what is the function of the integumentary system prevents dessication,reduces injury,maintains normal body temperature,synthesizes vitamin d,stores nutrients,prevents desiccation desiccation is drying out integumentary system consists of hair,hooves,claws,skin related glands sebum is oil vitamin d helps body absorb calcium adapose is fat dermis is the true skin what seperates the epidermis from the dermis basement membrane what are the three layers of the integumentary system epidermous (above),dermis (skin),and hypodermis(below)or sub-q subcutaneous epidermis 3 cell types are keratinocytes,melanocytes,merkel cells,and langerhans cells macro- means large wht do keratinocytes do produce keratin,make skin tough,waterproof skin melanocytes do what produce pigment,absorb uv radiation, merkel cells do what aid in sensation of touch,also known as touch cells langerhan cells do what phagocytize or eat foreign invaders what are the 5 epidermal layers? stratum germinativum aka basal layer,stratum spinosum aka spiny layer,stratum granulosum middle layer,stratum lucidium aka clear layer,stratum corneum aka horny layer wht epidermal layer sits on top of the basement membrane stratum germinativum what do langerhans cells do and wht layer is it found in? eat foreign invaders,found in the stratum spinosum glycolipids does what waterproof the skin what layer does skin cells start to die stratum granulosum lucid see through or clear function of stratum lucidum reduce friction between stratum corneum and stratum grandulosum stratum is composed of how many rows of keratocyte remnants 20-30 rows also known as dandruff what are the three epidermal layers of hairy skin stratum basal,stratum spinosum,and stratum corneum under a microscope tactile hair or (tylotrich hairs)look like fish scales with hair protruding from them what is the dermis composed of irregular connective tissue,also includes hair follicles,nerve endings,blood vessels,glands and smooth muscle dermal papillae helps do what cement the epidermis,and dermis together papillary layer sits were below the germinativum the thin superficial layer of dermis is called papillary layer what are the two dermal layers papillary layer and reticular layer reticular layer consists of dense irregular tissue,bundle of collagen fibers,and are found were bending takes place pigmentation presence or absence of melanin granules hypodermis is composed of blood and lymphatic vessels and nerves,special touch receptors hypodermal layer permits skin to do what move freely over underlying bone and muscle without putting tension on skin special features of integument are pigmentation,paw pads,planum nasale,erogots and chestnuts,cutaneous pouches in sheep keritinization as new keratinocytes are formed they push old ones away from nutrients and blood send them to the top were they loose nulei,cytosol,and organells =death paw pads thick layers of fat and connective tissue with sweat glands and lamellar corpuscles planum nasale is top of the nose in cats,pigs,sheep ,and dogs planum nasolabiale is the mussel of cows and horses what three epidermal layers are planum nasale composed of stratum germanativum,stratum spinosum,stratum corneum ergots and chsetnuts are dark horny structures found on legs of horses,ponies,and othe members of the equine family cutaneous pouches in sheep is infoldings of skin,contain fine hairs and oil glands,secrete fatty yellow substance that sticks to skin when dry hair shaft visible above the skin function of hair maintain body temperature/camouflage hair root buried within the skin hair follicle anchors the hair deepest part of the hair follicle expands to form a hair bulb at the base of the hair bulb is a mound of dermal cells called papilla hair strands are formed as epithelial cells mature,fill with keratin,and move away from the papilla what are the root sheath layers of the hair follicle connective tissue root sheath,external root sheath,and internal root sheath each hair strand is organized into three layers what are they cuticle,cortex,and medulla root hair plexus is web of sensory nerve endings(touch receptor) anagen phase cells are added at base of root,hair lengthens catagen phase period of transition between anagen and telogen phases telogen phase maximum length of hair is achieved,hair stops growing,folicle shortens,hair is held in a resting place diffrent hair colors result from the quantity and type of what? melanin incorporated into the air primary or guard hairs straight or arched,thicker and longer than secondary hairs secondary or wool type hairs softer and shorter,wavy or bristled in the dog tactile(or sinus)hairs contain numerous sensory endings,commonly known as whiskers why is tactile hair called sinus hair because of the large blood sinus located in the connective tissue portion of the follicle arrecture pili muscle is attached to each hair follicle,associated with the nervous system,contraction pulls hair to erect position what are the glands of the skin sebaceous glands,sweat glands,tail glands,anal sacs sebum glands does what coats the base of hair and skin,helps trap moisture,reduce skins risk of infection,and waterproof when the epithelial gland is lost in secretion the sebaceous gland classified as what a holocrine structure what is another name for sweat glands sudoriferous glands what do sweat glands do helps cool body through evaporation what are the two types of sweat glands eccrine,and apocrine excretory portion of sweat glands consists of simple coiled tube located in the dermis or hypodermis,empty on surface of skin through long duct apocrin sweat glands coiled portion buried in the dermis,single excretory duct ,empty into hair follicles tail gland function oval region at base of cats and dogs tail,thought to assist with recognition and identification of individual animals anal sac are located were relative to the anus 5 and 7 o clock position anal sac is connected to the lateral margin of the anus by what small single duct when a animal defecates or becomes frightened what happens some or all of the anal sac contents are expressed claws are pigmented,hard outer cover of distal digits,help maintain traction and defense for trapping prey dew claws evolutionary remnants of digits in the dog first digit,in cow and pig the medial and lateral dewclaws are the second and fifth digits another name for hoof is ungula hoofed animals are called ungulates hooves rest on tissue called corium,and is attached to periosteum of distal phalanx the skeletal foot of the horse includes distal part of second phalanx,distal sesamoid bone,entire third phalanx(coffin bone) the hoof and the corium for interdigitations called laminae the equine hoof is generally divided into three parts what are they the wall,the sole,and the frog the wall is external portion of hoof ,divided into the toe,the quarters,and heels the sole is plantar and palmar surface of hoof outer layers are avascular lack intervention the frog is triangular horny structure located between heels on underside of hoof the frog is diveded by central depression known as centarl sulcus,digital cushion a thick pad of fat and tissue lies beneath the sensative frog horns are composed of what keratine horns are simular to hair and corium lies where the root of the horn,and bound to the horn process by periosteum the wall of horn is thinner at the base than the apex
Of Mice and Men 