Overview of the Integumentary System.pdf

🌟 9/9/24, 7:11 PM Overview of the Integumentary System Integumentary System The integumentary system is the most superficial tissue layer of an animal's body, serving as...

🌟 9/9/24, 7:11 PM Overview of the Integumentary System Integumentary System The integumentary system is the most superficial tissue layer of an animal's body, serving as the largest organ of the body. It is formed in distinctive layers and includes components such as skin, secretory glands, hair, nails, etc. Skin Functions 🌈 The skin performs several essential functions: Physical barrier protection: The skin acts as the first line of defense of the innate immune system. Thermoregulation: The skin helps regulate body temperature through evaporative cooling (sweating), where body heat is transferred into sweat, which then evaporates, cooling the body. Sensory input: Nerve receptors in the skin detect physical stimuli. Vitamin D synthesis: Exposure to UV light enables the synthesis of vitamin D. Excretion of water and salts: Both water and salts are lost during evaporative cooling (sweating). Layers of the Skin 🌐 The skin is composed of three layers: Layer Description Epidermis The most superficial layer of the skin, composed of epithelial tissue and containing keratinocytes. Dermis The middle skin layer, located between the epidermis and the hypodermis, consisting mostly of connective tissue containing blood vessels for nourishment and nerve endings for sensation. Hypodermis The deepest layer, containing larger nerves and blood vessels, considered the subcutaneous layer, composed of connective tissue and fat which insulate the body and provide cushioning for underlying structures. Epidermis 🔍 The epidermis is the outermost layer of the skin, composed of epithelial tissue and containing keratinocytes. It protects against dehydration, UV radiation, and pathogens. Layers of the Epidermis 🔝 The epidermis is organized into five layers, also known as stratum: Layer Description Corneum The outermost, protective layer formed of corneocytes. Lucidum A layer of dead keratinocytes that are not yet differentiated into corneocytes, only present in palms and soles. Granulosum Contains keratinocytes that form a water barrier. Spinosum Contains keratinocytes with long extensions (spines), important for strength (desmosomes). Basale Precursor keratinocyte stem cells proliferate here, site of light touch sensation (Merkel cells) and melanin synthesis (melanocytes). A mnemonic to remember the order of the epidermal layers is: "Come, Let's Get Some Bagels" (Corneum, Lucidum, Granulosum, Spinosum, Basale). Dermis and Hypodermis 🌿 https://www.turbolearn.ai/content/72befddf-20d9-42ad-b382-d8617792cec6 1/2 9/9/24, 7:11 PM Overview of the Integumentary System Dermis The dermis is the middle skin layer, located between the epidermis and the hypodermis. It consists mostly of connective tissue containing blood vessels for nourishment and nerve endings for sensation. The dermis provides structural support to the skin and helps protect against injury. It is also the location of hair follicles in mammals. Hypodermis The hypodermis is the deepest layer of the integumentary system, housing blood vessels, nerves, connective tissue, and fat. The fat component of the hypodermis provides insulation and cushioning effects for the underlying structures. https://www.turbolearn.ai/content/72befddf-20d9-42ad-b382-d8617792cec6 2/2