Structure and functions of integuments

Structure & functions of Integuments The integuments is the the outer Vertebrates covering of the body of It is commonly referred as →Together with its derivatives it tary system. skin. makes the integumen- → It is continuous with the Мисощ membrane Lining the Mouth, Nostrul , eyelids, opening of rectum 1 ete. → The skin functions primarily to covere It firms the interface between the To the external environment. and protection oreganism and → The skin consists of Epidermis and Desemis Epidenmis: → Epidermis is denived from ectoderm of the embryo cells of the epidermis Fallowing cells ane present in the epidermin Keratinocytes: Tightly packed cells. Stratum basale, produce keratin. oniginate from b) Melanocytes: spiden like cells that produce melanin a) Langenhang cells i star shaped cells form bone Mannow Functions to activate the immune system. d) Mankel cells function as Sensory receptors. The epidermis consists of the following layers, from the inner to the outer region. a) stratum basale: Lower layer consists of single now. Keratinocytes, some Melanocyty and Markel cells. b) strratum spinosum sevenal layen thick.contain Ketratinolytes, 5) Striatum granulasum: consists of flattened Keratinocytes. Stratum lucidum! present only in thick skin and made up of a few rows of clear, flat, dead Keratinocytes e) stratum corneum: layers of cells. outenmort layere, contain many Dead skin Slough off. →The epidermis skin that is the Most superficial layer of the covers almost the entire boudy Sunface. →The epidermis rests upon the denmis → The epidermis does not contain is an avascular region. any blood Vessels. of the body.and →The epidermis is made of cells. sevenal specialized types Almost 90% of the epidermis is made oa Keratonocytes. Keratinocytes produce kercatin. Kercatin makes the epidermis tough, Scally and Water resistant →About 5% epidermal cell made of Melanocytes produce Utra Violet nadiation the Melanin 7 Melanocytes. to protect the skin from The epidermis most of the vertebrate body is annanged into four distinct layers. Ion the palm of the hand and plantan Surface of the feet, the skin is thicker than in the rrest of the body and there is fifth layen of epidermis. GOA The deepest negion of the epidermis is the Stratum basale which contains the stem cells that reproduce to form all of the other cells of the epidermis, 5) Striatum granulasum: consists of flattened Keratinocytes. Stratum lucidum! present only in thick skin and made up of a few rows of clear, flat, dead Keratinocytes e) stratum corneum: layers of cells. outenmort layere, contain many Dead skin Slough off. →The epidermis skin that is the Most superficial layer of the covers almost the entire boudy Sunface. →The epidermis rests upon the denmis → The epidermis does not contain is an avascular region. any blood Vessels. of the body.and →The epidermis is made of cells. sevenal specialized types Almost 90% of the epidermis is made oa Keratonocytes. Keratinocytes produce kercatin. Kercatin makes the epidermis tough, Scally and Water resistant →About 5% epidermal cell made of Melanocytes produce Utra Violet nadiation the Melanin 7 Melanocytes. to protect the skin from The epidermis most of the vertebrate body is annanged into four distinct layers. Ion the palm of the hand and plantan Surface of the feet, the skin is thicker than in the rrest of the body and there is fifth layen of epidermis. GOA The deepest negion of the epidermis is the Stratum basale which contains the stem cells that reproduce to form all of the other cells of the epidermis, oreganixm is fofonmed of both harum fal and beneficial Honces in the outer world. in the integumenis uments which thus. ane located promote the adaptive and sunrival Value of the organizm. 4- Excnction: Exenetory functions ane pentonmed by several vertebrate integumentary structunes. Among the fishes, some salt excretion occurs through the gills' integument. Respiccation: on Amphibians the skin is Moist and perform respination through the skin. 6) Thenmo. negulation: Among the binds and Mammals the skin and its derivatives like hains Senve feathers and a very Impontant function insulating the body against external temperature. 7) osmo regulation Regulation of the waten content of the body is accomplished by the skin. Manine and terrestrial in a The vertebrates which live hyperosmotic environment the skin too rapid loss of be Sunrounding Medium. Live în a the body warten to the prevent Im Presh Water forms which hypo-osmotic environment absorption of too much warten. it prevents 8) Pood Storage! Among birds and Mammals, especially Migratory birds, the fat present in the Skin acts as a hibernating Mammal's deepening layer of the Food Supply. a) Nourishment: The Mammary glands ane skin derivatives depend upon the for nourishment. of the mammah New born Mammab milk secreted by these glands 10) Locomotion: The webbing on the feet of ducks and frogs the fins of Fighes the wing-featheres of the binds, the flight Membranes of the bats are the Locomotory structurne denived from the integument. 11) Miscellaneous Functions: A no. of also can be centain groups other Functions performed by the integuments of →for example the Mammalian skin is the site for Manufacture F Vitamin. D. Lice ← Some of the Mammals. and amphibians have skin pouches called Man supials. which senve .E as brood pouches ofon the developing young. E → Among the binds differences in Structure eo loun and of the feather facilitate sex recognition. Different Derivaties of of Integuments → The skin itself is relatively simple but its derivatives ane mumerous and complex. → Depending upon the Idyer of skin from which they ane derived they may be epidenmal on The following structure. ane the dermal derivatives. derivatives of in teguments Scales: Epidermal Scales: Epideen anal found in binds, Scales Reptiles and Mammals. which are epidermal in denprivative. They are protective in nature I These ane denivatives of Stratum genminatum. Tuy ane overlapping in lizandı end to end in Turtles and and snakes but annanged Crocodiles. → They Undergo periodical Shadding called →n binds they are found as ecdysis. on the legs and feet. Im Rat they are found Denmal Scales! on tail and never Undengo Moulto ← The denmal scales a ane found in the fishes They ane derived from Mesodenm The scales of fish, also known as Placoid Scales, are cosmos, Leptoid, and gonoid, and they are found in Elasmobranchs. copmoid scales Fishes. are found in lung Fishes (Dipnoi) Leptoid scales are of two types Gonoid Scales are also known. Found in Amia as eycloid and etenoid as thomboid scales essually claws! →claws present ane pres which are in rreptiles, birds and Mammals identical in nature. A claw is made of a Unguis and a doresal scale like plate called the ventral plate the Subunguis. →The claw covers the terminal bou bong phalanx In the typical reptilian claw the Unguis in curved both longitudinally and transversely → The outer layers of reptilian claws ane shed and renewed periodically. 9gn binds Shedding of the entine claws is usual and growth and u Weaning away In the claws Of occur at a Mammals the mone on less congtantriate Subunguis is redduced in size and is continuous with the Baid at the end of the digit.. → Members of the cat family possess refractile elaws which when not in use into a Sheath. on not extended ane withdrawn Phalany. Unguis Subunguis. (claw) Dermig Epidermis. Nails: → claws are Modified into nails which ane characterists of primates (Mammals) Nails ane protective plates oven the Joes → The area Unden the nail hay fingentips and tre nerve endings, many As the nail grow more cells ane added at the nail bed. →olden cells get pushed away from the nail bert and the nail grows longen. Structure: A nail is divided into specifie pants. • Such as Root: The noot of the nail is actually beneath the skin. behind the fingen nail and extends sevenal Millimeteres Into the fingen.. →The fingernail noot produces most of the Volume of the nail and the nail bed. Nail plate cuticle Nail Root Nail plate: The nail plate is the actual fingernail, Hyponychi- Madeq keratin. Nail bed The pink appearance of [Structure of Nail z its pants the nail comes from the blood vessels underneath the nail Eponychium? The cuticle of the fingernail is also called the eponychium The cuticle is Situated between the skin of the fingere and the nail plate. Perionychium! The perionychium is the skin that overlies the nail plate on its sides. hang nails, ingrown nails. The perionychium is the site of Haites: →Hairs are of body and as characteristic of Mammals that serves for insulation sensitive tactile oregans. Like scales and Feathers ane abo confined epidermal products of the integuments. Higst the haire has two pants namely ote Hain follicle! Hain follicle is the Dopoint from which the hain grows. a tiny cup shaped pit buried. It is Epidenmis L in the fat of the scalp. shaft Hain follicle 2 Hain Shaft! The pant of the hair seen above the skin is called the hain Shaft. The hain shatt in made up of dead cells that have turned into kenatin. Humans have three types of hairs. Lanugo: The fine, Unpigmented hain that covers nearly the entire body of a foetus although mort has been replaced by with vellus by the time of the baby's bine! 2= Vallus hair: The Shont downy body hai're that grows in Moget places on the human body." 3: Terminal hair: The fully developed hairs, which is generally longen, thicken and danker and found in regions such as the axillany, beard and pubic. Feathers! → Birds ane Covered by Feathers Which are not found in any other group of animals. →They are dry, nonliving and confined products of Stratum corneum of epidermis. → Thay ane light Stitif, strong, elastic and waten proof →They mainly streamline and protect the body, congenve body heat and make broad surfaces of wings and tail used for flight. →an fowls there are following types of feathers ane found. Contour Feather these thet ane lange feathers cover the body, wings and tail. 2= Down Jeathen! They are the only feathers covering a chick and form the Main insulation layer Under the Contour feathers of the adult. 3= Pin feather! Shaft of ten with They have a slender a tiny tuft of hain like banbs on the end. They are found between the other feathers 4. Plumules! They are found beneath the contour feather where they form a soft downy Undercoat. 5= Bristles: Bristles are found anound the Mouth and eyes of chickens and ane thought to be primany used to aid the and protect Sensitive. aneas. Sensorry ability of binh alnits