow to somatic striated muscle. This one gets the critter running before it realizes consciously what it's doing. Its imperative could be termed move or die! The continuous GSE cell column of the spinal cord ventral gray horn is represented throughout the brainstem by an interrupted cell column of neurons supplying skeletal muscle of head somite origin. In the medulla there is the motor nucleus of CN XII, in the pons there is the motor nucleus of CN VI, in the midbrain it is represented by the the nearly continuous cell column of CNs III and IV.I see that specifically this is for head muscles, muscles that twist the ears like radar dishes, turn the head toward sounds, turn the eyes toward glimpses. Not so much the soma striated/legs; however, they will go anyway.
This is command central, the war room, if you will, of the brain. This is the old part, the part that is awfully hardwired, integrated, specific, survivalist. Even though it's old (remember amphioxus with a spinal cord, a vertebrate but headless; i.e. we vertebrates likely didn't even havea head to begin with) - it's considered to be an add-on, something that fish invented.
This is the part that will get us out of danger and the part we can trust to get us out of pain, if we let it. As manual therapists, if we understand this part, and take it into account, we will get much further in our careers with a lot less effort, because we will understand our patients better, as organisms that are also human. This is the part that the patients are bringing us that (usually) isn't working quite right, or at least doesn't feel to them that it's working right; they don't feel integrated with their own bodies. If we take care not to alarm them, give them no reason to run, not cause them any nocioception, help them move easily again, their nervous systems will right themselves without any fuss, provided they are intact. I think a whole treatment manual could be written on just this little diagram.
1.First, make sure there are no nocebos. Environment non-threatening, pleasant smell, friendly colors, therapist clean with good breath/good boundaries.
2. Next, pleasant skin input. No rough handling, soft warm confident hands, no nocioception, warm blanket. (Maybe some soft fleece blankets with color choice.. I like to offer patients a choice. Takes care of the first two nuclei at the same time.)
3. The taste buds, viscera afferents and efferents have to wait, or can be refreshed with ample clean water from the cooler. Encourage slow deep abdominal breathing to improve feedback into this system.
4. The throat musculature? Let the patient tell you their fears and hopes, their own way, in their own time. Treat the throat area on all the neck patients. Soothe it. Treat inside the mouth on TMJ patients. Handle heads. Handle handle handle tissue/skin of the head and neck and throat. Soothe it. Learn ways to handle skin over clavicles and sternums. Soothe it.
5. The body? Help it find ways to move that reduce stress/pain in the system. Ideomotor movement works awfully, awfully well.