named the _Obturatores Externi_ and _Interni_.
The _Obturator Internus_ springs from the inner Circumference of the Oval
Hole of the _Ischion_ and its _Tendons_ passing between the two _Gemelli_
are inserted in a small Cavity at the Root of the great _Trochanter_ or
_Rotator_.
The _Obturator Externus_ ariseth from the outward Circumference of the same
Hole of one _Ischion_, and is terminated in the side of the other near the
great _Trochanter_.
_What are the Motions of the Leg, and what are its Muscles?_
The Leg is mov'd four several ways, that is to say, it is bent, extended,
and drawn inward and outward, by the means of eleven Muscles _viz._ three
_Flexors_, four _Extensors_, two _Adductors_ and two _Abductors_.
The three _Flexors_ of the Leg are the _Biceps_, the _Semi-nervosus_, and
the _Semi-membranosus_.
The _Biceps_ hath two Heads, the longer whereof cometh out of the bottom of
the Prominence {51} of the _Ischion_, and the other from the middle and
exterior part of the _Femur_, and is terminated in the outward and upper
part of the _Epiphysis_ of the _Perone_ or _Fibula_.
The _Semi-nervosus_ hath its Origine in the Knob of the _Ischion_, and is
join'd backward to the top of the _Epiphysis_ of the _Tibia_. These three
Muscles are plac'd in the back-part of the Thigh below the Buttocks.
The four _Extensors_ of the Leg are the _Rectus_, the _Vastus Internus_,
the _Vastus Externus_, and the _Crureus_.
The _Rectus_ or streight Muscle of the Leg takes its rise from the
fore-part and the bottom of the _Ilion_, and descends in a right Line: It
covers with its _Tendon_, which is common to the three following, the whole
Knee-Pan, and adheres to the top of the _Tibia_, on the fore-part.
The _Vastus Internus_, being situated on the inside of the Thigh, hath its
beginning in the top of the Thigh inwardly, and a little below the lesser
_Trochanter_ or _Rotator_: Afterward it is ty'd to the _Tibia_ by a large
_Tendon_, common thereto with the preceeding.
The _Vastus Externus_ is plac'd on the outside of the Thigh, springing from
the top and the fore-part of the _Femur_, being united by the same _Tendon_
with the two preceeding.
The _Crureus_ proceeds from the top, and the fore-part of the Thigh-Bone,
between the two _Trochanters_; then covering the whole Bone, it is also
fasten'd to the Leg-Bone with the three preceeding Muscles, after having
cover'd the Knee-Pan with their common {52} _Tendon_, which serves likewise
as a Ligament to the Knee.
The two _Adductors_ of the Leg are the _Sartorius_ and the _Gracilis_.
The _Sartorius_ or the _Longissimus_ draws the leg inward, deriving its
Original from the upper _Spine_ of the _Ischion_; from whence it descends
obliquely thro' the inside of the Thigh, and cleaves to the top on the
inside of the _Tibia_.
The _Gracilis_ hath its Origine in the fore-part at the bottom of the _Os
Pubis_, and its Insertion in the top of the _Tibia_ on the inside.
The two _Abductors_ of the Leg are the _Fascia lata_, and the _Poplitaeus_.
The _Fascia lata_, or the _Membranosus_, is as it were a kind of large
Band, which covers all the Muscles of the Thigh. It proceeds from the
outward Lip of the _Os Ilion_, is ty'd by a large Membrane to the top of
the _Perone_ or _Fibula_ and sometimes descends to the end of the Foot.
The _Poplitaeus_, or _Sub-poplitaeus_, arises from the lower and external
_Condylus_ of the Thigh-Bone, passeth obliquely from the outside to the
inside, till it is lost in the upper and inner part of the Leg-Bone under
the Ham.
_What are the Motions of the Foot, and what are its Muscles?_
The Foot performs two Motions by the help of nine Muscles, as being bent by
two, and extended by seven.
The two _Flexors_ are the _Crureus Anticus_, and the _Peronaeus Anticus_.
The _Crureus_ or _Tibiaeus Anticus_, is plac'd along the _Tibia_, and takes
its rise from its upper and fore-part: Afterward it is bound by two {53}
_Tendons_ to the first _Os Cuneiforme_, or Wedge-like Bone, and to that of
the _Metatarsus_ or Instep, which stayeth the great Toe, after having
pass'd under the annular Ligament.
The _Peronaeus Anticus_ springs from the middle and outward-part of the
_Perone_ or _Fibula_, and insinuating it self thro' the Cleft which is
under the external _Malleolus_ before, sticks to the Bone of the
_Metatarsus_ that supports the little Toe.
The seven _Extensors_ of the Foot are the two _Gemelli_, or the _Soleus_,
the _Plantaris_, the _Crureus Posticus_, and the two _Peronaei Postici_.
The _Gemelli_ are the _Interior_ and the _Exterior_; the former having its
Source in the inner _Condylus_, and the other in the outward and lower of
the Thigh-Bone; from whence they extend themselves till they are fasten'd
to the _Talus_ or Ankle-Bone by a _Tendon_ common to them, with the two
following.
The _Soleus_ ariseth from the top on the back-part of the Leg-Bone and
_Perone_, and confounding its _Tendon_ with that of the _Gemelli_, sticks
close to the _Talus_.
The _Plantaris_, which lies hid between the _Gemelli_ and the _Soleus_,
hath its Origine from the _Exterior Condylus_ of the Thigh-Bone; then
uniting its _Tendon_ with the preceeding, it adheres to them; and this
common _Tendon_ is call'd _Chorda Achillis_.
The _Crureus_ or _Tibiaeus Posticus_, springs from the back-part of the
Leg-Bone, from whence extending it self downward, it passeth thro' the
Fissure in the _Internal Malleolus_, and cleaves to the inner-part of the
_Os Scaphoides_. {54}
The _Peronaei_, or _Fibulaei Postici_, are otherwise call'd the _Longus_
and the _Brevis_, whereof one proceeds from the upper and almost fore-part
of the _Perone_, terminating in the upper-part of the Bone, that supports
the great Toe in the _Metatarsus_, and the other from the lower part of the
_Perone_, adhering in like manner to the Bone with which the little Toe is
sustain'd.
_With what Motions are the Toes endu'd, how many Muscles have they, and
which be they?_
The Toes are bent and extended, as also drawn inward and outward, by the
means of twenty two Muscles, of which sixteen are Common, and six Proper.
The former are two _Flexors_, two _Extensors_, four _Lumbricales_, and
eight _Interossei_. The first _Flexor_ is nam'd _Sublimis_, and the other
_Profundus_.
The _Sublimis_ or _Perforatus_ derives its Original from the lower and
inner-part of the _Talus_ and is fixt in its proper place by four cleft
_Tendons_, which are inserted in the upper-part of the Bones of the first
_Phalanx_ of the four Toes. It is situated under the Sole of the Feet.
The _Profundus_ or _Perforans_ hath its beginning in the top and back-part
of the Leg-Bone and _Perone_, slips under the _Malleolus Internus_ thro'
the _Sinus Calcaris_, and makes four _Tendons_ which pass thro' the
Fissures of the _Tendon_ of the _Sublimis_, and cleaves to the Bones of the
last _Phalanx_ of the Toes, to bow them.
The first _Extensor_ is call'd the _Common_, and the other the _Pediaeus._
The _Common Extensor_, or the _Longus_, takes its rise from the top and
fore-part of the _Tibia_ in the place of its joyning with the _Perone_ or
{55} _Fibula_, and divides it self into four _Tendons_, which after having
pass'd under the Annular Ligament, are inserted in the Articulations of
every Toe.
The _Pediaeus_ or the _Brevis_, being plac'd over the Foot, proceeds from
the Annular Ligament, and the lower-part of the _Perone_, and sends forth
four _Tendons_, which are fixt to the first Articulation of the four Toes
on the outside, Thus this Muscle, together with the _Longus_, causeth their
Extension.
The four _Lumbrical_ Muscles of the Toes arise from the _Tendons_ of the
_Profundus_, and a Mass of Flesh at the Sole of the Feet. They are joyn'd
by their _Tendons_ with those of the _Interossei Interni_, and adhere
inwardly to the side of the first Bones of the four Toes, to incline them
toward the great Toe.
The _Abductors_, or those Muscles that remove the Toes from the great Toe,
are the eight _Interossei_, whereof four are call'd _Externi_, and as many
_Interni_. The former take their rise in the Spaces between the Bones of
the _Metatarsus_, and are terminated outwardly in the side of the first
Bones of the Toes. The Internal lie in the bottom of the Foot, and take up
the Spaces between the five Bones of the _Metatarsus_. They arise from the
Bones of the _Tarsus_, and the Intervals between those of the _Metatarsus_,
and are implanted with the four _Lumbricales_ inwardly, in the upper-part
of the Bones of the first _Phalanx_ of the four Toes.
Of the six Proper Muscles of the Toes, there are four appointed for the
great Toe, which cause it to perform the Motions of Flexion, {56}
Extension, and drawing forward or backward. The two others are the
_Adductor_ of the second Toe to the great Toe, and the _Abductor_ of the
little Toe, call'd _Hypothenar_.
The Proper _Flexor_ of the great Toe, arises from the top of the _Perone_
or _Fibula_, on the back part, passeth thro' the Ancle-Bone on the inside
to the sole of the Foot, and is fasten'd to the Bone of the last _Phalanx_.
The Proper _Extensor_ of the great Toe springs from the middle of the
fore-part of the _Perone_, passeth over the Foot, and hath its Insertion in
the upper-part of the Bone of the great Toe.
The Proper _Adductor_ of the great Toe, or the _Thenar_, taking its rise
inwardly on the side of the _Talus_, the _Ossa Schaphoidea_ and
_Innominata_, extends it self over the outward-part of the Bone of the
_Metatarsus_, which stayeth the great Toe, and adheres to the top of the
second Bone of the great Toe, which it draws inward.
The proper _Abductor_ of the great Toe, or the _Antithenar_, draws it
toward the other Toes. It derives its Origine from the Bone of the
_Metatarsus_, which supports the little Toe, slides obliquely over the
other Bones, and cleaves to the first Bone of the great Toe on the inside.
The _Adductor_ appropriated to the second Toe hath its Source in the first
Bone of the great Toe, on the inside, and sticks close to the Bones of the
second Toe, which it draws to the great Toe. {57}
The _Abductor_ of the little Toe, or the _Hypothenar_, proceeds from the
outward part of the Bone of the _Metatarsus_, that stayeth the little Toe,
and is inserted in the top of the little Toe, on the outside, to remove it
from the others.
_A List of all the Muscles in the Humane Body._
The Fore-head hath two Muscles 2
The hinder-part of the Head 2
The Eye-Lids 4
The Eyes 12
The Nose 7
The Ears on the outside 8
The Ears on the inside 6
The Lips 13
The Tongue 8
The _Uvula_, or Palate of the Mouth 4
The _Larynx_ 13
The _Pharynx_ 7
The _Os Hyoides_ 10
The Lower Jaw 12
The Head 14
The Neck 8
The _Omoplatae_ or Shoulder-Blades 8
The Arms 18
The Elbows 12
The _Radii_ 8
The Wrists 12
The Fingers 48
The Breast, or the Parts of Respiration 57
The Loins 6
The _Abdomen_ or lower Belly 10
The Testicles 2
The Bladder 1
{58}
The _Penis_ 4
The _Clitoris_ 4
The _Anus_ 3
The Thighs 30
The Legs 22
The Feet 18
The Toes 44
Total 425
* * * * *
CHAP. XII.
_Of the Anatomy of the Nerves, Arteries, and Veins in general._
_What is the Structure of the Nerves?_
The Nerves are round white Bodies enclos'd in a double Membrane,
communicated to them from the two _Meninges_ of the Brain: Their Office is
to convey the Animal Spirits into all the Parts.
_Where is the Root and first beginning of all the Nerves?_
All the Nerves take their Original from the _Medulla Oblongata_, and that
of the Spine.
_How is the distribution of them made thro' the whole Body?_
It is directly perform'd by Conjugations or Pairs, whereof one goes to the
Right-hand, and the other to the Left: There are nine Pairs of them that
proceed from the _Medulla Oblongata_ and enter into the Skull; and a Tenth
that comes from the Marrow which lies between the Occipital and the first
_Vertebra_ of the Neck. It {59} passeth thro' the Hole of the _Dura Mater_,
thro' which the Vertebral Artery enters, to distribute its Branches into
several Parts.
_To what Use are the nine Pairs of Nerves appropriated, which proceed from
the Root of the Brain?_
They are chiefly design'd for the Senses, and also for the Motion of their
Organs, of which the Ancients discover'd only seven.
The first Pair of Nerves is call'd the _Olfactory_, and serves for the
Smelling.
The second Pair is the _Optici_ or _Visorii Nervi_, and bestows upon the
Eyes the Faculty of seeing.
The third is term'd _Motorii Oculorum_, being serviceable for the Motion of
the Eyes.
The fourth Pair is nam'd _Oculorum Pathetici_, which shews the Passion of
the Mind in the Eyes, whereto it imparts a String as well as to the Lips.
The fifth is call'd the _Gustative_, and appropriated to the Taste, because
it sends Twigs more especially to the Tongue, as also to the Fore-head,
Temples, Face, Nostrils, Teeth, and Privy-Parts.
The Sixth is likewise for the Taste, and goes to the Palate.
The seventh is the _Auditive_ Nerve, that enters into the _Os Petrosum_,
where it divides it self into many Branches, which when gone forth, are
distributed to the Muscles of the Tongue, Lips, Mouth, Face, Fore-head,
Eye-Lids, &c.
The eighth is the _Os Vagum_, or wandering Pair, which is united to the
Intercostal Nerve, as also to the Recurrent, Diaphragmatick, Mesenterick,
&c. {60}
The ninth Pair, after having form'd a Trunk with the eighth, disperseth its
Twigs several ways, whereof one is join'd with the Twig to the tenth, to be
distributed together into the Muscle _Sternohyoideus_, and into the Tongue.
The _Intercostal_ and _Spinal_ are not Pairs of Nerves, but only Branches
or Twigs of other Pairs.
_What is the Distribution and Use of the thirty Pairs of Nerves that
proceed from the Spinal Marrow?_
There are seven that go forth from the several _Vertebra's_ of the Neck,
twelve from those of the Back, five from the Loins, and six from the _Os
Sacrum_, according to the following Progression.
The first of the seven Pairs of Nerves of the Neck proceeds from between
the Occipital Bone and the first _Vertebra_, nam'd _Atlas_, its Fibres
being lost in the Muscles of the hinder-part of the Head and Neck.
The second Pair springs from between the first and second _Vertebra_ of the
Neck; the Fibres whereof are lost in the Muscles of the Head, and in the
Skin of the Face.
The third Pair issueth from between the second and third _Vertebra_ of the
Neck; and its Fibres are lost in the Flexor Muscles and Extensors of the
Neck.
The fourth, fifth, sixth, and seventh Pairs proceed from between the
_Vertebra's_, as before, but their Fibres are lost in the Neck of the
_Omoplata_, in the Arm, and in the _Diaphragme_ or Midriff. Here it ought
to be observ'd by the way that the Arms receive Branches not only from the
{61} four last Pairs of the Nerves of the Neck, but also from the two first
Pairs of the Back, which are extended even to the end of the Fingers:
Whence it happens that in the Palsie of the Arms, Remedies are usually
apply'd to the _Vertebra's_ of the Neck; and that in Phlebotomy or letting
Blood, care must be taken to avoid pricking the Nerve, which accompanies
the Basilick Vein in the Elbow.
The twelve Pairs of Nerves that have their Beginning from between the
_Vertebra's_ of the Back, are each of them divided into two Branches, as
the others; and their Branches are distributed in like manner to the
Muscles of the Breast, and to those of the Back and _Abdomen_.
The five Pairs which take their Rise from between the _Vertebra's_ of the
Loins, have thicker Branches than the others, and the distribution of them
is made to the Muscles of the Loins, _Hypogastrium_, and Thighs.
Of the six Pairs of Nerves that proceed from the _Os Sacrum_, the four
Upper with the three Lower of the Loins, send forth Fibres of Nerves to the
Thigh, Leg, and Foot; and the two last Pairs impart Nerves to the _Anus_,
Bladder, and privy Parts.
_What is the Structure of the Arteries?_
The Arteries are long and round Canals, consisting of four sorts of Tunicks
or Membranes, which have their Rise from the left Ventricle of the Heart,
from whence they receive the Blood, and convey it to all the Parts of the
Body for their Nourishment.
_What is the Construction of these four Tunicks or Membranes of the
Arteries?_ {62}
The first being thin and Nervous in its outward Superficies, is in the
Inside a _Plexus_ or Interlacement of small Veins and Arteries, and Fibres
of Nerves, which enter into the other following Tunicks, to nourish them.
The second sticking close to the former, is altogether full of whitish
Glandules, that serve to separate the serous Particles of the Blood.
The third is intirely Musculous, and interwoven with Annular Fibres.
The fourth is very thin, and hath its Fibres all streight.
_Whence proceeds the Pulse or beating of the Arteries?_
It is deriv'd from the Heart, and exactly answers to its Motion of
_Diastole_ and _Systole_.
_By what Name is the first Trunk of the Arteries call'd, and what is the
Effect of the Distribution made thence to the whole Body?_
The first Trunk of the Arteries is nam'd _Aorta_, or the _thick Artery_,
which proceeds immediately from the left Ventricle of the Heart, whereto it
communicates before its departure from the _Pericardium_, one or two small
Branches call'd the _Coronary_: Afterward it is divided into two Branches,
whereof one goes upward, and is term'd the _Ascending Artery_; and the
other downward, under the Denomination of the _Descending Artery_.
The _Ascending Artery_ ariseth upward along the _Aspera Arteria_ or
Wind-Pipe, to the Clavicles, and is there divided into two Branches, call'd
the _Subclavian Arteries_, one whereof goes forward to the Right side, and
the other to the Left; and they both send forth on each side {63} divers
Branches, which take their Names from the several Parts, whereto they are
distributed; such are the _Carotides_ or _Soporales Interni & Externi_,
which pass to the Head; the _Mediastina_; the _Intercostal_; the _Axillar_,
and others.
The _Descending Artery_, before its departure from the Breast, affords
certain Branches to the _Pericardium_, Diaphragm, and lower Ribs; afterward
it penetrates the Diaphragm, and constitutes seven double Branches. The
first is of those that are call'd _Coeliack_, and which go to the Liver and
Spleen. The second Branch contains the _Upper Mesenterick_. The third the
_Emulgent_, which pass to the Reins. The fourth the _Spermatick_, which are
extended to the Genitals. The fifth the _Lower Mesenterick_. The sixth the
_Lumbar_. And the seventh the _Muscular_. But assoon as the great Trunk is
come downward to the _Os Sacrum_, it divides it self into two thick
Arteries nam'd the _Iliack_, which are distributed on both sides, each of
them making two Internal and External Branches, which likewise impart
Sprigs or lesser Arteries, to the Bladder, _Anus_, _Matrix_, and other
adjacent Parts: Then the Master-Branch forms the _Crural_ Arteries on the
inside of the Thighs, which are communicated by multiplying their Number
even to the ends of the Toes, in passing over the External Ancle-Bones of
the Feet.
_What is the Structure of the Veins?_
The Veins are long and round Canals made of four kinds of Tunicks or
Membranes, whose Office it is to receive the Blood that remains after the
Nourishment is taken, and to carry it back to the Heart to be reviv'd. {64}
_What is the Form of the four Tunicks that make the Canals of the Veins?_
The first is a Contexture of Nervous and streight Fibres. The second is a
_Plexus_ of small Vessels that carry the Nourishment. The third is all over
beset with Glandules thro' which are filtrated the serous Particles of the
Blood contain'd in the Vessels of the second Tunicle. The fourth is a
Series of Annular and Musculous or Fleshy Fibres.
_Which are the most numerous, the Arteries or the Veins?_
The Number of the Veins exceeds that of the Arteries; and there are scarce
any Arteries without Veins accompanying them.
_Where is the Beginning and Original of all the Veins?_
All the Veins have their Root in the Liver, and two of the three great
Trunks that proceed from thence, are call'd _Vena Portae_, and _Vena Cava_;
and the third is twofold, _viz._ the _ascending_ and the _descending_.
The _Vena Portae_ is distributed to all the Parts contain'd in the lower
Belly, and terminated in the Fundament; where it makes the Internal
Haemorrhoidal Veins.
The _Vena Cava_ is immediately divided into two thick Branches, one whereof
ariseth upward to the Right Ventricle of the Heart, and forms the
_ascending Vena Cava_; as the other goes downward to the Feet, and
constitutes the _descending_.
_What is the Distribution of the ascending _Vena Cava_?_
It perforates the Diaphragm, goes to the Heart, and ascends from thence to
the Clavicles, {65} after having communicated to the Midriff in passing, a
small Branch call'd the _Phrenicus_; as also one or two to the Heart, nam'd
the _Coronary_; and some others to the upper Ribs, besides the single
Branch, term'd _Azygos_, only on the right side. But the Trunk of the
_ascending Vena Cava_, being once come up to the Clavicles, is divided into
two Branches, well known by the Name of the _Subclavian_, one whereof
Shoots forth toward the Right side, and the other toward the Left; and they
both make various Ramifications like to those of the thick ascending
Artery, by producing the _Cervicalis_ or _Soporalis_, and the Internal and
External _Jugulars_ that go to the Head; as also the _Axillars_, which pass
to the Arms and Shoulders, forming the _Cephalick_, the _Median_, and the
_Basilick_ on the inside of the Elbow.
The _descending Vena Cava_ in like manner accompanieth the Ramifications of
the _Aorta_, or thick descending Artery, to the fourth _Vertebra_ of the
Loins, where it sends forth two Branches, nam'd the _Iliack_, one whereof
goes to the Right side, and the other to the Left, both inwardly and
outwardly; imparting divers Twigs or lesser Branches to all the Parts
contain'd in the _Abdomen_ or lower Belly, even as far as the Fundament,
where it makes the External _Haemorrhoidal_ Veins. Afterward the outward
Branch of the _Iliack_ descends in the Thigh, to form the _Crural_, and
others, as far as the _Saphaena_, together with those that are situated at
the end of the Feet.
* * * * *
{66}
CHAP XII.
_Of the Anatomy of the _Abdomen_, or lower Belly_.
_What is the clearest Division of the Human Body into various Parts, and
that which is most followed in the Anatomical Schools?_
It is that which constitutes three _Venters_, that is to say, the Upper,
the Middle, and the Lower, which are the Head, the _Thorax_ or Breast and
the _Abdomen_ or lower Belly, together with the Extremities, which are the
Arms and Legs.
_What is the lower Belly?_
It is a Cavity of the Body that contains the nourishing parts, as the
Reins, the Bladder, and all those that are appropriated to Generation in
both Sexes.
_What is to be consider'd outwardly in the lower Belly?_
Its different Regions, and the several parts therein contain'd.
_What are these Regions?_
They are the _Epigastrick_, the _Umbilical_, and the _Hypogastrick_.
_What is their Extent?_
It is from the _Xyphoides_ or Sword-like Cartilage to the _Os Pubis_, the
division whereof into three equal Parts, constitutes the three different
Regions; the _Epigastrium_ being the first upward, the _Umbilicus_ the
second, and the _Hypogastrium_ the third. {67}
_What Are the Parts contain'd in the _Epigastrium_, and what Place do they
possess therein?_
The Parts contain'd in the _Epigastrium_ are the Liver, the Spleen, the
Stomach, and the _Pancreas_ or Sweet-bread, which lies underneath: The
Stomach takes up the middle before, the Liver being plac'd on the Right
side, and the Spleen on the Left; so that these two sides of the
Epigastrick Region, are call'd the Right and Left _Hypochondria_.
_What Parts are there contain'd in the Umbilical Region, and what is their
situation?_