February 2nd, 2010

Kinesiologia ca stiinta

Am amintit deja încă de la începutul acestui capitol, în cadrul definiţi­ilor, de acest aspect al kinetologiei.

Ca orice ştiinţă, kinesiologia are legi precise după care se conduce. Sunt legi împrumutate din alte ştiinţe (fiziologie, fizică, biologie etc.) dar având şi propriile ei legi pe care şi le-a creat pe baza aplicării celor de mai sus în contextul activităţii fizice umane. în fond întreaga monografie de faţă nu este decât o expunere a acestor legi.

In general, după cum se ştie, ştiinţele au dezvoltat în cadrul lor capi­tole individualizate ca nişte subdiscipline ale ştiinţei-discipline de bază. Astfel fizica şi-a ramificat conţinutul prin studierea separată a mecanicii, electrici­tăţii, energiei nucleare etc. Tot astfel şi kinetologia ca ştiinţă are 3 mari com­ponente (subdiscipline):

A. Biomecanica sau „kinetologia mecanică” este aplicarea
legilor mecanicii la studiul mişcării.

  1. Biomecanica studiază „anatomia aplicată “, adică raporturile între structură şi funcţie. în acest cadru se vor discuta: raportul între forma unei articulaţii şi tipul ei de mişcare, între geometria muşchiului şi forţa lui, între structura coloanei şi gradul ei de mişcare, între aspectul părţii proxi-male a femurului şi presiunile exercitate etc. în acelaşi timp, se analizează şi impactul anormalităţilor structurale, înnăscute sau dobândite, asupra mişcării (activităţii fizice).
  2. Biomecanica înseamnă şi analiza fizică a mişcării, apli­carea legilor fizice ale mişcării la activitatea fizică a omului. In acest cadru, se va discuta despre: frecare, inerţie, rezistenţe, acceleraţie, velocitate, pârghii etc. Şi de asemenea analizează implicaţiile abaterilor de la aceste legi ale mişcărilor patologice.

B. Fiziologia exerciţiilor este cea de-a doua subdisciplină a kinetolo-
giei ştiinţifice reprezentând aplicarea legilor fiziologiei la studiul mişcării
umane. în cadrul acestei componente a kinetologiei teoretice se expun:

-     răspunsurile funcţionale imediate şi adaptările în timp la activitatea fizică a aparatelor şi sistemelor organismului (cardiovascular, respirator, meta­bolic, endocrin, sânge, termoreglare etc);

-     modalitatea în care se realizează şi se consumă „energia” în activi­tatea fizică;

-     limitele performanţei fizice şi ce reprezintă oboseala;

-     răspunsurile organismului la stresul fizic;

-     nivelul de fitness;

-     etc.

Anormalităţile proceselor fiziologice de mai sus reprezintă probleme de preocupare ale kinetologiei medicale căci pe aceste mecanisme fiziopatologi-ce îşi bazează programul de intervenţie componenta practică a acestei ştiinţe.

C. Comportamentul psihomotor, a 3-a subdisciplină, are ca material
de studiu rolul şi mecanismele SNC în procesele de comandă şi execuţie a
mişcărilor voluntare.

în această subdisciplină intră probleme ca:

-     modul de elaborare a necesităţii şi comenzii unei mişcări;

-     transmiterea acestei comenzi spre aparatul efector;

-     continua ajustare a parametrilor unei activităţi fizice (feedback-urile);

-    modul de formare a abilităţilor, a echilibrului şi stabilităţii;

-    etc.

Tot această subdisciplină a kinesiologiei se preocupă şi de implicaţiile anormalităţilor neurologice sau/şi psihice asupra proceselor de comandă şi execuţie ale activităţilor fizice.

Iată, aşadar, „dimensiunile” kinetologiei ştiinţifice care îşi integrează noţiuni de bază ale ştiinţelor fizice, biologice şi medicale.

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February 2nd, 2010

Cadrul Kinesiologiei

Kinetologia sau kinesiologia, termen introdus de Daily în 1857 la Paris, înseamnă „ştiinţa sau studiul mişcării”, căci „kinein” = mişcare, iar „logos” = a studia, a vorbi despre.

Pentru a încadra kinesiologia mai corect într-o definiţie ar trebui să spunem că este „ştiinţa mişcării organismelor vii şi a structurilor care  participăla   aceste mişcări”.

Desigur că în această definiţie poate intra şi studiul deplasării amoebei sau miriapodului ca şi a păsărilor sau omului. Evident că prin kinetolo­gie noi o vom înţelege numai pe cea referitoare la om şi numită „kinetolo­gie medicală”.

Ar trebui poate să atragem atenţia că în logica taxonomică de mai sus ar fi necesar să clasificăm mai întâi „kinetologia umană” şi ca o componentă a acesteia să vorbim de cea „medicală” deoarece teoretic putem accepta şi o „kinetologie nemedicală”. Nu este însă nevoie de o astfel de abordare căci kinetologia medicală preia tot ce s-ar putea spune într-un ca­pitol intitulat „kinetologie umană”*. De altfel, definiţia kinetologiei medicale este: „studiul structurilor şi mecanismelor neuromuscu-lare şi articulare care asigură omului activităţi mo­trice normale, înregistrând, analizând şi corectând me­canismele deficitare”.

Partea întâi a acestei definiţii acoperă după cum se vede întreaga problematică generală (medicală şi nemedicală) a kinetologiei umane în timp ce în partea a doua a definiţiei aspectul medical devine evident. Şi mai devin evidente şi componentele kinetoterapiei.

Aspectul ştiinţific, teoretic al kinesiologiei apare din prima parte a definiţiei „studiul structurilor şi mecanismelor neuromusculo-articulare” ale mişcării.

Tot din definiţie am văzut că kinetologia „înregistrează şi analizează” mecanismele deficitare ale mişcării. Altfel spus, a 2-a componentă a kinesio­logiei este „Evaluarea” – capitol considerat esenţial nu numai pentru inventarierea perturbărilor mişcării, ci şi pentru crearea programelor practice kinetice (vezi capitolul „Evaluare”).

In sfârşit, definiţia precizează rolul kinetoterapiei în „corectarea” mecanismelor deficitare ale mişcării. Este componenta practică, tera­peutică (kinetoterapia),   sau „arta” acestei ştiinţe numită kinesiologie.

Stricto sensum, kinesiologia are în studiu aparatul locomotor sau apara­tul mioartrokinetic sau mai corect neuro-mio-artro-kinetic.

Largo-sensum, kinetologiei îi revine însă şi sarcina de a studia şi modul în care activitatea acestui aparat influenţează celelalte aparate şi sisteme (mai ales cel cardiovascular, respirator, metabolic şi neuropsihic) precum şi modul în care aceste sisteme îşi exercită influenţa asupra aparatului neuromioarto-kinetic.

Şi încă nu am atins graniţele kinetologiei căci mai intervine un factor esenţial: „mediul” în care organismul se mişcă. în 1985, Higgins, parafrazându-l pe Aristotel, marele filosof al Antichităţii, considerat azi ca părintele kinetologiei nu numai pentru că este primul care înţelege acţiunea muşchilor, ci şi pentru că realizează interacţiunea între aceasta şi forţele externe ale mediului; Higgins, deci, stabileşte definitiv această corelare spunând: „miş­carea este inseparabilă de structura care o susţine (care o determină) şi de ambientalul care o defineşte”.

In această monografie există mai multe momente în care se discută şi se demonstrează justeţea acestei afirmaţii.

Ca multe alte ramuri ale cunoaşterii umane, kinetologia are o compo­nentă teoretică, ştiinţifică, şi una practică. Prezenta monografie urmăreşte să expună în primul rând componenta ştiinţifică, teoretică şi doar în subsidiar pe cea practică dar nu în aspectul aplicativ al artei kinetice, ci în explicarea bazelor teoretice ale acestei practici.

Termenul de kinesiologie are azi o triplă circulaţie. Ca ştiinţă, ca dis­ciplină şi ca profesie. Să analizăm pe rând aceste aspecte ale kinetologiei.

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January 31st, 2010

The Veins of the Brain

The veins of the brain possess no valves, and their walls, owing to the absence of muscular tissue, are extremely thin. They pierce the arachnoid membrane and the inner or meningeal layer of the dura mater, and open into the cranial venous sinuses. They may be divided into two sets, cerebral and cerebellar.

The cerebral veins (vv. cerebri) are divisible into external and internal groups according as they drain the outer surfaces or the inner parts of the hemispheres.

The external veins are the superior, inferior, and middle cerebral.

The Superior Cerebral Veins (vv. cerebri superiores), eight to twelve in number, drain the superior, lateral, and medial surfaces of the hemispheres, and are mainly lodged in the sulci between the gyri, but some run across the gyri. They open into the superior sagittal sinus; the anterior veins runs nearly at right angles to the sinus; the posterior and larger veins are directed obliquely forward and open into the sinus in a direction more or less opposed to the current of the blood contained within it.

The Middle Cerebral Vein (v. cerebri media; superficial Sylvian vein) begins on the lateral surface of the hemisphere, and, running along the lateral cerebral fissure, ends in the cavernous or the sphenoparietal sinus. It is connected
(a) with the superior sagittal sinus by the great anastomotic vein of Trolard, which opens into one of the superior cerebral veins;
(b) with the transverse sinus by the posterior anastomotic vein of Labbé, which courses over the temporal lobe.

The Inferior Cerebral Veins (vv. cerebri inferiores), of small size, drain the under surfaces of the hemispheres. Those on the orbital surface of the frontal lobe join the superior cerebral veins, and through these open into the superior sagittal sinus; those of the temporal lobe anastomose with the middle cerebral and basal veins, and join the cavernous, sphenoparietal, and superior petrosal sinuses.

The basal vein is formed at the anterior perforated substance by the union of
(a) a small anterior cerebral vein which accompanies the anterior cerebral artery
(b) the deep middle cerebral vein (deep Sylvian vein), which receives tributaries from the insula and neighboring gyri, and runs in the lower part of the lateral cerebral fissure
(c) the inferior striate veins, which leave the corpus striatum through the anterior perforated substance.

The basal vein passes backward around the cerebral peduncle, and ends in the internal cerebral vein (vein of Galen); it receives tributaries from the interpeduncular fossa, the inferior horn of the lateral ventricle, the hippocampal gyrus, and the mid-brain.

The Internal Cerebral Veins (vv. cerebri internæ; veins of Galen; deep cerebral veins) drain the deep parts of the hemisphere and are two in number; each is formed near the interventricular foramen by the union of the terminal and choroid veins. They run backward parallel with one another, between the layers of the tela chorioidea of the third ventricle, and beneath the splenium of the corpus callosum, where they unite to form a short trunk, the great cerebral vein; just before their union each receives the corresponding basal vein.

The terminal vein (v. terminalis; vena corporis striati) commences in the groove between the corpus striatum and thalamus, receives numerous veins from both of these parts, and unites behind the crus fornicis with the choroid vein, to form one of the internal cerebral veins. The choroid vein runs along the whole length of the choroid plexus, and receives veins from the hippocampus, the fornix, and the corpus callosum.

The Great Cerebral Vein (v. cerebri magna; great vein of Galen), formed by the union of the two internal cerebral veins, is a short median trunk which curves backward and upward around the splenium of the corpus callosum and ends in the anterior extremity of the straight sinus.

The Cerebellar Veins are placed on the surface of the cerebellum, and are disposed in two sets, superior and inferior. The superior cerebellar veins (vv. cerebelli superiores) pass partly forward and medialward, across the superior vermis, to end in the straight sinus and the internal cerebral veins, partly lateralward to the transverse and superior petrosal sinuses. The inferior cerebellar veins (vv. cerebelli inferiores) of large size, end in the transverse, superior petrosal, and occipital sinuses.

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January 31st, 2010

The Diploic Veins

The diploic veins or Venæ Diploicæ occupy channels in the diploë of the cranial bones. They are large and exhibit at irregular intervals pouch-like dilatations; their walls are thin, and formed of endothelium resting upon a layer of elastic tissue.

So long as the cranial bones are separable from one another, these veins are confined to the particular bones; but when the sutures are obliterated, they unite with each other, and increase in size. They communicate with the meningeal veins and the sinuses of the dura mater, and with the veins of the pericranium. They consist of :

(1) the frontal, which opens into the supraorbital vein and the superior sagittal sinus;

(2) the anterior temporal, which is confined chiefly to the frontal bone, and opens into the sphenoparietal sinus and into one of the deep temporal veins, through an aperture in the great wing of the sphenoid;

(3) the posterior temporal, which is situated in the parietal bone, and ends in the transverse sinus, through an aperture at the mastoid angle of the parietal bone or through the mastoid foramen;

(4) the occipital, the largest of the four, which is confined to the occipital bone, and opens either externally into the occipital vein, or internally into the transverse sinus or into the confluence of the sinuses (torcular Herophili).

Popularity: 11% [?]

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January 31st, 2010

The Veins of the Neck

The external jugular vein (v. jugularis externa) receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the posterior facial with the posterior auricular vein. It commences in the substance of the parotid gland, on a level with the angle of the mandible, and runs perpendicularly down the neck, in the direction of a line drawn from the angle of the mandible to the middle of the clavicle at the posterior border of the Sternocleidomastoideus. In its course it crosses the Sternocleidomastoideus obliquely, and in the subclavian triangle perforates the deep fascia, and ends in the subclavian vein, lateral to or in front of the Scalenus anterior. It is separated from the Sternocleidomastoideus by the investing layer of the deep cervical fascia, and is covered by the Platysma, the superficial fascia, and the integument; it crosses the cutaneous cervical nerve, and its upper half runs parallel with the great auricular nerve. The external jugular vein varies in size, bearing an inverse proportion to the other veins of the neck, it is occasionally double. It is provided with two pairs of valves, the lower pair being placed at its entrance into the subclavian vein, the upper in most cases about 4 cm. above the clavicle. The portion of vein between the two sets of valves is often dilated, and is termed the sinus. These valves do not prevent the regurgitation of the blood, or the passage of injection from below upward.

Tributaries.—This vein receives the occipital occasionally, the posterior external jugular, and, near its termination, the transverse cervical, transverse scapular, and anterior jugular veins; in the substance of the parotid, a large branch of communication from the internal jugular joins it.

The posterior external jugular vein (v. jugularis posterior) begins in the occipital region and returns the blood from the skin and superficial muscles in the upper and back part of the neck, lying between the Splenius and Trapezius. It runs down the back part of the neck, and opens into the external jugular vein just below the middle of its course.
The anterior jugular vein (v. jugularis anterior) begins near the hyoid bone by the confluence of several superficial veins from the submaxillary region. It descends between the median line and the anterior border of the Sternocleidomastoideus, and, at the lower part of the neck, passes beneath that muscle to open into the termination of the external jugular, or, in some instances, into the subclavian vein. It varies considerably in size, bearing usually an inverse proportion to the external jugular; most frequently there are two anterior jugulars, a right and left; but sometimes only one. Its tributaries are some laryngeal veins, and occasionally a small thyroid vein. Just above the sternum the two anterior jugular veins communicate by a transverse trunk, the venous jugular arch, which receive tributaries from the inferior thyroid veins; each also communicates with the internal jugular. There are no valves in this vein.
The internal jugular vein (v. jugularis interna) collects the blood from the brain, from the superficial parts of the face, and from the neck. It is directly continuous with the transverse sinus, and begins in the posterior compartment of the jugular foramen, at the base of the skull. At its origin it is somewhat dilated, and this dilatation is called the superior bulb. It runs down the side of the neck in a vertical direction, lying at first lateral to the internal carotid artery, and then lateral to the common carotid, and at the root of the neck unites with the subclavian vein to form the innominate vein; a little above its termination is a second dilatation, the inferior bulb. Above, it lies upon the Rectus capitis lateralis, behind the internal carotid artery and the nerves passing through the jugular foramen; lower down, the vein and artery lie upon the same plane, the glossopharyngeal and hypoglossal nerves passing forward between them; the vagus descends between and behind the vein and the artery in the same sheath, and the accessory runs obliquely backward, superficial or deep to the vein. At the root of the neck the right internal jugular vein is placed at a little distance from the common carotid artery, and crosses the first part of the subclavian artery, while the left internal jugular vein usually overlaps the common carotid artery. The left vein is generally smaller than the right, and each contains a pair of valves, which are placed about 2.5 cm. above the termination of the vessel.

Tributaries.—This vein receives in its course the inferior petrosal sinus, the common facial, lingual, pharyngeal, superior and middle thyroid veins, and sometimes the occipital. The thoracic duct on the left side and the right lymphatic duct on the right side open into the angle of union of the internal jugular and subclavian veins.
The Inferior Petrosal Sinus (sinus petrosus inferior) leaves the skull through the anterior part of the jugular foramen, and joins the superior bulb of the internal jugular vein.
The Lingual Veins (vv. linguales) begin on the dorsum, sides, and under surface of the tongue, and, passing backward along the course of the lingual artery, end in the internal jugular vein. The vena comitans of the hypoglossal nerve (ranine vein), a branch of considerable size, begins below the tip of the tongue, and may join the lingual; generally, however, it passes backward on the Hyoglossus, and joins the common facial.
The Pharyngeal Veins (vv. pharyngeæ) begin in the pharyngeal plexus on the outer surface of the pharynx, and, after receiving some posterior meningeal veins and the vein of the pterygoid canal, end in the internal jugular. They occasionally open into the facial, lingual, or superior thyroid vein.

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January 31st, 2010

Mecanismul miscarii

Mecanismul miscarii

Ansamblu de procese fiziologice, biochimice, biomecanice si psihologice, aflate in relatii de cauzabilitate si interdependenta care determina executia unei miscari.

Miscare ciclica
Act motric ale carui structuri se repeta periodic

Miscare aciclica
Act motric ale carui structuri nu sunt caracterizate prin repetare periodica.

Structura miscarii
Grupare caracteristica a elementelor actului motric care prin coordonarea si conditionarea lor reciproca ii confera unitate.

Momentul miscarii
Componenta structurala cea mai simpla care marcheaza aspectele statice ale executiei actului motric.

Fazele miscarii
Componenta structurala distincta a actului motric, alcatuita din mai multe momente.

Miscare ciclica
Faza principala
Faza intermediara

Miscari aciclice
Faza pregatitoare
Faza principala
Faza finala

Miscari combinate
Faza elanului
Faza bataii
Faza zborului
Faza aterizarii

Popularity: 11% [?]

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January 31st, 2010

Notiuni de baza ale kinetologiei

1. Miscarea omului
Expresie care indica totalitatea actelor motrice realizate de om pentru intretinerea relatiilor sale cu mediul natural si social si efectuarea deprinderilor specifice diferitelor discipline sportive.

2. Act motric
Fapt simplu de comportare realizat prin muschii scheletici in vederea obtinerii unui efect elementar de adaptare sau de construire a unei actiuni motrice.

3. Actiune motrica
Ansamblu de acte motrice astfel structurate incat realizeaza un tot unitar in scopul rezolvarii unor sarcini imediate care pot fi izolate sau inglobate in cadrul unei activitati motrice.

4. Activitate motrica
Ansamblu de actiuni motrice incadrate intr-un sistem de idei, reguli si forme de organizare in vederea obtinerii unui efect complex de adaptare a organismului si de perfectionare a dinamicii acestuia.

5. Gestul motric
Expresie care diferentiaza din multitudinea actelor motrice pe cele specifice educatiei fizice si sportului datorita intentionalitatii si finalitatii lor.

6. Motricitatea omului
Insusire a fiintei umane, innascuta si dobandita, de a reactiona cu ajutorul aparatului locomotor la stimuli externi si interni sub forma unei miscari.

7. Teoria miscarii
Generalizarea si ordonarea sistemului de cunostinte stiintifice privitoare la originea, esenta, legitatile biomecanice ale efectuarii miscarilor corpului omenesc.

8. Capacitate motrica
Sistem de posibilitati psihomotrice innascute si dobandite, prin care individul rezolva, la un anumit grad, diferite sarcini motrice.

9. Analiza miscarii
Proces (operatie, actiune) de descompunere a actului motric pentru stabilirea si examinarea elementelor sale din diferite puncte de vedere (tehnic, pedagogic si psihologic).

10. Invatare motrica
Procesul insusirii de catre individ, prin exersare, a gestului motric sub indrumarea pedagogului sau independent.

11. Sarcina miscarii
Obiectivul de ordin somatic, functional psihic sau de sinteza, cum este cel de performanta stabilit actului motric prin structura si particularitatile sale de executie.

12. Mecanismul miscarii
Ansamblu de procese fiziologice, biochimice, biomecanice si psihologice, aflate in relatii de cauzabilitate si interdependenta care determina executia unei miscari.

Sursa inspirationala: Tudor Sbenghe, Kinesiologie – Stiinta miscarii

Popularity: 13% [?]

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January 30th, 2010

The Veins of the Head and Neck

The veins of the head and neck may be subdivided into three groups:

(1) The veins of the exterior of the head and face.

(2) The veins of the neck.

(3) The diploic veins, the veins of the brain, and the venous sinuses of the dura mater.

1. The Veins of the Exterior of the Head and Face—The veins of the exterior of the head and face are:

- Frontal
- Superficial Temporal.
- Supraorbital.
- Internal Maxillary
- Angular
- Posterior Facial.
- Anterior Facial.
- Posterior Auricular
- Occipital

The frontal vein (v. frontalis) begins on the forehead in a venous plexus which communicates with the frontal branches of the superficial temporal vein. The veins converge to form a single trunk, which runs downward near the middle line of the forehead parallel with the vein of the opposite side. The two veins are joined, at the root of the nose, by a transverse branch, called the nasal arch, which receives some small veins from the dorsum of the nose. At the root of the nose the veins diverge, and, each at the medial angle of the orbit, joins the supraorbital vein, to form the angular vein. Occasionally the frontal veins join to form a single trunk, which bifurcates at the root of the nose into the two angular veins.

The supraorbital vein (v. supraorbitalis) begins on the forehead where it communicates with the frontal branch of the superficial temporal vein. It runs downward superficial to the Frontalis muscle, and joins the frontal vein at the medial angle of the orbit to form the angular vein. Previous to its junction with the frontal vein, it sends through the supraorbital notch into the orbit a branch which communicates with the ophthalmic vein; as this vessel passes through the notch, it receives the frontal diploic vein through a foramen at the bottom of the notch.

The angular vein (v. angularis) formed by the junction of the frontal and supraorbital veins, runs obliquely downward, on the side of the root of the nose, to the level of the lower margin of the orbit, where it becomes the anterior facial vein. It receives the veins of the ala nasi, and communicates with the superior ophthalmic vein through the nasofrontal vein, thus establishing an important anastomosis between the anterior facial vein and the cavernous sinus.

The anterior facial vein (v. facialis anterior; facial vein) commences at the side of the root of the nose, and is a direct continuation of the angular vein. It lies behind the external maxillary (facial) artery and follows a less tortuous course. It runs obliquely downward and backward, beneath the Zygomaticus and zygomatic head of the Quadratus labii superioris, descends along the anterior border and then on the superficial surface of the Masseter, crosses over the body of the mandible, and passes obliquely backward, beneath the Platysma and cervical fascia, superficial to the submaxillary gland, the Digastricus and Stylohyoideus. It unites with the posterior facial vein to form the common facial vein, which crosses the external carotid artery and enters the internal jugular vein at a variable point below the hyoid bone. From near its termination a communicating branch often runs down the anterior border of the Sternocleidomastoideus to join the lower part of the anterior jugular vein. The facial vein has no valves, and its walls are not so flaccid as most superficial veins.

Tributaries—The anterior facial vein receives a branch of considerable size, the deep facial vein, from the pterygoid venous plexus. It is also joined by the superior and inferior palpebral, the superior and inferior labial, the buccinator and the masseteric veins. Below the mandible it receives the submental, palatine, and submaxillary veins, and, generally, the vena comitans of the hypoglossal nerve.

The superficial temporal vein (v. temporalis superficialis) begins on the side and vertex of the skull in a plexus which communicates with the frontal and supraorbital veins, with the corresponding vein of the opposite side, and with the posterior auricular and occipital veins. From this net-work frontal and parietal branches arise, and unite above the zygomatic arch to form the trunk of the vein, which is joined in this situation by the middle temporal vein, from the substance of the Temporalis. It then crosses the posterior root of the zygomatic arch, enters the substance of the parotid gland, and unites with the internal maxillary vein to form the posterior facial vein.

Tributaries—The superficial temporal vein receives in its course some parotid veins, articular veins from the temporomandibular joint, anterior auricular veins from the auricula, and the transverse facial from the side of the face. The middle temporal vein receives the orbital vein, which is formed by some lateral palpebral branches, and passes backward between the layers of the temporal fascia to join the superficial temporal vein.

The pterygoid plexus (plexus pterygoideus) is of considerable size, and is situated between the Temporalis and Pterygoideus externus, and partly between the two Pterygoidei. It receives tributaries corresponding with the branches of the internal maxillary artery. Thus it receives the sphenopalatine, the middle meningeal, the deep temporal, the pterygoid, masseteric, buccinator, alveolar, and some palatine veins, and a branch which communicates with the ophthalmic vein through the inferior orbital fissure. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen Vesalii, foramen ovale, and foramen lacerum.

The internal maxillary vein (v. maxillaris interna) is a short trunk which accompanies the first part of the internal maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus, and passes backward between the sphenomandibular ligament and the neck of the mandible, and unites with the temporal vein to form the posterior facial vein.

The posterior facial vein (v. facialis posterior; temporomaxillary vein), formed by the union of the superficial temporal and internal maxillary veins, descends in the substance of the parotid gland, superficial to the external carotid artery but beneath the facial nerve, between the ramus of the mandible and the Sternocleidomastoideus muscle. It divides into two branches, an anterior, which passes forward and unites with the anterior facial vein to form the common facial vein and a posterior, which is joined by the posterior auricular vein and becomes the external jugular vein.

The posterior auricular vein (v. auricularis posterior) begins upon the side of the head, in a plexus which communicates with the tributaries of the occipital, and superficial temporal veins. It descends behind the auricula, and joins the posterior division of the posterior facial vein to form the external jugular. It receive the stylomastoid vein, and some tributaries from the cranial surface of the auricula.

The occipital vein (v. occipitalis) begins in a plexus at the back part of the vertex of the skull, From the plexus emerges a single vessel, which pierces the cranial attachment of the Trapezius and, dipping into the suboccipital triangle, joins the deep cervical and vertebral veins. Occasionally it follows the course of the occipital artery and ends in the internal jugular; in other instances, it joins the posterior auricular and through it opens into the external jugular. The parietal emissary vein connects it with the superior sagittal sinus; and as it passes across the mastoid portion of the temporal bone, it receives the mastoid emissary vein which connects it with the transverse sinus. The occipital diploic vein sometimes joins it.

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January 29th, 2010

The Veins of the Heart

Most of the veins of the heart open into the coronary sinus. This is a wide venous channel about 2.25 cm. in length situated in the posterior part of the coronary sulcus, and covered by muscular fibers from the left atrium. It ends in the right atrium between the opening of the inferior vena cava and the atrioventricular aperture, its orifice being guarded by a semilunar valve, the valve of the coronary sinus (valve of Thebesius).

Tributaries.—Its tributaries are the great, small, and middle cardiac veins, the posterior vein of the left ventricle, and the oblique vein of the left atrium, all of which, except the last, are provided with valves at their orifices.

1. The Great Cardiac Vein (v. cordis magna; left coronary vein) begins at the apex of the heart and ascends along the anterior longitudinal sulcus to the base of the ventricles. It then curves to the left in the coronary sulcus, and reaching the back of the heart, opens into the left extremity of the coronary sinus. It receives tributaries from the left atrium and from both ventricles: one, the left marginal vein, is of considerable size, and ascends along the left margin of the heart.

2. The Small Cardiac Vein (v. cordis parva; right coronary vein) runs in the coronary sulcus between the right atrium and ventricle, and opens into the right extremity of the coronary sinus. It receives blood from the back of the right atrium and ventricle; the right marginal vein ascends along the right margin of the heart and joins it in the coronary sulcus, or opens directly into the right atrium.

3. The Middle Cardiac Vein (v. cordis media) commences at the apex of the heart, ascends in the posterior longitudinal sulcus, and ends in the coronary sinus near its right extremity.

4. The Posterior Vein of the Left Ventricle (v. posterior ventriculi sinistri) runs on the diaphragmatic surface of the left ventricle to the coronary sinus, but may end in the great cardiac vein.

5. The Oblique Vein of the Left Atrium (v. obliqua atrii sinistri; oblique vein of Marshall) is a small vessel which descends obliquely on the back of the left atrium and ends in the coronary sinus near its left extremity; it is continuous above with the ligament of the left vena cava (lig. venæ cavæ sinistræ vestigial fold of Marshall), and the two structures form the remnant of the left Cuvierian duct.

The following cardiac veins do not end in the coronary sinus: the anterior cardiac veins, comprising three or four small vessels which collect blood from the front of the right ventricle and open into the right atrium; the right marginal vein frequently opens into the right atrium, and is therefore sometimes regarded as belonging to this group;  the smallest cardiac veins (veins of Thebesius), consisting of a number of minute veins which arise in the muscular wall of the heart; the majority open into the atria, but a few end in the ventricles.

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January 27th, 2010

Systemic Veins

The systemic veins may be arranged into three groups:

(1) The veins of the heart.

(2) The veins of the upper extremities, head, neck, and thorax, which end in the superior vena cava.

(3) The veins of the lower extremities, abdomen, and pelvis, which end in the inferior vena cava.

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