Integumentary-System - a topic to be discussed
- 2. What is the Integumentary System? The integumentary system is the body's outermost layer, comprised of skin, hair, nails, and glands. It acts as a protective barrier against external factors, helps regulate body temperature, and assists in sensory perception.
- 3. Main Components of the Integumentary System
- 4. The Skin is the body's largest organ, serving as a protective barrier. It has three main layers:Epidermis, Dermis, and Hypodermis.
- 5. Epidermis: The epidermis is the outermost layer of the skin, and protects the body from the environment. The epidermis is subdivided into five layers: Stratum Basale: The bottom layer, where new cells are made. It has special cells: • Basal cells: Create new keratinocytes. • Keratinocytes are the main skin cells found in the epidermis (outer layer of the skin). • Merkel cells: Help you feel touch. • Melanocytes produce skin-coloring melanin.
- 6. Melanocytes produce two pigment-determining melanins: Eumelanin: Your skin, eyes, and hair all have dark colours thanks to this particular type of melanin. Pheomelanin: This type of melanin is responsible for the pink or red coloration of your lips, nipples, vagina, and the bulbous structure at the end of the penis (glans), as well as your hair.
- 7. The Stratum Spinosum, also called the "spiny layer," is the second layer of the epidermis, found just above the stratum basale. In this layer, keratinocytes begin to change—they move upward, start producing more keratin, and become slightly flatter. The cells look spiny under the microscope because of desmosomes, which are strong connections that hold the cells tightly together and give the skin strength. This layer is also where Langerhans cells, are a special type of immune cell found mostly in the skin they help the body detect harmful invaders like bacteria, viruses, or other foreign substances.
- 8. The Stratum Granulosum, or "granular layer," is the third layer of the epidermis, found above the Stratum Spinosum. In this layer, keratinocytes continue to flatten and begin to die, losing their nuclei as they prepare to become part of the outer skin. These cells contain keratohyalin granules, which help form strong keratin.
- 9. The Stratum Lucidum is between the Stratum Granulosum and the Stratum Corneum. is a thin, clear layer found only in thick skin like the palms and soles. It’s made of dead cells and adds extra protection in areas with lots of friction or pressure.
- 10. The Stratum Corneum is the outermost layer of the epidermis and the part of the skin we can see and touch. It’s made up of many layers of dead and flat keratinocytes that are filled with keratin, making the skin tough and protective. As new cells move up from the layers below, the old cells in the stratum corneum shed off naturally.
- 11. Dermis The Dermis is the middle layer of the skin, found right under the epidermis. It’s thicker and made of strong connective tissue, which gives skin its strength and flexibility. The Dermis has two layers: the Papillary layer and the Reticular layer. The Papillary Layer is the upper part, containing capillaries, touch receptors, and dermal papillae that connect to the epidermis and support sensation.
- 12. The Reticular Layer is deeper and thicker, made of strong connective tissue with collagen and elastin fibers, sweat and oil glands, blood vessels, and nerves. Together, these layers give the skin strength, flexibility, and help with protection, sensation, and temperature control. Dermis
- 13. The Hypodermis, or Subcutaneous tissue, is the deepest layer of the skin. It contains fat cells (adipocytes) that store energy and keep the body warm, along with blood vessels and nerves. This layer helps insulate the body, provides padding, and anchors the skin to muscles using connective tissue.
- 14. Hair, also called pilus (plural: pili), comes in two types: Vellus hair is the light, thin hair that covers most of the body. Terminal hair is the thicker, darker, and longer hair found on the scalp, eyebrows, eyelashes, beard, and pubic areas, especially after puberty. Hair Shaft The visible part of the hair above the skin. • Made up of three layers: • Medulla: The soft center (not always present). • Cortex: The thick layer with keratin and pigment (gives hair its color). • Cuticle: The outermost layer, like protective scales.
- 15. Sebaceous Gland • Produces sebum (natural oil) that keeps hair and skin moisturized and protected. Arrector Pili Muscle • Tiny muscle connected to the hair follicle. • When it contracts (like when you're cold or scared), it makes your hair stand up (goosebumps). • Hair Follicle Layers • Inner Root Sheath: Helps guide and shape the growing hair. • Outer Root Sheath: Protective layer that supports the inner parts. •
- 16. Hair Bulb The base of the follicle where hair growth begins. • Contains two important parts: • Hair Matrix: Where cells rapidly divide to form the hair. • Hair Papilla: Contains blood vessels that bring nutrients and oxygen to support hair growth.
- 17. Nails are special skin structures made of hard keratin that protect the tips of our fingers and toes. They help us with tasks like picking things up or scratching. Onychodermal Band A thin line where the nail plate meets the hyponychium (under the free edge). It acts as a seal to protect against dirt and bacteria. • Here's a explanation of each part of the nail anatomy:
- 18. Nail Plate • The hard, visible part of the nail made of keratin. It lies on top of the nail bed and protects the tips of the fingers and toes. Nail Matrix • The growth center of the nail found under the skin at the base of the nail. It produces new nail cells that push older ones forward to form the nail plate. Cuticle (Eponychium) The thin layer of skin that covers the nail matrix. It protects the area from infection. •
- 19. Mantle • The deep skin layer at the base of the nail where the matrix lies. It houses the starting point of nail growth. Hyponychium • The skin under the free edge of the nail (where the nail sticks out). It also serves as a protective barrier against bacteria. Nail Bed • The skin beneath the nail plate. It provides nutrients and gives the nail its pinkish color due to blood vessels. Nail Folds • The skin that surrounds the sides and base of the nail. It helps anchor and protect the nail plate.
- 21. Glands • produce and release substances to help the body stay healthy and balanced. These substances can be oil, sweat, earwax, or even milk. The glands help protect the skin and regulate temperature. Sebaceous Glands (Oil glands) • These glands are connected to hair follicles. • They produce sebum, a natural oil that moisturizes and protects the skin and hair. • Sebum keeps the skin soft and waterproof, and it also has some antibacterial properties. • Most active during puberty because of hormone changes. • Found in: Face, scalp, chest — almost everywhere except palms and soles.
- 22. Sudoriferous Glands (Sweat glands) • These are the glands responsible for producing sweat, which cools the body and helps eliminate waste. Eccrine Sweat Glands • Most common type. • Produce watery sweat directly onto the skin. • Helps cool the body during heat or exercise. • Found in: Forehead, palms, soles, and all over the body.
- 23. Apocrine Sweat Glands • Found in specific areas like armpits and groin. • Sweat from these glands is thicker and milky because it contains fat and protein. • This type of sweat can smell when bacteria break it down (body odor). • Become active during puberty and respond to emotions or stress. • Found in: Armpits, groin, around nipples. There are special types of apocrine glands in the skin called Modified Sweat Glands.
- 24. Modified apocrine glands are special sweat glands that have unique functions. Two main types are the Ceruminous glands in the ear, which make earwax to trap dirt and protect the ear, and the Mammary glands in the breasts, which produce milk to feed and protect babies. These glands are more specialized than regular sweat glands.
- 25. THANKS