Which layer of the epidermis is not found in thin skinstratum lucidumDescribe characteristics of the stratum basale (7)It is a single layer of cells It has Basal cells, which use mitosis to produce new cells that get pushed upward that are called keratinocytes It has merkel cells (tactile cells) that are sensory receptive cells that respond to light touch. It has melanocytes which have melanin pigment for hair and skin color, they provide UV protection The cells of the stratum basale are anchored to the deeper dermis via hemidesmosomes at the basement membrane The ridges in the dermis that meet the stratum basale are referred to as the dermal papillae, which increase the strength of the connection between epidermis and dermisDescribe characteristics of the stratum spinosumIt has 8-10 layers of keratinocytes that are connected via desmosomes (gives the tissue a spiny appearance) In this layer the keratinocytes make keratin There can be langerhans cells or dendritic cells which are immune cells that phagocytize, engulf, pathogens that may enter the epidermisDescribe characteristics of the stratum granulosumIt has 3-5 layers of keratinocytes Keratinocytes produce a lot of keratin and granules that make the layer look dark and grainy The nuclei and other organelles start to disintegrate and cells die because the stratum basale is where the oxygen and nutrients are, so since you're getting farther from it, there's less resources for cells to liveDescribe characteristics of the stratum lucidiumIt is only found in thick skin The keratinocytes here are dead and flattened out The keratinocytes are filled with protein called eleidin, which is rich in lipids and is somewhat transparent (lucid), it acts as a barrier to waterDescribe characteristics of the stratum corneumThere are 15-30+ layers of keratinocytes There is an increase in keratinization (this process is called cornification) The cells shed periodically, the entire layer is replaced every 4 weeks because it is the highest layer that contacts the outside world the mostDescribe some characteristics of the dermisIt is deep to the epidermis It contains blood and lymph vessels, nerves, hair follicles and sweat glands It has 2 layers of ct called the papillary layer which is more superficial, made of areolar ct and the reticular layer that is mainly dense irregular connective tissueDescribe the papillary layer of the dermisIt has areolar connective tissue It's where you find the dermal papillae It has blood vessels (referred to as the sub papillary plexus), lymphatic vessels, tactile or meissner corpuscles which help you feel light touch and nerve fibers.Describe the reticular layer of the dermisThere a dense irregular CT found It has blood vessels, sweat glands, hair follicles (only in thin skin), a sensory structure called the lamellar or pacinian corposule are for deep pressure sensation or vibrational sensationDescribe the hypodermisAlso called the subcutaneous layer or superficial fascia Deep to the dermis Comprised of areolar and adipose ct Functions include binding of the dermis to deeper fascia of the muscles or bones, fat storage, insulation and cushioningDescribe characteristics of pigmentationIt is influenced by pigments via melanin (melanocytes), carotene (diet), and hemoglobin Sun exposure stimulates the melanocytes to create melanin and that's transferred to melanosomes which darken the skin. More sun exposure means more melanin and darker skin Excess uv sunlight exposure can cause damage to the skin such as wrinkles, and genetic damage, in the basal cells which are very mitotically active, uncontrolled cell growth can cause skin cancerWhat does carotene do to the pigmentation of your skinCarotene is found in carrots, so if you eat too many carrots your skin can turn a yellow orange colorHow can hemoglobin affect the pigmentation of your skinIf you have a sudden drop in oxygenation, otherwise referred to as shock, your skin can have an ashen or white color. Long term drops in oxygenation can lead to pale blue skin otherwise known as cyanosis.What are some accessory structures of the skinHair, nails, sweat glands, sebaceous glandsWhat is the purpose of hairIt provides protection to the skin, sensory input, and thermal regulation. Thermal regulation is not so relevant to humans anymore, but in dogs and cats a lack of fur can lead to hypothermiaWhat is the material of the hair calledKeratinWhat is the structure of hairThe exposed part of hair is referred to as the hair shaft. Deep to the skin is the hair root, which grows from the hair matrix (all the way at the bottom of the hair follicle which is where the mitotically active cells are that make the keratin to make hair) of the hair bulbWhat is the hair papillaIt is a space at the bottom of the hair bulb where the blood vessels are and the nerves enterWhat is the inner middle and outer layer of the hair calledThe inner most part of a piece of hair is called the medulla, which is surrounded by the middle part called the cortex, and the most external is the cuticleWhat is external to the hair rootThe internal and external root sheaths. These are generated by the hair follicle and not part of the hair itselfWhat is the arrector pili muscle?It is attached to the hair follicle and when it contracts it makes the hair stand up. It will somewhat distort the skin and create goosebumpsWhat are sebaceous glandsThey are glands that secrete oil, otherwise known as sebum. Helps lubricator the hair root and shaft and skin. Helps with waterproofing, so we don't lose too much water through the skin. It also has a bit of an antibiotic propertyWhat is hair color determined byThe amount of melanocytes and melanin as well as the type of MelaninWhat is the function of nailsThey protect the ends of your fingers and toes as well as helping to pick up small objectsWhat are nails composed of?Densely packed dead keratinocytes or keratinWhat are the parts of the nailThe nail body which sits on the nail bed, the nail route which is where the nail grows from, the free edge which is the white part of your nail that extends past your fingertips, and the lunula (the white crescent) The nail cuticle or eponychium is a lateral nail fold that anchors the nail in placeWhat are sweat glandThey are also referred to as sudoriferous glands. And they produce watery sweat to cool down the bodyWhat are the two types of sweat glandeccrine and apocrineWhat is an eccrine sweat glandtype of gland that produces a hypotonic (slightly salty) sweat for thermoregulation. These are in the palms of your hands, soles of your feet, forehead. The sweat produced is mainly water with a bit of salt, wastes and dermicidin (antibiotic). Secreted through merocrine glandsWhat is an appocrine sweat glandIt produces watery sweat with organic compounds. These are found near hair follicles in the axilla or armpits, groin, nipples. The organic compounds can lead to odor and they're linked to pheromone communication. Think app for appocrine and app for apply (deodorant because it produces odor)What are some functions of the integumentary systemIt gives protection from the external environment. It protects against elements of nature including wind water and UV sunlight. Also protects against water loss. It protects against abrasive activity. It protects against pathogens (dermicidin against microbes) and protects against harmful chemicals. It helps with thermoregulation via sweating which is watery and evaporates cool. It helps with vasodilation of the skin capillaries , which helps with radiative heat loss. Makes you shiver so the muscle contractions help generate heat Helps with vasoconstriction of the skin capillaries to help with heat retention Vitamin d synthesis- the epidermis synthesizes vitamin D with us light exposureExplain vitamin d synthesisVitamin d synthesis- the epidermis synthesizes vitamin D with us light exposure Vitamin d is converted into calcitriol- active form (kidneys). It's important for the appropriate amount of absorption of calcium and phosphorous for healthy bones A lack of sunlight exposure can cause a vitamin d deficiency which can possibly lead to rickets- softening of the bones Vitamin d is also important for general immunity against bacterial, viral, and fungal infectionsDescribe the sensory element of the integumentary systemThe skin has sensory nerve structures that detect touch temperature and pain It has meissner ( also called tactile) corpuscle. Found in the dermal papillae It has pacinian (also called lamellated) corpuscle. They are deeper and respond to deeper pressure It has merkel cells which are found in the stratum basale. They are sensory cells and associated with nerves, they respond to light pressureWhat is skin cancerSkin cancer is abnormal uncontrolled cell growthWhat is the treatment for a benign tumorA benign tumor is harmless and can safely be removedWhat is a treatment for a malignant tumorMalignant tumors are cancerous and can metastasize or spread and be fatal so they must be treated immediatelyWhat is basal cell carcinomaIt is a kind of cancer that affects mitotically active stem cells in the stratum Basale. It can reach the skin surface as an uneven patch, bump, growth on head, neck, arms and back (areas that get a lot of sunlight exposure).What is the treatment for basal cell carcinomaIt can be surgically removed. It can also be frozen through cryo- surgery, and it can also be treated with topical ointmentWhat is squamous cell carcinomaIt affects keratinocytes of stratum spinosum. It causes lesions on the scalp ears and hands. Squamous cell carcinoma is more aggressive than basal cell carcinoma. Treatment includes surgery and radiation treatment.What is melanomaUncontrolled growth of melanocytes. This is the most dangerous and fatal kind of skin cancer and it is highly metastatic. It presents as an asymmetrical brown or black patch with uneven borders. It can be treated with surgery and immunotherapy. It can be diagnosed by the ABC DE mole diagnosis. A is for asymmetry, B is for borders (irregular), C is for color (brown/black), D is for diameter (>6mm) , E is for evolvingWhat is eczemaIt is an allergic reaction that manifests as dry itchy patches of skin that resemble rashesWhat is acneHair follicle infections. Areas rich in sebaceous glands (face and back), can get blocked pores. Acne is caused by infection from acne causing bacteria called propionibacterium and staphylococcusWhat are BurnsDamage to the skin by heat radiation electricity or chemicals. If a burn is bad enough the skin cells will die which can lead to massive losses of fluid and you can lose pathogen protection. Use the rule of nines to determine the size and treatment of a burn.What is a first-degree burnIt is a superficial burn that only affects the epidermis and leaves little little to no scarWhat is a second-degree burnIt is a burn that affects the epidermis and a portion of the dermis there is swelling and blistering and it can scarWhat is a third-degree burnIt is a burn that fully extends into the epidermis and the dermis and requires medical attention and can cause scarring and long-term tissue damageWhat is a fourth-degree burnIt is a burn that affects underlying muscle and bone. It requires medical attention, debridement and grafts, and will leave severe scarring and tissue damageWhat is a scarCollagen rich skin formed after the process of wound healingWhat is a keloidA raised or hypertrophic scarWhat is a bedsoreIt is a sore on the skin that develops when regions start necrotizing due to constant pressure and lack of blood supply. Also called decubitus ulcersWhat are stretch marksThey result when the dermis is stretched beyond the limits of elasticityWhat are calluses and cornsSecond areas of skin arising due to constant abrasion