test 2

• 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)

long,short,flat,irregular,sesamoid

• long longitudinal axis,expanded ends
• bones of arm,forearm&hand and thigh,leg and foot

cube-like,with roughly equal lengths and widths-bones of wrists and ankle

plate like with broad surfaces-vranial bones of the skull,ribs,scapulae

usually connected to several other bones facial bones of the skull,vertebrae

small-nodular,embedded in tendons adjacent to joins*patella

• compact bone-continuous extracellular matrix with no gaps surround
• spongy bone-composed of branching bony struts(trabeculae) surrounded by spaces

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

• (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

connected by epiphyseal plates/metaphyses(ossified in adults) to diaphysis-shaft

• 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)

• composed of spongy bone(containing bone marrow) surrounded by compact bone
• external surface covered by periosteum(or hyaline cartilage at articular surfaces)

supporting connective tissue

(undifferentiated) stem cells in the periosteum and endosteum;give rise to osteoblasts

bone forming cells in the periosteum and endosteum;non-mitotic

bone-maintaining and repairing cells trapped in lacunae of bone matrix and connected through cytoplasmic extensions & gap junctions in canaliculi;developed from osteoblasts

• 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

blood vessels and nerves enter bone tissue through perforationg (volkmanns) canals

carry blood vessels and nerves from nutriant foramina to central canals of compact bone

around central canals form cylindrical osteons

form the outer layer adjacent to periosteum

in lacunae receive o2% nutrients from extracellular fluid surrounding blood vessels through cytoplasmic extensions in canaliculi

• blood vessels&nerves enter spaces through perforating canals of compact bone
• concentric lamellae with no central canals form trabeculae

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

a complete cellular layer containing osteoblasts, osteoprogenitor cells,and osteoclasts

1skull,mandible,and clavicles develop from vascularized sheets of undifferentiated connective tissue(mesenchyme)

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

3periosteum

4lamellar bone(collagen fibers arranged in parallel within lamellae)

5lamellar

6by filling in spaces with bony matrix

hyaline cartilage model

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

2their lacunae enlarge

3vascular buds from the periosteum break down the cartilaginous lacunae,forming marrow cavity(in diaphysis)

4deposit spongy bone; becomes compact in most of the diaphysis and the surface of epiphyses

5only the epiphyseal plates are still composed of carilage

epiphyseal plates until ossify at 23females and 25males becoming epiphyseal lines

(zone of calcified cartilage) ossifies,the layer near epiphysis(zones of proliferating&hypertophic cartilage) add more cartilage

from pituitary gland;before maturity causes premature ossification of epiphyseal plates-pituitary dwarfism(short stature,normal proportions)

before maturity prevents ossification of epiphyseal plates,growth never stops(gigantism)

abnormal cartilage formation due to mutation causes achondroplasia(head and torso of normal sie,shortened limbs)

osteoblasts of periosteum deposit compact bone(circumferential lamellae)

the marrow cavity

with growth in length after maturity in response to physical stress

*hypersecretion of growth hormone after maturity.acromegaly-thickening of bones and soft tissues

osteoclasts and osteoblasts continually resorb and deposit bone tissue throughout life,remodeling it; 3-5% of bone calcium is exchanged each yr

highly regulated total bone mass in adult skeleton remains nearly constant

exercise causes gain of bone mass

lack of exercise causes loss of bone mass

• secreted by throid gland lowers blood
• inhibiting osteoclasts and stimulating osteoblasts
• increasing excretion of ca+2 by kidneys

• 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

• 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)

• is required for collagen synthesis
• present in fruits and vegetables
• absence in diet causes scurvy

incomplete break,occurs on the convex surface of the bend in the bone

involves an incomplete longitudinal break

complete and fragments the bone

complete break occurs at a right angle at a right axis of the bone

occurs at an angle other than a right angle to the axis of bone

caused by twisting a bone excessively

sped up by setting the setting of the bone(aligning at ends) immobilizing it in a cast

• internal callus composed of woven spongy bone
• external callus composed of hyaline cartilage
• replaced by compact lamellar bone

• 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)

• 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

articulations-points contact between 2 bones;makes possible bone growth and movement

immovable

slightly movable

freely movable

bones in close contact connected by dense connective tissues(with many collagen fibers)

suture flat bones of skull held by sutural ligament smooth& amphiarthrotic in newborns,interdigitating& synartrotic in adults

root of tooth held in alveolus by periodontal ligament; synartrotic

long bones ulna&radius tibia&fibula) connected interosseous membrane;amphiarthrotic(allows twisting

bones connected by 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

• 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)

most nurmerous joints in skeletal system

• 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

• bands of dense regular connective tissue
• hold articular surfaces together
• reinforce joint capsule

• 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

the study of cellular structure&function,as well as aspects of biology,chem,&physics

• 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

• 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

• 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

light microscope

16-early 17 centuries,italian-invented the compound(two lenses) microscope

(17th-early 18th centuries,Dutch) developed a simple(one lens) microscope with high magnification and resolution;1st to observe microorganisms

(17th-early 18th centuries,British)-used the compound(two lenses) microscope to describe and name plant cells

passes visable light through specimen, then through glass lenses,which refract the light to magnify the image of the specimen

objects image size/object size when viewed with naked eye

• 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

visual differences between parts of the specimen-increased by staining

• uses visible light
• resolution 200nm
• max useful magnification:1,500x
• can be used to study live cells

• 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

• uses eletrons,which strike the specimen2discharge 2dary electrons
• coated with gold vapor
• resolution less than TEM
• max50,000 produces 3-d images

• plasma membrane
• cytoplasm
• nucleus

phospholipid bilayer w/ embedded proteins enclosing

cellular contents between membrane&nucleus;composed of cytoplasmic organelles,suspended in cytosol

double membrane enclosed region containing most of the cell's genome;lost by red blood cells as they mature

cell membrane,fluid mosaic,cholesterol

selectively permeable barrier surrounding all living cells 8nm thick

• 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

in membranes of human cells reduces fluidity at body t(37),lowers the t,at which membrane solidifies-moderates fluidity of cell membranes

more than 50 kinds of proteins in plasma membrane of rbc,diff sets in diff cells*determine most of cell function

penetrate hydrophobic core of lipid bilayer

not imnedded in lipid bilayer,often attached 2 exposed parts of integral proteins,perform many functions

• 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

• 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

• 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

• 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

• a single flagellum propels each sperm cell
• flagellum undulates

• propel fluid(mucus) over surface of epithelia(lining trachea)
• cilia beat like oars

• tension  made of two intertwined of actin 7nm
• maintains&changes cell shape
• muscle contraction
• cytoplasmic streaming
• cell motility&division

• fiberous proteins supercoiled into thicker cables
• 8-12nm
• more permanent than microtubules or microfil
• framework of cytoskeleton

• especially common in epithelial tissues
• tight junctions.desmosomes,gap

form continuius seals arouind cells

fasten cells together into strong sheets

provide cytoplasmic channels between adjacent cells;allow free passage of water,ions&other water molecules

• 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

• 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

• 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

a system of interconnected membrane-bound flattened sacs,enlongated canals &fluid-filled vesicles

• 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

• enzymes synth lipids(fats,phospholipids,steroids)
• enzymes detoxify drugs(alchol) abundant in liver cells
• stores Ca+2 in muscle cells(sarcoplasmic reticulum)

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• occurs in cytosol
• breaks down glucose into 2 pyruvates
• forms NADH
• generates 2 ATP by substrate level phosphorylation/1 glucose

• occurs in mitochondrial matrix
• breaks down pyruvates into CO2
• forms NADH&FADH2
• generates 2 ATP by substrate level phosphorylation/1 glucose

• occurs at inner mitrochondrial membrane
• uses NADH&FADH2
• generates 32-34 ATP/1 glucose

• 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

• 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)

• 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

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

O2,CO2,fatty acids,alcohol,steroid hormones enter/leave cells by simple diffusion across lipid bilayer of cell membrane

diffusion of a hydrophilic substance across the cell membrane with the help of 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

• 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

ability of a solution to cause a cell to gain or loose water by osmosis depends on concentration of impermeant solutes

0.9nacl no net movement h2O

• 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

• 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

• used to move large molecules(proteins&polysaccharides)&larger particles across the cell membrane
• requires expenditure of energy

intake of biological molecules and particulate matter by formation of new vesticles from the cell membrane

engulfing of A particle by pseudopodia

envelopment of an extracellular fluid droplet(containing needed substance) into a vesticle;nonspecific

enables the cell to acquire bulk quantities of specif substances from extracellular fluid

secretion of biological molecules by fusion of vesticles with cell membrane

combines endocytosis and exocytosis to selectively transport a substance or particle from 1 end of cell2 another;moves substances across epithelis

• 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)

• 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

• 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

• 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

• 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

• 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

• 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

• 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

cells must be attached to a substrate in order to divide

crowded cells stop dividing

• 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

• 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

• 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

• 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

• 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

• 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

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

• 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

• 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)

• 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

• the study of tissues
• epithelial,connective,muscle,nervous

• cover body surface&organs,line body cavities&hallow organs
• form protective barriers,perform secretion,absorption,excretion

• apical surface-exposed externally or internally to an open space
• basolateral surface-attached to underlying connective tissue by basal lamina of basement membrane

• 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

• 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

• 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

• 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

• 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

• 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

lines larger ducts of mammary,sweat&salivary glands and of pancreas;lines ovarian follicles&seminiferous tubules

• cells near the apical surface elongated the most
• lines male urethra&ductus deferens and pharynx

• 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

• 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)

• 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

• 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)

• 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

• losse-areolar,adipose,reticular
• dense
• regular,irregular,elastic

cartilage and bone

blood&lymph

the most common type of fixed cells;produce fibers of extracellular matrix

contains singlw,enormous lipid droplet

stem cells that respond to injury by producing fibroblasts&other connective tissue cells

orginate as white blood cells;attached fibers(fixed) or actively move (free);phagoctize pathogens(bacteria,viruses)and cell debris

located near blood vessels;release heparin(anticoagulant)&histamine(increases capillary permeability)as part of inflammation response to infection

white blood cells;develope into antibody producing plasma cells in response to a specialized pathogen

synthesize&store brown pigment melanin;abundant in connective tissues eye and dermis of skin

fibroblasts of connective tissue proper

composed of protein collagen(white);grouped in lonf;parallel bundels;provide tensile strength

composed of protein elastin(yellow);branch,forming complex networks;provide elasticity

thin collagen fibers;highly branched;provide supporting framework for internal organs

ground substance contains a loose network of collagen&elastic fibers

• 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

• cells adipose stores fat within cytoplasm as an enormous droplet
• extracellular matrix reduced
• cushions joints&organs,provides thermal insulation(subcutaneous fat)stores energy

reticular fibers form a supporting framework for internal organs(liver,spleen,lymph nodes)

ground substance contains a dense network of collagen or elastic fibers

• 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

• 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

• 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

• 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

• fine collagen fibers in extracellular matrix
• forms embryonic skeleton(replaced by bone) connects ribs to sternum,covers joint surfaces,supports nost and respiratory passages

dense network of elastic fibers in extracellular matrix supports external ears and epiglottis

dense network of collagen fibers in extracellular matrix forms intervertebral disks

• supporting connective tissue
• forms adult skeleton provides support&protection&attachment for muscles;contains marrow-produces formed elements of blood;stores calcum&phosphorus

osteocytes r in lacunae(spaces) within solid extracellular matrix(contains calcium phosphate&collagen fibers) deposited by osteoblasts(become osteocytes)

blood vessels of periosteum(connective tissue covering)enter bone thru perforating canals&lie in central canals of osteons(compact bone)

cylinder shaped structural unit of compact bone composed of concentric lamellal(layers of bone) around the central canal containing blood vessels

by cytoplasmic processes lying witin canaliculi of extracellular matrix 2 each other &the blood vessels in central canal nutrients diffuse thru cytosol

• blood
• cells suspended in fluid extracellular matrix(plasma)lacks fibers except during blood clotting

(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)

Composed of epithelium &under,inning connective tissue;cover body surfaces&line body cavities

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

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

• covers external surface of body,composed of keratinized stratified squamous epithelium(epidermis)&areolar&dense irregular connective tissue(dermis)
• skin glands secrete sweat&oils

Line joints ,composed of arolar tissue

Can shorten or thicken taping atp allow movement of body parts and internal organs

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

• 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

• striated,involuntary
• composed of mononucleated branched muscle cells interconnected by desmosomes&gap junctions at intercalated disks,incapable of division

Contracts spontaneously without externalstimulation  makes up bulk of heart wall pumps blood thru heart chambers&int blood vessels

• 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