January’s Theoretical Tasks

The end of the month approaches rapidly so, in anticipation of February’s tasks arriving, I thought I’d better update my blog with further info on the theoretical tasks for January. Alongside the practical task of making the elder bark salve for bruises, as described below, Sarah asked us to research the structure & functions of the skin and how bruises form as well as which other herbs are useful for bruises.

Having just completed a diploma in anatomy and physiology last summer this was a good test to see how much I had remembered!

Structure & Function of the skin

I am keeping this to a fairly basic explanation (be grateful – my A&P textbook takes about 50 pages to explain what I am going to try and summarise in a couple of paragraphs!).

The skin is part of the integumentary system, which comprises skin, hair & nails and is one of the largest organs in the body. It has a number of primary functions:

·         Protection – the skin is the first line of defence against invading microorganisms, forming a physical barrier between the external and internal environment and also secreting sebum & sweat which form an acidic layer which may also assist with destroying microorganisms.

·         Temperature Regulation – Sweating and increased blood flow to the surface of the skin helps with cooling the body. Decreasing the blood flow to the skin and raising the hair follicles (goose bumps) helps insulate the body.

·         Sensitivity – the skin contains various types of sensory nerve ending at different depths which detect touch, temperature, pressure, pain.

·         Excretion – of water, heat, toxic waste & small amounts of salt – e.g. when sweating

·         Secretion – of sebum, which prevents that skin from drying out & helps waterproof it as well as containing an anti-sceptic ingredient which kills bacteria (as mentioned above)

Additional functions of the skin are: synthesis of vitamin D when stimulated by ultra-violet light (e.g. from the sun); a reservoir for blood; and absorption of certain substances (even though the skin is mainly impermeable, certain substances such as essential oils can be absorbed though it – if you don’t believe me, try rubbing some fresh garlic on the soles of your feet and see how long it takes before you can taste it and smell it on the rest of your body!).

There are essentially 3 parts to the structure of the skin: the epidermis; the dermis; and the sub cutaneous layer.  Basic diagram below copied from http://dermatology.about.com/cs/skinanatomy/a/anatomy.htm

The epidermis is the most superficial and consists of 5 layers, which are made up of 4 different types of cells (keratinocytes, melanocytes, langerhans cells and merkel cells).  The deepest layer of the epidermis is the basal layer (or stratum germinativum), which is where the skin cells are still living and can reproduce by mitosis, thereby ensuring the skin can heal & renew itself. The cells of the produced in the stratum germinativum grow & push older cells upwards towards the surface of the skin until they become part of the “prickle cell” layer (stratum spinosum), which is where melanocytes (the melanin producing cells which give the skin its colour) are found.  The stratum granulosum lies above the straum spinosum & is where the cells start to die & become keratinised, which toughens the outer layers of skin. The stratum lucidum, which lies superior to the stratum spinosum is most evident in the palms of the hand & soles of the feet. It is mde up of tough, dead keratinized cells & provides an extra layer of protection for those areas that may experience the most use/ friction. Finally, we have the most superficial lay (the stratum corneum), which is where the now flattened keratinised cells lie on the surface of the skin overlapping each other and forming a waterproff covering. It is from this layer that the skin is shed (desquamation). The whole process from basal layer to desquamations takes between 3-6 weeks.

The dermis is thicker than the epidermis and composed of elastic tissue, collagen & connective tissue. It has 2 layers: the papillary layer, which contains the skin’s capillary beds allowing blood to flow to the skin bringing nutrients and oxygen & removing wastes and CO2, and also some of the sensory nerve endings which detect various sensations; and the reticular layer which contains the hair follicles, sebaceous glands & sweat glands.

The subcutaneous layer (or hypodermis) connects the dermis to the underlying tissue such as muscle, bone etc. it protects, insulates & acts as an energy store.

How does a bruise form?
Bruises (or in medi-speak contusions) are generally caused by some sort of blow or knock that may or may not be painful at the time. They are also often found around the sites of other, possibly more serious, injuries (HINT: it’s worth checking if there are bits of bone sticking out of the person’s fractured shin before you start vigorously massaging in the bruise salve! ;-)).

Bruises form when the capillaries in the skin rupture (often due to a blow) and cause bleeding into the skin and the interstitial spaces (space between cells) in the underlying tissues. In a skin bruise, the trapped blood appears first as a red mark with swelling then as a purple or blue-black mark, which as it heals may turn green and yellow. Although we usually relate bruises to the skin, it is also possible for muscles and bones to bruise and these deeper bruises may be considerably more painful (to the extent of limiting activity) and also take longer to heal.

It is worth noting that in some cases, bruises may not be caused by a blow but may be a symptom of a more serious condition or a nutrient deficiency. Taking blood thinners like aspirin may also contribute to easy bruising – worth bearing in mind if you bruise really easily with no apparent cause.

Why Elder bark? Elder bark (best known as a powerful emetic – i.e. makes you sick) is not the first herb that is usually highlighted for use on bruises, although the leaves are cited in Culpeper – the modern uses bit – and other books as being useful in this respect. Therefore this question has been the cause of some interesting email debate amongst the apprentices. From what I have read & in my few books about the properties of elder I like the suggestions put forward by Jackie & Leslie about elder being good against the heat of a new injury (Matthew Wood) and it having astringent properties & properties that may encourage the dispersal of fluids. This would support the idea of applying the salve as quickly as possible after a knock to stop blood gathering in the area and I have so far tried my salve on both old & new bruises & certainly have found it more effective on the latter… Also love the common-sensical approach taken by Sarah in setting the task – i.e. it’s the middle of winter & elder leaves are not available so why not use what’s available and let the tree heal you in the way that is most needed…

Other herbs that are useful for bruises include:

There are quite a few, just some examples below:

Arnica Montana (also known as mountain daisy and mountain tobacco)– very effective as a compress for bruises where there is no open wound. Flowers are the part used. To make the compress 1 tablespoon of the tincture should be mixed with 500ml water (David Hoffman, 1990). Ann McIntyre also notes that the dilute tincture or cream used over any unbroken surface will ease pain, relieve rheumatic joints, and painful swollen feet. Do not take internally as can cause irritation of mucous membranes of stomach & bowel, may also cause allergic reaction if applied to broken skin. Image taken from http://en.wikipedia.org/wiki/File:Arnica_montana_-_K%C3%B6hler%E2%80%93s_Medizinal-Pflanzen-015.jpg

Yarrow (Achillea millefolium) (aerial parts used) I have heard yarrow referred to as a kind of “cure all” plant, as well as being effective specifically against colds & flu. However, it seems it also acts on the blood as a regulator of high blood pressure & irregular menstruation and helping speed the clotting process (hence its nickname of nosebleed I assume!). Hoffman states that yarrow makes an effective compress for bruises and that an infusion of yarrow combined with horsechesnut can help strengthen the blood vessel walls, which may help in the long term if you tend to bruise easily. The more I look at the manifold properties of this amazing little plant, the more glad I am that it is on my study list this year as I think it really could warrant a full article on its own!

NB: I have found a couple of internet references to people having developed an allergic reaction (photosensitivity)  to yarrow and to it being toxic in large doses (tho’ would assume most things are?) - if anyone has any thoughts/ info about this feel free to comment….

Comfrey (symphytum officinale) (roots, rhizomes & leaves) – also known as knitbone, bruisewort. Ann McIntye recommends a poultice or ointment for bruises and sprains. It contains a chemical called allantoin, which encourages wound healing & can also be absorbed into the skin and then into the underlying tissues. This has made it a well known traditional remedy for healing broken or fractured bones and wounds. it has also been used for treating dry coughs & bronchitis & to soothe the gastric tract. NOTE: It is worth noting that there is some debate as to whether this herb should be taken internally, with some authors suggesting that internal use should be avoided completely due to potential liver damaging (hepatotoxic) effects, others suggesting the prolonged usage should be avoided & others suggesting that it is OK to use the leaves & aerial parts. I reckon it’s a case of look at the evidence, consider what you are using it for & make your own mind up ;-)!

Calendula (calendula officinalis) (flowers), also known as English marigold. Has antiseptic and astringent properties and is also well known for its anti bacterial properties which make it a good remedy for fungal infections. However, as with many of the other plants listed here it seems to act powerfully on the blood in a range of situations and is cited all over the place as being effective against internal & external bleeding & bruises, strains & scalds. Image taken from http://en.wikipedia.org/wiki/File:Calendula_officinalis.jpg

Witch hazel (Hammamelis virginiana) (bark & leaves) I can remember my mum dabbing “magic” distilled witch hazel on bumps and bruises when my brother & I were kids. Ann McIntyre writes that its primary use is as an astringent, which make it a good remedy for both internal & external bleeding. It is a common remedy for burns, bruises, insect bites and skin inflammation. I have also seen it indicated for varicose veins and broken capillaries.

Solomon’s seal (polygonatum multiflorum) (root) according to Culpeper “dispels congealed blood that comes of blows & bruises.” In Culpeper modern uses it states that, as well as use on bruises, the root is used as a decoction as an effective treatment for piles and that taken internally it can relieve neuralgia

I have also found references to the helpful properties of common knapweed (centaurea scabiosa) and sweet marjoram (origanum majorana) when it comes to treating bruises & sprains.

AND FINALLY....
Herbal Terminology
The first three terms to learn are:

Astringent = Produces a contraction of organic tissue and/ or reduces secretions and discharges
Bitter = Herb that increases digestion and stimulates appetite
Expectorant = Promotes expulsion of mucous from the respiratory tract