Overview
This lecture introduces the integumentary system, focusing on the skin, its structure, and main functions, including protection, immunity, sensation, and thermoregulation.
Integumentary System Overview
- The integumentary system is made up of the skin and its appendages (nails, hair, sweat glands).
- Appendages include hair, nails, and various glands associated with the skin.
- The skin is the largest organ of the body, weighing about 21 pounds.
Functions of the Skin
- The skin acts as a barrier, being impermeable to water and prevents entry of harmful molecules like viruses.
- It plays a role in immunity by secreting antibodies and enzymes (like lysozyme) that fight pathogens.
- Langerhans cells in the skin help capture and destroy invading bacteria.
- The skin provides sensation, allowing perception of pain, temperature, and various types of touch.
- It helps in thermoregulation (body temperature control) through sweating and blood vessel dilation/constriction.
Key Terms & Definitions
- Integumentary system — consists of skin and appendages (hair, nails, glands).
- Appendages — structures associated with the skin, such as hair, nails, and sweat glands.
- Lysozyme — enzyme secreted by skin to break down bacterial cell walls.
- Langerhans cells — immune cells in the skin that ingest pathogens.
- Thermoregulation — process of controlling body temperature, partly through sweat and blood flow changes.
Action Items / Next Steps
- Review the main functions of the skin.
- Prepare for upcoming lessons detailing the structure and specific functions of skin appendages.