KAAP309 Lecture Notes - Lecture 5: Stratified Squamous Epithelium, Keratinocyte, Intermediate Filament
10 Apr 2018
School
Department
Course
Professor
Document Summary
Biological: dendritic cells in epidermis, macrophages in dermis. Synthesizes vitamin d precursor (in presence of sunlight) Up to 5% of total blood volume. Consists of two (or three) major regions. Hypodermis (superficial fascia)-- a layer of loose connective tissue below the dermis (some say it"s not part of skin) Composed of keratinized stratified squamous epithelium, consisting of four distinct cell types and 4 or 5 layers. Cell types include keratinocytes, melanocytes, merkel cells, and langerhans" cells. Outer portion of the skin is exposed to the external environment and functions in protection. Langerhans cell(= epidermal dendritic cells)-- epidermal macrophages that help activate the immune system. Merkel cells--functions as touch receptors in association with sensory nerve endings. Layers of the epidermis-- stratum basale (basal layer) Deepest epidermal layer firmly attached to the dermis. Consists of a single row of the youngest keratinocytes. Cells undergo rapid division, hence its alternative name, stratum germinativum. Layers of the epidermis-- stratum spinosum (prickly layer)
