test 2

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test 2
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  1. skeletal system
    • composed-bones,cartilages,and ligaments;performs the following functions:
    • support-legs,pelvis,vertebral column
    • movement-thru leverage
    • protection-skull,vertebral col,rib cage,pelvis
    • storage-calcium,phosphate,other ions,lipids(yellow marrow)
    • blood cell production(red bone marrow)
  2. bone shapes
    long,short,flat,irregular,sesamoid
  3. long bones
    • long longitudinal axis,expanded ends
    • bones of arm,forearm&hand and thigh,leg and foot
  4. short bones
    cube-like,with roughly equal lengths and widths-bones of wrists and ankle
  5. flatbones
    plate like with broad surfaces-vranial bones of the skull,ribs,scapulae
  6. irregular bones
    usually connected to several other bones facial bones of the skull,vertebrae
  7. sesamid bones
    small-nodular,embedded in tendons adjacent to joins*patella
  8. types of bone tissue
    • compact bone-continuous extracellular matrix with no gaps surround
    • spongy bone-composed of branching bony struts(trabeculae) surrounded by spaces
  9. parts of long bone(epiphyses)
    expanded ends,articulate (from joints) with other bones,covered by hyaline articular (joint cartilage)*composed mostly of spongy bone enclosed by a thin layer of compact bone
  10. periosteum
    • (except the articular surfices covered by hyaline cartilage)surfice of bone is covered by periosteum it is composed of dense irregular connective tissue 
    • -continuous with ligaments and tendions
    • -contains blood vessels&nerves that enter the bone
    • -contains bone-forming cells
  11. epiphyses
    connected by epiphyseal plates/metaphyses(ossified in adults) to diaphysis-shaft
  12. diaphysis
    • composed mostly of compact bone surrounding spongy bone and medullary cavity,lined with endosteum(also coats trabeculae of spongy bone)-incomplete cell layer containing bone-forming&bone -dissolving cells
    • contains bone marrow(yellow in adults and found in spongy bone)
  13. structure of short,flat,and irregular bones
    • composed of spongy bone(containing bone marrow) surrounded by compact bone
    • external surface covered by periosteum(or hyaline cartilage at articular surfaces)
  14. bone tissue is what type of tisue
    supporting connective tissue
  15. osteogenic/osteoprogenitor cells
    (undifferentiated) stem cells in the periosteum and endosteum;give rise to osteoblasts
  16. osteoblasts
    bone forming cells in the periosteum and endosteum;non-mitotic
  17. osteocytes
    bone-maintaining and repairing cells trapped in lacunae of bone matrix and connected through cytoplasmic extensions & gap junctions in canaliculi;developed from osteoblasts
  18. osteoclasts
    • multinucleate bone-dissolving cells in the endosteum;formed by fusion of stem cells that give rise to monocytes(white blood cells);ruffled border faces the bone;reside in resorption bays
    • -extracellular matrix
    • -2/3 inorganic matter by weight mostly calcium phosphate salt,resists compression
    • 1/3 organic matter-collagen fibers and protein-carbohydrate complexes;resist tension
  19. nutrient foramina
    blood vessels and nerves enter bone tissue through perforationg (volkmanns) canals
  20. volkmanns canals
    carry blood vessels and nerves from nutriant foramina to central canals of compact bone
  21. concentric lamellae
    around central canals form cylindrical osteons
  22. circumferential lamellae
    form the outer layer adjacent to periosteum
  23. osteocytes
    in lacunae receive o2% nutrients from extracellular fluid surrounding blood vessels through cytoplasmic extensions in canaliculi
  24. spongy bone
    • blood vessels&nerves enter spaces through perforating canals of compact bone
    • concentric lamellae with no central canals form trabeculae
  25. periosteum
    contains outer(fibrous) and inner(cellular) layer.Collagen fibers of the periosteum are continuous with those of the bone,adjacent joint capsules,and attached tendons and ligaments
  26. endosteum
    a complete cellular layer containing osteoblasts, osteoprogenitor cells,and osteoclasts
  27. (intramembranous ossification)flat bone development
    1skull,mandible,and clavicles develop from vascularized sheets of undifferentiated connective tissue(mesenchyme)
  28. (intamembranous ossification)osteogenic cells
    2in the sheets give rise to osteoblasts, which rapidly deposit spongy bone with trabeculae of woven bone(collagen fibers randomly arranged; no lamellea)between them
  29. (intramembranous ossificaion) connective tissue becomes?
    3periosteum
  30. (intramembranous ossification)woven bone is replaced by
    4lamellar bone(collagen fibers arranged in parallel within lamellae)
  31. (intramembranous ossification)where do compact and spongy bone mature
    5lamellar
  32. (intramembranous ossification)how do layers of spongy bone matrix become compact
    6by filling in spaces with bony matrix
  33. (endochondral ossification) mostt bones develop from
    hyaline cartilage model
  34. (endochondral ossification)what does perichondrium become?
    1periosteum; its osteoblasts produce a bony collar of compact bone around the model,causing deposition of calcium phosphate in extracellular matrix(calcification of cartilage),cutting off nutrition to the chondrocytes
  35. (endochondral ossification)what happens to chonrocytes when they die
    2their lacunae enlarge
  36. (endochondral ossification)what happens at the primary(diaphysis and secondary(epiphyses)ossification centers?
    3vascular buds from the periosteum break down the cartilaginous lacunae,forming marrow cavity(in diaphysis)
  37. (endochondral ossification)what happens when osteoblasts invade the model
    4deposit spongy bone; becomes compact in most of the diaphysis and the surface of epiphyses
  38. (endochondral ossification)by the time of birth
    5only the epiphyseal plates are still composed of carilage
  39. where does bone growth occur
    epiphyseal plates until ossify at 23females and 25males becoming epiphyseal lines
  40. what happens at the epiphyseal plate at the layer nearest to the diaphysis
    (zone of calcified cartilage) ossifies,the layer near epiphysis(zones of proliferating&hypertophic cartilage) add more cartilage
  41. what does the hyposecretion of growth hormone does
    from pituitary gland;before maturity causes premature ossification of epiphyseal plates-pituitary dwarfism(short stature,normal proportions)
  42. what does hypersecretion of growth hormone do
    before maturity prevents ossification of epiphyseal plates,growth never stops(gigantism)
  43. achondroplasia
    abnormal cartilage formation due to mutation causes achondroplasia(head and torso of normal sie,shortened limbs)
  44. appositional growth(bone growth in girth)
    osteoblasts of periosteum deposit compact bone(circumferential lamellae)
  45. osteoclasts of endosteum enlarges what(growth in girth)
    the marrow cavity
  46. occurs simultaneously
    with growth in length after maturity in response to physical stress
  47. acromegaly(in girth)
    *hypersecretion of growth hormone after maturity.acromegaly-thickening of bones and soft tissues
  48. about remodeling  bone tissue
    osteoclasts and osteoblasts continually resorb and deposit bone tissue throughout life,remodeling it; 3-5% of bone calcium is exchanged each yr
  49. resorption and deposition
    highly regulated total bone mass in adult skeleton remains nearly constant
  50. hypertrophy
    exercise causes gain of bone mass
  51. atrophy
    lack of exercise causes loss of bone mass
  52. what does the hormone calcitonin do?
    • secreted by throid gland lowers blood
    • inhibiting osteoclasts and stimulating osteoblasts
    • increasing excretion of ca+2 by kidneys
  53. parathyroid hormone
    • secreted by parathroid glands increases blood ca+2(opposite calcitonin)
    • stimulating osteoclasts and inhibiting osteoblasts
    • decreasing excretion of ca+2 by kidneys
    • causing kidneys to convert vitamin D from inactive to active form,which increases Ca+2 absorption in intestine
  54. vitamin D crucial to bone tissue
    • increases ca+2 absorption in intestine
    • pro-vitamin d synthesied from dietary cholesterol by intestinal enzymes
    • converted to V D(cholecalciferol) by UV light in skin; further modified by liver;activatd kidney
    • eggs and in milk
    • ca+2&D poorly absorbed bones soft&deformed
    • rickets(children)osteomalacia(adults)
  55. Vitamin C
    • is required for collagen synthesis
    • present in fruits and vegetables
    • absence in diet causes scurvy
  56. greenstick fracture
    incomplete break,occurs on the convex surface of the bend in the bone
  57. fissured fracture
    involves an incomplete longitudinal break
  58. comminuted fracture
    complete and fragments the bone
  59. transverse
    complete break occurs at a right angle at a right axis of the bone
  60. oblique fracture
    occurs at an angle other than a right angle to the axis of bone
  61. spiral fracture
    caused by twisting a bone excessively
  62. healing of a bone fracture
    sped up by setting the setting of the bone(aligning at ends) immobilizing it in a cast
  63. healing bone fracture(broken ends r joined by)
    • internal callus composed of woven spongy bone
    • external callus composed of hyaline cartilage
    • replaced by compact lamellar bone
  64. bone marrow
    • occupies medullary avities of long bones and spaces between trabeculae of spongy bone
    • red marrow all bone marrow red at birth(hematopoiesis)produce red blood cells
    • yellow bone marrow replaces red bone marrow with age;mostly fat;does not produce blood cells;can transform into red bone marrow in the event of servere or cronic anemia(decrease in number of red blood cells)
  65. aging skeletal system
    • after age 30 osteoblasts become less active than osteoclasts-reabsorption outpaces deposition causing osteopenia(bone loss)*reducing bone density
    • osteoporosis-servere osteopenis compromising physical health and activity common in white postmenopausal women(weakens bones in compression,maycause kyphysois(widows hump),makes fractures esp. of thigh bone(hip fracture likly) 50% of people over 50 have osteopenia or osteoporosis
    • reduced protein synthesis by osteoblasts makes bones more brittle-fracture more easily and heal slower
  66. joints
    articulations-points contact between 2 bones;makes possible bone growth and movement
  67. synarthrosis
    immovable
  68. amphiarthosis
    slightly movable
  69. diarthrosis
    freely movable
  70. fibrous joints
    bones in close contact connected by dense connective tissues(with many collagen fibers)
  71. fibrous suture
    suture flat bones of skull held by sutural ligament smooth& amphiarthrotic in newborns,interdigitating& synartrotic in adults
  72. gomphosis fibrous
    root of tooth held in alveolus by periodontal ligament; synartrotic
  73. sydesmosis fibrous
    long bones ulna&radius tibia&fibula) connected interosseous membrane;amphiarthrotic(allows twisting
  74. cartilage joints
    bones connected by cartilage
  75. sychondrosis(cartilage)
    • bones connected by hyaline cartilage;synarthrotic epiphyseal plates of immature long bones-become synostoses(bony joints) of maturity
    • between manubrium of sternum & 1st rib(a) between costal cartilages of ribs 2-7& body of sterum-diarthrotic synovial joints
  76. symphysis(cartilaginous joints)
    • symphysis-bones connected by a pad of fibrocartilage(attached to hyaline cartilage covering articular surface)amphiarthrotic
    • pubic symphysis of pelvis(b) allows maternal pelvic bones to move during childbirth
    • intervertebral disks between bodies of adjacent vertebrae(c)-each composed of a band of fibrocartilage(annulus fibrosus) around gelatinous core(nucleus pulposus)
  77. synovial joints
    most nurmerous joints in skeletal system
  78. diarthotic(synovial joints
    • facing surfices of bones r covered with hyaline cartilage minimizes friction,cushions joint
    • separted by joint cavity containing synovial fluid-lubricates joint,nourishes articular cartilages
    • surrounded by joint capsule composed of fibrous capsule-synovial membrane-produces synovial fluid
  79. ligaments(synovial joints)
    • bands of dense regular connective tissue
    • hold articular surfaces together
    • reinforce joint capsule
  80. structures of some synovial joints
    • menisci-discs of fibrocartilage acting as cushions between articular surfaces(knee joint)
    • bursae-fibrous sacs lined with synovial membrane and filled with synovial fluid;include tendon sheaths;cushion and aid movement of tendons (connect muscle t bone)passing over joints
  81. cytology
    the study of cellular structure&function,as well as aspects of biology,chem,&physics
  82. cell theory
    • cells r building block of living organism
    • from division of preexisting cells
    • smallest units that perform all vital functions physiological functions
    • each cell maintains homeostasis at cellular level;homeostasis at the level of the tissue;organ;organ system,&organism reflects the combined&coordinated actions of many cells
  83. cells of humans and other multicellular organisms include
    • germ cells-give rise to gamestes/sex cells(sperm/egg);can divide indefinitely(if fertilization occurs)
    • somatic cells-all other body cells;divide a limited number of times(40-60)&die
  84. human cells
    • CELL-basic unit of structure&function body contains 10trill&260types.all cells of an individual have identical genome(dna)sequence
    • DIFFERENTIATED CELLS-specialized sequences due to expressions of diff genes(dna sequences encoding proteins)arise from division of less specialized cells(stem cells)
    • can vary in size&shape depending on function
  85. microscopy discovery and early study of cells was made possible by the invention of
    light microscope
  86. galileo galilei invented
    16-early 17 centuries,italian-invented the compound(two lenses) microscope
  87. Antony van Leeuwenhoek
    (17th-early 18th centuries,Dutch) developed a simple(one lens) microscope with high magnification and resolution;1st to observe microorganisms
  88. Robert Hooke
    (17th-early 18th centuries,British)-used the compound(two lenses) microscope to describe and name plant cells
  89. light microscope
    passes visable light through specimen, then through glass lenses,which refract the light to magnify the image of the specimen
  90. magnification
    objects image size/object size when viewed with naked eye
  91. resolution
    • minimal distance between 2 points at which they can still be distingished as 2 points
    • limited by the wavelength of radiation used to illuminate specimen/limits useful magnification
  92. contrast
    visual differences between parts of the specimen-increased by staining
  93. light microscope
    • uses visible light
    • resolution 200nm
    • max useful magnification:1,500x
    • can be used to study live cells
  94. transmission electron microscope(tem)
    • uses electrons,which pass thru the specimen
    • specimens r sliced ultrathin&strained w/ heavy metals that absorb electrons
    • produces 2-d images
    • resolution 0.5nm
    • max useful magnification 200,000x
  95. scanning electron microscope(sem)
    • uses eletrons,which strike the specimen2discharge 2dary electrons
    • coated with gold vapor
    • resolution less than TEM
    • max50,000 produces 3-d images
  96. all cells contain
    • plasma membrane
    • cytoplasm
    • nucleus
  97. cell(plasma) membrane
    phospholipid bilayer w/ embedded proteins enclosing
  98. cytoplasm
    cellular contents between membrane&nucleus;composed of cytoplasmic organelles,suspended in cytosol
  99. nucleus
    double membrane enclosed region containing most of the cell's genome;lost by red blood cells as they mature
  100. membrane structure contains
    cell membrane,fluid mosaic,cholesterol
  101. cell membrane
    selectively permeable barrier surrounding all living cells 8nm thick
  102. fluid mosaic
    • proteins embedded in a phospholipid bilayer-hydrophilic phosphate"heads"on the outside,hydrophobic fatty acid"tails"on the inside
    • highly permable2nonpolar molecules(O2,CO2)can dissolve in lipidbilayer
    • somewhat permable to h2opolar,but small
    • impermable to larger polar molecules(glucose)&ions
  103. cholesterol
    in membranes of human cells reduces fluidity at body t(37),lowers the t,at which membrane solidifies-moderates fluidity of cell membranes
  104. membrane proteins and their functions
    more than 50 kinds of proteins in plasma membrane of rbc,diff sets in diff cells*determine most of cell function
  105. integral proteins
    penetrate hydrophobic core of lipid bilayer
  106. peripheral proteins
    not imnedded in lipid bilayer,often attached 2 exposed parts of integral proteins,perform many functions
  107. glycocalyx
    • short branced carbohydrates r covalently bonded to glycoproteins&glycolipids on the outside of the cell membrane
    • provides lubricantion&protection,anchoring&locomotion,receptors,cell-cell regnition
  108. cytoskeleton
    • a network of protein fibers thru cytoplasm
    • maintains cell shapes,provides anchorage4organelles&cytosolic enzymes
    • interactions with polar proteins allow movement of whole cells along extracellular fibers,beating of cilia&flagella,amoeboid movement of whole cells,formation of food vacuoles,movement of vesicles
  109. microtubules
    • resist compression
    • can be rapidly assembled or disassembled@the plus end 
    • centrome-2centrioles(9 triplets of microtubles  each)90degree to each other microtubule organizing center of the cell
    • replicating centrosomes form the mitotic spindle which guides chromosomes movement during cell division
    • form cillia&flagella
  110. cilia&flagella
    • microtubule-containing extensions of the cytoplasm
    • contain a ring of 9doubles+central doublet(9+2)microtubles
    • connected by flexable cross-linking proteins
    • attached 2 a basal body made up of 9 triples of microtubules
    • outer doublets r connected 2 eachother by dynein(motor protein),responsible 4 the bending of cilium/flagellum
  111. flagellum
    • a single flagellum propels each sperm cell
    • flagellum undulates
  112. cilia
    • propel fluid(mucus) over surface of epithelia(lining trachea)
    • cilia beat like oars
  113. microfilaments resist what
    • tension  made of two intertwined of actin 7nm
    • maintains&changes cell shape
    • muscle contraction
    • cytoplasmic streaming
    • cell motility&division
  114. intermediate filiments(keratin family)
    • fiberous proteins supercoiled into thicker cables
    • 8-12nm
    • more permanent than microtubules or microfil
    • framework of cytoskeleton
  115. intercellular junction
    • especially common in epithelial tissues
    • tight junctions.desmosomes,gap
  116. tight junctions
    form continuius seals arouind cells
  117. desmosomes(anchoring junctions)
    fasten cells together into strong sheets
  118. gap(communicating)junctions
    provide cytoplasmic channels between adjacent cells;allow free passage of water,ions&other water molecules
  119. nucleus
    • enclosed in nuclear envolope(double membrane,perforated by nuclear pores regulate entry&exit of mrna ribosomes,proteins
    • *contains dna in (chromosomes made chromotin of dna&associated proteins(all this diffuses mass between cell division&become condensed during cell divisions
    • nucleolus(1ormore)present in non-dividing nucleus(rRNA trans from dna&ribosome assembly
  120. cytoplasmic organelles:ribosomes
    • complexes of rRNA&protein assembled in the nucleolus of the nucleus made of small&large subunits*site of protein synthesis
    • free ribosomes*r suspended in cytosol*site of cytosolic protein synths
    • bound ribosomes attached2outside of nuclear envelope&rough endoplasmic reticulum*site of membrane,organelle,export preotein synth
    • *structure identical can alter between 2 roles
  121. DNA 2 polypeptide
    • gene-dna sequence dictating production of a single protein;thousands of bases long-some genes code for rna molecules that r never translated into protein rRNA,tRNA
    • transcription synth of messenger RNA(mrna)from dna template(gene)
    • translation-synth of polypedtide under direction of mRNA at ribosome
    • DNA ->RNA->protein
  122. endoplasmic reticulum(er)
    a system of interconnected membrane-bound flattened sacs,enlongated canals &fluid-filled vesicles
  123. rough er
    • bound ribosomes attached2external surface r sites of membrane,organelle&export protein synthesis
    • enzymes synthesize&attach short carb chains to export(secondart)(glyco)proteins,which r carried by transport vesicles-functions as membrane factory4cell grows by synth of membrane proteins&phospholipids
  124. smooth er
    • enzymes synth lipids(fats,phospholipids,steroids)
    • enzymes detoxify drugs(alchol) abundant in liver cells
    • stores Ca+2 in muscle cells(sarcoplasmic reticulum)
  125. golgi apparatus
    • a stack of membranebound flattened sacs(cisternae)
    • receives transport vesticles(membranous sacs)from er(at cis face)&modifies&stores their contents*modifies carb chains of secondary glycoproteins
    • manufactores secondary sugars
    • products r carried to their destinations by vesticles budding from trans face
  126. lysosomes
    • membranous sacs of enzymes in acidic enviro used2digest proteins,carbo&nucleic acids
    • made by rough er&trans2golgi apparatus forfurther processing;bud off from trans face
    • digest phagocytocytized particles(infecting bacteria)by fusing with food vacules
    • digest damagd/wornout organelles*autophagy
  127. peroxisomes
    • membranous sacs of enzymes;smaller than lysosomes
    • produced by growth&subdivision of exsisting peroxisomes;enzymes synthesized at free ribosomes
    • contains enzymes(peroxides)that trans H from various substances 2 O2,producing H2O2
    • breakdown fatty acids into smaller molecules as engery source 4 mitrochondria*detox alchol&other poisons
    • another enzyme(catalase)converts H2O2-H2O
  128. mitochondria
    • generate ATP(powers metabolism)from glucose&other nutri in presence O2*aerobic resp
    • capable of fision,reproduced by fission
    • enclosed by 2 membranes
    • outer membrane-smooth
    • intermembrane space
    • inner membrane folded into cristae
    • mitochondrial matrix contains mitrochondrialDNA,ribsomes&enzymes(most encoded by nuclear genes)
    • evolved from free-living bacteris thru endosymbiosis w/ eukaryote ancestor
  129. cellular respiration
    • uses energy released from oxidation of glucose(&other organic molecules)in O2 2 generateATP;released CO2&H2O
    • OXIDATION loss of electrons(complete or partial)
    • electron donar(less electronegative-has less affinity4electrons)reducing agennt,becomes oxidized
    • REDUCTion gain of electrons*completeRpartial
    • electron acceptor(more electronegative has more affinity4electrons-oxidizing agent,become reduced
  130. Stepwise energy harvest in cellular respiration
    • if energy is released from a fuel all at once;it cannot be harnessed efficiently to do work Glucose&other organic fuelsRbroken in a series of steps,each catalyzed by an enzyme
    • At key steps electronsRstripped from glucose,usually as part of H atoms H(& free electrons) r passed 1st to an electron carrier
    • NAD+(nicotinamide adenine dinucleotide)electron carrier;functions as an electron acceptor(oxidizing agent)during cellular resp
    • NADH(reduced NAD+)donates electrons to the top pf electron transport chain(a series of proteins built into inner mitrochondrial membrane)
    • electronsRpassed down electron transport chain to O2(2 increasingly more electroneg electron acceptors) releasing energy in series of steps,captured as ATP
  131. stages of cellular resp
    • substrate level phosphorylation-transfer by an enzyme of a phosphate group from an organic substrate to ADP,generating ATP
    • glycolysis
    • citric acid cycle
    • oxidative phosphorylation
    • cellular resp transfers 40% of chemical energy in glucose to ATP;the rest is lost 2 heat-used for thermoregulation
  132. glycolysis
    • occurs in cytosol
    • breaks down glucose into 2 pyruvates
    • forms NADH
    • generates 2 ATP by substrate level phosphorylation/1 glucose
  133. Citric acid cycle
    • occurs in mitochondrial matrix
    • breaks down pyruvates into CO2
    • forms NADH&FADH2
    • generates 2 ATP by substrate level phosphorylation/1 glucose
  134. oxidative phosphorylation
    • occurs at inner mitrochondrial membrane
    • uses NADH&FADH2
    • generates 32-34 ATP/1 glucose
  135. glycolysis1
    • occurs in the cytosol,does not require O2&non is realeased
    • 1glucose molecule consumed=2atp consumed
    • generates 4atp by substrate-level phosphorylation
    • forms 2 NADH molecules
    • forms 2 pyruvic acid molecules
    • under anarobic conditions(insufficient o2 in skeletal muscles during high-intensity excersize)the main metabolic pathway4ATP generation
    • NAD+is regenerated by converting pyruvic acid into lactic acid
    • Build-up of latic acid(oxygen debt) eventually inhibits glycolysis
    • Lactic acid diffuses into blood&is carried2liver
    • where it is converted into glucose usingATPgenerated by oxidative phosphorylation during recovery
  136. citric acid cycle
    • occurs in the mitochondrial matrix completes oxidation of glucose-releases CO2
    • does not use O2
    • pyruvic acid(produced by glycolysis)is converted to Acetyl CoA
    • Acetyle CoA combines with oxaloacetic acid,forming citric acid,which enters the cycle;oxaloacetatic acid is recycled
    • electrons(&H atoms)r tranferred to NAD+&FAD(flavin adenine dinucleotide)
  137. oxidative phosphorylation
    • occurs in the mitochondrial matrix(adjacent to inner mitochondrial membrane)
    • NADH&FADH2donate electrons2electron transport chain-series of proteins&non-proteins components built into inner mitochondrial membrane
    • electronsRpassed down electron transport chain2increasing more electronegative electron acceptors
    • O2 acts as the final electron acceptor;upon being reduced combines w/ H+ to form H2O
    • energy released during electron transport is used to pump H+ into intermembrane space of a mitrochondrion;more energy is released per NADH than per FADH2
    • Electrochemical H+ gradient across the inner mitochonfrial membrane drives ATP synthesis by ATP synthases
  138. diffusion
    movement of molecules of any substance to spread evenly into available space due to random thermal motion of molecules occurs along concentration gradient of diffusing substance does not require expenditure of energy
  139. simple diffusion
    O2,CO2,fatty acids,alcohol,steroid hormones enter/leave cells by simple diffusion across lipid bilayer of cell membrane
  140. facilitated diffusion
    diffusion of a hydrophilic substance across the cell membrane with the help of transport proteins
  141. transport proteins
    • allo passage of water and various hydrophilic molecules across cell membrane
    • transmembrane proteins
    • specific to a particular molecule/ion
    • channel proteins have a hydrophilic channel
    • carrier proteins shuttle molecules/ions across lipid bilayer;exhibit saturation
  142. osmosis
    • diffusion of H2O across selectively permeable membrane along its own concentration gradient
    • h2O diffuses across cell membrane primarily thru protein channels*aquaporins
    • occurs from lower impermeant solute concentration,generating osmotic pressure
    • if consentration of H2O&solutes in intracellular&extracellular fluids is the same->osmotic pressure is same
  143. tonicity
    ability of a solution to cause a cell to gain or loose water by osmosis depends on concentration of impermeant solutes
  144. isotonic
    0.9nacl no net movement h2O
  145. filtration
    • movement of h2o&smaller molecules thru afilter (porous membrane)under hydrostatic pressure,leaving larger molecules(proteins)behind occurs in capularies,with capillary walls acting as the filter&hydrostatic pressure generated by the heart
    • retained proteins recover most of H2O by osmosis*direct expenditure of energy not required
  146. active transport
    • movement of a molecule against its concentration gradient used 2 move na+,k+,Ca+2,H+,sugars&amino acids across cell membrane
    • requires expenditure of energy(up to 40% of cells energy supply)
    • carried out by pumps-ATP-powered carrier proteins*sodium potassium pump-moves Na+ out& 2K+ into the cell@ a time
  147. bulk transport
    • used to move large molecules(proteins&polysaccharides)&larger particles across the cell membrane
    • requires expenditure of energy
  148. endocytosis
    intake of biological molecules and particulate matter by formation of new vesticles from the cell membrane
  149. phagocytosis
    engulfing of A particle by pseudopodia
  150. pinocytosis
    envelopment of an extracellular fluid droplet(containing needed substance) into a vesticle;nonspecific
  151. receptor-mediated endocytosis
    enables the cell to acquire bulk quantities of specif substances from extracellular fluid
  152. exocytosis
    secretion of biological molecules by fusion of vesticles with cell membrane
  153. transcytosis
    combines endocytosis and exocytosis to selectively transport a substance or particle from 1 end of cell2 another;moves substances across epithelis
  154. the cell cycle
    • series of changes a cell goes thru from the time it forms until it divides
    • checkpoints actions of several types of proteins control the cell cycle
    • restriction checkpoint determines whether a celll will divide,stay specialized&perform its specialized function,or die
    • in a cell with 24hr cell cycle(some human cells)
  155. interphase
    • cell grows by producing proteins&cytoplasmic organelles(including replication of centrome),replicates its chromosomes
    • G1 5-6hr
    • Sphase10-12 chromosomes r replicated
    • G2phase4-6hr-centrosome replicated
  156. mitosis
    • division of nucleus(karyokinesis)does not alter chromosome number,occurs in diploid somatic cells(2n=46 chromosomes) followed by
    • cytokinesis division of cytoplasm
    • meiosis division of nucleus that halves chromosome number producing haploid games(eggs&sperm),n=23chrom) from diploid germ cells(2n=46 chromo)
    • mitotic phase(less than 1 hr)consisting of prophase metaphase anaphase telophase/cytokinesis
  157. chromosome structure
    • in a non dividing cell each chromosome is a long thin chromatin fiber&cant be seen under light microscope
    • at start of cell division(after dna deplication)chromosomes condense by dense coiling and folding of the chromatin fiber
    • at the start of mitosis each chromosome consists of 2 sister chromatids each containing an identical dna molecule,attached along length by adhesive proteins
    • centromere point of closest attachment of sister chromatids
    • during cell division sister chromatids separate&move into nuclei of 2 new cells*now individual chromosomes
  158. stages of mitosis
    • G2 nuclear envolope bounds the nucleus,nucleolus present,chromosomes decondensed
    • prophase nucleus disappears,nuclear envolope fragments,chromosomes condensed,mitotic spindle forms between centrosomes,microtubules of mitotic spindle attach 2 chromosomes at centromeres;pull chromosomes back&forth
    • metaphase longest20mins centrosomes at opposite poles of cell,chromosomes arranged on the metaphase plate(equatorial plane)
    • anaphase shortest stage of mitosis(a few min) adhesive proteins cleaved,sister chromatids pull apart toward opposite poles of the cell
    • telephase and cytokinesis
    • formation of 2 daughter nuclei,formation of nuclear envolopes,appearence of nucleoli,decondensation of chromosomes,cytoplasm divides(cytokinesis)by cleavage
  159. cytokinese
    • division of cytoplasm following mitosis;begins during telophase
    • occurs by cleavage ,cleavage furrow is formed near metaphase plate thru action of contractile ring of cortical microfilaments&myosin motor proteins
    • deepens,until the cell is pinched in 2
  160. controls of cell cycle
    • all somatic cells divide a limited number of times(40-60)&then die because of shortening telomeres(non-coding chromosome ends)at dna replication
    • in embryonic cells,enzyme telomerase(present at much lower levels in somatic cells) restores telomeres,allowing the large number of cell divsions necessary for development of a new organism
  161. growth factor
    • protein released by certain cells that simulates other cells to divide 
    • (pdgf-platelet derved groth factor stimulates fibroblasts(connective tissue cells) to heal a wound
  162. anchorage dependence
    cells must be attached to a substrate in order to divide
  163. density dependent inhibition
    crowded cells stop dividing
  164. cell death(apoptosis
    • a cell that does not differentiate or divide undergoes apoptosis(programmed cell dealth)
    • apoptosis sculpts organs during development causes uterus to shrink after childbirth ,peels away damaged skin after sunburn;synchronized with mitosis
  165. cell death(death receptor and enzymes)
    • death receptor on doomed cells membrane receives signal to die,activates caspases(enzymes) destroy enzymes that replicate &repair dna,activate enzymes that cut up dna,fracture mitrochondria,abolish the cells ability to adhere to other cells
    • dying cells round up,cell membrane forms blebs(bulges) nucleus bursts,mitrochondria decompose
    • cell shatters cell membrane encapslate fragments preventing inflammation then fragments engulfed by phagocytes
  166. cancer
    • set of diseases caused by somatic cells escaping control mechanisms that normally limit their growth
    • caused by mutations(dna changes) in genes that regulate cell cycle
  167. proto-oncogenes
    • code for proteins that stimulate normal cell growth&division converted into cancer-causing oncogenes by a genetic change that 
    • increases the amount of proto-cogene product
    • increases the activity of proto-cogene product
  168. tumor suppressor genes
    • code for proteins that prevent cancer by repairing DNA controlling cell adhesion,or inhibiting cell cycle
    • any mutation that decreases normal activity of a tumor suppressor gene may contribute to the onset of cancer
  169. cancer cells
    • do not respond to normal signals that regulate the cell cycle
    • divide excessively&invade other tissues
    • kill the organism if unchecked
    • lack of density-dependent inhibition&anchorage dependence
    • do not require growth factors to divide
    • stop dividing at random points in cell cycle
    • can go on dividing indefinitely because of high levels of telomerase
  170. transformation
    conversion of a normal cell to a cancer cell,more tham 1 somatic cell mutation is generally needed to produce full fledged cancer including appearance of at least one oncogene&loss of several tumor suppressor genes,bodys immune system destroys tranformed cells,surviving transformed cells proliferate,forming tumor
  171. tumor
    • mass of abnormal cells remain at the orgiginal site;can be completly removed by surgery
    • malignant tumor abnormal cells become invasive(spread throughout organs impairing function)cancer
    • metastasis cancer cells separate from a malignant tumor&travel thru bloos&lymph vessels to other parts of the body to form new tumors
  172. factors contributing to cancer&cancer treatment
    • inheritance of an oncogene or a mutant tumor-suppressor gene predisposes an individual to cancer(15% of colorectal cancers,5-10% of breast cancers)
    • exposure to mutagens(chems,radiation
    • increases with age
    • high energy radiation(cancer cells loose ability to repair damage to dna)
    • metastatic tumors can be treated with chemotherapy(toxic to actively dividing cells)
  173. cells are organized into what
    • tissues layers or groups of similar cells with common function
    • may be packed&held together by intercellular junctions(tight,desmosomes,and/or gap)or widley separated by extracellular matrix
  174. histology
    • the study of tissues
    • epithelial,connective,muscle,nervous
  175. epithelia
    • cover body surface&organs,line body cavities&hallow organs
    • form protective barriers,perform secretion,absorption,excretion
  176. epithelia surfaces
    • apical surface-exposed externally or internally to an open space
    • basolateral surface-attached to underlying connective tissue by basal lamina of basement membrane
  177. facts about epithelia
    • avascular lack of blood vessels-nutrients diffuse from underlying connective tissue
    • cells readily divide->injuries heal quickly;cells relaced continuously in epidermis of skin and digestive lining
    • cells packed tight by demosomes and tight junctions
    • classified according to cell shape squamous,cuboidal,columnar number of cell layers simple,stratified
  178. simple epithelia
    • single layer of thin flattened cells
    • common at sights of diffusion/filitration
    • lines aveoli of lungs,forms walls of capillaries,lines larger blood&lymph vessels,covers membranes that line body cavities
  179. simple cuboidal epithelium
    • single layer of cube shaped cells
    • lines follicles of thyroid gland,covers ovaries,lines kidney tubules(secretions&reabsorption)and ducts of salivary glands,pancreas,and liver secretion
  180. simple columnar epithelium
    • single layer of elongated cells with nuclei near the basement membrane it is ciliated lines uterine tubes;cilia extend from apical surface increased by microvilli
    • glandular goblet cells secrete protective mucus
  181. pseudostratified columnar epithelium
    • aingle layer of cells of different lengths-all attached to basement membrane,not all reach apical surface
    • lines passages of the repiratory system(trachea,bronchi)
    • inhaled dust&microorganisms trapped in mucus(secreted by goblet cells)and swept by cilia
  182. stratified epithia
    • cells near the apical surface flattened the most
    • keratinized forms epidermis of cells at the apical surface dead&filled with keratin-form dry,tough covering that prevents h2o loss &entry of chemicals &microorganisms
    • nonkeratinized lines oral cavity&esophagus,anal cavity,vagina;cells at apical surface alive&moist
  183. stratified cuboidal epithelium
    lines larger ducts of mammary,sweat&salivary glands and of pancreas;lines ovarian follicles&seminiferous tubules
  184. stratified columnar epithelium
    • cells near the apical surface elongated the most
    • lines male urethra&ductus deferens and pharynx
  185. transitional epithelium
    • lines urinary bladder,ureters&superior urethra
    • specialized2 change in response 2 increased tension
    • consists of multiple layers of cuboidal calls when relaxed
    • consists of 2-3 layers of flattened cells when stretched
  186. glandular epithelium
    • composed of cells specialized to produce &secrete substances into ducts or body fluids
    • found with columnar or cunboidal epithelium,consitute a gland
    • exocrine glands secrete their products into ducts that open into surface(sweat&salivary glands,pancreas)unicellular(goblet cells)multicellular
    • exocrine glands-lack ducts,secrete their products into extracellular fluid&blood(thyroid gland,adrenal glands,pancreas)
  187. multicellular exocrine glands
    • secretory portion may be tubular or alveolar(sac like)
    • simple gland communicates with the surface through a duct that doesn't branch before reaching the secretary portion secretory may be branched or coiled
    • compound gland communicates w/ surface throu a duct that branches repeatedly before reaching the secretory portion
  188. modes of glandular secretion
    • merocrine glands-release fluid product exocytosis-most exocrine glands(salivary&sweat glands,pancreas.goblet cells)
    • apocrine glands-released pinched off portions of secretory cells contains the product mammary glands(combination of merocrine&apocrine secretion)
    • holocrine glands release entire cells containing the product sebaceous glands(of hair follicles)
  189. connective tissues
    • the most abundant tissue type of weight
    • binds structures,provide support and protection,store energy,store&support sunstances,protect against infection,repair tissue damage
    • cells surrounded by extensive extracellular matrix composed of protein fibers
    • ground substances(non-fibrous proteins,other molecules,fluid) cells can divide-vascularity(amount of blood vessels)varies between types
  190. connective tissue proper
    • losse-areolar,adipose,reticular
    • dense
    • regular,irregular,elastic
  191. supporting connective tissue
    cartilage and bone
  192. fluid connective tissues
    blood&lymph
  193. fibroblasts
    the most common type of fixed cells;produce fibers of extracellular matrix
  194. adipocytes(fat cells)
    contains singlw,enormous lipid droplet
  195. mesenchymal cells
    stem cells that respond to injury by producing fibroblasts&other connective tissue cells
  196. macrophages
    orginate as white blood cells;attached fibers(fixed) or actively move (free);phagoctize pathogens(bacteria,viruses)and cell debris
  197. mast cells
    located near blood vessels;release heparin(anticoagulant)&histamine(increases capillary permeability)as part of inflammation response to infection
  198. lymphocytes
    white blood cells;develope into antibody producing plasma cells in response to a specialized pathogen
  199. melanocytes
    synthesize&store brown pigment melanin;abundant in connective tissues eye and dermis of skin
  200. connective tissue produced by
    fibroblasts of connective tissue proper
  201. collagen fibers *connective tissue
    composed of protein collagen(white);grouped in lonf;parallel bundels;provide tensile strength
  202. elastic fibers
    composed of protein elastin(yellow);branch,forming complex networks;provide elasticity
  203. reticular fibers
    thin collagen fibers;highly branched;provide supporting framework for internal organs
  204. loose connective tissue
    ground substance contains a loose network of collagen&elastic fibers
  205. areolar(loose connective tissue)
    • syrupy ground substance contains a loose network of collagen &elastic fibers
    • highly vascular
    • binds skin 2 deeper structures,fills spaces between muscles,underlies most epithelia
  206. adipose tissue(adipocytes)
    • cells adipose stores fat within cytoplasm as an enormous droplet
    • extracellular matrix reduced
    • cushions joints&organs,provides thermal insulation(subcutaneous fat)stores energy
  207. reticular connective tissue(loose connective tissue)
    reticular fibers form a supporting framework for internal organs(liver,spleen,lymph nodes)
  208. dense connective tissue
    ground substance contains a dense network of collagen or elastic fibers
  209. dense regular connective tissue
    • consists mainly of closely packed collagen fibers->has great tensile strength in a single direction
    • also contains fibroblasts&elastic fibers
    • forms ligaments(attach bone to bone)&tendons(attach muscle to bone)
    • poorly vascularized
  210. dense irregular connective tissue
    • consists mainly of randomly organized collagen fibers->has considerable tensile strength in many directions
    • also contains fiberblasts&elastic fibers
    • forms dermis of skin
    • well vascularized
  211. elastic tissue
    • consists mainly of elastic fibers in parallel strands or branching networks->highly elastic
    • contains fibroblasts&collagen fibers
    • forms ligamentum nuchae&ligamenta flava of the vertebral column;present in walls of the larger arteries
  212. cartilage
    • supporting connective tissue
    • cells(chrondrocytes) in lacunae(spaces) within gelatinous extracellular matrix(contains protein-polysaccharide complexes&water)
    • avascular nutrients diffuse throu ground substance from blood vessels of perichondrium-connective tissue covering
  213. hyaline cartilage
    • fine collagen fibers in extracellular matrix
    • forms embryonic skeleton(replaced by bone) connects ribs to sternum,covers joint surfaces,supports nost and respiratory passages
  214. elastic cartilage
    dense network of elastic fibers in extracellular matrix supports external ears and epiglottis
  215. fibrocartilage
    dense network of collagen fibers in extracellular matrix forms intervertebral disks
  216. bone
    • supporting connective tissue
    • forms adult skeleton provides support&protection&attachment for muscles;contains marrow-produces formed elements of blood;stores calcum&phosphorus
  217. osteocytes
    osteocytes r in lacunae(spaces) within solid extracellular matrix(contains calcium phosphate&collagen fibers) deposited by osteoblasts(become osteocytes)
  218. highly vascular
    blood vessels of periosteum(connective tissue covering)enter bone thru perforating canals&lie in central canals of osteons(compact bone)
  219. osteon
    cylinder shaped structural unit of compact bone composed of concentric lamellal(layers of bone) around the central canal containing blood vessels
  220. osteocytes r connected by what
    by cytoplasmic processes lying witin canaliculi of extracellular matrix 2 each other &the blood vessels in central canal nutrients diffuse thru cytosol
  221. fluid connective tissues
    • blood
    • cells suspended in fluid extracellular matrix(plasma)lacks fibers except during blood clotting
  222. formed elements
    (cells and cell fragments) r produced in red bone marrow;include rbs that trabsport 02 and help transport co2,wbc fightinfection;some migrate into connective tissues thru capillary walls,platelets play key role in blood clotting,lymph wbc suspended in extracellular fluid(blood plasma filtered throu capillary walls)
  223. Tissue membranes
    Composed of epithelium &under,inning connective tissue;cover body surfaces&line body cavities
  224. Mucous membranes
    Line cavities &tubes that open to the outside composed of nonkeratinized stratified squamous or pseudo stratified or simple columnar epithelium&layer of areolar tissue goblet cells in the epithelial umm secret mucus
  225. serous membranes
    line body cavities that do not open 2 the outside&reduce friction between organs&cavity walls,viseral membrane covers the internal organ,parietal membrane lines the body cavity,made of simple squamous epithelium& a thin layer of areolar tissue,cells secrete lubricating serous fluid
  226. cutaneous membrane(skin
    • covers external surface of body,composed of keratinized stratified squamous epithelium(epidermis)&areolar&dense irregular connective tissue(dermis)
    • skin glands secrete sweat&oils
  227. Synovial membrane
    Line joints ,composed of arolar tissue
  228. Contractile
    Can shorten or thicken taping atp allow movement of body parts and internal organs
  229. Skeletal muscle tissue
    Striated voluntary composed of multinucleated muscle fibers formed by fusion of multiple embryonic cell ,can be produced from undifferentiated satellite cells in an adult forms skeletal muscle allows movement of body parts
  230. smooth muscle tissue
    • non-striated,involuntary
    • composed of mononucleate spindle-shaped muscle cells
    • capable of division
    • forms part of the walls of internal organs(digestive tract,urinary bladder,uterus,bloos vessels)propels food down digestive tract,empties urinary bladder,expels newborn,constricts blood vessels
  231. cardiac muscle tissue
    • striated,involuntary
    • composed of mononucleated branched muscle cells interconnected by desmosomes&gap junctions at intercalated disks,incapable of division
  232. Autohythmic
    Contracts spontaneously without externalstimulation  makes up bulk of heart wall pumps blood thru heart chambers&int blood vessels
  233. Neural tissue
    • Forms the brain, spinal cord,and nerves;made up of
    • neurons capable of generating and transmitting electrochemical signals
    • incapable of division
    • neuroglia support &nourish neurons

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