INTEGUMENTARY SYSTEM

• • Some single celled protozoa have only a plasma membrane for an external covering

  Function: respiration and excretion (simple diffusion)
• • Protozoa, such as Paramecium have a thick protein coat called pellicle outside the plasma membrane.Function: it is a semirigid structure that transmits the force of cilia or flagella to the entire body of the protozoan.
• II. MULTICELLULAR INVERTEBRATE

  Composed of following layers of cells

  1. Epidermis (cilia, glandular cells)
  2. Basement membrane
  3. Connective tissues
• The outermost layer of the skin, and protects the body from the environment. - EPIDERMIS
• A dead layer of polysaccharides and protein present in the animals. Composed of chitin and proteins. - CUTICLE
• The periodic shedding of exoskeleton or cuticle for growth - MOLTING
• Some cnidarians (e.g. corals) have mucous glands that secrete a calcium carbonate (CaCO3) shell. It is hard and rigid - SHELL
• The outer covering of parasitic flukes and tapeworms is a complex syncytium (multinucleated cell) - TEGUMENT
• Epidermis that is one cell thick and multilayered cuticle - NEMATODES AND ANNELIDS
• Thin usually ciliated epidermis CaCO3 containing connective tissues. - ECHINODERMS
• Complex integument, part of integument form of exoskeleton. - ARTHROPODS
• The largest external organ of the human body. Regulating body temperature, sensation (touch, pressure, temperature, and pain). - SKIN
• The outermost layer of the epidermis is composed of multiple layers of dead skin, flattened keratinocytes called corneocytes. - STRATUM CORNEUM
• only present in thick skin, such as the palms of the hands and soles of the feet. - STRATUM LUCIDUM
• in this layer, keratinocytes begin to fill with keratin, lose their nuclei, and flatten out. - STRATUM GRANULOSUM
• consists of several layer of keratinocytes that are undergoing differentiation and maturation - STRATUM SPINOSUM
• deepest layer of the epidermis. - STRATUM BASALE
• Lies beneath the epidermis and contains various structures. It provides structural support to the skin and contributes to its elasticity and strength. - DERMIS
• Superficial layer of the dermis, consisting of loose connective tissue with papillae that extend into the epidermis. - PAPILLARY LAYER
• Deeper and thicker layer of the dermis, composed of dense irregular connective tissue. - RETICULAR LAYER
• The subcutaneous layer is the deepest layer, composed mainly of fat and connective tissue, serving as insulation and energy storage. - HYPODERMIS
• Glands are organs or structures in the body that secrete substances for various functions. These secretions can be released into ducts, onto a surface, or into the bloodstream.
• secrete their products into ducts, which then carry the secretions to the body's surface or into cavities. - EXOCRINE GLANDS
• Sweat Glands - also known as sudoriferous glands, are exocrine glands found throughout the body, with the highest concentration in the palms, soles of the feet, and forehead.
• Eccrine Sweat Glands are the most numerous and widely distributed sweat glands in the human body, found in almost all areas of the skin, particularly on the palms of the hands,
• Apocrine Sweat Glands are larger than eccrine glands and are primarily found in specific areas of the body, including the axillae (armpits), groin, and areola of the nipples.
• Sebaceous glands, located in the dermis, produce sebum, an oily substance that lubricates the skin and hair, preventing dryness and brittleness.
• Salivary glands - found in and around the mouth, produce saliva, a fluid rich in enzymes, electrolytes, mucins, and antimicrobial compounds.
• Ceruminous glands, located in the ear canal's outer third, produce cerumen, or earwax, along with sebaceous glands and dead skin cells.
• Mammary glands - located in mammalian breast tissue, produce milk for offspring during lactation.
• Endocrine glands secrete hormones directly into the bloodstream rather than through ducts.
• Hair is a filamentous structure that grows from follicles found in the skin of mammals.
• Cuticle - the outermost layer with overlapping

  scales providing strength and flexibility.
• Cortex - the middle layer with elongated cells determining hair color, strength, and elasticity.
• Follicle Bulb - a bulb-shaped structure at the base containing actively dividing cells responsible for hair growth.
• Papilla - a small projection supplying nutrients and oxygen to the hair matrix, supporting growth.
• Hair Matrix - the region within the bulb producing new hair cells
• Follicle - a sheath-like structure surrounding the root, extends from the epidermis into the dermis and houses various essential structures for hair growth and maintenance, including the hair bulb, dermal papilla, and sebaceous gland. Associated arrector pili muscles contract in response to stimuli, causing goosebumps.
• Nails - are hard, protective structures made of a protein called keratin that grow from specialized epithelial cells in the skin called nail matrix.
• Nail plate - covers the fingertip or toe, consisting of translucent keratinized cells