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43 Cards in this Set
- Front
- Back
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what is the integumentary system?
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skin.
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what are the functions of the integumentary system?
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protection, sensation, temperature regulation, vitamin D protection, excretion.
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what is the epidermis?
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outer part of the skin, made of stratified squamous epithelium, no blood vessels, older cells are filled with keratin and die, melanin (pigment), older cells are pushed superficially.
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thick skin
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palms, bottom of feet
many layers in stratum corneum |
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thin skin
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lacks stratum lucidum, has hair
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skin color
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melanocytes produce melanin in melanosomes
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vitamin d
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produced by cells in epidermis
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dermis
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inner part of the skin, made of connective tissue, 2 layers - deep: reticular layer and superficial: papillary layer (fingerprints)
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hypodermis
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not part of the school, also called subcutaneous tissue, a lot of adipose tissue
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accessory skin structures
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hair, glands, nails
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hair follicle
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hair bulb - base of hair root
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hair root
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hair grows in stages: growth, then rest.
matrix cells that divide, get keratinized, then die. |
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medulla
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inner core of hair
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what determines hair color?
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melanin
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smooth muscles (arrector pili)
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contraction makes hair stand on end, improves heat insulation, creates larger appearance.
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sebaceous glands
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produce oily secretion, holocrine type, the duct usually opens into upper part of the hair follicle
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sweat glands
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merocrine or aprocrine with openings directly on the surface or into the hair follicle
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ceruminous glands
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modified merocrine sweat glands, produce cerumen
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mammary gland
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modified aprocrine sweat glands, produce milk.
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nails
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dead cells, modified stratum comeum
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what are functions of the skeletal system?
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support, protection, movement, storage (calcium, phosphorus, fat), blood cell production.
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what is the most important cartilage for the skeletal system?
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hyaline cartilage (elastic)
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what forms cartilages extracellular matrix?
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chondroblasts (build)
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what live in lacunae (small holes)?
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chondrocytes (maintain)
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what is perichondrium?
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connective layer covering cartilage to protect the cartilage
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what is articular cartilage?
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cover bones in joints (lubrication and low friction)
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what is the extracellular matrix of bones?
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calcium phosphate for storage
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what is ossification or osteogenesis?
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the process of creating bone, using osteoblasts
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what are osteocytes?
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live in lacunae, they are connected to each other by processes called canaliculi (small canals), maintain bones
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osteoclasts
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they destroy bone by reabsorbing bone matrix by decalcifying in an acidic environment or releasing proteolytic enzymes.
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what are bone cells produced from?
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stem cells.
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which two ways can bone fibers be oriented?
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woven- oriented randomly, usually new bone, remodeling may take place to remove woven bone and replace with lamellar
lamellar- same direction, sheets called lamellae, tougher and stronger |
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which are the two densities of bones?
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cancellous or compact
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cancellous
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spongy
has trabeculae oritned along the stress in the bone formed by lamellae |
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compact
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much more dense
osteon- circular, formed by cylinders central canal with blood vessels concentric lamellae with osteocytes outer surface= circumferential lamellae perforating canals- run perpendicular to the long axis BONES BLEED IF BROKEN |
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types of bones
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long (limbs), short (wrist), flat (skull) or irregular
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long bones
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limbs, toes, fingers
diaphysis (shaft)- mostly compact bone epiphysis- develops from different center of ossification (hump on end of bone) growth occurs at the epiphyseal plate medullary cavitiy filled with marrow (hollow inside) periosteum- connective tissue membrane covering the bone |
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what do flat and irregular bones in the skull have?
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sinuses filled with air instead of marrow
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intramembranous ossification
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on collagen membranes, development of skull bones
outside of bones are younger |
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endeochondral ossification
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at the surface of cartilage
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bone growth
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length- add more bone on ends to increase length
width- rapid growth (osteon formation), slow growth (circumferential lamellae, the remodeling into osteons) |
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what factors are needed for bone growth?
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vitamin D- absorption of calcium from intestines (lack->rickets)
vitamin C- collagen synthesis (lack->scurvy) hormones (growth, thyroid, sex) |
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bone repair
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hematoma formation, callus formation, callus ossification, bone remodeling
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