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ETHICS MIDTERM KANT'S MORALITY AND FREEDOM According to Kantian Philosophy, FREEDOM is a concept which involved in the moral domain. Kantian Freedom is closely linked to the notion of autonomy meaning "law itself; thus freedom falls obedience to a law that I created myself" "To act freely is to act autonomously. To act autonomously is to actc according to a law I give myself. When I act according to the laws of the natute, demands of social convention, when I pursue pleasure and comfort, I am not acting freely. To act freely is not tocsimply choose a means to a given end.To act freely is to choosecthe end itself, for its own sake." KANTIAN NOTION OF FREEDOM Contrasts of Kant's Notion of Moral Law 1. DUTY vs INCLINATION (morality) only the motive of duty, acting according to the law I give myself confers moral worth to an action. Any other motive, while possibly commendable, cannot give and an action moral worth Scenario 1: Duty vs Inclination A nurse, Maria, is working in a hospital She Is assigned to care for a difficult patient, Mr. Johnson, who is known for being rude and demanding. Maria feels a strong inclination to ignore Mr. Johnson's requests and provide minimal care due to his behavior. However, according to her duty as a nurse, Maria knows she must provide the same level of care to all patients regardless of their behavior. Scenario 2: Duty and inclination in accordance to Emmanuel Kant's Morality Sara, a Muslim American nurse, is working in a hospital where there is a shortage of staff. One day, she finds out that her colleague, Lisa, a Hindu Indian nurse, made a medication error that harmed a patient. Sara knows that according to her duty as a nurse, she should report the error to the authorities. However, Sara also feels a strong inclination to protect Lisa, as they are good friends, and she fears that reporting the error may harm Lisa's career. Scenario 3: Nurse Johnson is assigned to administer medication to patients in a hospital. One day, while on duty, she notices that one of her patients is in severe pain and requires immediate attention. However, Nurse Johnson is feeling exhausted and overwhelmed due to working long hours without a break. Despite knowing her duty to provide timely care to the patient, Nurse Johnson decides to take a break and relax for a while, prioritizing her inclination to rest over her duty to attend to the patient's needs. 2. AUTONOMY vs HETERONOMY (freedom) I am only free when my will is determined autonomously, governed by the law I give myself Being Scenario 1: Autonomy vs. Heteronomy Sarah, a high school student, is given the freedom to choose her extracurricular activities. She decides to join the debate club because she enjoys public speaking and critical thinking. Her parents support her decision but let her make the choice independently. Sarah feels empowered and motivated by her ability to make her own decisions In contrast, Sarah's friend Emily is pressured by her parents to join the school choir despite not having much interest in singing. Her parents believe that being part of the choir will improve Emily's confidence and social skills. Emily feels obligated to obey her parents' wishes, even though she would prefer to explore other activities. Scenario 2 David, a college student, is faced with a difficult decides on about whether to cheat on an upcoming exam. Despite feeling overwhelmed by the pressure to perform well, David chooses not to cheat because he believes it is morally wrong. On the other hand, David's classmate, Tom, decides to cheat on the exam after being persuaded by his friends who argue that everyone else is doing it and that the consequences are minimal. 3. Categorical vs Hypothetical Imperatives (reason) Kant acknowledges two ways in which reason can command the will, two imperatives. Hypothetical Imperatives uses instrumental reason: " If i want X, I must do Y" Hypothetical Imperatives is always conditional. Categorical Imperatives is non-conditional. Situation 1 [categorical] A student wants to pass their exam. If the student wants to pass the exam, they must study diligently Scenario 2 [hypothetical] A person wants to lose weight. If the person wants to lose weight, they must exercise regularly and eat healthily. Scenario 3 [categorical] A nurse encounters a patient in the hospital who requires immediate medical attention. However, the nurse is unsure if she should assist the patient because it is her break time, and she wants to relax. Scenario 4 [ categorical] A nurse is assigned to administer medication to a patient However, the nurse mistakenly believes that she can skip certain safety protocols to save time. ROLE OF FREEDOM IN MORALITY Morality refers to the cultivation of virtue Virtue: the development of character traits so that choosing the good becomes the matter of habit But in order to be truly Virtues, a person must be set free to cultivate such virtue, or not. FREEDOM: THE FOUNDATION OF MORAL ACT Freedom is humans' greates quality, a reflection of our creator. The power rooted in: Reason and Will To Act or Not To Act To Do This or That To Perform Out of Responsibility Good and Evil are forged out from freedom. And that as a person reaches a higher level of freedom, he becomes more capable of higher levels of morality. However, the sinful person becomes a slave. The concept of Freedom is a central premise in Religious Morality, and Secular Culture greatly exalts freedom. FREEDOM AND FREE WILL Freedom is rooted in "reason and will", "to act or not to act", "to do this or that", and to perform deliberate actions on one's own responsibility is a premise in religious morality (i.e. Catholics). Since our secular culture greatly exalts freedom. Freewill "the power of acting without of the constraint necessity or fate" -Oxford Dictionary "the notional capacity or ability to choose between different possible courses of action unimpeded. Free will is closely linked to the concepts of moral responsibility, praise, culpability, sin, and other judgements which apply only to actions that are freely chosen." -Philosophical notion FREEDOM FREEWILL Refers to the ability to act according to one’s own will, without coercion or constraint. Often associated with external circumstances, such as legal rights or societal norms Can be limited by external factors, such as laws, regulations, or societal expectations. Implies, the absence of external restrictions on one’s actions Refers to the philosophical concept that individuals have the ability to choose their actions freely. Often associated with internal mental states, such as intentions, desires, and beliefs. Implies the ability to make choice that are not determined by external factors alone. Raises questions about determinism, the idea that all events, including human actions, are ultimately determined by causes to external to the will Reason and Will Difference Similarity Reason -the ability to think, understand, and form judgement based on logic -is often associated with intellect and rationality -more objective and impartial -faculty of the mind - Both involve conscious process and can be influenced by various factors - Both play a role in decision-making and guiding behavior Will -ability to make conscious choices -desire and motivation -more of an intentional process -influenced by emotions and desires Faculty of the soul/spirit -Both are considered important aspects of human nature in many philosophical and psychological theories FREEWILL AGAINST ALL ODDS "if man has freewill, then are we truly free?" Freewill in Philosophy VS Freewill in the Scientific Notion Freedom, Freewill and Chaos Freewill in the Scientific Notion Chaos Theory (Physics and Quantum Mechanics) interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to have completely random states of disorder and irregularities. Chaos Theory (Psychology) is a theory that explains events that seem unforeseeable and erratic on their surface but are controlled by deterministic explanations. The chaos theory definition is applied to nonlinear systems that are significantly impacted by the circumstances of their starting position. The theory explains that extremely small changes in the initial circumstances of a situation can result in extreme differences later on. Chaos Theory (Leyman's) describes the qualities of the point at which stability moves to instability or order moves to disorder. CHAOS THEORY: Butterfly Effect "one small occurrence can influence a much larger complex system" evokes the idea that a small butterfly flapping its wings could, hypothetically, cause a typhoon. Or it could not - the mind-boggling part of the butterfly effect is that it's virtually impossible to predict whether a small system will lead to chaotic behavior ETHICAL THEORIES I. Consequentalism Il. Moral Subjectivism III. Ethnocentricism IV. Social Contract Theory V. Feminist Ethics VI. Situation Ethics Vil.Divine Command Theory VIII. Natural Law Theory IX. Rawl's Theory of Justice X. Ethical Nursing Theories REASON AND IMPARTIALITY Reason and Impartiality are not absolute to a particular group of people, while Morality is absolute. REASON the capacity for consciously making sense of things, establishing and verifying facts, applying logic, changing or justifying practices, intitutions, and beliefs bassed on new or existing information (Kompridis, 2000) CONSEQUENTIALISM: Only the consequenecs, or outcomes, of actions matter morally. Acts are deemed to be morally right (or wrong) solely on the basis of their consequeces. e.g.: Lying (considered wrong) Consequentialism: "If lying is may help save a person's life, then lying is deemed to be the right thing to do." theoretical flaw: difficult; no one can predict the future; objectionable Principles of Consequentialism 1. Whether an act is right or wrong depends only on the results of that act; 2. The better consequences an act produces, the better or more right that act. MORAL SUBJECTIVISM Right and Wrong is determined by what YOU, the subject just happens to think or "FEEL" is right or wrong Theories under Moral Subjectivism A. Simple Subjectivism B. Individualist Subjectivism C. Moral Relativism D. Ideal Observer E. Ethical Egoism F. Utilitarianism G. Teleotonlogy H. Deontology I. Virtue Ethics A. Simple Subjectivism view that ethical statements reflect sentiments, personal preferences and feelings rather than objective facts B. Individual Subjectivism Individualist, a view put forward by Protagoras, saying that "there are as many distinct scales of good and evil as there are individuals in the world." Egoism, maintains that every human being ought to pursue what is in his or her self-interest inclusively. C. Moral Relativism or Ethical Relativism, view that "for a thing to be right, it must be approved by society", leading to the conclusion of different things are right for people in the different societies and different time periods D. Ideal Observer view that 'what is right is determined by the attidtudes that a hypothetical ideal observer"(a being who is perfectly rational, imaginative, and informed) E. Ethical Egoism Right and wrong is determined by what is in your self-interest. Or is it immoral to act contrary to your self-interest based on Psychological Egoism, that WE by nature, act selfishly. Egocentricism and Sociocentrism E1. Egocentricism -the common tendency to consider one's personal opinion. - "an egocentric thinker thinks or does not recognized or even entertain any other opinion; thinks that their opinion alone matters, and all other opinions fare less compared to his own" E2. Sociocentrism - when an entire community (not just an individual) or social group imposes its own worldview and thinks of it as an unquestionable. e.g Religious groups (Islam, Christians, and Jewish) Political Factions Postcolonial Mentality F. Utilitarianism a theory that holds that the best way to make moral decision is to look at the potential consequences of each available choices, then pick the option that either does most to increase happiness or does to increase suffering. G. Teleontology refers to the philosophical study of the nature and essence of teleology, which is the study of purpose or goal-directedness in nature. can be understood as the study of the purpose or ultimate goals behind things, particularly in the context of healthcare and nursing. It involves examining why certain healthcare practices are carried out and what they aim to achieve for the well-being of patients. H. Deleontology or Deontological Ethics is an approach that focuses on the rightness or wrongness of actions themselves, as opposed to the rightness or wrongness of the consequence of those actions I. Virtue Ethics is an excellent trait of character. Is a disposition, well entrenched in its possessor. emphasizes an individual's character as the key element of ethical element of ethical thinking. States that only good people can make good moral decision. Therefore, the best way to be moral is to constantly seek to improve oneself. Virtue ethics encourages nurses to embody virtues like empathy and kindness, which guide their actions and decisions Examples Compassionate Care: A nurse provides emotional support and comfort to a grieving family, demonstrating empathy and compassion. Honest Communication: A nurse is truthful and transparent in communication with patients and families, reflecting honesty as a virtue. Advocacy: A nurse advocates for a patient's needs, showing fairness and a commitment to justice. I1. Eudaimonism holds that the proper goal of human life is eudamonia (which can be variously translated as "happiness") and that this goal can be achieved by a lifetime of practicing arête (the virtues), in one's everyday activities, subject to the exercise of phronesis (practical wisdom) or dilemmas which might aruse. I2. Ethics of Care developed by Annette Baier (1987), is focused upon feminine mentality,wherein it is to exemplified by women such as: taking care of others, patience, ability to nurture, and self sacrifice, etc. I3. The Theory of Natural believe that every person is endowed with certain inalienable rights, such as right to life, right to property, right to liberty. Kant's Good Will and Sense of Duty to act out of sense of moral "obligation" or "duty" ETHNOCENTRISM -is the belief in the inherent superiority of one's own ethnic group or culture. It involves judging other cultures based on the standards and values of one's own culture, often leading to a biased perspective where one's own culture is seen as the "norm" or the standard by which all other cultures are measured. Ethnocentrism can result in prejudice, discrimination, and misunderstanding towards other cultures. Implications for Nursing Practice Cultural Imposition: Nurses may unintentionally impose their own cultural beliefs on patients, which can lead to misunderstandings and conflicts. For example, a nurse might assume that a patient's reluctance to accept a particular treatment is due to ignorance rather than cultural beliefs Barriers to Communication: Ethnocentrism can create barriers in communication between nurses and patients. When nurses view their cultural norms as superior, they may struggle to understand the perspectives of patients from different backgrounds, leading to ineffective communication and reduced trust. Impact on Patient Compliance: Patients who perceive that their cultural beliefs are not respected may be less likely to comply with medical advice or treatment plans. This non-compliance can result in poorer health outcomes and increased healthcare disparities among ethnocultural groups IV. SOCIAL CONTRACT THEORY posits that moral obligations arise from agreements among individuals in society. It suggests that ethical rules are those that rational individuals would agree to for mutual benefit. Application in Nursing in nursing, social contract theory can inform professional codes of conduct and ethical standards that nurses agree to uphold. Examples Professional Codes: Nurses adhere to professional codes that outline ethical responsibilities, such as respecting patient rights and maintaining professional boundaries. Teamwork: Nurses work collaboratively with other healthcare professionals based on agreed-upon roles and responsibilities. Patient Rights: Nurses respect and advocate for patient rights such as the right to refuse treatment, as part of their professional obligations. V. FEMINIST ETHICS a complex set of interrelated perspectives that emphasize interpersonal concerns such as caring, interdependence, and the ethical requirements of particular relationships. Such concerns are traditionally identified with women, but Feminist Ethics should not be thought of as a theory only for women. Feminist ethics can guide care that prioritizes empathy, nurturing, and the well-being of patients and their families. Examples Holistic Care: Nurses provide care that considers the emotional and social needs of patients, not just their physical health. Supportive Relationships: Nurses foster supportive relationships with patients and their families, emphasizing care and empathy Advocacy for Vulnerable Groups: Nurses advocate for the rights and needs of vulnerable patient groups, reflecting a commitment to social justice. VI. SITUATION ETHICS argues that ethical decisions should be made based on the unique circumstances of each situation, rather than adhering to fixed rules. Sițuation ethics can guide decisions that require flexibility and adaptation to individual patient needs. Examples: Emergency Situations: In emergency situations, nurses mayneed to act quickly without following standard protocols, prioritizing immediate patient needs. Cultural Sensitivity: Nurses adapt care practices to respect the cultural beliefs and values of diverse patients. End-of-Life Care: Nurses make decisions about end-of-life care based on the specific needs and wishes of the patient and their family. VII. DIVINE COMMAND THEORY (DCT) is a metaethical theory that posits that moral values and obligations are grounded in the commands of God. According to this theory, actions are morally right if they align with God's commands and morally wrong if they contradict them. This perspective asserts that morality is not based on human reasoning or societal norms but is derived from divine authority. Is higher than human act Key Features of DCT 1.God's Sovereignty: DCT emphasizes that God's will is the ultimate foundation for all moral principles. What God commands is inherently good, while what He forbids is inherently bad. 2. Objective Moral Standards: The theory asserts that moral truths exist independently of human opinions or cultural contexts. These truths are rooted in divine commands. 3. Moral Simplicity: Actions can be categorized as right or wrong based on their alignment with God's commands, making moral decision-making straightforward according to this framework. 4. Religious Texts as Guidance: Ethical guidance is derived from sacred texts, such as the Bible or the Qur'an, which provide the commandments and principles that followers are expected to uphold. 5. Absolute Moral Laws: Since God's commands are seen as unchanging, the moral laws derived from them are also considered fixed and universal. 6. Limitations on Autonomy: Adherents to DCT may find their personal freedoms constrained by divine dictates, emphasizing obedience to religious laws over individual preferences. Applications of DCT in Nursing: Guiding Ethical Decisions Nurses who subscribe to DCT may use their understanding of divine commands to guide their ethical decisions in clinical settings

BASIC STRUCTURE AND PROMINENT FUNCTIONS OF VERTEBRATE INTEGUMENT INTRODUCTION The integument or the outer cover of the body is commonly referred to as the skin. Together with its derivatives it makes up the integumentary system. It is continuous with the mucous membrane lining the mouth, eyelids, nostrils, rectum and the openings of the urino-genital ducts. The skin functions primarily to cover and protect the tissues lying beneath it. In other words, it forms the external protective covering of an animal. Forms interface between organism and external environment. Part that the predator sees first, and which offers the first line of defense. Abundantly supplied with sensory nerve endings, which are affected by environmental stimuli and play an important role in communication. General metabolism of the body, temperature regulation and water loss. Character of the skin and its derivatives shows variation in different regions of the body, in different individuals, in the same individual as age advances and in different groups of vertebrates. The type of environment whether aquatic or terrestrial is of importance in connection with these variations. The evolution of vertebrate integument is correlated with the transition of vertebrates from an aquatic to a terrestrial environment. Nevertheless, basic similarities exist in the integument of all vertebrates. INTEGUMENT PROPER In Annelids, Arthropods, integument consists of single layer of cells, the EPIDERMIS, together with an outer non-cellular CUTICLE, secreted by the cells. Annelids have a body covered with an external thin collagenous cuticle (never shed or molted). In Arthropods, the chitinous and rigid cuticle makes up the exoskeleton. Periodic shedding of this cuticle is termed Ecdysis. THE VERTEBRATE SKIN DIFFERS FROM INVERTEBRATE SKIN TWO LAYERS – Outer epidermis derived from ectoderm Inner dermis or corium of mesodermal origin. The relative amount of the two layers varies with the environment. EPIDERMIS – the epidermis is made of stratified epithelium (several layers of columnar epithelium cells). These cells are held together tightly by minute intercellular bridges found on the surface of cells. The innermost layer is stratum Malpighii or stratum germinativum placed over a thin basement membrane. These cells divide constantly to produce new cells. Move upwards, tend to become flattened, protoplasm becomes horny (keratinisation). In fishes and amphibians, this keratinised layer forms a cuticle, but in amniotes, it forms stratum corneum, of hard, horny, flat, cornified cells made largely of keratin, which is tough, waterproof and insoluble protein. It affords protection against mechanical injuries, fungal and bacterial attacks and prevents desiccation. In many Tetrapoda, this layer is shed periodically in pieces or all at once. No stratum corneum in cyclostomes and fishes (since they are fully aquatic) here the epidermis has mucous glands, secreting mucus to keep the skin slimy and protects it from bacteria. The epidermis has no blood vessels and is nourished by capillaries in the dermis. The epidermis rests on a thin basement membrane which separates it from the dermis Dermis has an outer loose layer and inner dense layer Made up of dense connective tissue having cells, muscles, blood vessels, lymph vessels, collagen and elastic fibres, and nerves. Amphibians and reptiles -collagen fibres at right angles in three planes Birds and mammals, they have an irregular arrangement. Substances pass by diffusion from the dermis to the epidermis. Skin contains pigment, if present in epidermis, it occurs as a diffuse substance or as granules. If in dermis, then in the form of granules in special branching cells called chromatophores. The pigment can either collect as a central ball making the skin lighter or spread out into all the branches making the skin darker, thus, chromatophores bring about colour variations. Chromatophores are of many kinds, Melanophores that contain brown to black pigment Lipophores or xanthophores which contain yellow red fatty pigments Iridocytes or guanophores contain crystals of guanine which reflect light. Under dermis, the skin has subcutaneous loose areolar tissue which separates the skin from the underlying muscles, it may contain fat and muscles, especially in mammals. Integument of Anamnia shows a decrease in thickness and also a decrease in the degree of ossification. These are of advantage in allowing greater mobility and in amphibians, they permit respiration by the skin. But in Amniota, the skin becomes progressively thicker to prevent loss of water and to retain body heat. STRUCTURE OF INTEGUMENT IN CYCLOSTOMATA Epidermis is multi-layered (stratified) but has no keratin. It has three types of unicellular gland cells: mucus glands (secrete mucus), club cells (scab-forming cells) and granular cells (unknown function). Below epidermis is the cutis formed of collagen and elastin fibres. Star- shaped pigment cells are also present in the cutis. STRUCTURE OF INTEGUMENT IN PISCES The epidermis has several layers of simple and thin cells, but there is no dead stratum corneum. The outermost cells are nucleated and living. The stratum Malpighii replenishes the outer layers of cells which have some keratin. Unicellular goblet or mucous gland cells are found in the epidermis, as in all aquatic animals. The mucous makes the skin slimy reducing friction between the body surface and water, protects the skin from bacteria and fungi and assists in the control of osmosis. Multicellular epidermal glands like poison glands and light producing organs may also be found. The epidermis rests on a delicate basement membrane. The dermis contains connective tissue, smooth muscles, blood vessels, nerves, lymph vessels and collagen fibres. The connective tissue fibres are generally not arranged at right angles but run parallel to the surface. Scales are embedded in the dermis and projected above the epidermal surface. The colours of fishes are due to chromatophores and iridocytes. STRUCTURE OF INTEGUMENT IN AMPHIBIA: The epidermis has several layers of cells, six to eight cells in thickness and is divisible into three layers: stratum corneum, stratum germinativum and a basal portion in contact with the basement membrane. The outermost layer is a stratum corneum, made of flattened, highly keratinised cells. Such a dead layer appears first in amphibians and is best formed in those which spend a considerable time on land. The stratum corneum is an adaptation to terrestrial life (protects body and prevents excessive loss of moisture). In ecdysis, stratum corneum is cast off in fragments or as a whole in some. (moulting / desquamation i.e., removal of unicellular sheet of stratum corneum). The dermis is relatively thin in amphibians, it is made of two layers - upper loose stratum spongiosum and a lower dense and compact stratum compactum. Connective tissue fibres run both vertically and horizontally. Blood vessels, lymph spaces, glands and nerves are abundant in the stratum spongiosum. There are two kinds of glands, multicellular mucous glands and poison glands in the dermis, but they are derivatives of the epidermis. Mucous gland produces mucus (slimy protective covering, helps in respiration). Amphibian skin is an important organ of respiration. Poison glands produce a mild but unpleasant poison which is protective. In the upper part of the dermis are chromatophores. (melanophores and lipophores) Ability of the skin for changing colour to blend with the environment is well developed. INTEGUMENT IN REPTILIA. The integument is thick and dry, it prevents any loss of water, it has almost no glands. The only glands present are scent glands for sexual activity. The epidermis has a well-developed stratum corneum well adapted to terrestrial life. The horny scales of reptiles are derived from this layer. Ecdysis is necessary to remove dead outer layers, hence scales are shed periodically in fragments or cast in a single slough as in snakes and some lizards Scales often form spines or crests. Below the epidermal scales are dermal bony plates or osteoderms in tortoises, crocodiles and some lizards (Heloderma). The dermis is thick and has an upper layer and a lower layer, upper layer has abundance of chromatophores in snakes and lizards. Lower layer has bundles of connective tissue in which collagen fibres lie at right angles. Leather of high commercial value can be prepared from the skin of many reptiles like lizards, snakes and crocodiles. Many lizards and snakes have elaborate colour patterns, they may be for concealment or as warning colours. There is marked colour change in certain lizards such as chameleon, the colour may change with the environment for concealment or it may change in courtship or threat. The ability of chameleons and some other animals to change colour is known as metachrosis. (metachromatism) In Calotes, chromatophores are controlled by the posterior lobe of pituitary whereas in chameleons they are controlled by the Autonomic Nervous System. INTEGUMENT IN BIRDS Thin, loose, dry and devoid of glands. There is only a uropygial gland at the base of the tail, its oil is used for preening (to clean and tidy its feathers with its beak) and waterproofing the feathers (aquatic birds) Epidermis is delicate except on shanks and feet where it is thick and forms epidermal scales. The rest of the body has a protective covering of epidermal feathers. The keratin producing powers of the epidermis are devoted to producing feathers and scales. The dermis is thin and has interlacing connective tissue fibres, abundant muscle fibres for moving feathers, blood vessels and nerves. The dermis has an upper and lower compact layer, between which is a vascular layer, the dermis also contains fat cells. The skin has no chromatophores. Pigment is found only in feathers and scales. Colour patterns in birds are vivid (concealment, recognition and sexual stimulation) Colours are produced partly by pigments and partly by reflection and refraction from the surface of the feathers. INTEGUMENT IN MAMMALS Skin is elastic and waterproof, much thicker than in other animals, especially the dermis is very thick and is used in making leather. Epidermis is thickest in mammals. Outer stratum corneum containing keratin, cells not dead as believed before. Below this is stratum lucidum (barrier layer), chemical called eleidin Below this stratum granulosum, darkly staining granules of keratohyalin Below this is stratum spinosum whose cells are held together by spiny intercellular bridges. Lastly stratum germinativum which rests on a basement membrane Dermis is best developed in mammals. Upper layer is papillary layer made up of elastic and collagen fibres with capillaries in-between, thrown into folds called dermal papillae, especially in areas of friction Greater lower part of dermis is reticular layer, having elastic and collagen fibres. In both layers there are blood vessels, nerves smooth muscles, certain glands tactile corpuscles and connective tissue fibres in all directions. Below dermis the subcutaneous tissue contains a layer of fat cells forming adipose tissue In the lowest layer of epidermis there are pigment granules, no pigment bearing chromatophores in mammaIs (in man, branching dendritic cells or melanoblasts) FUNCTIONS OF THE INTEGUMENT ▪ PROTECTION ▪ TEMPERATURE CONTROL ▪ FOOD STORAGE ▪ SECRETION ▪ EXCRETION ▪ SENSATION ▪ RESPIRATION ▪ LOCOMOTION ▪ DERMAL ENDOSKELETON ▪ SEXUAL SELECTION 1. Protection: The integument forms a covering of the body and is protective. It protects the body against entry of foreign bodies and against mechanical injuries. It protects the tissues against excessive loss of moisture, this is very important because both aquatic and terrestrial animals are dependent upon water in their bodies for various metabolic activities. The integument forms protective derivatives, such as scales, bony plates, layer of fat, feathers and hair which reduce the effect of injurious contacts. In some animals the skin shows protective colouration which makes the animals resemble their environment, thus, making them almost invisible to their enemies. Poison glands of toads, slippery skin of aquatic animals and an armour of spines of some mammals are protective devices of the integument. The skin forms a covering which prevents the passage of water and solutes in one of the following ways: (a) By formation of cuticle in Protochordata and embryos of fishes and amphibians, (b) By secreting a coat of mucus in fishes and aquatic amphibians, and (c) By formation of keratin layers in the epidermis of tetrapoda. Keratin is formed from the cytoplasm of degenerating cells of the epidermis which finally form a layer of horny stratum corneum. 2. Temperature Control: Heat is produced constantly by oxidation of food stuffs in tissues. This heat is distributed evenly by the circulating blood. The body heat is lost constantly with expired breath, with faeces and urine, and from the surface of the skin. The integument regulates heat and maintains a constant temperature in endothermal animals. In birds the heat is regulated by adjustment of feathers which retain a warm blanket of air, when feathers are held close to the body, they remove warm air and body cooled, when feathers are fluffed out, they keep the warm air enclosed. In mammals, constant evaporation of sweat regulates the body heat. In cold weather contraction of skin’s blood capillaries reduces the loss of body heat. In some animals, fat in the skin prevents loss of heat because it is a non-conductor of heat. 3. Food Storage: The skin stores fat in its layers as reserve food material which is used for nourishment in times of need. In whales and seals the fat of the skin forms a thick layer, called blubber which is not only reserve food but also maintains the body temperature. 4. Secretion: The skin acts as an organ of secretion. Glands of the skin are secretory. In aquatic forms there are secretory mucous glands whose secretions keep the skin moist and slippery. In mammals, sebaceous glands secrete oil which lubricates the skin and hairs. Mammary glands produce milk for nourishment of the young. In birds uropygial glands secrete oil for preening the feathers. Odours of scent glands attract the opposite sex. Lacrymal glands’ secretion wash the conjunctiva of eyeball in mammals. Ear wax (cerumen) secreted by the glands of auditory meatus greases the eardrums and avoids insects to enter the canal. 5. Excretion: The integument acts as an organ of excretion. Shedding of the corneal layer during ecdysis removes some waste substances. In mammals metabolic waste (salts, urea and water) is removed from the blood by means of sweat. Chloride secreting cells are found in gills of marine fishes. 6. Sensation: The skin is an important sense organ because it has various kinds of tactile cells and corpuscles which are sensory to touch, temperature changes, heat, cold, pressure and pain. 7. Respiration: In amphibians, the moist skin acts as an organ of respiration, in frogs the respiratory function of the skin is greater than that of the lungs. 8. Locomotion: Derivatives of the integument bring about locomotion in some animals, such as the fins of fishes aid in locomotion in water, the web of skin in the feet of frogs and aquatic birds aid in swimming, feathers of the wings and tail of birds are used for flying, and extensions of the integument forming “wings” of flying lizards, extinct pterodactyls, flying squirrels and bats. 9. Dermal Endoskeleton: The skin contributes to the endoskeleton. It forms the dermal bones of vertebrates and also forms parts of the teeth. Endoskeleton of head protects the brain and sense organs. In the body it protects the soft, tender viscera. 10. Sexual Selection: The skin acts as an organ of sexual selection. It provides the feathers of birds which often have brilliant colours which are for sexual attraction. Some integumentary glands of mammals produce odours far attracting the opposite sex. Antlers of male deer distinguish it from female. Besides the above functions, mammalian skin synthesizes the vitamin D with the help of Sebum of sebaceous glands. Brood pouches beneath skin in some fishes and amphibians protect unhatched eggs. Nasal glands of tetrapods, keep the nostrils free of dirt and water. Skin also has the power of absorption of oils, ointments, etc

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