BIO 304 . Human Anatomy & Physiology . American River College
Skin Functions and Accessory Structures
Module 4 . Integumentary System
Protection, thermoregulation, sensation, vitamin D; plus hair, glands, and nails. Watch the video, then complete the retrieval check below to unlock your spaced-recall cards.
How to use this sheet Toggle the toolbar above. Notes prints the full reference for review. Study prints as a fill-in-the-blank worksheet, print it, then write each definition while you watch the video or read your book. Quiz me is on-screen typing practice; type the term, click Reveal to check yourself.
- List the seven major functions of the integumentary system and identify the structure responsible for each.
- Trace the role of sweat glands and dermal vasculature in thermoregulation.
- Identify the accessory structures (hair, glands, nails) and the layer of skin each is anchored in.
Major functions
- Barrier (physical, chemical, biological)Keratin and lipids in the epidermis block water loss and pathogen entry. · Acid mantle (pH 4 to 6) discourages microbial growth.
- ThermoregulationSweat glands: evaporation cools the body. · Dermal vessels dilate or constrict: dump heat or conserve it.
- SensationMeissner (light touch), Pacinian (pressure), Ruffini (stretch), free nerve endings (pain, temperature).
- Vitamin D synthesisUV-B converts 7-dehydrocholesterol in the epidermis to cholecalciferol (D3).
- Limited excretionSweat carries small amounts of urea, salts, and water.
Accessory structures
- Hair follicleAnchored in dermis. Arrector pili muscle pulls hair upright (goosebumps). Sensory function via root hair plexus.
- Sebaceous glandConnected to hair follicle. Secretes sebum (oily, antimicrobial). Acne starts when these clog.
- Eccrine sweat glandThroughout body surface. Watery sweat for thermoregulation. Independent of hair follicles.
- Apocrine sweat glandAxillae, groin, areolae. Develops at puberty. Thicker secretion, bacterially modified to produce body odor.
- NailHard keratin plate over the nail bed. Protects the distal phalanx and improves fine motor function.
Step 3 . Retrieval check
Now explain it back, in your own words.
In 60 words or more, pull together what the video just taught you. Include the key concepts. This is the point where the learning actually sticks. After you submit, your spaced-recall cards for this topic unlock.
Zoomed image
Spaced recall unlocked
Nice work finishing the video.
Your spaced-recall cards for this topic are ready. Open the pre-work to activate them and start drilling.