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92 Cards in this Set
- Front
- Back
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What is the hypodermis?
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Subcutaneous tissue just deep to the skin. Not part of skin but shares skins protective functions. Also referred to as superficial fascia because it is superficial to the tough connective tissue wrapping (fascia) of skeletal muscles, consists mostly of adipose tissue.
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What is the epidermis?
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Keratinized stratified squamous epithelium consists of 4 distinct cell types and 4 or 5 layers.
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What are the cells of the epidermis?
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Keratinocytes, melanocytes, dendritic, and tactile cells
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What is the role of keratinocytes?
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To produce keratin which is the fibrous protein that helps give the epidermis it's protective properties. Most epidermal cells are keratinocytes
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What is callus?
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Persistent friction causes a thickening of epidermis
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Where do keratinocytes come from?
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Stratum basale
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What are melanocytes?
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Synthesize pigment melanin. Are found in the deepest layer of the epidermis. They accumulate on sunny side of keratinocyte nucleus forming a pigment that protects the nucleus from the damaging effect of the suns uv light.
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What are dendrite cells?
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Star shaped dendritic cells that arise from bone marrow and migrate to epidermis. Also referred to as langerhans cells. The ingest foreign substances and key activators of our immune system.
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What are tactile cells?
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Tactile or (Merkel) cells are present at the epidermal-dermal junction. Serves as a sensory receptor for touch.
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What are the names of all the skin layers?
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Stratum basale, spinosum,granulosum,lucidum, and corneum.
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What is the stratum basale?
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The deepest epidermal layer consists of single layer stem cells.some newly formed cells become part of the more superficial layer see occasional melanocytes and dendrititic cells. Also referred to stratum germinativum or germination layer.
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What is the stratum spinosum?
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The prickly layer which is several layers thick of keratinocytes Unified by desmosomes. Cells contain thick bundles of intermediate filaments made of pre keratin.
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What is stratum granulosum?
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Thin layer consisting of 4 to 6 cell layers where keratinocytes appearance changes drastically , and the process of keratinization begins
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What are the two types of granules that appear from keratinization in the stratum granulosum?
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Keratohyaline granules which help form keratin in upper layers and lamellar granules that contain water resistant glycolipid that is spewed into the extra cellular space and is a major factor in slowing water loss across the epidermis.
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What is the stratum corneum?
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Outer most epidermal layer. Keratin and the thickened plasma membrane of cells in this stratum protect the skin from abrasion and penetration. Glycolipid between its spells nearly waterproof this layer. Dead cells that protect the body from external harm.
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What is the dermis?
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The second major skin region which is strong flexible connective tissue. It has two layers the papillary and reticular.
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What is the papillary layer?
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Thin superficial papillary layer is areolar connective tissue in which fine interlacing collagen and elastic fibers form loosely woven mat. Which is heavily invested in small blood vessels
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What does the papillary layer do?
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The looseness of this connective tissue allows phagocytes and other defensive cells to wander freely as they patrol the area for bacteria that have breached the skin.
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What is the dermal papillae?
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Peg like projections that indent overlying epidermis. Some contain capillary loops, others house pain receptors,and touch receptors. In thick skin they lay on large mounds called dermal ridges which help it gripping and sense of touch .
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What is the reticular layer?
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The deeper reticular layer accounting 80% of the thickness of the dermis , is course , irregularly arranged , dense fiberous connective tissue.
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What is the cutaneous plexus?
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Lies between the reticular hypodermis layer
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What are flexure lines?
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A third type of skin marking are dermal fold that occur at or near the joints.
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What are the three pigments that contribute to skin color?
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Melanin, carotene, and hemoglobin.
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What is melanin
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Is a polymer made of tyrosine amino acids. It's two forms range in color form reddish to yellow to brownish black. Only found in deeper layers of epidermis. It's synthesis depends on an enzyme in melanocytes called tyrosinase,
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What is carotene?
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It's a yellow to orange pigment found in certain plant products such as carrots. Carotene can be converted to vitamin A which is essential for normal vision. Accumulates in the stratum corneum and in the fatty tissue of the hypodermis.
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What is hemoglobin?
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The pinkish hue of fair skin reflects the crimson color of oxygenated pigment in red loos cells circulating through the dermal capillaries.
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What are the skin appendages that are part of the integumentary system?
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Hair, hair follicles, nails, sweat glands, and sebaceous oil glands.
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What is the pili?
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Are flexible strands produced by hair follicles and consist largely of dead keratinized cells.
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What are the two advantages of hard keratin?
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Tough and durable and it's individuals cells do not flake.
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What are the three concentric layers of keratinized cells in hair?
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The medulla, cortex, and cuticle
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What is the medulla?
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It's central core consists of large cells and air spaces. The medulla which is the only part of the hair that contains soft keratin is absent in fine hairs,
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What is the cortex?
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A bulky layer surrounding the medulla consisting of several layers of flattened cells.
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What is the cuticle?
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The outermost layer of the hair is formed from a single layer of cells overlapping one another. The most heavily keratinized part of the hair which provides strength and helps keep the inner layers tightly compact.
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Structures of hair follicle
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Fold down from the epidermal surface into the dermis. The skin surface expands to form an HAIR BULB. A knot of sensory nerve endings called Hair follicle receptors or ROOT HAIR PLEXUS WRAPS AROUND EACH HAIR BULB. HAIR ACTS AS A SENSTIVE TOUCH RECEPTOR.
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What is the hair papilla?
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A nipple like bit of dermal tissue that protrudes into the hair bulb. The papilla contains knot of capillaries that supples nutrients tot the growing hair and signals it to grow.
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What is the wall of hair follicle composed of?
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An outer peripheral connective tissue sheath or fibrous sheath derived from dermis a thickened basal lamina called the glassy membrane and an inner epithelial root sheath derived mainly from an invagination of the epidermis.
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Where is the hair matrix originated from?
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Hair bulge
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What is at rector pili?
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A bundle of smooth muscles associated with each hair follicle causes goosebumps
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Where is terminal hair found
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Pubic region, eyebrows, and scalp
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Where is vellum hair found ?
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Children n adult females
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What is hirsutism?
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Excessive amounts of hair
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What is alopecia?
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Baldness
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Nail matrix is responsible for what
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Nail growth
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Sweat glands
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Or sudoriferous glands are distributed over the entire body except certain parts of gentilia and and nipples two types of sweat glands apocrine and eccrine. Bothe associated with myoepthial cells to contact when stimulated by nervous system,
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What is eccrine glands
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Also called merocrine glands numerous in palm, soles of feet, and forehead, each is a simple coiled tubular gland. Secretory part lies in the dermis. And the duct open Ina funnel shaped pore.
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Secretion of eccrine gland commonly called what
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Sweat is a hypotonic filtrate of the blood that passes through the secretory cells of the sweat glands and is released in excoxyosis. Sweat is acidic with a PH of between 4 and 6
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What is apocrine glands?
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Approximately 2000. Largely confined to the axillary and anogenital areas . They are also merocrine glands but larger that eccrine glands lie deeper in dermis or even in the hypodermis and their ducts empty into hair follicles.
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What are ceruminous glands?
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Modified apocrine glands found in the lining of the external ear canal.
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What is the mammary glands?
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Specialized sweat glands secretes milk
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What are sebaceous glands?
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Or oil glands are simple branched alveolar glands that are found all over the body except in the thick skin of the palms and soles. Largely in face neck and upper chest.
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What are sebum?
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Oil substance secreted by sebaceous glands LOOK ON PAGE 162
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Function of skin
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Protection, body temperature regulation, cutaneous sensation, metabolic functions, blood reservoir, and excretion
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Three barriers of skin
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Chemical, physical, and biological.
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What does chemical layer protect from
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Include skin secretions and melanin. Acid mantle slows the multiplication of bacteria and low ph of skin secretions. Dermcidin in sweat and bactericidal substances ins sebum kill bacteria outright. Skin cells secrete antibiotics such as defensins. Wounded skin release large quantities of protective peptides called cathelicidins that are preventive of infection such as in streptococcus bacteria. Melanin shields from UV light.
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What does physical barrier protect from
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Prevent water loss bacteria invasion
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What are substances that DO penetrate the skin
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Lipid soluble substances, oleoresins, organic solvents, salts of heavy metals, and selected drugs
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What are the biological barriers?
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Dendritic cells, dermal macrophages, and DNA
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What is the skeletal structure made of
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Variety of cartilage tissue molded to fit its body location and functions. Cartilage consists primarily of water.
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Perichondrium
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The cartilage which contains no nerves or blood vessels is surrounded by a layer of dense irregular connective tissue.
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Three types of cartilage tissue
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Hyaline, elastic, and fibrocartlage.
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What is hyaline cartilage?
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Provides support and flexible and resilience . They are the most abundant skeletal cartilages. Their Chondrocytes are spherical and the only fiber type in their matrix is fine collagen fibers.
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What does skeletal hyaline cartilage include
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Articular, costal, respiratory, and nasal
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Elastic cartilages
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They contain more stretchy elastic fibers and so better able to stand up to repeated bending. They are found only two skeletal locations.
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Fibrocartlage
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Highly compressible with great tensile strength. It consist of roughly parallel rows of Chondrocytes alternating with thick collagen fibers. Fibrocartlage occurs in sites that are subjected to both preassure and stretch such as padlike cartilages of the knee and discs between vertebrae
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Cartilage is
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Has a flexible matrix which can accommodate mitosis. Cartilage is the ideal tissue to use in rapidly lay down th embryonic skeleton and to provide new skeleton growth
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What are the two ways cartilage grows
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Appositional growth from outside and interstitial growth from inside
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How many bones in human skeleton
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206 which are divided into two groups axial and appendicular
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What is axial skeleton composed of
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It forms long axis of the body and includes bones of the skull, vertebral column, and rib cage these bones support, protect, and carry out other body parts
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What is appendicular skeleton composed of
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Consists of the bones of the upper and lower limbs and the girdles shoulde bones and hip bones that attach the limbs to the axial skeleton
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What is function of appendicular skeleton
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Locomotion and manipulate our environment.
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What are classified as long bones in reference to limb bones
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All except patella, wrist, and ankle bones
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Examples of short bones
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Roughly cube shaped wrist and ankle bones are examples.
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What is sesamoid bones
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Special type of short bone hat form in a tendon such as patella
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Flat bones and their examples
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Thin flattened and usually a bit curved examples are sternum, scapulae, ribs, and most skull bones
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Irregular bones example
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Vertebrae and hip bone
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7 functions of bones
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Support, protection, movement, mineral and growth factor storage, blood cell formation, triglyceride storage, and hormone production.
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What is compact bone
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External layer of bone
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What is spongy bone
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Or trabeculae is the internal layer of bone in living bones the opens spaces between trabeculae are filled with red or yellow bone marrow.
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In flat bones the spongy bone is referred to as
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Diploe
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Diaphysis
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Is a shaft that forms the long axis of a bone with relatively thick collar compact bone that surrounds a central medullary cavity which in adults contains fat which is called yellow marrow cavity.
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Epiphysis
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Ends of the long bones contains spongy bone. A thin layer of hyaline cartilage covers the joint surface of each epiphysis.
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Periosteum
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Glistening white double layer membrane that covers the external surface of the entire bone except the joint surfaces. The outer fibrous layer of the periosteum is dense irregular connective tissue. The inner osteopenia layer consists primarily of primitive cells osteopenia cells that give rise to all bones except bone destroying cells.
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Endosteum
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Delicate connective tissue membrane that covers internal bone surfaces. The endosperm covers the trabeculae of spongy bone and lines the canals that pass through the compact bones,
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Where is red marrow found
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Typically found within the trabecular cavities of spongy bone of long bones and in the diploe of flat bones . This is why both these cavities are called red marrow cavities. In adults red marrow production routinely occurs long bones of the heads of the femur and humerus.
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Hemopeosis. Much more active in
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Diploe and irregular bones
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What are the five major cells of bone tissue
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Osteogenic, osteoblasts, osteocytes, bone lining cells, and osteoclasts
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Which one of the five major bone cells do not originate in the mesenchymal
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Osteoclasts
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Osteogenix cells
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Also called osteoprogenitor cells are mitotically active stem cells found in the membranous periosteum and endosteium . In growing bones they are flattened or squamous cells.
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When osteogenic cells are stimulated they differciate into what cells
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Osteoblasts or bone lining cells.
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Osteoblasts
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Are bone forming cells that secrete the bone matrix they are actively mitotic. The unmineralized bone they secrete includes collagen and calcium binding proteins that make up the initial unmineralized bone or osteoid. Also play a role in matrix calcification.
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What do osteoblasts become when completely surrounded by the matrix being secreted.
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Osteocytes
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Osteocytes
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Are mature
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