Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
THE SKIN (INTEGUMENTARY SYSTEM) Rhonda Ghorbani, MD Reading: Klein and McKenzie, pp 211-219; Gartner and Hiatt Chapter 11, p217 Learning Objectives: List the basic functions of the skin and describe its overall structure Describe basic skin embryology State the names of the layers of the epidermis and how to distinguish them histologically Explain ultrastructural (electron microscopic) features of the epidermis and the epidermal/dermal junction Describe the process of keratinization in the epidermis, hair, and nail Describe the formation of the water barrier in the epidermis Name the non-keratinocytic cells in the epidermis and state their functions Explain the structure and components of the dermis, including types of nerves and vascular system State the segments and layers of the hair follicle Describe the relationship between hair size and phase of hair growth Describe the structure, location, and function of different types of cutaneous glands Describe the structure and growth of the nail Key Words: arrector pili muscle, dermal papillae (dermal ridges), dermal sheath, dermis, duct of sweat gland, epidermis, external root sheath, glassy membrane, hair bulb, hair follicle, hair matrix, hair papilla, hair root, hair shaft, hypodermis, internal root sheath, interpapillary pegs (rete pegs), Meissner's corpuscle, melanocytes of epidermis, melanosomes (melanin granules), myoepithelial cell, Pacinian corpuscle, papillary layer of dermis, reticular layer of dermis, sebaceous gland, stratum basale, stratum corneum, stratum granulosum, stratum lucidum, stratum spinosum, sweat gland INTRODUCTION Skin is one of the largest organs in the human body, representing 15-20% of total body weight. It serves many functions, including: S – SENSATION (it is a receptor for pain, pressure, touch, temperature) C – CONVERSION (of precursor molecules into vitamin D) R – REGULATION (of heat) A – ABSORPTION (of certain lipid-soluble therapeutic substances) P E – EXCRETION (of waste products via sweat glands) The skin can be divided into compartments:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EMBRYOLOGY Epidermis: single-layered ectoderm multilayered periderm stratified squamous epithelium o Vernix caseosa: desquamated periderm/epidermis; slippery; protective and aids in birth Dermis: mesoderm mesenchyme dermis composed of multiple cell types Hair: epidermal invagination lanugo hairs (fine, lightly pigmented) mature hairs Melanocytes: neural crest become melanoblasts in mesenchyme mature in epidermis EPIDERMIS Avascular layers of keratinocytic and non-keratinocytic cells Thickness ranges from 0.1 – 1.0 mm, depending on location o The terms “thin” and “thick” skin refer to the thickness of the epidermis o Thin skin = hairy skin (most of the body) o Thick skin = hairless skin (glabrous skin on palmar/plantar surfaces, i.e. palms/soles)
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 16


This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online