Lab Activity 5 The Integumentary System Martini Chapter 5 Portland Community College BI 231 Skin Epidermis Superficial layer Made of stratified squamous keratinized epithelium 4 5 Layers Dermis Underlying connective tissue layer 2 Layers Hypodermis Not part of the skin it is deep to the dermis Primarily adipose tissue 2 Layers of the Epidermis 1 Stratum corneum Outermost layer 20 30 cell layers thick Cells are dead and flattened Full of keratin Constantly being rubbed off 2 Stratum lucidum Thin translucent layer of dead keratinocytes Found only in thick skin 3 Layers of the Epidermis 3 Stratum granulosum Cells contain granules The upper part of this layer has cells that are beginning to die Lamellated granules contain a waterproofing glycolipid that is secreted into the extracellular space Keratohyaline granules combine with intermediate filaments to form keratin fibrils 4 Layers of the Epidermis 4 Stratum spinosum several cell layers Cells also dividing Cells contain bundles of intermediate filaments made of pre keratin 5 Stratum basale single row of cells Adjacent to the dermis Constantly dividing and pushing up layers 5 6 Dermis The dermis is the connective tissue layer under the epidermis 1 Papillary Layer Superficial dermal region Areolar connective tissue Contains capillaries lymphatics and sensory neurons Dermal Papillae the fingerlike projections from the superior surface Epidermal ridge The epidermal layer that dips down into the dermal papillae Create fingerprints 7 Epidermis Epidermal ridge Papillary Layer Dermal Papillae Reticular Layer 8 Finger Prints Epidermal Ridge 9 Dermis 2 Reticular Layer Deepest skin layer Dense irregular connective tissue Contains the arteries veins sweat and sebaceous glands Cleavage lines the deep creases like in the palm where collagen and elastic fibers are arranged in parallel bundles 10 Cleavage Lines 11 Hypodermis Dermis Subcutaneous layer that is not part of the skin Beneath the dermis layer Composed of adipose and areolar connective tissue Hypodermis Highly vascular 12 Cells of the Epidermis Keratinocytes The main cells of the epidermis Produce keratin a fibrous protein that gives skin its durability and protective capabilities Melanocytes Spidery black cells In stratum basale Produce melanin the pigment that protects skin from UV damage 13 Cells of the Epidermis Langerhans Cells Also called epidermal dendritic cells In stratum spinosum Macrophages that migrated from the bone marrow that phagocytize pathogens Immunologic surveillance cells 14 Cells of the Epidermis 15 Hair Root Everything that is not sticking out of the skin Shaft The part sticking out of the skin Bulb Active growing site 16 Hair Histology 17 Arrector Pili Muscle Arrector pili muscle Smooth muscle that pull hair upright during fright or cold goose bumps 18 Apocrine Sweat Glands Apocrine glands secrete a protein and fat rich substance that bacteria can use for nutrients creates body odor Found in the armpits around nipples and in the pubic region Secrete products into hair follicles or directly onto the surface Begin functioning at puberty 19 Apocrine Sweat Glands Red arrow Apocrine Sweat Glands Green arrow Hair follicle 20 Eccrine Merocrine Sweat Glands Eccrine sweat glands are not associated with hair follicles Ducts open directly on the surface of the epidermis 21 Sebaceous Glands Sebaceous glands Produce oily substance called sebum Helps waterproof the skin Acne infection of the sebaceous gland 22 Sebaceous Follicle Sebaceous glands not associated with hair follicles Secrete their product directly on the skin surface Located on face back chest nipples and external genitalia 23 Pancinian Lamellated Corpuscle Lie deep in the dermis Respond only when deep pressure is first applied Monitor high frequency vibrations 24 Meissner s Tactile Corpuscle Located in the dermal papillae Receptor for light touch 25 Merkel Cells Merkel Cells At the junction of the sensory nerve endings In stratum basale 26 Fingernails Scale like modification of the epidermis Free edge part that grows away from the finger Body visible attached portion Root Embedded in skin and sticks to the nail bed Nail Bed Extension of the stratum basale beneath the nail Nail Matrix Proximal part of the nail bed responsible for nail growth Lunula white crescent area Most active growth region of nail matrix 27 Fingernail Structures 28 Lab Activity 6 Body Membranes Martini Chapter 4 Pages 129 131 Body Membranes The majority of the body s structures are lined by epithelial membranes An epithelial membrane is a continuous multicellular sheet composed of epithelium bound to an underlying layer of connective tissue 30 Epithelial Membranes Cutaneous skin Mucous lines body cavities open to the exterior e g digestive and respiratory tracts Serous moist membranes found in closed ventral body cavity mesothelium for reducing friction 31 Epithelial Membranes Serous 32 Mucous Membrane Line all body cavities open to the exterior Epithelial cells resting on a lamina propria loose connective tissue Goblet cells columnar epithelial cells with large mucus containing vacuoles Usually secrete mucous but not always Respiratory tract GI tract Urinary tracts Genital tracts 33 Mucous Membrane 34 Serous Membranes Line all body cavities closed to the exterior and the internal surface of the organs Simple squamous epithelium with small amount of areolar connective tissue Is double layered Parietal layer covers the cavity Visceral layer covers the organs There is serous fluid between the layers to reduce friction when they slide against each other 35 Serous Membranes 36 Parietal Layer Special name depending on the organ it is associated with Parietal peritoneum covers abdominal wall Parietal pleura covers chest cavity Parietal pericardium outside layer of sac surrounding the heart 37 Pericardial Membranes 38 Pleural Membranes 39 Peritoneal Membranes Parietal peritoneum is the blue line Visceral peritoneum is the pink lines Peritoneal cavity is the gray 40 Synovial Membranes Composed entirely of connective tissue Line cavities of joints Secrete synovial fluid for lubrication 41 Lab Activity 7 Bone Histology Martini Chapter 6 Bone Tissues Spongy Bone Honeycomb of small needle like pieces called trabeculae Organized in an open framework Provides considerable strength with reduced weight The open spaces between the trabeculae are filled with bone marrow 43 Bone Tissue Compact Bone Bones are composed of both compact and spongy bone tissue