Integumentary System

What structures comprise the integumentary system?

Skin, hair, nails, glands, and nerve endings.

What are the primary functions of the skin?

Protection, sensory input, excretion, immunity, vitamin D synthesis, and thermoregulation.

How does the skin thermoregulate?

Via sweat glands (evaporative cooling), the piloerection reflex ("goosebumps"), and blood vessel dilation or constriction.

What are the layers of the epidermis from external to internal?

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.

What are keratinocytes?

The main epidermal cells producing the waterproof protein keratin.

What are melanocytes?

Cells that produce melanin to protect against UV light.

What are Langerhans cells?

Immune cells in the epidermis that detect pathogens and initiate immune responses.

What are Merkel cells?

Specialized skin cells connected to sensory neurons acting as mechanoreceptors.

What characterizes the dermis?

The thick middle layer of dense connective tissue providing strength and elasticity, containing hair follicles, glands, nerve endings, and blood vessels.

What mechanoreceptors are found in the skin?

Tactile (Meissner's) corpuscles (light touch) and Lamellar (Pacinian) corpuscles (vibration and deep pressure).

What are the types of sudoriferous (sweat) glands?

Eccrine glands (everywhere, regulate temperature) and Apocrine glands (armpits and pubic regions, pheromones).

What do sebaceous glands secrete?

Sebum onto hair follicles to moisturize skin and prevent microbial growth.

What do ceruminous glands produce?

Wax in the ear canal to trap pathogens and debris.

What is the hypodermis?

The deepest layer of loose connective tissue and adipose tissue acting as a shock absorber, insulator, and energy storage.