ANATOMY AND PHYSIOLOGY

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1 Chapter 1: Intrductin 13 Anatmy and Physilgy I ANATOMY AND PHYSIOLOGY Anatmy (Greek a cutting up ) Physilgy (Greek relatinship t nature ) is always related t CORE PRINCIPLE IN A&P Structure and Functin Cre Principle One f mst basic principles in A&P; knwn as principle f cmplementarity f structure and functin: Frm f a structure is always such that it best suits its functin Frm fllws functin; applies t each level f rganizatin even dwn t chemical level CHARACTERISTICS OF LIVING ORGANISMS Living Organisms share distinct prperties: Cellular cmpsitin: cells are basic units f life Metablism: Living rganisms carry ut a number f chemical reactins cllectively knwn as metablism, where building utweighs breaking dwn prcesses, includes tw frms: Increase in size f individual cells prcess that an rganism uses t eliminate ptentially harmful waste prducts created by metablic prcesses r irritability ability f rganisms t sense and react t changes r stimuli in their envirnment

2 Chapter 1: Intrductin LEVELS OF STRUCTURAL ORGANIZATION AND BODY SYSTEMS ability f an entire rganism t mve r mvement f individual cells r f materials within r between cells f an rganism takes fllwing tw frms in Chemical level smallest level is fundatin fr each successive level, ranges frm atms t cmplex mlecules hydrgen atm, lithium atm multicellular rganisms: water mlecule, glucse mlecule Individual cells reprduce within rganism during grwth prtein mlecule, DNA mlecule and t replace damaged r ld cells Organism itself reprduces t yield similar ffspring Cellular level frmed by grups f many different types f mlecules cmbined in specific ways t frm cellular structures mitchndrin, Glgi apparatus, nucleus muscle cell, nerve cell; smallest unit f life tw r mre cell types cperate t perfrm a cmmn functin Cnsist f tw cmpnents: cells and surrunding extracellular matrix Vary frm membrane sheets that cver bdy cavities t irregularly shaped cartilage fund in nse cnsists f tw r mre tissue types cmbined t frm a structure r rgan skin, femur, heart, kidney Cnsist f tw r mre rgans that tgether carry ut a brad functin in bdy rgan systems functin tgether t make up wrking human bdy, an rganism 14

3 Chapter 1: Intrductin DIRECTIONAL TERMS ANATOMICAL POSITION cmmn frame f reference frm which all bdy parts and regins are described: Bdy is always referred t as if it were in anatmical psitin, even when it s in anther psitin Right and left always refers t right and left sides f bdy being described, nt ur wn Anterir / Psterir Cranial / Caudal Superficial / Deep REGIONAL TERMS Antebrachial Axillary Brachial Cervical Cstal Crural Femral Gluteal Ventral / Drsal Superir / Inferir Prximal / Distal Medial / Lateral REGIONAL TERMS Bdy can be divided int tw regins: axial regin, which includes head, neck, and trunk and appendicular regin which includes upper and lwer limbs r appendages 15 Mammary Nasal Occipital Lumbar Pectral Sternal Tarsal Vertebral Figure 1.7a Reginal terms. CONCEPT BOOST: PUTTING ANATOMICAL TERMS TOGETHER REGIONAL TERMS Figure 1.7b, c, d Reginal terms. Start with regin left crural Describe depth f incisin deep t skin and muscle but superficial t bne Put it all tgether wund is n left antermedial crural regin, 6 centimeters prximal t tarsal regin and 10 centimeters distal t patellar regin; pellet is ldged deep t skin and muscle but superficial t bne Add descriptive directinal terms (need t use prximal and distal, since describing limbs) anterir, n medial side, prximal t tarsal regin and distal t patellar regin

4 Chapter 1: Intrductin PLANES OF SECTION Sagittal Midsagittal Parasagittal Frntal (crnal) Transverse (hrizntal) Oblique Figure 1.8a Planes f sectin. Figure 1.8b Planes f sectin. BODY CAVITIES Drsal Bdy Cavity largely lcated n psterir side f bdy; subdivided int tw cavities: Figure 1.8c Planes f sectin. Ventral Bdy Cavity separated int tw divisins by diaphragm: Thracic Abdminpelvic Cranial cavity Vertebral (spinal) cavity Figure 1.9a The drsal and ventral bdy cavities. Figure 1.9b The drsal and ventral bdy cavities. 16

5 Chapter 1: Intrductin Thracic cavity divided int three smaller cavities: 17 Abdminpelvic cavity subdivided int tw cavities: Abdminal cavity Pleural cavities Pelvic cavity Mediastinum (nt within serus membrane) Pericardial cavity BODY CAVITIES Abdminpelvic cavity can be divided up int segments r quadrants Quadrants: Right upper quadrant (RUQ) Right lwer quadrant (RLQ) Left upper quadrant (LUQ) Left lwer quadrant (LLQ) Figure 1.9 The drsal and ventral bdy cavities. Segments: Right and left hypchndriac regins Epigastric regin Right and left lumbar regins Umbilical regin Right and left iliac r inguinal regins Hypgastric regin ABDOMINAL PAIN (P. 20) Cmmn cmplaint f individuals seeking health care Cause f pain can be difficult t diagnse due t number f structures in abdminpelvic cavity; fur quadrant system makes this easier RLQ LUQ

6 Chapter 1: Intrductin Serus membranes : Thin sheets f tissue; frm certain cavities fund in ventral cavity; surrund heart, lungs, and many abdminal rgans Within cavity between tw layers is an extremely thin layer f fluid called serus fluid Visceral layer utermst layer attached t surrunding structures (wall f cavity) Figure 1.11 Hw a serus membrane envelps the heart. Bdy has three serus bdy cavities frmed by three main serus membranes: Pleural membranes Parietal pleura Visceral pleura Thin space enclsed by pleural membranes frms Pericardial membranes Parietal pericardium (separates heart frm mediastinum) Visceral pericardium (lies directly n heart muscle) Space created by pericardial membranes frms Figure 1.12a The serus membranes f the ventral bdy cavities. Peritneal membranes, surrunds sme f abdminal rgans Parietal peritneum Visceral peritneum Space between these layers frms The peritneum desn t cver every rgan Figure 1.12b The serus membranes f the ventral bdy cavities. 18

7 Chapter 1: Intrductin HOMEOSTASIS Physilgical Prcesses Operate t Maintain Bdy s (maintenance f internal envirnment) Hmestatic imbalances disturbances in Feedback Lps Cre Principle tw mechanisms vital t maintenance f hmestasis: less cmmn than negative feedback lps; effectr activity increases and reinfrces initial stimulus; - ppse initial change in a regulated variable; reduce utput hmestasis can lead t disease r death if uncrrected Each regulated variable has a set pint r an established nrmal value (within a nrmal range) T prevent imbalance, mst variables are cntrlled - prvide infrmatin abut stimuli (regulated) variables; maintained within a narrw range, clse t a nrmal value change is cmpared t set pint change is crrected Figure 1.14 Cntrl f bld cltting by a psitive feedback mechanism. CHILDBIRTH, PITOCIN, AND POSITIVE FEEDBACK LOOPS (P. 26) Childbirth begins with labr; ccurs by psitive feedback: Figure 1.13b Cmparisn f hw negative feedback mechanisms cntrl rm and bdy temperature. Pitcin (synthetic xytcin) 19

8 Chapter 1: Intrductin 20

9 Chapter 2: The Chemistry f Life 21 MATTER Matter anything that has mass and ccupies space; Chemistry study f matter and its interactins smallest unit f matter that retains riginal prperties Made up f even smaller structures called subatmic particles ELEMENTS IN THE PERIODIC TABLE AND THE HUMAN BODY The human bdy is made up f fur majr elements: BIOCHEMISTRY Bichemistry the chemistry f life cmpunds generally d nt cntain carbn bnded t hydrgen; include water, acids, bases, and salts thse that d cntain carbn bnded t hydrgen Als 7 mineral elements and 13 trace elements WATER Water (H2O) makes up 60 80% f mass f human: The medium fr metablic reactins Absrbs and transprts heat Salts - can disslve in water t frm catins and anins called Capable f cnducting electrical current SALTS AND ELECTROLYTES Acts as a lubricant between tw adjacent surfaces Imprtant rles in metablism

10 Chapter 2: The Chemistry f Life CARBOHYDRATES CARBOHYDRATES, cmpsed f carbn, hydrgen, and xygen, functin primarily as fuel; als have structural rles mnmers frm which all carbhydrates are made Examples: glucse, fructse, galactse, ribse, and dexyribse Figure 2.14 Carbhydrates: structure f mnsaccharides. are frmed by unin f tw mnsaccharides cnsist f many mnsaccharides jined t ne anther Glycgen is the strage plymer f glucse; mstly in skeletal muscle and liver cells Strach Figure 2.16 Carbhydrates: the plysaccharide glycgen. LIPIDS THE GOOD, THE BAD, AND THE UGLY OF FATTY ACIDS (P. 56) Hydrphbic mlecules including fats and ils Fatty acids lipid mnmers cnsisting carbn chains Saturated fatty acids Nt all fatty acids were created equally: The Gd: Omega 3 Fats The Bad: Saturated Fats Unsaturated fatty acids 22

11 Chapter 2: The Chemistry f Life THE GOOD, THE BAD, AND THE UGLY OF FATTY ACIDS Nt all fatty acids were created equally (cntinued): 23 TRIGLYCERIDE The Ugly: Trans Fats Mst cmmn lipid in bdy Figure 2.18 Lipids: structure and frmatin f triglycerides. PHOSPHOLIPIDS Cmpsed f a glycerl backbne, tw fatty acid tails and ne phsphate head A mlecule with a plar grup (phsphate head) and a nnplar grup (fatty acid tail) Figure 2.19 Lipids: structure f phsphlipids. Table 2.3 Organic Mlecules. STEROIDS PROTEINS Macrmlecules: Fur-ring hydrcarbn structure Enzymes cmpnent f cell membrane Are invlved in mvement Functin in the bdy s defenses Receptrs

12 Chapter 2: The Chemistry f Life 24 Twenty different are used t make prteins Figure 2.21a, b Prteins: structure f amin acids. ENZYME DEFICIENCIES (P. 44) NUCLEOTIDES AND NUCLEIC ACIDS Makes up genetic material Examples f cmmn enzyme deficiencies: Tay-Sachs Disease Severe Cmbined Immundeficiency Syndrme (SCIDs) Phenylketnuria built frm mnmers f nucletides Nucletide structure: Nitrgenus base with a hydrcarbn ring structure Five-carbn sugar (ribse r dexyribse) Figure 2.24a Structure f nucletides. Adensine triphsphate (ATP) DNA Adenine attached t ribse and three phsphate grups; main surce f chemical energy in bdy Cmpsed f tw chains that twist arund each ther Synthesized frm ADP and a phsphate using energy frm xidatin f fuels (like glucse) Prductin f large quantities f ATP requires xygen; why we breathe air Figure 2.25a Nucletides: structure and frmatin f ATP. t frm a duble helix DNA cntains genes prvide recipe r cde fr prtein synthesis prcess f making every prtein Figure 2.26a Structure f nucleic acids and Table 2.3 Organic Mlecules.

13 Chapter 2: The Chemistry f Life DNA exhibits cmplementary base pairing; Adenine DNA cntains: Dexyribse alternating always pairs with Thymine and Guanine always pairs with Cytsine with phsphate grup Bases: Figure 2.26a Structure f the nucleic acids DNA and RNA. RNA Ribnucleic Acid single strand f nucletides Can mve between nucleus and cytsl RNA cntains the sugar ribse Figure 2.26b Structure f the nucleic acids DNA and RNA. 25

14 Chapter 2: The Chemistry f Life 26

15 Chapter 3: The Cell BASIC PROCESSES OF CELLS Cell metablism Transprt f substances cell has prduced r ingested t a variety f destinatins between cell and surrunding envirnment Cell reprductin prcess that is necessary fr grwth and develpment and fr replacement f ld and damaged cells OVERVIEW OF CELL STRUCTURE Plasma membrane Mst animal cells have 3 basic cmpnents: Prvides cell with structural supprt, means f Defines intracellular space (cntains intracellular fluid cmmunicatin, and cell identificatin ( )), r cytsl, and separates it frm extracellular space (cntains extracellular fluid ( )) Figure 3.1 The basic cmpnents f a generalized cell. Cytplasm cnsists f: Cytsl Nucleus Cntains mst f cell s and is primary lcatin fr making mst Organelles variety f cellular structures with very specific functins DNA and RNA cntrl mre specific rganelle functins by cding fr and synthesizing prteins Cytskeletn 27

16 Chapter 3: The Cell THE PHOSPHOLIPID BILAYER Cell Size and Diversity: Cells vary widely in size and structure This structural variatin is an example f Structure-Functin Principle Figure 3.2 Cell diversity. Nte that cells are nt drawn t same scale. Phsphlipids have tw key prperties: A phsphate grup ( ) Tw fatty acids ( ) that face ne anther frming a waterresistant barrier Figure 3.3a The frmatin f a phsphlipid bilayer. Membrane Prteins: Transprt substances acrss plasma membrane as prtein channels; thers are carrier prteins that directly bind t and transprt substances int and ut f cell Figure 3.3b, c The frmatin f a phsphlipid bilayer. - bind t chemical messengers called ligands; trigger sequence f events within cell when bund Figure 3.5b Functins f membrane prteins. Figure 3.5a Functins f membrane prteins. speed up chemical reactins; vital t maintaining hmestasis Figure 3.5c Functins f membrane prteins. 28

17 Chapter 3: The Cell give cells shape and help maintain structural integrity Figure 3.5d Functins f membrane prteins. - hld adjacent cells t ne anther, anchring cells within a tissue and/r allwing cell t cell cmmunicatin Figure 3.5e Functins f membrane prteins. Other membrane cmpnents include lipids, carbhydrates, glyclipids, and glycprteins: lipid mlecule, stabilizes plasma membrane s fluid structure during temperature changes Glyclipids and glycprteins, serve t identify cell as part f bdy 29 DRUGS AND MEMBRANE RECEPTORS (P. 74) Many drugs are designed t resemble ligands that bind t membrane receptrs: Agnists Antagnists Figure 3.4 The fluid msaic mdel f the plasma membrane. TRANSPORT ACROSS THE PLASMA MEMBRANE The phsphlipid bilayer is selectively permeable Substance may crss plasma membrane in several ways: PASSIVE TRANSPORT PROCESSES Passive transprt include the fllwing prcesses: Diffusin

18 Chapter 3: The Cell Cncentratin gradient basic frce that drives many types f passive transprt Dye mlecules will scatter due t their wn kinetic energy, which all mlecules have as lng as thermal energy (heat) is present Mvement will cntinue until the dye is unifrm thrughut cntainer (equilibrium) Diffusin Figure 3.6 Diffusin and equilibrium. Simple diffusin mstly nnplar slutes like xygen, carbn dixide, lipids, and hydrcarbns; pass straight thrugh phsphlipid bilayer withut need fr membrane prtein Figure 3.7a Passive transprt: simple and facilitated diffusin. mvement f water acrss a selectively permeable membrane dwn its cncentratin gradient Water mves frm area with cncentratin f slute (mre water mlecules) acrss membrane t area with cncentratin f slute (less water mlecules) Osmtic pressure driving frce exerted by slute mlecules; causes water mlecules t mve until equilibrium is reached - invlves charged r plar slutes such as ins and glucse; crss phsphlipid bilayer with help f a carrier r channel Figure 3.7b, c Passive transprt: simple and facilitated diffusin. Figure 3.8 Passive transprt: smsis. 30

19 Chapter 3: The Cell Tnicity way t cmpare smtic pressure gradients between tw slutins cytsl and ECF Hypertnic ECF slute cncentratin f ECF is higher than inside cell Osmtic pressure gradient pulls water ut f cell and cell Nrmally ECF is Figure 3.9a Tnicity: effects f istnic, hypertnic, and hyptnic slutins n cell vlume. shrinks r Figure 3.9b Tnicity: effects f istnic, hypertnic, and hyptnic slutins n cell vlume. Hyptnic ECF slute cncentratin f ECF is lwer than DEHYDRATION, SPORTS DRINKS, AND WATER (P. 79) inside cell Osmtic pressure gradient pulls water int cell causing the cell t swell and pssibly rupture r 31 Strenuus exercise results in water and electrlyte lss thrugh sweating; ECF becmes hypertnic; hypertnic ECF draws water ut f cells by smsis Sprts drinks Plain water Figure 3.9c Tnicity: effects f istnic, hypertnic, and hyptnic slutins n cell vlume. ACTIVE TRANSPORT VIA MEMBRANE PROTEINS Active transprt prcesses require energy in frm f ATP t prceed as slutes mve against their cncentratin gradients frm cncentratin t cncentratin Figure 3.10 Primary active transprt by the Na+, K+ pump.

20 Chapter 3: The Cell 32 ACTIVE TRANSPORT VIA VESICLES Active transprt using carrier prteins and channels is effective but has limitatins; large macrmlecules are t big t fit s must be transprted by ther means: are small sacs filled with large mlecules Enclsed in a phsphlipid bilayer; allws them t fuse with r be frmed frm plasma membrane Figure 3.11 Secndary active transprt. Endcytsis: (fluid-phase endcytsis r cell drinking ) prcess where cells engulf fluid drplets frm ECF ( cell eating ) prcess where cells ingest large particles like bacteria r dead r damaged cells r parts f cell Figure 3.12 Endcytsis: phagcytsis. Receptr-mediated endcytsis similar t pincytsis; uses receptrs t fill vesicles with a specific mlecule Figure 3.13b Endcytsis: pincytsis and receptr-mediated endcytsis. Figure 3.13a Endcytsis: pincytsis and receptr-mediated endcytsis. large mlecules exit cell; knwn as secretin; vesicles fuse with plasma membrane, pening int ECF mlecules are brught int cell by endcytsis, transprted acrss cell t ppsite side, and then secreted by excytsis Figure 3.14a Excytsis.

21 Chapter 3: The Cell CYTOPLASMIC ORGANELLES Organelles are cellular machinery with specific functins vital t maintaining hmestasis Figure 3.14b Excytsis. MITOCHONDRIA PEROXISOMES membrane-bund rganelles invlved in chemical energy prductin Use xygen t carry ut several chemical reactins that prduce hydrgen perxide (H2O2); xidizes txic chemicals t less txic cmpunds that can be eliminated frm bdy befre causing damage Certain phsphlipids synthesized in perxismes are critical t plasma membranes f specific cells r nervus system. Figure 3.16 Structure f the mitchndrin. RIBOSOMES Ribsmes Free in cytsl; usually make prteins needed within cell itself Bund t membranes f ther cellular structures; prduce prteins destined fr exprt utside cell Figure 3.18 Schematic structure f the ribsme. ENDOPLASMIC RETICULUM Endplasmic reticulum (ER) large flded phsphlipid bilayer Exists in tw frms: (RER) has ribsmes bund t it and (SER) des nt Table 3.2 Cytplasmic Organelles. 33

22 Chapter 3: The Cell Rugh endplasmic reticulum Packages secretry prteins int transprt vesicles made f a phsphlipid bilayer Prduces membrane cmpnents fr membrane-bund rganelles and plasma membrane, including integral and peripheral prteins 34 Smth endplasmic reticulum (SER) Stres calcium ins by pumping them ut f cytsl fr future use Capable f several detxificatin reactins; limits damage caused by certain substances Invlved in lipid synthesis, manufacturing majrity f plasma membrane phsphlipids and chlesterl as well as a number f lipprteins and sterid hrmnes GOLGI APPARATUS grup f flattened membranus sacs filled with enzymes and ther mlecules Prteins and lipids made by ER are further mdified, srted, and packaged fr exprt in the Glgi Prducts packaged in Glgi can be secreted frm cell by excytsis Figure 3.19 The endplasmic reticulum. Table 3.2 Cytplasmic Organelles. CYSTIC FIBROSIS (P. 92) Figure 3.20 The Glgi apparatus. In cystic fibrsis, sme cells are missing a prtein cmpnent f a chlride in channel

23 Chapter 3: The Cell 35 LYSOSOMES rganelles respnsible fr digestin f wrn ut cell cmpnents r whle cells in sme cases Macrmlecules are brken dwn int smaller subunits that can be released t cytsl fr dispsal r reused t manufacture new macrmlecules Table 3.2 Cytplasmic Organelles and Figure 3.15 The cell and its rganelles. Figure 3.21 Functin f the endmembrane system. LYSOSOMAL DISEASES (P. 95) LYSOSOMAL DISEASES Grup f diseases resulting frm deficiency f ne r mre acid hydrlases f lyssmes: Hurler syndrme Gaucher s disease Niemann-Pick disease Tay-Sachs disease THE CYTOSKELETON Cytskeletn Gives the cell its characteristic shape and size by creating an internal framewrk Prvides strength, structural integrity, and anchring sites Perfrming specialized functins in different cell types; fr example, phagcytsis by macrphages r cntractin by muscle cells CENTROSOME / CENTRIOLES When cell is nt dividing, centrsme is a micrtubule-rganizatin center lcated clse t nucleus

24 Chapter 3: The Cell TYPES OF FILAMENTS 36 CELLULAR EXTENSIONS Cellular extensins are frmed by the inner framewrk f the cytskeletn: Figure 3.22 The centrsme with centriles. MICROVILLI Increase surface area f cells in rgans specialized fr absrptin Figure 3.23 Micrvilli. CILIA Hair-like prjectins that stick ut f the cell Table 3.4 Cilia and Flagella. FLAGELLA Beats in a whip-like fashin prpelling entire cell Table 3.4 Cilia and Flagella. Table 3.4 Cilia and Flagella.

25 Chapter 3: The Cell PRIMARY CILIARY DYSKINESIA (P. 99) 37 THE NUCLEUS Rare genetic disrder characterized by defect in ne r mre prtein cmpnents f cilia and flagella gverning bdy that directs activities f the ther cellular cmpnents Affects many types f cells: respiratry passage linings, middle ear, uterine tubes (females), sperm (males) hused in nucleus cntains cde r plans fr nearly every prtein in bdy within DNA are direct different types f RNA t build a wide variety f prteins THE NUCLEUS Nucleus cnsists f three main structures: membrane that surrunds nucleplasm that cntains nuclear pres DNA and assciated prteins are fund in nucleusas a lse structural arrangement knwn as chrmatin in a nn-dividing cell - synthesis f ribsmal RNA and assembly f ribsmes Figure 3.25 The nucleus. NUCLEAR ENVELOPE Figure 3.26 The nuclear pre. CHROMATIN AND CHROMOSOMES cnsists f ne extremely lng DNA mlecule and histne prteins Reduces length f strand by abut ne-third Figure 3.27a Chrmatin.

26 Chapter 3: The Cell 38 During perids f cell divisin, chrmatin threads cil tightly and cndense int thick structures called chrmsmes Sister chrmatids each chrmsme cnsists f identical cpies Figure 3.27 Chrmatin and chrmsmes. DNA & RNA Practice Exercise PROTEIN SYNTHESIS DNA Gene expressin prductin f prtein frm specific gene G -- Tw prcesses actually make a specific prtein: Transcriptin Translatin DNA Transcriptin mrna Translatin Prtein DNA mrna G -- A-- A -- G-- G -- T-- T -- A-- A -- C-- C -- GENES AND THE GENETIC CODE changes in DNA due t mistakes in cpying DNA r induced by agents called mutagens Cmmn mutagens include ultravilet light and ther frms f radiatin, chemicals such as benzene, and infectin with certain viruses

27 Chapter 3: The Cell 39 TOXICITY OF THE DEATH CAP MUSHROOM (P. 104) Amanita phallides (and ther Amanita) are respnsible fr 95% f mushrm-related fatalities wrldwide A phallides is tasty and resembles many nntxic mushrms; main txin inhibits RNA plymerase; prevents frmatin f new strands f mrna REVIEW The prcess thrugh which mrna is made is termed a. Translatin b. Replicatin c. Synthesis d. Transcriptin REVIEW During transcriptin, free nucletides frm the nucleplasm are hydrgen bnded t a. Each ther b. Cmplementary nucletides f the DNA template strand c. Ribsmes d. RNA plymerase REVIEW A strand f mrna cntains the a. Instructins t build a ribsme b. Instructins t build a prtein c. Instructins t build a carbhydrate d. Instructins t build a lipid REVIEW Prtein synthesis is als called a. Transcriptin b. Replicatin c. Translatin d. Differentiatin REVIEW During translatin, the language f is translated int the language f. a. Nucletides, amin acids b. Amin acids, nucletides c. Nucletides, cdns d. Anticdns, nucletides

28 Chapter 3: The Cell REVIEW The DNA triplet TAG is cmplementary t the mrna cdn. a. ATC b. c. d. UAG 40 THE CELL CYCLE Almst all cells g thrugh the cell cycle An rdered series f events frm frmatin f cell t its reprductin by cell divisin Cell divisin is required fr grwth and develpment as well as fr tissue repair and renewal CGG AUC PHASES OF THE CELL CYCLE Cell cycle includes tw main phases: interphase and M phase r cell divisin Interphase perid f grwth and preparatin fr cell divisin: G1 phase (1st gap) S phase (synthesis) G2 phase (2nd gap) Figure 3.33 The cell cycle. REVIEW Nuclear envelpe enclses nucleus Centrile pairs duplicated DNA replicatin ccurs in which phase f the cell cycle? Nucleus and nuclelus are clearly a. G1 b. c. d. G2 visible and individual chrmsmes are nt distinguishable Figure 3.35a Interphase, mitsis, and cytkinesis. S M

29 Chapter 3: The Cell PHASES OF THE CELL CYCLE 41 MITOSIS M is perid f cell divisin; highlighted by tw verlapping prcesses: Divisin f genetic material in 4 stages Prphase Mitsis ccurs when newly replicated genetic material is Metaphase divided between tw daughter cells Anaphase Telphase Cytkinesis ccurs when cell s prteins, rganelles, and cytsl are divided between tw daughter cells METAPHASE PROPHASE Chrmatin becmes cmpact t frm chrmsmes (tw sister chrmatids) Centriles migrate t ppsite sides f cell t rganize spindle fibers Spindle fibers frm each centrile attach t each sister chrmatid ANAPHASE TELOPHASE Cytkinesis may begin at end f this stage Cytkinesis finishes t divide cytsl and rganelles equally between tw new daughter cells Chrmsmes uncil, becming chrmatin

30 Chapter 3: The Cell 42 OVERVIEW OF MEIOSIS Cell divisin can ccur either by (prcess that smatic cells are capable f) r that ccurs in cells destined t becme gametes Meisis cell divides t frm daughter cells with half number f chrmsmes Smatic cells are diplid (2n) because they have full paired set f chrmsmes 2016 Pearsn Educatin, Inc. Meisis prceeds thrugh fur basic phases: prphase, metaphase, anaphase, and telphase Phases ccur in tw successive divisins, unlike MEIOSIS I (FIRST MEIOTIC DIVISION) mitsis, where is first meitic divisin and is secnd First divisin separates hmlgus pairs t prduce haplid (n) cells Prphase I, Metaphase I, Anaphase I, Telphase I Meisis II separates chrmatids f each chrmsme; cells stay haplid Prphase II, Metaphase II, Anaphase II, Telphase II 2016 Pearsn Educatin, Inc. MEIOSIS II (SECOND MEIOTIC DIVISION) Figure 26.1 Stages f meisis. Fr simplicity, the cell is shwn with nly tw pairs f hmlgus chrmsmes Pearsn Educatin, Inc. Figure 26.1 Stages f meisis. Fr simplicity, the cell is shwn with nly tw pairs f hmlgus chrmsmes Pearsn Educatin, Inc. COMPARING MITOSIS AND MEIOSIS Figure 26.2 Cmparing mitsis and meisis Pearsn Educatin, Inc.

31 Chapter 3: The Cell 43 SPINDLE POISONS (P. 111) Mittic spindle is critical t prcess f mitsis; if assembly r disassembly is inhibited by chemicals called spindle pisns (made by fungi and plants), errrs in cell divisin ccur that culd lead t cell death Examples: SPINDLE POISONS inhibit micrtubule functin; fragment frmed micrtubules; used t treat cancer inhibits assembly f micrtubules; treats gut inhibits functin/assembly f micrtubules in fungi (nt humans); antifungal agent fr skin, hair, and nails prevent disassembly f micrtubules; treat cancer Adverse effects (especially in cells that divide rapidly like stmach, skin, and bne marrw) nausea, vmiting, hair lss, decreased bld cell prductin PHASES OF THE CELL CYCLE Mst cells in the bdy prgress thrugh the cell cycle but at vastly different rates depending n their functin Cell cycle is precisely cntrlled s that cell frmatin is balanced with cell death CELL CYCLE CONTROL AND CANCER Cell may nt prceed with divisin if the fllwing cnditins are nt favrable: Grwth factrs are secreted by ther cells CELL CYCLE CONTROL AND CANCER Cells that cannt pass thrugh checkpints and cannt be repaired underg a prcess f prgrammed cell death called Ex. during fetal develpment hands and feet are initially webbed; cells in webs die t separate fingers and tes CELL CYCLE CONTROL AND CANCER When changes in DNA f a cell cause lss f cell cycle cntrl, uncntrlled cell divisin results and cells may frm a grwth r mass knwn as a tumr cnfined t its riginal lcatin and des nt invade surrunding tissues made up f cancer cells

32 Chapter 3: The Cell 44 CELL CYCLE CONTROL AND CANCER Figure 3.36 Cancerus tumr f kidney cells.