Human Anatomy: A History of Studying the Human Body PDF

HELP!!! MEDS1002 How to learn Essentials ofanatomy Human Anatomy Sarah Croker History of studying anatomy Lecturer, School of Medical Sciences, University of Sydney COMMONWEALTH OF AUSTRALIA...

HELP!!! MEDS1002 How to learn Essentials ofanatomy Human Anatomy Sarah Croker History of studying anatomy Lecturer, School of Medical Sciences, University of Sydney COMMONWEALTH OF AUSTRALIA Copyright Regulation WARNING Sarah Croker This material has been reproduced and communicated to you by or on behalf of the University of Sydney Lecturer, School of Medical Sciences pursuant to Part VB of the Copyright Act 1968 (the TEQSA PRV12057 Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. CRICOS 00026A Do not remove this notice The University of Sydney Page 2 We recognise and pay respect to the Elders and communities – past, present, and emerging – of the lands that the University of Sydney's campuses stand on. For thousands of years they have shared and exchanged knowledges across innumerable generations for the benefit of all. Early anatomy scholars Claudius Galen - Roman physician (born in Greece), lived around 129 to 216 CE - Had very theoretical training, common at the time. Very widely read in philosophy, religion, mathematics, grammar. - Extremely prolific writer with more than 130 works in medicine alone; this formed the foundation of medical knowledge for well over 1000 years. - Dissection of human bodies was considered taboo, therefore Galen dissected animals (often Barbary macaques). - Consequently had some misunderstandings about human anatomy. - Quite a lot was fairly accurate (his identification and description of around 300 muscles are still mostly used today). The University of Sydney https://en.wikipedia.org/wiki/Galen#/media/File:Galenus.jpg The first anatomy theatre The University of Bologna - This university officially approved human dissection in 1405 CE - Professor would sit on elevated chair; Reader would read instructions (usually from Galen); Lecturers and Demonstrators would carry out the dissection. - Influenced the design of university theatres everywhere. The University of Sydney https://www.globonaut.eu/inside-oldest-anatomical-theatres-in-the-world/ Early anatomy scholars Andreas Vesalius - Born Andries van Wezel in Belgium, lived 1514 to 1564. - Was a great believer in carrying out dissections himself as a teacher, and also distributed pictures to his students. - He believed knowledge was gained by observing and experimenting, not merely learning the texts that were already published. - His great work was De Humani Corporis Fabrica (On the Fabric of https://en.wikipedia.org/wiki/Andreas_Vesalius the Human Body) published in 1543. #/media/File:Vesalius_Fabrica_portrait.jpg - Led to a blossoming of anatomy research and teaching in Europe. The University of Sydney  De Humani Corporis Fabrica - Vesalius - 273 illustrations, with text. https://nyamcenterforhistory.org/2014/10/30/brains-brawn-beauty- andreas-vesalius-and-the-art-of-anatomy/#jp-carousel-4700 The University of Sydney A move towards more hands-on learning - During the Renaissance period, observation of dissection was the main teaching strategy. - Gradually, students carrying out the dissection, individually or in small groups, came to be the favoured model of learning. - However this lead to a very high demand for bodies to dissect… The University of Sydney https://www.sciencephoto.com/media/776444/view/ anatomy-class-dissection-female-medical-students The demand for bodies - Bodies were sent to medical school to be used for dissection in the teaching of anatomy from a range of society’s classes who had no say in the matter: - Executed criminals - Political prisoners - Poor people who died in workhouses - People who couldn’t afford a funeral - Some anatomy schools that were part of hospitals used their own patients (this could be in exchange for treatment while still living). The University of Sydney The demand for bodies - The demand for bodies to dissect for teaching was so high that it encouraged unethical behaviour and criminal activities. - Freshly buried people were taken from their graves and sold to medical schools. - Consequently, the industry of protecting the graves of newly-buried people (through cages, bars, and even security guards) was born. The University of Sydney https://www.theirishplace.com/heritage/ matter-grave-body-snatching-ireland/ The demand for bodies - For some people, even waiting until people were buried to take their bodies was not enough…. - William Burke and William Hare lived in Edinburgh, and in 1828 discovered that they could make a profit by murdering people and selling their bodies to a professor at the university medical school. They did this 16 times. - Hare was convinced to turn in Burke in exchange for immunity. Burke was tried and hung… and publicly dissected. The University of Sydney https://en.wikipedia.org/wiki/Burke_and_Hare_murders The demand for bodies - Public were so disgusted that this led to reforms such as the Anatomy Act of 1832 in the UK, making grave-robbing a greater crime. (Rebekah will speak about some of this next week when she discusses body donation). - Education practices have altered somewhat to make better use of bodies for dissection. In many cases dissection is not used, but prosection and other supplementary methods are used instead. - However there are still places in the world today where the bodies of criminals and other disenfranchised peoples are used…I will touch on this in my lecture next week. The University of Sydney Unethical use of human bodies during the Nazi era - Some of the many crimes against humanity committed by the Nazi regime included crimes against the bodies of those were killed as political prisoners and in death camps. - Regarding anatomy, dissections were carried out. - From these, a large number of medical illustrations were made, comprising textbooks – particularly the Pernkopf atlas, Atlas of Topographic and Applied Human Anatomy. Some derivations of these are still in use today (e.g. the atlas by Sobotta uses images from Pernkopf). - This highlights the importance of gaining specific consent from people who donate their bodies, so that they know how their bodies will be used after their death. The University of Sydney The trade in skeletons - Until a few decades ago, it was expected of medical students that they would have their own “half-skeleton” (sometimes full) to study from. - These were real human bones. Where did they all come from? - India was a source of much of the world’s teaching skeletons, especially around Kolkata. - Until the ban on this trade in 1985, as many as 60 000 skeletons a year were being exported. - These skeletons are now found throughout the world in anatomical and medical teaching institutions. - It is therefore important to respect these bones and care for them. Discussions continue globally about the best steps forward. The University of Sydney The trade in skeletons - Under present day rules, it is illegal to trade in human remains in Australia. - It does happen in the other places around the world (e.g. USA). The University of Sydney Studying anatomy now - In the current times, we are much more conscious of our ethical responsibilities, and our respect for those whose bodies we study. - But modern technologies and changing ways of teaching bring their own challenges to consider when dealing with the sensitive subject of learning from human bodies. The University of Sydney Modern representations of human body donors Images – We can now share images very very easily, faster and to a wider audience than at any point in history. - Is this what our body donors would have wanted? - What about their families? 3D printing - This is an accurate representation of the body of a person. - Is this what our body donors would have wanted? The University of Sydney Body donation in Australia & New Zealand 19 < 50 / ~1500 Body -donor programs Most receive fewer than 50 - Each year approximately bodies per year. - (17 in Australia). - = 1500 bodies are used in - All are embedded in - Central programs receive up - total across both countries. - Universities. to 150 per year. bodies - Most bodies are Most are over-subscribed & embalmed. - NZ has one on each Island. - - have reduced their - Some States (Vic, Tas, WA, SA) Increasing use of frozen - have central mortuary which acceptance - area to between bodies, especially for - 10 and 50km. - receive all bodies. - - surgical training, medical - Others have multiple programs Oldest - programs have donor device training & testing, - NSW (8), Qld (4). registers with over 3000 continuing education. - - - donors. - The University of Sydney Body donation in Australia & New Zealand 4-8 16-100 > 10K I Each jurisdiction has a NZ has a minimum age of Students, anatomists & researchers learn - - statutory retention period 16 for body donation; in which ranges from 4 – 8 Australia it is 18. and benefit from the - - - - years. - Youngest donor recorded donated bodies each - - Most bodies are retained - was 23. Centenarians are - year. - for up - to two years or in increasingly common. perpetuity. - Most donors are aged >60 D Most donors consent to when they register. - - indefinite retention. Many couples and family - members donate, including intergenerational. The University of Sydney Body donation is well supported by the community in Australia & New Zealand. Donors and their families are treated respectfully and recognised in ceremonies and memorials. The University of Sydney Where do the bodies come from in other countries? What are the most common origins of bodies used in anatomy laboratories internationally? - Consenting donors 3 - Paid “donation” by educational/research institutions 7 - Purchased from third parties – eg body brokers 7 - Unclaimed bodies 2 - Bodies of prisoners J - Imported from other countries? 3 The University of Sydney Habicht et al. 2018 Academic Medicine: 93 (9): 1293–1300 ThisTheversion was released by IFAA on 22 August 2022 University of Sydney Reasons: - Lack of enabling legislation - Religious or cultural beliefs - Financial reasons - Lack of appropriate infrastructure and expertise - Absence of advocates driving change - Insufficient number of bodies to meet needs The University of Sydney Why does it matter? The University of Sydney “There are several ethical concerns associated with the use of unclaimed bodies in medical education. The first, most general concern is lack of informed consent. Compounding this, by definition, unclaimed bodies come from vulnerable populations of people: functionally, those who are poor and/or have little-to-no social capital.” Timeline 1977 new 1883 1901 New 1920 1949 Donor 1963 All Anatomy Act; 1st UG Anatomy New Program consenting 1985 Human program Act Dean introduced donors Tissue Act The University of Sydney Anatomy Act 1881 (NSW) - Modelled on British Anatomy Act of 1832 - Enabled procurement of unclaimed bodies from public institutions - Public institutions were not defined but excluded gaols - Limited anatomical examination by issuing licenses - Established framework for reporting and regulation - Included capacity for consented donors - Contained the first “decency” clause The University of Sydney Public Institutions - Hospitals, e.g. Sydney Hospital, The Coast Hospital - Public Asylums, e.g. Rookwood & Liverpool Asylums - ”Lunatic” Asylums, e.g. Callan Park & Gladesville Asylums - Morgues - Waterfall Sanitorium The University of Sydney Public Asylums - Established very early via charitable institutions (e.g.Benevolent) - Recognition of the responsibility to infirm and ex-convicts - Demand exceeded capacity - Provided housing, food, work (if fit to do so) in institutional settings - Initially focused on men - Some medical care – improved after 1903 Rookwood Royal Commission - Included: Parramatta, Macquarie St, George St (all in Parramatta); Hyde Park, Rookwood, Liverpool. The University of Sydney Mental Asylums - Also established very early – 1811 Liverpool Lunatic Asylum (closed 1839) - First purpose built was Tarban Creek (Gladesville) in 1825. - Prior to this mentally ill were incarcerated – (e.g. Parramatta Criminal Asylum) - Considerable prejudice towards mentally ill. 1843 Dangerous Lunatics Act - Required certification by two independent medical experts. - Circumstances demonstrating insanity included “ a purpose to commit suicide or a crime” The University of Sydney - “Lunacy” - The 1878 Lunacy Act defined an insane person as: “any person who shall for the time being be idiotic, lunatic or of unsound mind and incapable of managing himself or his affairs and whether found insane by inquisition or otherwise.” Grounds for Insanity could be physical or moral: The University of Sydney  In 1900, according to the Statistical Register of NSW, moral causes of insanity included: “domestic trouble, adverse circumstances, mental anxiety, religious excitement, love affairs and seduction, fright and nervous shock, isolation and nostalgia.” The University of Sydney  And physical causes of insanity included: “intemperance in drink, intemperance (sexual), venereal disease, self-abuse, sun stroke, accident, pregnancy, parturition and puerperal state, lactation, uterine and ovarian disorders, puberty, change of life, fevers, privation and overwork, phthisis, epilepsy, disease of skull or brain, old age, other bodily disorders and chronic ill health, excess of opium, previous attacks, hereditary influence ascertained, congenital defect ascertained, other ascertained causes.” (NSW Statistician’s Office, 1900). The University of Sydney Why might a body be unclaimed ? - lack of family as immigrants or (ex-)convicts - barriers of time & distance for notification of death - language barriers - state of poverty and/or illness - financial situation (cost of care, burial & cost-shifting) - institutional discrimination The University of Sydney The University of Sydney The University of Sydney Who were they? - Between 1883 – 1983 the Medical School received 7609 bodies. - Many were ex-convicts or immigrants, assisted and free. - They ranged in age from 0 to 110. - They were older at death than the NSW population. - Seventy were aged 2 or less. The University of Sydney  0 20 40 60 80 100 120 140 160 180 1883 1885 1887 1889 The University of Sydney 1891 1893 1895 1897 1899 1901 1903 1905 1907 1909 1911 1913 1915 1917 1919 1921 1923 1925 1927 1929 Ma le 1931 1933 1935 Female 1937 1939 1941 1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 Figure 1. Total number of bodies received annually. Male, Female 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983  Where did they die? This varied over time. The University of Sydney  Figure 2. Source of bodies as % of total bodies received 1883 - 1983 Lunatic/Mental Asylums, Public Asylums, Morgue, Babies (age < 2 & stillborn), Private (not on Register but consented), Donor, Missing (white) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 1883 1885 1887 1889 1891 1893 1895 1897 1899 1901 1903 1905 1907 1909 1911 1913 1915 1917 1919 1921 1923 1925 1927 1929 1931 1933 1935 1937 1939 1941 1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 The University of Sydney Morgue Babies Lunatic/Mental Asylums Private Public Asylums Donor Missing What can we learn from this?- - The public were and are willing to support body donation for education and research. - The public including asylum residents understood the importance of anatomy for education, and although individuals may find it unpalatable, the community was, and is supportive. - Accepting body donors comes with responsibilities – to honour the election of the deceased and to respect and accord dignity to their gift and their body. The University of Sydney  Historical and archaeological insights into Australian Aboriginal mortuary practices and repatriation Denise Donlon [email protected] Curator, Shellshear Museum of Physical Grave Posts. Djon Mundine, Bandjalung Anthropology and Comparative Anatomy people, The Aboriginal Memorial.National Gallery Discipline of Anatomy & Histology Australia. School of Medical Sciences Why am I presenting on Australian Aboriginal considerations around death and anatomy? While I am not indigenous to Australia, I have been asked to give this presentation as I am a biological anthropologist and have taught and researched in the area of Aboriginal burials, skeletal remains and repatriation for over 20 years. Biological/physical anthropology - the study of human biological variation and evolution, usually with an emphasis on skeletal remains. In this lecture I will mainly confine my comments to historical and archaeological accounts of ways of Aboriginal ways of dealing with death and burial. I will comment on death and burial in Australia in general but will focus on the Sydney region. I will also discuss the repatriation of Aboriginal skeletal remains to communities. WARNING: I will be showing diagrams of bones and burials but not any images of real human bones.  Historical accounts of death and burials Early observations (18th century) in Sydney by British settlers can inform us about Aboriginal attitudes to death. David Collins (judge, soldier, secretary to governor) came to Sydney on the First Fleet and wrote an account of the first few years of the colony. 'An account of the English colony in New South Wales...' by David Collins, 1798) He observed two main ways of disposing of the dead: 1. Burial 2. Cremation followed by burial. He suggested the type of funeral indicated the deceased's age or status. - Those beyond- middle aged were cremated. - The most common locations were around estuaries, harbours or along the coastline, often in shell middens. Carved trees were often associated with burials. Rituals were associated with the preparation of the corpse and grave goods were sometimes buried with the dead. Ref. Murray, Lisa 2013 Death and dying in nineteenth century Sydney. The Dictionary of Sydney  Mid 20th century accounts – social anthropologists Ronald and Catherine Berndt. Aboriginal death always associated with ritual designed to help the spirit adapt to their changed circumstances. The body may pass from life to the Land of the -- Dead - Some Rituals -The camp in which the person died may be abandoned. -The body may be wrapped in possum coat. -The mourners may scars arms and shoulder Catherine and Ronald Berndt -Taboos: may not speak the name of the dead Worked mainly in Western Australia - Certain foods may not be eaten. and the Northern Territory -Clay caps may be worn by close relatives Berndt and Berndt 1992 - Inquest An inquest is any enquiry into the cause of death Often held to find the person or group responsible for the death. Not necessarily followed by revenge. Inquests may take the form of examination of the ground near the corpse or grave or removal and examination of the viscera. Alternatively, a certain person may see the ‘murderer; in a vision. The behavior of a person may indicate guilt. Berndt, R and Berndt, C. 1992 What can Archaeology tell us about Aboriginal attitudes to death in the past? Research into burials can tell us about mortuary practices and rituals in the past. They can tell us where and how people were buried. The presence of grave goods is particularly powerful. Examination of skeletal remains can inform us about health and disease.  Types of Mortuary practices Burial – common in Sydney Exposure on a platform or tree on on the ground Desiccation or mummification – Torres Straits Cremation – burial followed by burial Bone points ‘muduks’ – south coast NSW Placing in a hollow tree Placed in a coffin or canoe, wrapped in bark – observed in Sydney Secondary ‘burial’ –skeletonized bones and hair - may be carried around as relics or placed in a hollow log or cave or wrapped and reburied - - - - Grave goods – often associated with a burial e.g. bone points, tooth necklaces, spear, possum rug, - dingo bones, shells, fish bones, red or yellow ochre. Necklace of Tasmanian devil canines - - -- from Lake Nitchie, western NSW. - - -  A cremation in Sydney 1798 https://dictionaryofsydney.org/sites/default/files/media/6e074cb0be93709bfa07ce140b861fea195a5826.jpg James Neagle From the collections of the State Library of New South Wales [a1341022 / Q79/60 v. 1, opp. p. 608] (From 'An account of the English colony in New South Wales...' by David Collins, 1798) After the cremation was over the bones and ash were buried and a mound formed on top. Barangaroo (Bennelong’s first wife) was cremated like this. Described by David Collins -  Who were Barangaroo and Bennelong? Barangaroo was an Aboriginal woman - from the area around Manly and a highly skilled fisherwoman. She survived the smallpox epidemic of - 1789’ - She was one of the few women in Sydney who had the knowledge of laws, teaching - - and women’s rituals. - Bennelong was an Aboriginal man from the - Parramatta River area. Bennelong (left) and Barangaroo (right).Natural History Museum He was a mediator and interpreter with the British - and sailed to England with Governor Phillip. He died in 1813 and was buried in James - Squire’s orchard at Kissing Point. A traditional ritual revenge combat was fought, and thirty men - - were - wounded with spears. Ref. Dictionary of Sydney  An Aboriginal funeral 1817 Traditional burials continued in Sydney until the⑤1820s. Later some were buried within = the settlement An Aboriginal Funeral, painted by Joseph Lycett in 1817. The funeral procession, each person painted with traditional white body paint, carry the body. - Burial markers Mounds Bark and wood poles Bora ring. Eromanga Qld Stones – also prevent interference by dingoes/dogs Bora rings Carved trees Grave posts (Melville and Bathurst Islands, NT) An 1820 depiction of three carved trees, a burial in the centre and ‘mourning’ seats to the right. G. H. Evans / National Library of Australia  Sydney Basin study Analysis of burial practices and bones of approx. 200 Aboriginal burials from the Sydney Basin. Includes remains held in museums or reburied. (Donlon 1995) Agent of disturbance Of those that were known, the most common agent of disturbance was building construction, - followed by erosion and accidental digging. Method of Acquisition Most skeletons were acquired by Museums and Universities via the police or NSW Department of Forensic Medicine. Second largest group came from donations from the public The 55 skeletons excavated came from 9 burial grounds (Donlon 1995) Landforms in which remains were found Most found around Port Jackson, Botany Bay, Broken Bay and along the coastline, many in shell middens. (Donlon 1995) Method of burial Inhumation (burial) the most common method. Unlikely that many cremations would be found given the fragmentary nature of the bone (Donlon 1995) Position of the body Many bodies were buried in flexed positions rather than extended on their backs as with European burials. Diagrams by Winifred Mumford - from Aboriginal skeletal remains manual NPWS of NSW.  Antiquity of burials Skeletal remains were determined to be from the pre-European contact period if they showed heavy tooth wear and no dental decay. Findings - Sydney Basin Burials One of the most important findings of this project was the awareness of a loss of information which has resulted from poor recording and reporting of Aboriginal burials. As building construction is the most likely agent of disturbance then the rate at which burials are found is likely to increase. No large burial ground has ever been found in Sydney. Results of this project suggest such a burial ground is most likely in a large sand body near a harbour or bay and near a headland. Excavations of burial grounds suggest a more complex and varied picture of mortuary practices than information obtained from historical records. Repatriation of Aboriginal skeletal remains Repatriation – the taking of people back to their country All the major and many university museums in Australia hold collections of Aboriginal skeletal remains Most have policies to repatriate them. At the University of Sydney, the process is done in conjunction with Indigenous Heritage Officer at Chau Chak Wing Museum. Reports produced - Community report No photos and in plain English - Scientific report Photos, measurements, discussion of biological profile, health, disease and trauma. University of Sydney- Repatriation Policy For well over a century the University has assembled a collection of Aboriginal and Torres Strait Islander Ancestral remains. In considering all matters relating to such remains, the University will be guided by the principle that the rights of the indigenous people are of primary concern. The University has an Advisory Committee, who consult with Aboriginal and Torres Strait communities or organisations regarding the return to appropriate communities and the future management of Ancestral remains held by the University. If requested, the University accepts a responsibility for the on-going curatorial care of the unprovenanced Ancestral remains The University undertakes to treat these remains and items with all due respect and dignity and to maintain an ongoing contact with Aboriginal and Torres Strait Islander communities or organisations regarding the future care or return of such items.  The Shellshear Museum: research and collaboration with Aboriginal people regarding burials and skeletal remains There is a long tradition of study into the history, anatomy and anthropology of Australian Aboriginals. Influential anatomists/physical anthropologists from this department Raymond Dart – human evolution in Africa Joseph Shellshear – human evolution in China N.W.G. Macintosh N.W.G. Macintosh – Australian Aboriginal history, art, the dingo/ Alan Thorne – Aboriginal origins and evolution in South and Australia Physical and forensic anthropology at the University of Sydney today Undergraduate teaching: ANAT2009: Comparative Primate Shellshear Museum of Physical Anthropology Anatomy & Comparative Anatomy, Department of Anatomy & Histology Research -Forensic anthropology of the Sydney region. - Human vs non-human bone - Taphonomy (what happened to the body after death) Repatriation of Aboriginal remains Field work -Salvage of Aboriginal burials -Historic cemeteries analysis -Forensic casework (with Dept Forensic Medicine) --Recovery of war dead (with RAAF) Salvage excavation - Narrabeen Remains found next to a bus stop by electrical tradesman during digging.  Diagram shows the position of top half of the Salvage excavation – skeleton. The lower half had been removed by the Narrabeen Beach electrician. A complete skeleton uncovered in 2005 in a sand dune behind Narrabeen Beach. The Aboriginal community on whose traditional land he was found consented to a salvage excavation as the remains were in danger of being damaged. Dated to approx. 4000 years BP. (oldest burial on NSW coast) A spear point found in his lumbar vertebra Considered a ritual spearing as punishment A young adult man 183 cm tall. These remains are in the custodianship of the Shellshear Museum  Ceremonies around death today Ceremonies around death are extremely important to Indigenous people and take precedence over all other activities. Correct ceremonies should be held, and the whole person must be buried or disposed of (depending on individual communities). When an Indigenous person dies away from the homeland the body will need to be escorted and taken back to the homeland It is culturally appropriate to allow the “smoking” of a room in which a patient has died, even a hospital ward. It is important that all parts of a “body” be sent back: clothes worn at death or worn in hospital are deemed important parts of the person. Such items need to be collected and stored appropriately. Ceremonies and rituals vary throughout Australia, (Maddocks and Rayner 2003) both in the past and today The Skin MEDS1002 Dr. Katie Dixon  Skin structure Basic structure: Epidermis Dermis Hypodermis Accessory structures: Hair Hair follicles Sweat glands Sebaceous glands Nails Frolich, Human Anatomy, Skin  Skin functions Largest organ of the body 15-20% of total body mass Functions: Physical barrier Thermoregulation Sense organ Immunological Vitamin D production Excretion Frolich, Human Anatomy, Skin  Layers of the skin EPIDERMIS Keratin cells thin after DERMIS /hypodems mostly fat HYPODERMIS http://www.lab.anhb.uwa.edu.au/mb140/corepages/integumentary/integum.htm Rodriguez, Nestor et al. (2021) Advances in Polymer Science (Polymer, Vol 286) I Epidermis I The most superficial layer = protective Keratinocytes are the main cell type (~85%) Cells differentiate as they move up the layers of the epidermis until they are eventually exfoliated from the top layer - - -  Thick and thin skin In some places on the body, the epidermis is much thicker “Thick” skin has no hair follicles Soles of feet, palms of hands ↓ Thuskin thick skin Example https://www.foot.expert/post/epidermis Atlas of Dermatology, Dermatopathology and Venereology, Springer Link 2021  Cells of the epidermis Keratinocytes (85%) – barrier, external covering Melanocytes (5%) – pigment-producing cells * S Langerhans’ cells (2-5%) – immune cells Merkel’s cells (6-10%) – sensation epidermis peoply die more Histology: a text and atlas 8th edition 2018. Pawlina (Ch. 15) Dermatomes interest no need A dermatome is an area of skin that is mainly supplied by a single spinal nerve.  Dermis The middle layer = tensile strength and stretch Contains collagen and elastin fibres Contains other structures ; Fair folicule Fingerprint – genetically unique pattern, seen microscopically as undulations - between epidermis and dermis - Usyd slide collection: Yellow 23. Captured by Chad Moore / Sam Dowland Histology: a text and atlas 6th edition 2011. Ross & Pawlina (Ch. 15) I Hypodermis I The bottom layer = subcutaneous - fat, superficialJ fascia “band, door frame” 6Skin Loose connective tissue, adipose tissue function Anchors to underlying structures Histology: a text and atlas 6th edition 2011. Ross & Pawlina (Ch. 15) Energy storage, insulation Variable thickness Skin-associated structures Apocrine sweat gland empties Orbic hair - into hair follicle, &smelly sweat1- armpit Eccrine sweat gland is totally separate, temperature regulation Sebaceous glands secrete sebum hair into hair follicle ingrown Arrector pili muscle contraction >>> sebaceous gland secretion into hair follicle Goosebumps! - > exampl Nails = plates of keratinized cells Nerve endings for sensation Histology: a text and atlas 8th edition 2018. Pawlina (Ch. 15)  Nerve endings in skin Types Pacinian corpuscles: fingertips 2 deeper dermis, hypodermis pressure changes, vibrations Meissner’s corpuscles top of dermis lips, palms light touch - Histology: a text and atlas 8th edition 2018. Pawlina (Ch. 15) Sebaceous glands Produce and secrete sebum Sebum coats hair & skin surface Cells produce sebum & then die! * * Sebum discharged into hair follicle > Sebaceous * gland * ** * Histology: a text and atlas 6th edition 2011. Ross & Pawlina (Ch. 15) Acne Affects more than 90% of Australian adolescents aged 16–18 years. Has a profound impact on self-esteem, mood and psychological status. Moderate-to-severe acne has the potential to cause permanent scarring. How does acne form? Sebaceous -a Accumulation of gland shed dead cells and keratin Excess sebum Q Accumulation of epithelial Accumulation of shed Cutibacterium acnes Marked inflammation production proliferation cells and keratin keratin and sebum Scarring Mild inflammation Bacterial ③ proliferation + inflammation Severe inflammation ④ and scarring Source: The Lancet 379 2012 I Acne ( of waand made bet Vitamin A derivative Causes shrinkage of sebaceous glands Reduces sebum production it's Reduces bacterial cause growth (indirectly) - not antieea Normalises follicle keratinisation that how stop +M terover for Anti-inflammatory ingra Sunburn – ultraviolet radiation types of skin ancer ­Ozone disrupts transmission of λ