Download Lecture 1 – Anatomy Basics

Biology 218 – Human Anatomy
Integumentary System
Clemens
Text: Chapter 5
Learning Objectives
1. Describe the two major regions of the skin and identify the tissues that form them.
2. Identify the cell types and layers of the epidermis.
3. Differentiate between thin skin and thick skin.
4. Describe accessory structures of the skin, including hair, nails, and skin glands.
A. Functions of the Skin
protection
body temperature regulation - sweat, circulation
sensation
metabolic functions - vitamin D synthesis
B. Structure of the Skin
1. Epidermis
- keratinized stratified squamous ET
Cell types:
keratinocyte
melanocyte
Langerhans cell
Merkel cell
Layers:
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum (thick skin only)
stratum corneum
2. Dermis
papillary region - areolar CT
reticular region - dense irregular CT
3. Subcutaneous layer = hypodermis
C. Types of Skin
1. Thin skin
2. Thick skin
D. Accessory Structures
1. Hair
2. Nails
3. Skin Glands
sebaceous glands
sudoriferous (sweat) glands
eccrine sweat glands
apocrine sweat glands
ceruminous glands (ear wax)
E. Sensory Receptors in the Skin
tactile disc (Merkel disc)
corpuscle of touch (Meissner corpuscle)
lamellated corpuscle (pacinian corpuscle)
free nerve endings
Additional terms:
Epidermis
epidermal ridges
melanin
Dermis
dermal papillae
lines of cleavage
Hair
shaft
root
bulb
medulla
cortex
cuticle
hair follicle (= epithelial
root sheath)
dermal root sheath
papilla of the hair
hair matrix
arrector pili
vellus hairs
terminal hairs
Nails
nail body
nail root
lunula
eponychium (cuticle)
hyponychium
Biology 218 – Human Anatomy
Clemens
Study Questions
1. What are the two major regions of the skin and what specific tissues are found in
each region?
2. What types of cells are found in the epidermis and what are their functions?
Which cell type is most abundant?
3. List and describe the five layers of the epidermis in thick skin.
4. What substances produce the pigmentation (color) of the skin?
5. Distinguish between the papillary region and the reticular region of the dermis.
6. What are lines of cleavage in the skin and why are they important clinically?
7. Identify the parts of a hair and a hair follicle. What type of tissue forms the hair
follicle? What is the hair matrix and the papilla of the hair?
8. Distinguish between vellus hairs and terminal hairs.
9. What is an arrector pili? What type of tissue is it composed of? What structures in
the skin is it attached to? List two reasons why the arrector pili might contract.
10. Describe and differentiate between sebaceous glands and sudoriferous (sweat)
glands. Where specifically are sebaceous glands found? Identify where on the
body you would find eccrine sweat glands and apocrine sweat glands.