Lecture Notes by Hugo Lj. Odhner
Development of the Nervous System
As a tissue is regarded, the nervous system develops from the ectoderm or outer germ layer of the blastula within the first days of embryonic life: An elongated germinal disk is formed from the flattening blastula and grows into two and finally three germ layers. The outer layer soon produces a fold, which, closing, develops into the neural tube, from which the tissues of the nervous system gradually grow out. The tube remains as the ventricles of the brain and as the central canal of the spinal cord.
The Nervous System is generally divided into two parts.
One is enclosed in the cranium and in the neural canal of the vertebral column,
and is called the Central Nervous System or the Cerebrospinal System. This
is concerned in all conscious sensations and voluntary actions. The other
part is composed of a double chain of ganglia situated at the sides of the
vertebral column and connected by fibres with each other and with the central
nervous system, and is called the Sympathetic System. Taken together with
certain nerve paths such as the Vagus Nerve which are sometimes designated
as "parasympathetic", the Sympathetic System is called the Autonomic Nervous
System because it has to do with unconscious sensations and involuntary motor
Among the general functions of the nervous System the
following are generally recognized:
To these Swedenborg adds two additional offices:
9. The "cortical glands" manufacture certain vital
fluids and assist in their purification. These fluids rejuvenate and vivify
the red blood. Swedenborg therefore classifies the brain, as a whole and as
to distinct parts, among the glands. The fluids elaborated in the cortical
glands not only flow out through the nerve fibres but are also mixed with
other essences in the ventricles and veins. The chemical function of the brain
is largely directed to the ventricles and culminates in the pituitary gland.
It is perhaps interesting that graphic recordings of
cardiac action as reflected in peripheral circulation show rhythmic changes
corresponding to respiration. - Dr. Robert Alden
11. The inmost essence of the nervous system serves as the procreative essence
of the seed.
Swedenborg notes that the brain is a) better protected than any other organ of the body; b) informed more directly than other parts by the sense organs of the head; c) nourished by the richest blood; d) the terminus of the blood vessels and the origin of the fibres. Since these nerve fibres, both sensory and motor, proceed from and to the cortical substances, the cortical glands must be the seat of the soul. Additional confirmations are found in the manner in which the arteries of the brain are so arranged as to break the force of the pulse lest the blood dominate the brain.
The Central Nervous System is composed of three parts - the Cerebrum, the Cerebellum, and the Medulla. The Medulla has two portions: the Medulla Oblongata and the Medulla Spinalis. In front and partly around the upper Medulla the Pons Varolii is situated.
The Cerebrum is distinctly divided by a deep cleft - the longitudinal fissure - into two halves or hemispheres, which are separated by the tough "Falx Cerebri" - a projection of the Dura Mater. The hemispheres are united especially by a thick band of nerve fibres called the Corpus Callosum. The Cerebrum is separated from the Cerebellum by the "interior lamina" of the Dura Mater. But it communicates with the Cerebellum by fibres of the Medulla Oblongata, by common blood vessels, etc.
The Axes and the Ventricles
Swedenborg describes the parts of the brain as being situated about two axes, which usually coincide with the connected cavities which are called "ventricles". The longitudinal axis runs "like a perpetual duct or canal"(997) from the septum lucidum (or "fifth" ventricle) through the third ventricle and down into the minute central canal of the spinal cord even to the "cauda equine". Swedenborg postulated the existence of this central canal although it was not yet verified. (998)
The transverse axis runs through the "straight
sinus" - a venous canal beginning from the middle of the occipital bone
third ventricle and thence through the infundibulum into the pituitary gland.
Both these "axes" are designed to allow for the motion
of the tissues and organs around them. In them are conveyed the fluids of
the cerebrum; the transverse axis, however, conveys both blood (in the "straight
sinus") and spiritous essences.(999)
The brain tissue - aside from the characteristic neuroglia
cells which serve the purpose of a supporting connective tissue - is
made up of two types of substance, a) the gray, cineritious, or
substance, and b) the white, or medullary substance. The nerve cells
are massed in the gray matter. The medullary substance consists mostly
of nerve fibres.
Coverings of the Brain
The coverings of the brain are, the Pia Mater,
which Swedenborg regards as purely vascular rather than fibrous; the Arachnoid
Tunic which is less universal, but very delicate, and separated from
the Pia by the subarachnoid cavity which is filled with cerebrospinal fluids;
and the Dura Mater which is tendinous, made up of fibres "returning
from the body." (1001)
The Pia of today consists of membrane and vessels; though
it could be considered as being entirely vascular,
supported by the arachnoid. The subarachnoid spaces are considered filled
by an "arachnid" meshlike or weblike
interweaving of fibres, rather than being a spongy tissue being formed into
cell-like compartments. - Dr. Robert
The subarachnoid spaces are filled with a spongy tissue which is formed
into cell-like compartments. Fluid passes easily from
these spaces into the veins of the dura mater by way of arachnoid villi
which protrude into the dura. The sub-dural spaces are
also filled with a similar fluid.(1002)
It's interesting that although the arach. villi are presumed to filtrate cerebrospinal fluid into the venous system, this has not been proven; and it's believed by many that there may also be a direct filtration into veins and venous sinuses elsewhere. - Dr. Robert Alden
The Functions of the Cerebrum in General
The Cerebrum maintains and regulates the internal sensories
which are contained in its globe. (1004) It moderates
their states and operations.(1005) It connects the organs
of bodily sense with the sensories of the soul(1006)
by fibres which serve as vehicles of the sensations to the soul.(1007) It is therefore called the Common Sensory.(1008)
But it is also the means of determining the ends of the soul into choice and act; it is the Common Motory of the voluntary part (as distinguished from the involuntary cerebellum).(1010)
The sensories reside in the cerebrum in three lobes.(1011) At the crown or the highest lobe, they are in the
most vigilant state of potential expansion and intentness. The sulci enable
the brain to expand and animate.
My impression is that Swedenborg did not grasp the significance
of how the infoldings of the cortex increase cortical area; and the physical
sructure of the brain does not allow for expansion on this basis. - Dr. Robert
In the sensory-motor areas, perception and volition are present together.(1012)
The royal road of the sensations from the body is by
way of the Corpora Striata (including the caudate and lenticular nuclei).
By the same way the soul descends into action. These bodies are therefore
a conjoining medium - a Mercury. (1013)
[This section is not identified. ORO]
Note: This chart will need to be redone.
V. Secondary or Apperceptive Center of Vision Destruction causes Psychic Blindness loss of power of interpreting or distinguishing sight images. (Recognition by hearing and touch remains good.)
E1 On both sides. Half of each aye is blinded by a lesion off one of the E centers
Cortical Motor Aphasia - Can not articulate words.
Cortical Auditory Aphasia - Can not understand their own words, nor those of others.
Cortical Visual Aphasia - Cerabral blindness.
Subcortical Auditory Aphasia - Can speak but not hear.
Subcortical Visual Aphasia - Destruction of axons and secondary centers (interpretive).
Psychic blindness (?) Opt.Thal.(7)
Subcortical Motor Aphasia -A break in fibres between Broca's Area and Face Motor Centers.
education the right Face Motor Area can assist to speak.)
Swedenborg here anticipates modern science in announcing the principle of the localization of brain functions. How he arrived at his conclusions is analyzed by Prof. Martin Ranstrom in "Emanuel Swedenborg's Investigations in Natural Science and the Basis for His Statements concerning the Functions of the Brain". Univ. of Upsala, 1910.
Modern diagrams of brain functions may be found in Herrick;s "Introd. to Neurology", 1934, pp. 339, 337.
The cerebrum is a conglomerate gland. It supplies a refined
lymph mixed with spirits, to enter into the composition of the blood globule.
What does he mean by spirits? Is a blood globule a cell?
Conglobate = rounded mass or ball. Conglomerate = parts collected from venous
sources. - Dr. Marlin W. Heilman
The Corpora Striata, on the floor of the lateral ventricles and the sides of the infundibulum (1016), also excite the choroid plexuses to emit a lymph with which the spirit from the cerebrum is copulated. This lymph is called a purer blood, for it serves as a serum for the animal spirit. (1017)
The secretory function of the cerebrum is carried out
in the posterior part, around the longitudinal sinus. Here sensations are
not so readily perceived as in the anterior region. The fibres of this posterior
region are not carried into the corpora striata but into the corpus callosum.
The corpora striata mediate all expressions of the rational mind and the animus, even as it had mediated in the formation of the body. (1020)
The cerebrum joins the fibres with the blood vessels, and vice versa. The corporeal fibres enter the blood vessels (composing the inmost coat of the arteries) and ascend back by the carotids to the cortical glands, which they enter. (1021) The cerebrum completes the "circle of life" by sending back to the fibres the spirit of the (resolved) blood. Besides the "corporeal fibres" supply the glands with the purest elements which furnish the animal spirit with its elementary or corporeal nature.(1022)
The cerebrum therefore claims lordship over the blood.
It distributes the arteries over itself to supply all its glands, and rules
the veins in the sinuses.
The cerebrum expands and constricts and thereby excites
all things below it into a universal or animatory motion.(1024)
Three Universal Essences in the Body
In the work on The Brain three universal essences are listed:(1034)
1. The "soul" is properly the only substantial
and essential thing in the body. >From it are derived all the composite
"If you abstract from the animal spirit [all parts
of elementary and terrestrial origin], what then remains is nothing
but a form derived from the determinations of the soul, or the veriest being
of the body..."(1041)
3. The Red Blood
These three essences have their respective determinants:
1. Thesimplest fibres, which are like rays of the soul.
The Chain of Uses
The cerebrum is thus the uniting medium between soul and body.(1046) Its quality appears from the chain of uses, the circle of ends and effects, by which this intercourse is carried on.(1047) This appears especially in the case of morbid states, injuries or diseases which break the connection of things.(1048)
In the cerebrum, the soul unfolds its purest and simplest
organical forms: the cortical substances. The cortical gland is in the
sphere of ends, the cerebrum as a whole in the sphere of causes. Each gland
is a cerebrum in least effigy and in a higher sphere.
The fornix carries few, if any, fibres from the callosum, the latter bearing
association fibre from one to another
hemisphere. - Dr. Robert Alden
Cerebral fibres also pass into nerves - as into the olfactory and the optic nerves. Fibres also pass towards the ear, the tongue and the cuticles: but nevertheless they are invested with fibres from another region, as from the corpora striate, the medulla oblongata, the spinal marrow, and especially the cerebellum. They are encircled with membranes and entwined with blood vessels.
While the fibres of the cerebrum are directed to the sense organs and voluntary muscles, those from the cerebellum tend toward the viscera. Yet both kinds of fibres may summon to their assistance the fibres of the medulla oblongata and the spinal medulla.(1050) Thus as far down as the Pons, the cerebral fibres are associated only with those of the corpora striata. Below the Pons the fibres of the cerebellum are added. From the medulla oblongata on, its fibres also are associated.(1051)
It is the work of the cerebrum to be a plane of mental
principally. The soul of the cerebrum issues its commands, but the more
robust fibres of the corpora striate execute them, so that the brain may
have a rest so far as the concerns of the body go.(1052)
For voluntary muscular movements are provided
fibres derived from the cerebrum, the corpora striata, and the medullae,
Fibre Tracts and Organs within the Cerebrum
For a brief review of the uses of the various parts and organs of the brain, see the report of Dr. A. Acton's lecture on the subject.(1056)
Corpus Callosum. Swedenborg notes that this tract of transverse fibres, which unites the two hemispheres and forms a road for the anterior ventricles, connects the cortical substances from side to side and also the upper lobes with the posterior. The fibres are mainly derived from the posterior parts and only sparingly from the frontal cortex. No fibres stop in the middle but they spread like wings from side to side.(1057) The corpus callosum serves many uses:
a) It acts as a steady support for the structures around it which are in constant motion.(1058)
b) Moved by the corpora striate and the optic thalami, it distills animal spirit into the lateral ventricles and also sends nervous juice (between the fibres) towards the optic thalami.(1059) It is the road which leads to the chemical laboratory of the brain, i.e. to the ventricles.(1060)
c) It serves to propagate sensations, especially that of sight.(1061)
Fibre Paths. Neurologists list the fibres of the
brain into three main categories:
a) Projection Fibres. These comprise sensory and motor fibres which connect the cortex with the brain stem. If traced from the cortex they are seen to converge as the "corona radiata" into the flattened internal capsule and thence in part to the cerebral peduncle. Usually, any nucleus which sends fibres to the cortex receives some in return. The motor fibres from the precentral motor centers of the cortex which go to the spine, are now called the "pyramidal tract"; these fibres control intentional actions. Certain extra-pyramidal tracts, like the cortico-pontile system, are concerned with tonic activities, and reciprocations with the cerebellum.
b) Commissural fibres. These transverse fibres connect the two sides of the brain. The hippocampal commissure connects the olfactory cortex, while the corpus callosum connects the two sides of the neopallium or non-olfactory cortex.
c) Association fibres. These connect different parts of the cerebral cortex of each hemisphere, so that all regions are interconnected in bewildering complexity, and able to influence the motor centers and the conscious life. Notable among the longer tracts is the "superior longitudinal fasciculus" which connects the sensory association area in the parietal region with the intellectual area in the frontal lobe.
Optic Thalami. These bodies, situated on either
side and also somewhat behind the third ventricle, aid the cerebrum,
Swedenborg shows, in three functions. (1064)
a) Motor uses. The thalami are not moved except
the cerebrum initiates the motion. They do not depend on fibres from the
Corpora Striata, but only on those of the cerebrum. While the fibres of the
corpora striata bend around the thalamus towards the anterior portions of
the medulla, the fibres of the thalamus run towards the posterior region,
obliquely, and are bent towards the corpora quadrigemina and the fourth ventricle.
b) Sensory uses. While the corpora striata refer to the sense of smell(1066), the optic thalami are placed over the sense of sight. The optic nerve fibres pass directly into the thalami while the nerves of hearing and taste are rooted in the medulla oblongata and those of touch in the spinal marrow.(1067)
The optic nerve fibres do not pass directly into the thalami, but probably have some connections there. The Thalami have some motor fibres; but are chiefly nuclei involving sensory tract reception and distribution to higher centers. Fibres of hearing and taste are included. - Dr. Robert Alden
The fibre paths of the corpora striata pass to the cortex by the "centrum ovale" or"corona radiata" (1068), while those of the thalami are said by Swedenborg to pass through the "centrum semicirculare" (inner capsule), the corpus callosum, and fornix. (1069) "Every cortical particle is rendered conscious of the modes and the least difference of each sense..." Sight and smell are rooted in both hemispheres, but hearing, taste and touch are in addition mediated by the medullae.
c) Chemical uses. From their position at the bottom of the ventricles, the thalami by their expansion and constriction excite the other organs and serve as general regulators and dispensers of the fluids.(1070)
Corpora Striata. These bodies contain striations or layers of gray matter. They are placed as reception courts for the cerebrum, as well as a gate from the cortex to the medulla.(1071) Above them spread the wings of the corpus callosum. They serve as balances and bars for the medullary fibres which pass through them, and as the roots or beginnings of the medulla oblongata. By their expansions they function as the prime motors of the ventricles or chemical laboratories of the cerebrum.
The striated bodies (and these include the thalamus
in this sense) can initiate motions which at first originate with the cerebrum
and were thus voluntary. Thus voluntary acts by daily habit
become spontaneous and of second nature.(1072)
Note: Gray notes the following fibre paths which pass through the internal capsule:
1. From thalamus to frontal lobe.
In the pyramidal tract motor fibres descend without interruption from the precentral gyrus of the cerebral cortex to the spinal cord. (1075)
Pineal Gland. This small gland is placed in
the median line at the threshold of the cerebral laboratory and at the crossing
two "axes", at the roots of the straight sinus and under the vascular intrusion
of the branch of the vertebral artery which forms
the choroid plexus of the third ventricle.
Here, according to the views of Swedenborg's contemporaries,
the cerebrum - through an "anus" - pours in spirit from the
lateral ventricles, and the cerebellum, through the choroid plexus of the
cerebellar arteries, the serum. (Quain states that the
pineal gland receives sympathetic nerve fibres).
The gland has no fibres derived directly from the cortex, but extends fibrous bands to the thalami. It does not take part in the voluntary determinations or intellectual functions of the brain. (1079)
The Pineal Gland sends fibres towards any sense organ except the eye. The connection with the eye is through the optic thalami, by which the cerebellum may receive visual effects. (1080)
I do not believe that any of these concepts are credited today. Deterioration of the pineal is seen frequently without evidence of gross physiologic or organic change elsewhere. There is no known relationship to instinct, sexuality, etc. The pineal is observed to begin to degenerate in early childhood; whence it is concluded that it may have a principal function prior to birth. But this is not known, if it is so. - Dr. Robert Alden
The Anus. Swedenborg points to an influence exerted
by the pineal gland over the fluids of the cerebrum by reason of its
position over the foramen called the "anus". He supposed with his
contemporaries that such an "anus" or posterior opening
existed between the lateral ventricles, the third ventricle, and the aqueduct,
under the pineal gland. (Its existence was denied by
Monroe in 1783, later affirmed by Meirzejewsky in 1872, but now is generally
I've attempted to investigate the possible existence
of the "anus", without having done so by direct study of brains and sections.
Serial Kodachrome sections, etc., show no plausible place for such an opening.
But it is interesting to me that in large areas the lateral and third ventricles
are separated from the external fluid spaces only by a thin membrane within
the various fissures. - Dr. Robert Alden
Corpora Quadrigemina.(1084) The dilation of the aqueduct of Sylvius is effected by the aid of various neighboring organs and especially by the action of the corpora quadrigemina, to allow the flow of the cerebral "lymph" from the "anus" into the third ventricle. The Aqueduct of Sylvius was thus conceived by Swedenborg to be "almost completely" closed off from the fourth ventricle by the "valve of Vieussens". Modern anatomists all maintain that the aqueduct provides an open channel between the third and fourth ventricles.
The brain is entirely supplied from two pairs of arteries,
the internal carotids and the vertebrals. At the base of the brain these
anastomose to form the remarkable Circle of Willis. The carotids enter the
circle from an anterior direction, the vertebrals from
The above arrangement makes possible a neutralizing of the pulse and assures
the brain a constant blood supply even if one of
the supplying vessels should become clogged.(1086)
The choroid plexuses of the ventricles are supplied
The choroid plexus of the third ventricle receives its blood from the branch of the posterior cerebral, which is distinguished as the posterior choroidal artery. The posterior cerebral draws its blood from the vertebral artery through the basilar trunk. The posterior choroidal passes into the third ventricle above the corpora quadrigemina and below the splenium.
The two choroid plexuses of the fourth ventricle invaginate the roof of the ventricle from below the cerebellum. They stretch upward forming a T-shaped structure. They are supplied with blood from a branch of the vertebral artery which originates from the subclavian.
Veins of the cerebrum. These veins possess no valves and no muscular coats. They open into the cranial venous sinuses.
The veins of the cerebrum belong to two groups, internal
The blood of the whole brain, including the cerebellum, drains through the internal jugular veins.
The larger choroid plexuses - those of the lateral ventricles - perform the function of absorbing spirit from the fimbria of the Fornix, mixing it with the elements of the blood and perspiring the resultant fluid into the ventricles.(1089) The exudations of the smaller plexus of the third ventricle that is more closely related to the cerebellum, are also directed towards the infundibulum, where the pituitary gland is waiting to extract suitable elements for the blood stream(1090)
D. THE CEREBELLUM(1091)
The substance of the brain (which may be called the
exemplar of all glands) can be distinguished into three degrees:
Involuntary action and unconscious sensation.
The cerebrum has the power of sensating, noticing, and by imagination representing things which have been objects of its senses, thus presenting material ideas.(1097) The cerebellum also feels the smallest changes of state in its body, but these sensations are unconscious to the cerebrum.(1098) But by these unconscious sensations the cerebellum is able to care for every bodily part.(1099) Although the soul is everywhere, still it cannot feel or sensate everywhere, but only in the brain. In the cerebellum, sensation does not reach the mind but is passed on to the soul.(1100)
The Par Vagum and the Great Sympathetic are the special nerves of the cerbellum, whereby involuntary actions are effected as well as unconscious sensations. All the rest, except those sent out to the genital members from the restiform process of the cerebellum, are under the control of the cerebrum.(1101) As to the lumbar and sacral nerves, see Gener. 44.
All the fibre that flows into the testicles descends from the medulla of the cerebellum, not from the cerebrum: hence the innermost and vital essence of the seed owes its origin to the cerebellum. If the conception of the seed depended on the will, i.e., the cerebrum; its faculties would soon perish.(1102)
The "involuntary" is twofold: one is man's hereditary
which he has from his parents; the other inflows through heaven from the
The cerebellum is disciplined by the cerebrum.(1109)
Fibres from the cerebrum are joined with fibres
from the cerebellum so that man's voluntary things may be ruled by the involuntary.(1110)
The cerebellum is awake when the cerebrum is asleep(1111), but is seemingly asleep when the cerebrum is awake.(1112) Love cannot sleep.(1113)
The Pons, straddling the front of the cerebellum between
the midbrain and the medulla oblongata, bridges between the two
halves of the cerebellum and also connects the medulla and the cerebrum.
It is composed of interwoven transverse and
longitudinal fibres and intermixed with gray matter. Swedenborg calls it
the "marriage chamber" of the fibres of the cerebrum
(and of the central ganglia of the thalami and striata) with those of the
cerebellum. The "offspring" are a number of pairs of
nerves - especially the trigeminal, abducent, facial, and acoustic. (1119)
1. The brain tissue is protected by being embedded and suspended in fluids. The origin and flow of cerebro-spinal fluid is briefly described in the Writings:
In the cortex of the brain the red blood corpuscles
are broken up and the "spirits" resorbed from them are received by the
cortical glands to be "conjoined" with new spiritual essences. Thence they
are carried by fibres into the ventricles, and thus
through the infundibulum into the blood.(1122)
In the pituitary gland the fluid is separated and by three ways is conveyed toward the jugular vein, to be consociated with the chyle from the thoracic duct. (1129) From the jugular vein it is thus brought to the heart and the lungs and is then distributed by the heart partly to the head, partly to all the viscera and members of the body(1130) to vivify the whole mass of the blood. (1131)
Note on the Pituitary Gland:
Three kinds of humors are present in the brain which may stagnate and cause disorders. The grossest is the subdural fluid; the next is that which gathers in the mamillary processes. Both of these drain through the sieve-like lamina and the mucous membranes of the nose. (1134) The third kind is collected in the lateral ventricles and is discharged through the infundibulum. (1135)
Luschka and Magendic; the aqueduct of Sylvius; or of both foramina of Monroe; then internal hydrocephalus develops. This certainly suggests that the principal source of subarachnoid fluid is the ventricles. In addition, if all cerebrospinal fluid is removed, X- Ray studies show that the ventricles fill up first. - Dr. Robert Alden
2. In his physiological treatises, Swedenborg took
great pains to describe the brain and its fluids. Apart from the "spirituous
fluid" (flowing through the simple fibre) and the "animal spirit" or "purer
blood" (which was conveyed in the medullary fibre), he recounts lymphs of three kinds.(1136)
3. It is notable that the ventricular fluid drawn from the cerebrum is destined to enter the blood stream more directly, while the fluid derived from the cerebellum and the fourth ventricle is designed to enter the nerves before it is restored to the blood by way of the glands. (1143)
a) From the fibres of the callosum the nervous juice passes into the lateral ventricles and thence through the foramen of Monro (also called "vulva") into the third ventricle which adds its own contribution. (1144) Here some is absorbed by the infundibulum and the pituitary gland, for the uses of the blood. On the basis of admittedly incomplete anatomical data, Swedenborg believed that the superfluous portion of the fluids of the lateral ventricles was urged toward a posterior foramen (called "anus") which leads it under the pineal gland into the aqueduct and thence into the third ventricle.(1145) This way is governed by the pineal gland. The fluid in the various cerebral ventricles may flow back and forth according to need. (1146)
b) The finer nervous juice of the fourth ventricle enters the nerve roots which are abundant here and in the spine, and passes into the interstices between the fibres or their fascicles. (1150) When the nerves unfold their fibres, as in muscle tissues, the released nervous juice goes beneath the coatings of the muscles and seeps under the aponeuroses and into the periostea, and thus into the integuments of the spinal cord. Thence it rises into the aura mater and the pericranium, and serves either as nutriment for the hair and bones or it is exterminated by being discharged into the subdural spaces. During this circulation the essential parts of the juice are gradually salvaged by various conglobate glands throughout the body, and thus restored to the blood and the brain. (1151)
4. As to the composition of the nervous juice (or ventricular fluid), the vital elements are derived from the cortical substances, but the bulk is a liquid secreted from the choroid plexuses. (1152) According to Maximow and Bloom, the fluid which comes from the brain substance does not go into the ventricles but flows outward into the subarachnoid spaces in perivascular channels. (1153)
On some histological sections I've seen these perivascular channels penetrate the cortex deeply, are extensive and very clearly seen. In some disease states they may be seen to contain white blood cells which have entered from the subarachnoid spaces, apparently. - Dr. Robert Alden
5. The arachnoid tunic, taken in connection with its substructures, serves the brain in place of lymphatics. (1154) From the ventricles the fluid enters the subarachnoid spaces only through filters (or foramina) in the roof of the fourth ventricle; the fluid there enters the cerebellomedullary fossa, whence it distributes itself in all directions around the brain.
From these lymph-spaces there is a rapid drainage of the coarser fluids through the arachnoid villi into the great veins (or sinuses) in the aura mater, as well as a slower seepage into the true lymphatic system by way of an indirect perineural course.
6. The direction of the flow of the cerebrospinal fluid seems to depend on the motion of the brain and the amount of the fluid, which is constantly renewed. (1155) Gray notes an ascending current in the central canal of the cord, possibly originating from the ependymal lining of the canal. Swedenborg allows that the fluid flows to and also from the fourth ventricle in the cavity "between the meninges of the medulla spinalis." (1156)
G. MOTION OF THE BRAINS AND ITS EFFECTS (1157)
In embryos, or in man when not breathing, the animatory
motion of the brains coincides with the pulsations of the arteries; but
after birth it coincides with the respiration of the lungs. (1158)
a) When the cortical substances (or grey
cells) expand (in diastole), they do so simultaneously in the cerebrum,
medulla and cord. The cortical glands then imbibe the "purer blood" resolved
from the arterioles. The medullary or fibrillary
substances at the same time are contracted (in systole) and the interstices
between the glands and between the medullary fibres
close up, as do also the veins and ventricles.(1161)
b) When the cortical substances constrict in systole, the sinuses and ventricles expand and the medullary fibres are no longer cramped.(1164) The "purer blood" (or animal spirit) pours freely from the cortical glands through the nerve fibres, and thus the contracting cerebrum inspires the costal nerves, and the cerebellum the vagus and the sympathetic, to cause the lungs to inhale.(1165) The fourth ventricle sends its fluid pressing into the subarachnoid spaces, both within the cranium and (especially) in the vertebral column. A new supply of this ventricular fluid is also conveyed from the fourth ventricle into the spinal column, chiefly into the central canal of the cord. (1166)
A refined lymph (being superfluous) exudes from the medullary substance of the cerebellum during its systole; and this descends from the fourth ventricle into the vertebral cavity to bathe the roots of the nerves. (1167)
H. CORRESPONDENCES OF THE BRAIN (1168)
1. The physiological references in the Writings exhibit a picture of the Brain consistent with the descriptions in the physiological works of Swedenborg, but less detailed. (1169)
2. Through man alone is there a descent from the
heavens into the world and an ascent from the world into the heavens. This
effected through the brain and its interiors. (1170)
3. Correspondences of the Brain.(1172)
The brain, like heaven, is in the sphere of ends or
uses.(1173) The complex network of the fibres corresponds
to the order of
heavens(1174) and the cortical glands are compared to
Two apparently conflicting teachings are given about the correspondence of the right and left sides of the cerebrum.
a) The right hemisphere of the cerebrum corresponds to those who are in the understanding of truth and good and thence in an affection of them. (1181) [Both bound versions put this slightly differently: "The right hemisphere of the cerebrum corresponds to those who are in the will of good and thence in the will of truth, while the left corresponds to those who are in the understanding of truth and good and thence in an affection of them."]
The operation of heaven as regards rational or intellectual things is into
the left side of the cerebrum, in the region of the temple.(1182)
Genii are not permitted to inflow into the left side of the head (i.e. by persuasions), but only into the right side, or by cupidities, and thence into the left side of the chest.(1183)
I don't see any cause to doubt the validity of extensive evidence indicating one-sided dominance of the brain. This carries even to there being a dominant eye, ear, side of face, etc. Destruction of the dominant speech center causes serious handicap; and I don't believe can fully be compensated for by the opposite, comparable, area. - Dr. Robert Alden
b) The right hemisphere of the cerebrum is allotted to intellectual things and the left, to affections. The reverse is the case in the body, for so the fibres flow.(1184) The right eye, with the left cerebral hemisphere, represents intellectual things of good; the left eye, with the right side of the brain, represents intellectual things of truth. (1185)
One of the more puzzling central systems to me is the extensive ramifications of the olfactory system; which takes up a good deal of the_ and other structures. Connections are amazingly complex, to the thalamus, brainstem and cortex. The meaning of this is very obscure to me. - Dr. Robert Alden
The cerebellum and the heart correspond to the
inmost heaven(1187) and to the will and its love (1188) or to the unconscious will and general involuntary
COMPARATIVE NOMENCLATURE OF THE CRANIAL NERVES
A. The Writings present
the general concept that the nerves are composed of bundles of fibres descending
form their beginnings in the "corticalglands".(1221)
The fibres, fascicles, and nerves represent a series of discrete degrees
in a simultaneous order.(1222)
It may be of note in connection with nerve fibres making the structure, etc., that when a peripheral nerve is damaged there is a degeneration of the part it supplied (if this is the sole nerve source), which may include not only muscle but skin, etc. This indicates an intimate connection between structure and nerve supply. Similarly, polio in child causing extensive motor paralysis of a leg not only affects the growth of muscles but also leads to arrest in growth of the entire limb. Of course disuse is an important factor here. - Dr. Robert Alden
B. In his Physiological Works, Swedenborg recognizes two kinds of nervefibres and nerves, motor and sensory. Most nerves contain some fibres of each type. Sensory fibres are softer, fuller of spirit than the motor nerves.(1229) But every cortical gland is at once a sensory and a motory, although each differs from every other.(1230) Compare the dendrite and axon of the typical neuron.
ACTION proceeds according to certain fibres, not according to all, into the muscular motor fibres.(1232) By its diastole and constriction, the brain expels its spirit and purer blood through its simple and compound fibres, thus producing action by a real communication by means of a fluid. It is necessary that the 'spirit' should be expelled through the simple fibres at the same time; but the Intellectory does not thereby will the action, but only concurs.(1233)
Considering the presumptive evidence that the nerve impulse is of an electrical nature, this would seem quite correct if one conceives of diastole as being the initiation of flow on a pressure gradiant (as in a battery hookup). rather than as its being a "wringing out" of the brain as the heart does blood. It is my understanding of electronics that electron activity expands and contracts according to its degree. This is illustrated by the actual physical expansion of a wire that has been overheated by a high current load, as in a toaster. - Dr. Robert Alden
Muscular action is thus due to the pressure of the
expanding nervous fibre upon the muscle which them expels its blood; there
thus an equilibrium.(1234) In the motive rings of the
blood vessels the nerve fibres terminate by dividing into least threads, and
the nervous juice from between the fascicles is then released, to be recovered
later through the glands.(1235)
Voluntary action is a special and particular
animation of a definite number of cortical glands of the cerebrum.(1237) But
spontaneous actions flow from a general animation of both cerebrum
and cerebellum which produces an equilibrium by means
of antagonistic muscles. The skeletal muscles thus receive fibres from both,
as do also some viscera (such as the trachea, lungs,
The Writings note that the motion of the muscles, whence action comes, would immediately cease unless there were in it a conatus from. man's will. (1241) In the body itself, the internal viscera act and the externals react. (1242) In the muscles, the arteries act and the little coats from the ligaments react - thus representing an alternate action of the heart and the lungs. (1243) The lungs consociate the motions of the cerebrum and cerebellum. (1244)
2. SENSATION (1245)
"The external senses, which are five - touch, taste, smell, hearing, and sight - have each a correspondence with the internal senses... The sense of touch corresponds in general to the affection of good; the sense of taste, to the affection of knowing; the sense of smell, to the affection of perceiving; the sense of hearing to the affection of learning and also of obedience; and the sense of sight to the affection of understanding and of being wise.(1246)
Conscious sensation is possible only when the lungs respire.(1247) Heart and lungs are the two fountains of all bodily action and sensation.(1248) "The lungs act as first in the senses, and the heart as second...for all the organs of the senses correspond to such things as are of the understanding."(1249) "It appears as if sensation, as also apperception, comes by influx from the external; but this is a fallacy, for it is the internal that perceives through the external. The senses placed in the body are nothing by organs or instruments that serve the internal man in order that it may be sensible of what is in the world; wherefore the internal flows into the external, causing it to feel...; but not the reverse.''(1250)
"... The interior man sees and perceives in the exterior
what is done outside of this... From no other source is the faculty of
"The internal... gives to the external the power of
sensation."(1252) It is the spirit which sensates in the
body, and therefore
"All the senses are excited and produced from influx. In man there are only the organic forms... which have no sense until something adapted flows in from without. It is the like with the internal sensories which are of thought and affection and which receive influx from the spiritual world." (1255)
SENSATION according to the Physiological Works, proceeds
along the fibres to their origins in the cortical substances.(1256)
Without the highly elastic fluid or 'spirit' in the medullary
fibres arising from the cortical glands there is no sensation.(1257) No
sensation can ascend immediately (without fibres) to the soul.(1258)
Mode of transmission. "As soon as the fibre
is compressed, the action or animation of the cortical gland must cease...
the cause of sensation; which exists essentially only in the soul itself."(1261) "If the nervous fibre that carries the spirit" from
brain "is touched or in any way straitened, the spirit has no opportunity
of escaping in another direction like the blood through
anastomoses. Hence, the instant it is compressed, its beginning cannot by
feel the change arising from the touch..."(1262)
3. RELATION OF ACTION AND SENSATION
Intellection is the last of Sensation. Yet it does
not at once turn into Will or Action, but "there are intermediate operations
mind which connect the last of Sensation with the first of Action."(1266) Thus Swedenborg's physiology does not reduce man's
life to a mere mass of inevitable reflexes (whether "conditioned" or not).
Still, sensation and action together make up the circle
of bodily life. If there is not sensation, there would be no will or action.(1267)
According to the Rational Psychology, the end
of sensations and the beginning of actions "meet in the same inmost sensory
There has been much speculation as to the manner in
which the nerves convey the impulses which transmit sensory stimuli or
cause muscles to contract.
Modern neurologists deny the presence of any fluid within the nerve fibres, although they admit that these are bathed in cerebrospinal fluid between the fascicles.
As previously noted, more recent work makes it clear that an axon or dendrite is comprised of fibrils which are submicroscopic tubules. These are presumed to carry a fluid substance possibly for nutrition of the nerve fibre; but not to be directly related to transmission-of impulses, since this agrees more with electric-type phenomena. - Dr. Robert Alden
Certain data have been ascertained in the effort to
discover the nature of the nerve impulse. It is now supposed that nerve
impulses differ only in the rate of propagation and the frequency of transmission.
The sensation to which they give rise would
thus depend on the locus in the brain-structure where they eventually terminate.
It is claimed that the "size" of the impulse
traveling up a nerve fibre does not depend on the energy of the original
impulse but on the energy available in each section of
the nerve fibre. The individual fibre seems to respond with all its available
energy, yet the strength of a sensation varies with the
intensity of the stimulus because more fibres are stimulated. The
nerve impulse is not a simple electric current, but its passage
along the fibre gives rise to tiny electric currents which can be measured
by the use of electrodes and amplifiers. The impulse
travels at about 300 feet a second in some fibres.
The Membrane Theory of Nerve Impulse is describe
by Ruch.(1272) According to this, the electrical phenomena
indicators of chemical reactions within the nerve fibre. The fibre in a
state of rest is like a tubular membrane carrying negatively
charged ions, but surrounded by ions which are charged positively. But when
the fibre is activated, a chemical action begins
which destroys the polarization and allows the opposite charges to neutralize
each other the membrane becomes permeable and
the positive ions farther along move in to neutralize negative ions, so
that the nerve impulse can "roll" on down the fibre. While
this occurs, the area through which the impulse has passed remains momentarily
permeable and its charges are neutralized so
that no stimulus can affect it and no opposite charges be built up. But
after this "refractory phase" has passed, the membrane is
restored as impermeable and thus excitable. (See Diagram)
Transmission across a synapse at least involves a chemical exchange. Certain chemicals facilitate transmission, others inhibit. In some nerves acetyl choline is concentrated at synapses but is in delicate balance with its neutralizer, choline esterase. When nerve is stimulated acetyl choline is used up at the synapse. If it is neutralized the impulse ceases at the synapse; though stimulation above it is transmitted. - Dr. Robert Alden
[Un-identified text. ORO]
+ 1273 Fibre 251, 254, 259, 266, 266b, 275, 291, 258; AS 9; see Part IV, below.
We perceive, writes Dr. Wilder Penfield, "that the secret of functional activity in the living brain is the movement within its transient electrical potentials travelling the fibers of the nervous system (Sherrington's phrase)". (Penfield and Roberts, Speech and Brain Mechanisms", Princeton University Press, 1959, p. 14.)
Fig. II-8. Somatic sensation. Cross-section of the left hemisphere along the plane of the postcentral gyrus. The afferent pathway for discriminative somatic sensation is indicated by the unbroken lines coming up, through the medial Iemniscus, to the transmitting strip on the postcentral gyrus. and from there on by the broken lines into the centrencephalic circuits of integration. There is, no doubt, close inter-relationship between sensory and motor activity of the units shown in this Figure and the preceding one, across the central fissure. From Penfield and Jasper, 1954.
Fig. II-7. Voluntary motor tracts. Cross-section through right hemisphere along the plane of the precentral gyrus. The pathway of control of voluntary movement is suggested from gray matter, somewhere in the higher brain stem, by the broken lines to the motor transmitting strip of the precentral gyrus. From there it runs down the cortico-spinal tract, as shown by the unbroken lines toward the muscles. The sequence of responses to electrical stimulation on the surface of the cortex (from above down, along the motor strip from toes through arm and face to swallowing) is unvaried from one individual to another. From Penfield and Jasper, 1954.
1168 The Correspondence of the nervous system, as a whole, in its supreme sense: The human body as a whole corresponds to the entire Body of Divine Truth- or in the Word in all its forms. Relative to the rest of the body, the Brain and Nervous System may be likened to the Writings or the Heavenly Doctrine which finds its confirmations int he literal sense like nerve fibers terminating in the external tissues and organs. The viscera would then represent the New Testament, and the Muscles and Bones would stand for the prophetic Old Testament. See N.C. Life 1938, p. 163 ff.
1267 R. Ps. 25; see Brain 100. The circle of spiritual life is described in the Writings as a process of Reformation and Regeneration: to know, to understand, to will and to do (AC 242:4); or a progression from love to thought and from thought to love. DP 29:3, cp. D. Love x:2; SD 757; AC 1057:2-4. 1458.