Exam 2Ch. 5 Integumentary System (skin)  Integumentary system functions Protection Temperature regulation Sensation Vitamin D production Blood reservoir Excretion Glands of integumentary system  Suderiferous glands (sweat) Eccrine (merocrine): produce clear perspiration  Apocrine: have proteins and fat rich substances in sweat, white sweat  Ceruminous: produce ear wax  Mammary: produce milk  Sebaceous gland (oil)  Hair structure Shaft: portion projecting from scalp surface Root: portion enclosed within the follicle  Medulla: innermost layer of hair shaft  Cortex: thickest hair layer, contains hair pigment  Cuticle: outermost layer of hair, formed from dead cells which form a barrier that gives hair shaft strength Follicles (hair bulb, connective tissue root sheath, basement membrane, epithelial root sheath, hair matrix, arrector pili muscle) Layers of integument  Epidermis Stratified: multiple layers of cell Uppermost layers are flat, avascular Keratinized stratified squamous epithelium  Cells- Keratinocytes: most cells are filled with keratin, helps protect things from penetrating into deeper tissues, produce keratin, 90% of cells - Melanocytes: produce pigment melanin, stain deeper layers of epidermis- Epidermal dendritic cells: macrophages, immune defense- Tactile cells: for the use of touch - Dendritic cells: phagocytize invading pathogens  Layers- Stratum cornuem, lucidum, granulosum, spinosum, basale  Dermis Dense irregular connective tissue Layers: these layers give skin its elasticity- Papillary layer: composed of areolar connective tissue, very uneven, has fingerlike projections, furnish nutrients, allow heat to radiate to skin surface, consists of pain and touch receptors, regulation of body temp Dermal ridges: finger like projections that produce fingerprints- Reticular layer: deepest skin layer, dense irregular connective tissue, has many arteries and veins, sweat and sebaceous glands, and pressure receptors Hypodermis: innermost and thickest layer of skin, acts as an energy reserve  Skin color Pigments that produce skin color Melanin: a lot = brown skin, a little = white skin  Hemoglobin: pigment that gives blood its color, produces rosy complexion  Carotene: yellow-orange pigment present primarily in the stratum corneum and the adipose tissue in the hypodermis, carrots = carotene rich food  Patterns of global variation in colorCh. 6 Bone cells Osteoblasts: bone forming cells that secrete osteoid Osteocytes: mature bone cells  Osteoclasts: degrade bone matrix and release Ca2+ into blood  Osteoprogenitor cells: work in the growth or repair of bones  Bone composition Organic components Collagen fibers: found in matrix, bone flexibility  Inorganic components Calcium salts: give the bone its hardness  Bone marrow  Yellow: adipose tissue Location: medullary cavity Red: forms blood cells  Location: in children = marrow cavities, adults= spaces between trabeculae of spongy bone  Compact and spongy bone Compact bone (cortical bone) Looks smooth and homogeneous  Long bone, flat bones,  Spongy bone (cancellous/trabecular bone) Composed of small trabeculae (bars) of bones and lots of open space  Short bones, flat bones  Gross anatomy of long bone Diaphysis: shaft of long bone, made up of cortical bone and contains bone marrow and adipose tissue (fat)  Medullary cavity: central cavity of shaft, where red/yellow bone marrow is stored  Metaphyses: wide portion of a long bone, considered part of the growth plate, part of the bone that grows during childhood Epiphyseal line: line that forms when cartilage is done helping bone grow Epiphysis: rounded end of the long bone  Periosteum: a thin layer of connective tissue that covers most of the external surface of the bone  Endosteum: contains osteoblasts and osteoclasts, lines the shaft  Nutrient foramen: external opening for the entrance of blood vessels in a bone Hormonal control of bone remodeling in response to blood calcium levels Parathyroid hormone and its effect Stimulates the generation of new osteoclasts Regulates blood calcium levels Increases blood calcium levels by stimulating osteoclasts which break down bone and release calcium into blood stream  Ossification process  Endochondral ossification: cartilage bone formation Except for the collar bones, all bones of the body inferior to the skull form in the embryo by this process, uses hyaline cartilage bones as patterns for bone formation, begins in the center of the shaft of a developing bone Intramembranous ossification Helps during fetal development, rudimentary bone tissue is created, process during natural healing of bone fractures, no cartilage present during this, rudimentary formation of bones of head  Osteon structure: a central canal and all the concentric lamellae surrounding it Central canal Haversian canal: arrangement is conductive to mineral salt deposits and storage which gives bone tissue its strength  Lacunae: chambers within dense bone matrix which contain living bone cells  Lamellar bone: compact bone Volkmann’s canals (perforating canals): these canals run at right angles to the shaft and complete the communication pathway between the bone interior and its external surface  Canaliculi: tiny canals radiating outward from a central canal to the lacunae of the first lamella and then form from lamella to lamella, allow each cell to take up what it needs for nourishment  Osteogenic tissues (location and function)PeriosteumEndosteum Osteogenic: originating in the bone, produces bone  Bone repair A hematoma forms Fibrocartilaginous callus forms Bony callus forms Bone remodeling occurs Ch. 7 Axial skeleton: bones that lie around body’s center of gravity Appendicular skeleton: bones of limbs, or appendages  Names and locations and relative positions of all bones emphasized in class Skull (Cranium, Facial bones) Thoracic cage (Ribs, sternum) Vertebral column Vertebrae (cervical, thoracic, lumbar, sacrum, coccyx) Bones of pectoral girdle (clavicle, scapula)  Upper limb Arm (Humerus)  Forearm- Ulna, Radius - Hand (Carpals, Metacarpals, Phalanges) Bones of pelvic girdle Coxal bones (Ilium, ischium, Pubis)  Lower limb  Thigh (femur)