tailieunhanh - Ebook Lippincott's pocket histology: Part 2

(BQ) Part 2 book "Lippincott's pocket histology" presents the following contents: Integumentary system, digestive system, respiratory system, urinary system, endocrine system, male reproductive system, female reproductive system. | Integumentary System 8 introduction The integumentary system is composed of skin which is comprised of the epidermis and dermis. Found within skin are numerous accessory structures such as glands sensory structures hair and nails. The hypodermis lies deep to the dermis and is often composed of adipose connective tissue though it is not a part of the skin sensory and accessory structures of the skin may be found in this layer. Skin can be classified into thick and thin skin. THE INTEGUMENTARY SYSTEM r THICK SKIN Structure Function Location Epidermis Keratinized stratified squamous epithelium composed mostly of keratinocytes that are organized into five layers or strata 1. Corneum Keratinized anucleate cells 2. Lucidum Newly keratinized anucleate cells 3. Granulosum Flattening cells filled with keratohyaline granules Protection from friction and desiccation 1. Protection and waterproofing 2. Protection and waterproofing 3. Keratin fiber organization initiation of keratinization Palms and soles Superficial Deep continued 115 LIPPINCOTT S POCKET HISTOLOGY r THICK SKIN continued 1 Structure Function Location Epidermis 4. Spinosum 4. Keratinocyte Mature kerati- maturation nocytes 5. Basale Single 5. Where skin layer of cuboi- stem cells and dal stem cells FsY melanocytes and melanocytes .si yr V 1 reside ỷ y. . Jpg Dennis Connective tis- Provide support Deep to epi- sues organized to epidermis and dermis into two layers connect it to hypodermis 1. Papillary der- 1. Contain blood 1. Superficial mis Loose con- and nerve 20 of the nective tissue supplies to dermis 1 V the epidermis Wl cushion - L y shock absorp- tion 2. Reticular der- 2. Structural 2. Deep 80 mis Dense support of the irregular con- - strength and dermis nective tissue elasticity Additional Concepts Dermal papillae Finger-like papillary dermal tissue extensions increase surface area for epidermal and dermal contact. At sites that encounter high mechanical stress dermal papillae are longer and closely packed.