BIOL 430 - LABORATORY #3
Integumentary System
References:
Text: Chapter 5
Lab Manual: Exercise 5 – The Integumentary System
MasteringA&P > Study Area > PAL:
- Anatomical Models > Integumentary System
- Histology > Integumentary System
Pre-Lab Assignments: p. 124-125
Learning Objectives:
1. Identify the tissue, cells and layers of the epidermis.
2. Identify the tissues and layers of the dermis.
3. Identify the glands, muscle and sensory structures of the skin.
4. Identify the anatomical features of the epidermis, dermis and hypodermis from light
micrographs.
5. Describe the features of the selected pathologies.
Cutaneous membrane
Epidermis:
Keratinized stratified squamous epithelium
Cells:
Keratinocytes
Melanocytes
Tactile epithelial (Merkel) cells + free nerve ending = Tactile disc
Dendritic cells (Langerhans cells)
Layers:
Stratum
Stratum
Stratum
Stratum
Stratum
basale
spinosum
granulosum
lucidum (thick skin only)
corneum
Thick vs. Thin Skin
Differences in # of layers in various strata
Presence/absence of stratum lucidum
Presence/absence of sebaceous glands and hair
Thickness of dermis
Dermis:
Papillary layer:
Areolar connective tissue
Dermal papillae – these projections form the epidermal ridges (fingerprints)
Blood vessels – Subpapillary plexus
Receptors: Refer to Chapter 13 – Table 13.1; p. 491-492
Free nerve endings
Free nerve ending associated with Tactile cells – Tactile disc
Tactile (Meissner) corpuscles
Reticular layer:
Dense irregular connective tissue
Blood vessels – Dermal vascular (cutaneous) plexus
Hair follicles (do not need to know details of hair structure on p. 132)
Arrector pili muscle and sebaceous glands associated with hair follicles
Glands
Sebaceous glands:
Ducts generally open into hair follicles
Produce sebum
Holocrine – mode of secretion
Sweat (sudoriferous) glands:
Eccrine - Watery secretion – body temperature regulation
Ducts open to skin surface
Apocrine - Secretions rich in proteins and fats
Axillary, nipple, anogenital areas
Ducts open into hair follicles
(deeper location in dermis compared to eccrine)
Merocrine – mode of secretion
Receptors:
Refer to Chapter 13 – Table 13.1; p. 491-492
Lamellar (Pacinian) corpuscle
Hair follicle receptor (root hair plexus)
Bulbous corpuscles (Ruffini endings)
Hypodermis (Subcutaneous layer):
Adipose and Areolar connective tissues
Highly vascular