By Dr Raghuram Y.S.MD (Ay) & Dr Manasa, B.A.M.S
The terms Sira, Dhamani and Srotas are used interchangeably in Ayurveda. All of these structures transport something or the other from one part of the body to the other. The description of each of these shows that they are different structures serving different functions in the body. Sira Sharira i.e. study of siras is equated to angiology hence, considered as ‘Ayurveda Angiology’.
Read – Dhamani Sharira Meaning, Function, Functions, Distribution
Table of Contents
Definition of Sira
According to Atharva Veda – ‘Siras are those which carry impure blood. They are actually called Hira instead of Sira. Those of which carry pure blood are called dhamani’.
With this reference we understand that the sira is vein and dhamani is artery. But, Master Sushruta’s explanation of sira encompasses many structures i.e. veins, arteries, lymphatic and nerves.
Master Charaka says ‘Since there is movement of blood in these structures they are called as sira’. Sarana means ‘to go’ or ‘to move from one place to the other’.
Master Gangadhara tells ‘Sarana means the movement of rasa and other tissues. The structure in which such movement takes place is called as sira’. Here we get a doubt since Gangadhara has specifically mentioned ‘rasadinam gamanat’ i.e. many more tissues other than blood flow or move in these siras. But the structures which carry all the tissues are called as srotas. Sira and Srotas have been used as synonymous to each other by many authors. Dhamani is also a synonym of sira and srotas. The name of the same structure can be sira, dhamani or srotas depending on what kind of function they are rendering. But they are anatomically and functionally different since, they have been described separately in spite of being used interchangeably.
Another fact is that the srotas carry the tissues which are in the process of transformation and siras carry the formed blood and lymph / plasma tissue.
Read – Rasa Dhatu: Definition, Formation, Circulation, Imbalance Diseases, Treatment
Origin, Root, Number of Siras
Master Sushruta says that there are a total number of 700 siras in the human body. The functions of the siras are to provide nutrition to every part of the body. Therefore they are spread out in the entire body. This has been explained with suitable examples –
Understanding the functions of Siras with examples of water carriers and small channels – Just like the water carriers sprinkle water to every plant in the garden / grove and just like the small canals / channels carrying water convey water to every part of the field and nourish the crops therein, the siras spread all through the body and nourish all structures therein.
Understanding the structure of sira with examples of veins of leaves – Just like the veins and venules are spread over the leaf, the siras spread all through the body. They branch and re-branch as they spread out.
Read – Shaareera: Ayurvedic Study Of Anatomy And Physiology
Root of origin of siras – Umbilicus is the root of origin of siras. After taking their origin in the navel the siras spread upwards, downwards and side-wards. They spread throughout the body from the navel. This may be the explanation in relation to fetal circulation and limited to that part of explanation from the modern perspective. The life element of all living beings is located in the navel. And the navel exists on the basis of the life elements connected to it. The navel is surrounded by the siras in a way similar to the spokes of a wheel which surround the axle of the wheel. From this example we understand that the navel is the axle and the siras taking their origin from the navel and also surrounding the navel form the spokes of the axle. Thus, the navel and the siras around it look like the wheel and its spokes. Just like the axle is dependent on the spokes and spokes on the axle, the life element is located in the navel and the source of existence of the navel is the pranas i.e. life elements connected to it.
The prana which is connected to the navel in this context should be understood as ‘blood’. Siras convey blood and blood is an important life element, we live when the blood flows uninterruptedly to each and every corner of the body. The navel is surrounded by siras also means that the navel is surrounded by blood – described as life element in this context.
When we look at the fetal circulation we understand that the blood circulation to and from the child happens through the baby’s navel. The nutrition to the baby from the mother passes through the placenta, umbilical cord and navel of the child to the child. This has to happen uninterruptedly since the baby in the womb doesn’t have its own circulation and oxygenation system which is operating. The baby and sustenance of its life and growth of the baby is totally dependent on the mother and the mechanism of fetal circulation which connects the mother with the baby. If this connection gets cut off from the baby’s navel or if the fetal circulation is hampered it may result in the death of the child in the womb. If the child has insufficient blood and nutrition supply through the fetal circulation, the child might take birth with many abnormalities. From this perspective the navel might have been said to be the root and origin of siras. Therefore this description is from the embryological point of view.
Read – Embryology As Per Ayurveda
Why only 700 siras – 700 siras should be understood as the larger branches of siras. They would further branch into smaller branches as they spread throughout the body and thus thousands of siras are formed.
If we carefully observe the meanings of the above mentioned 3 examples, the examples explain 3 different kinds of siras.
|Sl No||Example describing siras||Type of sira referred to by the example|
|1||Water carrier||Larger siras – probably the 700 siras mentioned by Sushruta|
|2||Channels / small canals conveying water to the plants / crops in the fields||The secondary branches of the above said 700 siras, siras of moderate size – size of these siras are smaller than the larger siras|
|3||Veins and venules of the leaves||The tertiary branches of the siras, the smallest branches which probably branch out from the moderate sized siras mentioned above|
Read – Srotas: Body Channels and Duct systems – Easy Explanation
Note – If sira is taken as vein, the study should be done in a reverse way. Analogy / example 3 explains the formation of venules at the capillary level, joining to become the secondary tributaries (analogy / example 2). These secondary tributaries join together to become larger veins (water carrier example / analogy 1) which drain into the heart. If we need to use the word artery for sira we can also consider the word ‘branches’ instead of ‘tributaries’ and their distribution can be understood in a descending way i.e. analogy 1 to analogy 3.
Relation of siras with functions of the body and body parts – Important privileged functions like extension, flexion, speech, sleeping awakening etc are under the control of siras. This means to say that if the siras and their branches extend to every part of the body and provide them with the needed nutrition the mentioned functions will be possible in an unhampered way. The word ‘adi’ which means ‘etc’ explains that many functions of the body are dependent on how the siras and their branches are distributed in the entire body.
Read – Upadhatu Of Rakta: Sira, Kandara – Sub Tissues Of Rakta
There are 700 siras in the body. These siras too take their origin from the main root 40 siras.
Division of 40 root siras
|Sl No||Name of the Sira||Number|
|1||Vatavaha – those conveying vata||10|
|2||Pittavaha – those conveying pitta||10|
|3||Kaphavaha – those conveying kapha||10|
|4||Raktavaha – those conveying blood||10|
Further division of 40 siras
- The siras located in the seats of vata and conveying vata are 175 in number.
- The siras located in the seats of pitta and conveying pitta are 175 in number.
- The siras located in the seats of kapha and conveying kapha are 175 in number.
- The siras located in the seats of blood i.e. liver and spleen and conveying blood are 175 in number.
Thus the 10 root siras each transporting vata, pitta, kapha and blood are further divided into 175 branches each. Thus the 40 root siras make a total of 700 siras i.e. 175×4 = 700 siras.
Read – Sankhya Shaareera: Count Of Body Parts As Per Ayurveda
Vatavaha Siras, Vata transporting siras
The root vata carrying siras are 40 in number. They are further divided into 175 siras. The further sub-division of 175 siras are as below mentioned –
|Sl No||Seat of Vata carrying siras||No of siras||Sub-divisions of these siras|
|1||Limbs||100||Right upper limb||25|
|Left upper limb||25|
|Right lower limb||25|
|Left lower limb||25|
|2||Trunk – Thorax + Abdomen||34||Buttock, Penis (genital), Pelvis||08|
|Chest / Thorax||10|
|3||Above the level of clavicle / collar bone (neck and head)||41||Neck||14|
|Ears (both together)||04|
|Eyes (both together)||08|
Pittavaha, Kaphavah and Raktavaha Siras
The division and subdivisions of pitta, kapha and blood carrying siras will be the same as that being mentioned for vata carrying channels.
The difference is that there are 10 siras carrying pitta in the eyes and 2 in the ears. The same are the number of siras carrying kapha and blood to eyes and ears.
Read – Channels Of Circulation And Doshas
Functions of un-vitiated and vitiated vata in vata carrying siras
Most of the physical and mental functions of our body are under the control of vata. Vayu would render these functions in a perfect and uninterrupted way being in its siras.
The intellect would not deviate from its normal functions. Many more functions of normal and balanced vayu are carried out by the vayu being in its own siras. The strength, color, complexion, reflection and immunity will be at their optimum when the balanced vayu operates being in its siras. When the vitiated vata gets located in its siras and operates from therein it would cause wide array of disorders of vata origin.
Read – Symptoms Of Vata Dosha Increase And Imbalance – Vata Vruddhi Lakshana
Functions of un-vitiated and vitiated pitta in pitta carrying siras
The balanced pitta being in its siras induces good virtues and functions. It brings about color and complexion, taste towards food, good digestive capacity and digestion of food, state of well being etc. Many more functions of normal and balanced pitta are carried out by the pitta being in its own siras. The digestive fire is kept in its uncontaminated form and in its fullest strength. This fire would digest the food in a proper way and produce good quality nutritive juices which help in proper nutrition of the body.
When the vitiated pitta gets located in the siras and operates from therein it would cause a wide array of disorders of pitta origin.
Read – Pitta Dosha – General Introduction
Functions of un-vitiated and vitiated kapha in kapha carrying siras
The balanced kapha, while being in and circulating in its own siras, induces unctuousness and lubrication to body parts, integrity of the bony joints and strength and immunity. Many more functions of normal and balanced kapha are carried out by the kapha being in its own siras.
The visceral organs and the joints are free of diseases and function effortlessly when balanced and uncontaminated kapha circulates in its siras.
When the vitiated kapha gets located in the siras and operates from therein it would cause a wide array of disorders of kapha origin.
Read – Kapha Dosha – General introduction
Functions of un-vitiated and vitiated blood in blood carrying siras
Pure and uncontaminated blood being and circulating in its own siras nourishes the tissues, bestows good color and complexion and sensation of touch. Many more functions of normal and balanced blood are carried out by the blood being in its own siras. The pure blood flowing in its own siras would nourish and take care of the wellbeing of the sense organs. It bestows color, stability to the body parts, nourishment and enrichment of tissues.
When the vitiated blood gets located in the siras and operates from therein it would cause a wide array of disorders of blood origin.
Read – Raktavaha Srotas: Description, Vitiation Symptoms, Treatment
All siras convey all the doshas!
Siras do not convey only vata, pitta or kapha. They carry in them all the doshas and hence called as sarvavaha i.e. ‘those carrying all the doshas’. The doshas which get aggravated and tend to spread out from their seats definitely move in all abnormal directions which don’t belong to them when they are severely aggravated. In this perspective also we should consider that all siras convey all the doshas. All the siras convey all the doshas immaterial of the doshas being normal or vitiated.
Read – Qualities Of Vata, Pitta and Kapha Dosha – Easy Explanation
Classification of Siras based on color
|Sl No||Name of the sira based on dosha or tissue they carry||Color of the sira||Other features||Modern correlation|
|1||Vatavaha – carries vata, filled with vata||Aruna – Reddish brown||Filled with vata||Nerve?|
|2||Pittavaha – carries pitta||Nila – blue||Hot on touch||Veins|
|3||Kaphavaha – carries kapha||Goura – white||Cold on touch and firm||Lymphatics|
|4||Raktavaha – carries blood||Rohini – Shiny red||Neither too hot nor too cold on touch||Arteries|
Traditionally the word sira has been compared to the blood vessels carrying impure blood i.e. veins. But many experts are of the opinion that the siras are not just veins, in fact sira is a word which describes the blood vessels. While Nila, Goura and Rohini colored siras carrying pitta, kapha and blood respectively are compared to veins, lymphatics and arteries there is always a debate on what the siras having aruna color should be compared to. Since these siras carry vata, they should be associated with all activities. Therefore it is wise to consider that aruna colored siras are nerves. But nerves are not hollow structures and this builds up a doubt if rohini sira is a nerve or not!
Effects of puncturing ‘Not to be punctured‘ siras
Siravedha or venesection is one of the types of bloodletting therapy. But all siras should not be punctured as a part of therapy. Some siras are meant not to be punctured. They are called as avedhya siras. If these siras are punctured while doing therapy they either cause deformity or death.
Among the 400 siras located in the limbs (upper and lower together) – ‘the not to be punctured siras’ are 16 in number.
Among the 136 siras located in the trunk – ‘the not to be punctured siras’ are 32 in number.
Among the 164 siras located above the level of clavicle (head and neck) – ‘the not to be punctured siras’ are 50 in number.
Read – Raktamokshana Benefits, Types, Procedure, Indications
Not to be punctured Siras
‘Not to be punctured’ siras of the limbs – 16 siras
Out of the 400 siras located in the limbs 100 siras are found in each limb. Out of these 100 siras in each limb 4 siras are vital and should never be punctured. They are –
- Jaladhara sira – 1
- Urvi sira – 2
- Lohitaksha sira – 1
Same siras should not be punctured in each of the 4 limbs. This makes a total of 4×4 = 16 siras in the limbs (2 upper and 2 lower limbs) which should not be punctured. It is said that Jaladhara sira is located in the ‘talahrdaya marma’. Urvi and Lohitaksha siras apart from being siras are also marmas (vital points of the body).
Read – Marma Shaareera: Definition, Composition: Vital Points of The Body
The ‘not to be punctured’ siras of the trunk (chest and belly) – 32 siras
There are a total number of 136 siras in the trunk. The distribution is as below mentioned –
|Sl No||Seat / site of siras||Total number|
|2||Flanks (in both flanks together)||16 siras (8 towards left and 8 on right side)|
|3||Spine||24 siras (12 on each side of the spine)|
|4||Abdomen / belly||24 siras|
|5||Thorax / chest||40 siras|
1. ‘Not to be punctured Siras’ in pelvis
Out of the 32 siras located in the pelvis and around the hips 8 siras are ‘not to be punctured’. They are –
- Vitapa – 2 on each vitapa = 4
- Katikataruna – 2 on each katikataruna = 4
2. ‘Not to be punctured Siras’ in the flanks
Out of the 16 siras in the flanks 8 siras are present in either side.
Among these 4 siras should not be punctured. They are –
- Urdhwaga Sira – 1 sira moving upwards on each side of the flank = 2
- Parsvasandhi – 1 sira located in the parsvasandhi region on either side = 2
3. ‘Not to be punctured Siras’ in the spine
Among the 24 siras in the back 12 are placed on either side of the spine.
2 siras should not be punctured amongst these 24 siras. They are the urdhvagamini brhati siras – 1 on each side = 2 in number.
4. ‘Not to be punctured Siras’ in the abdomen
Among the 24 siras located in the abdomen 2 siras located on either side of the median line above the level of penis should not be punctured. This sums up to 2 siras on either side of the median line = 4 siras.
5. ‘Not to be punctured Siras’ in the thorax
There are 40 siras in the chest region. Among them 14 siras should not be punctured. They are –
- Hrdaya – 2
- Stanamula – 2 on either side = 4
- Stanarohita – 2 on either side = 4
- Apalapa – 1 on either side = 2
- Apastambha – 1 on either side = 2
Total siras ‘not to be punctured’ in the trunk
|Sl No||Region of the siras||No of Siras in this region||Number of siras not to be punctured|
The ‘not to be punctured’ siras of head and neck (regions above the level of collar bones) – 50 siras
There are a total number of 164 siras in head and neck i.e. in the regions of the body above the level of collar bones. Out of these 50 siras should not be punctured. The distribution of siras and ‘not to be punctured siras’ are as explained below.
|Sl No||Seat / site of siras||Total number|
|2||Jaw (lower)||16 siras (8 on each side of the lower jaw)|
|3||Tongue||36 siras (16 beneath the tongue and 20 on the tongue)|
|5||Eyes||38 siras (19 siras in each eye)|
|6||Ears||10 siras (5 in each ear)|
|7||Forehead region around nose and eyes||60 siras|
|8||Temples||10 siras (5 on each side)|
Note – The number of Siras in the head and neck are mentioned to be 164 by Master Sushruta. But at the end of chapter 7 of Sharira Sthana (wherein description of siras have been given) the count doesn’t tally with 164 siras. In fact when we count all the siras mentioned by Sushruta which are distributed in the head, neck and structures therein we will get 262 siras i.e. 98 siras more than the number mentioned by Sushruta in the earlier part of the same chapter. The reason for this is unknown. There might be repetition of some siras. Example we can see that after having mentioned siras of nose and eye separately he once again includes the nose and eyes along with forehead and gives different number of siras (see tab). There is also a possibility that he has considered only 164 siras and has not taken the smaller branches in the count but has thought of mentioning them while explaining the ‘not to be punctured siras’. But the count difference is not seen in the explanation of siras related to limbs and trunk. OOn the other hand the number of siras of head and neck and the count both perfectly tally in Master Vagbhatas enumeration of these siras in Ashtanga Sangraha.
1. ‘Not to be punctured Siras’ in neck
There are 56 siras in the neck.
Among these siras 16 siras should not be punctured. They are –
- Marma siras = 4+8 = 12 siras (4 nila and 8 matruka)
- Krukatika = 2
- Vidhura = 2
2. ‘Not to be punctured Siras’ in lower jaw
Among the 16 siras in the lower jaw 2 siras on each side located in the jaw joints (temporo-mandibular joint) should not be punctured. So, 4 siras in the jaw should not be punctured totally.
3. ‘Not to be punctured Siras’ in the tongue
Among the 36 siras, 16 siras are located beneath the tongue. Among these 4 siras should not be punctured –
- Rasavaha siras (those carrying nutrition) = 2
- Vagvaha siras (those responsible for production of speech) = 2
4. ‘Not to be punctured Siras’ in Nose
There are 24 siras in the nose. Among these 5 siras should not be punctured. They are –
- 4 siras located in the nasal cavity
- 1 sira located in the soft palate
5. ‘Not to be punctured Siras’ in eyes
There are 38 siras in both eyes together. Among these 2 siras should not be punctured i.e. 1 sira located in the outer angle of the eye (one in the left outer angle and one in the right outer angle) = 2 siras.
6. ‘Not to be punctured Siras’ in ears
There are 10 siras in the ears. Among these 2 siras (one in each ear) carrying sound (responsible for perception of sound) should not be punctured.
7. ‘Not to be punctured Siras’ in the part of the forehead related to eyes and nose
In this region there are 60 siras. Among these 7 siras should not be punctured. They are –
- Those which are situated at the margin of hairs = 4
- Located in the region of avarta marma (one on each side) = 2
- Located in the region of sthapani = 1
8. ‘Not to be punctured Siras’ in temples
There are 10 siras in the temples. Among these 2 siras should not be punctured. They are 1 sira in each temple = 2 siras.
9. ‘Not to be punctured Siras’ in head
There are 12 siras in the head. Among these 8 siras should not be punctured. They are –
- Utkshepa = 2 siras
- Simanta = 5
- Adhipati = 1
Read – Blood Letting Therapy – Siravyadha – Astanga Hrudaya Sutrasthana 27
What are Siras?
Understanding the term sira from the definition and origin point of view – Siras are hollowed out structures which carry plasma and blood tissue in them (according to the definition). The siras convey rasa and blood to different parts of the body. The term sira is used as synonym or interchangeably with dhamani and srotas which are the other structures which are related to transportation and distribution of vital ingredients in the body including those materials needed for tissue construction. The origin of siras is said to be the umbilicus. This explanation is limited to the ‘embryological explanation of fetal circulation’. The outreach of siras are ‘entire body’ since sarana, the function of sira is explained as ‘transportation of blood from one place to the other’.
Sira understanding from the perspective of similes given in the treatises – The water carrier simily explains the siras nourishing the structures. This is the outward flow of nourishing material which can be possible only through arteries because veins bring back the blood to the heart. The definition of siras also tells the same. Sarana means to transport or things in the siras moving to different parts of the body. The leaf analogy too explains the outwards branching of siras and their distribution all through the body. This can either be branches of arteries or nerves. But nerves are not hollow and do not carry anything. All these analogies are given by Sushruta in the same context, one after the other.
If siras are taken as veins and dhamanis (due to their pulsation property) as arteries, the water carrier analogy explains larger veins, the ‘channels in the field’ analogy explains the secondary tributaries formed by the joining of smallest veins and in turn join together to become the larger veins. The ‘veins and venule on the leaf’ analogy explains the tributaries at the origin i.e. venules at the capillary level. These join to form the secondary veins or intermediate veins.
From the functional aspect of siras – the functions like extension, flexion, speech, sleeping, awakening etc are under the control of the nervous system and siras need to be considered as nerves. If these functions are said to be taking place due to proper blood supply to the organs related to these functions, then siras need to be considered as arteries.
From the perspective of dosha wise classification of siras – The functions of vata, pitta, kapha and blood are also carried about by the balanced presence of these components in siras and put into circulation through the same siras. These functions include intellectual functions, functions of mind and body, nourishment, enrichment of tissues, color, complexion, lubrication, integrity, immunity, digestive functions, strength, reflection etc . These functions relate to the functions of the nervous system / nerves or arteries.
From the perspective of color of the siras – Siras carrying vata are reddish brown and the description resembles the nerves. Vata functions are carried through nerves and the nervous system. Siras carrying pitta are said to be blue in color and resemble the structure of veins. Siras carrying kapha are white in color and resemble the structure of lymphatics. Siras carrying blood are shiny red and explain the structure of arteries and arterioles. Many experts therefore opine that siras are not just veins. The word sira should be understood contextually. Ayurveda masters have given a generalized name to many structures as sira through which something is conveyed from one place to the other and the term encompasses all the structures mentioned in this paragraph.
From the siravedha perspective – Siravedha i.e. venesection which is a part of bloodletting therapy in Ayurveda points towards the term sira as vein because artery or nerve cannot be punctured. Master Sushruta has enlisted some siras (described above) which should not be punctured as a part of surgical process or vensection therapy / bloodletting therapy. These siras might be the greater veins or important arteries or nerves or congruence of these structures at a point making a marma i.e. vital structure or point wherein it shall not be punctured. The other siras can be punctured and hence the ‘can be punctured’ section of siras are superficial veins which can be punctured for therapy. The siras which fall under the category of ‘not to be punctured’ siras may comprise arteries, deeper veins, larger veins, nerves or marma points.