Integumentary derivative

vertebrate integument and its derivative
development general structure and function of integument and its derivative
gland, scales,horns, claws,nails, hooves, feathers and hairs.

1. Integument and its derivative -By zooomania

2. Integument There is nothing more conspicuous about an organism than its skin.  It is our primary means of identifying the organism, and is what defines the boundary of its body.  Skin is also the primary means through which an organism interacts with its environment.

3. Function : support and protect soft tissues against abrasion, microbes reception and transduction of external stimuli - i.e. heat, chemical, tactile transport of materials involved in excretion, secretion, resorption, dehydration, rehydration heat regulation respiration nutrition/nutrient storage - i.e. storage of vitamins, synthesis of Vitamin D locomotion coloration - cryptic or display

4. Basic structure of the integument: The integument consists primarily of the skin and its derivatives.  Skin is a functional unit composed layers of fairly distincy epidermis (derived from ectoderm) and dermis (derived from the dermatome of somites) that are separated by the basement membrane.

5. Epidermis   It is relatively thin in most animals T he upper layer composed of mostly dead, differentiated cells (stratum corneum) with a lot of keratin which helps the skin maintain some protection against water loss and bacteria

6.  Dermis It is more of a connective tissue than protective I rregularly-shaped connective tissue cells that produce the extracellular matrix, including collagen and elastic fibers .

7. THE INTEGUMENT AND ITS DERIVATIVES Epidermis Dermis

8. EPIDERMIS FUNCTION The epidermis, derived from somatic ectoderm, is the exterior-most covering of the chordate body. It provides protection against the invasion of microorganisms, provides flexibility in motion, and seals in moisture. As will be seen, it also gives rise to a variety of differentiated structures such as feathers, hair, horns, claws, nails and glands.  

9. Epidermal Derivatives of the Integument The production of all of the following structures involves keratinization . Epidermal Scales : a continuous layer of repetitious thickenings of the stratum corneum. Claws and Talons : curved, laterally compressed keratinized projections from the tips of digits. Hooves : enlarged keratinized plates found on the ends of ungulate digits. Nails : keratinized epithelial cells.

10. Glands Specialized to secrete specific products (oil, sweat, milk, etc.), these structures are derived by an infolding of the epidermis. In many cases they retain a connection to the stratum corneum whereby their secretions can be released at the skin surface.

11. THE DERMIS AND ITS DERIVATIVES The dermis is generally much thicker than the epidermis and lies more deeply. It is made of a fibrous mass of connective tissue (collagen) and is of mesodermal origin. It may directly produce dermal (membrane) bone. The dermis is important in defence against injury and in the maintenance of body heat. Deeper regions of the dermis often contain fatty deposits, smooth muscle, blood vessels and nerves.

12. Dermal Bone Once present in some extinct fish . Now dermal bone is present in turtle dermal bone, antlers, and in the dermal armour of armadillo. In most modern vertebrates, dermal bone (membrane bone) is formed from embryonic mesenchyme by intramembranous ossification, and contributes to the skull and skeleton, rather than being manifested externally. An exception is teeth, which are partly derived from dermal bone..

13. Fish Scales Fish scales are also called dermal scales since they are derived mainly from the dermis. 1.Cosmoid Scales 2.Ganoid Scales. 3.Placoid Scales:  4) Teleost (bony fish) scales 4 a) Cycloid Scales   4 b) Ctenoid Scales: 

14. scales

15. TEETH Teeth are composed of three main parts.  Enamel , the hardest substance in the body, covers the tooth surface. It is epidermal in origin.   Ganoin  is a form of enamel.  Dentin  is similar to bone in structure but is harder. It is located beneath the enamel and forms the walls of the third component of teeth, the pulp cavity. These are of dermal origin.  Cosmine  is a form of dentin. Dermal bone called cementum is also present in mammalian teeth.

16. teeth

17. Thank you.