Bellairs / Osmond Atlas of Chick Development

3. Auflage 2014
ISBN: 978-0-12-384952-6
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 692 Seiten

The Atlas of Chick Development, Third Edition, a classic work covering all major event of chick development, is extensively updated with new and more detailed photographs, enlargements showing regions of special-interest and complexity, and new illustrations. The revised text and expanded illustrative material describe the intricate changes that take place during development, together with accounts of recent experimental and molecular research that has transformed our understanding of morphogenesis. These wide-ranging updates make this book an essential resource for developmental biologists, geneticists, molecular biologists, poultry scientists, biochemists, immunologists, and other life scientists who use the chick embryo as their research model. Individuals joining this burgeoning area, ignited by the increased insight into events surrounding organ and tissue differentiation, will find this a valuable tool to help grow a basic knowledge of morphogenesis. - Remains the established standard-the only book providing a comprehensive description of chick development from fertilization to hatching - Contains more than 750 photographs and illustrations, including 410 labelled histological sections and 85 new high-quality plates, showing the major anatomical events from the earliest stages to 13 days of incubation - Includes more than 200 labelled and detailed scanning electron micrographs, showing various tissues in great detail - Leads the reader to important reviews on aspects of this rapidly moving field, along with extensive and updated references

BSc (hons) in Zooloy, University of Birmingham UK 1947PhD in Zoology (Embryology), University of London 1951, supervised by Sir Gavin deBeer and Michael Abercrombie.Apart from brief periods in Anatomy Department, Cambridge and Department of Biology, St Bartholomew's Hospital Medical School, academic posts have all been at UCL (University College London). Retired 1991 as Emeritus Professor in Embryology.Research predominantly on early chick embryos concerned mainly with problems of tissue interaction, gastrulation and segmentation.Founder member of Embryologists' Club, the predecessor of BSDB (British Society of Developmental Biology). Served on several editorial boards, including JEEM (now Development) and Anatomy and Embryology. Publications: approximately 120, including 2 books, 5 edited books.

Autoren/Hrsg.

Bellairs, Ruth

Osmond, Mark

Inhaltsverzeichnis

1;Front Cover;1
2;The Atlas of Chick Development;4
3;Copyright;5
4;Contents;6
5;Preface to First Edition;12
6;Preface to Second Edition;14
7;Preface to Third Edition;16
8;Note on Plates;18
9;Glossary;20
10;Some Highlights in the History of Chick Embryology;32
11;Chapter 1 - The Hen’s Egg and its Formation;34
11.1;THE REPRODUCTIVE TRACT OF THE HEN;34
11.2;THE OVIDUCT;36
11.3;THE OVULATION CYCLE IN THE LAYING HEN;36
11.4;THE VITELLINE MEMBRANE (PERIVITELLINE LAYER);37
11.5;TRANSPORT OF MATERIALS ACROSS THE VITELLINE MEMBRANE;37
11.6;ALBUMEN AND THE CHALAZAE;38
11.7;THE EGG SHELL AND ITS FORMATION;38
11.8;THE LAID EGG;38
12;Chapter 2 - Techniques;40
12.1;‘MILKING’ HENS;40
12.2;STORAGE OF EGGS;40
12.3;INCUBATION;40
12.4;STAGES OF DEVELOPMENT;41
12.5;LABELLING TECHNIQUES;41
12.6;CULTURE TECHNIQUES;42
12.7;GRAFTING AND TRANSPLANTS;43
12.8;IN OVO TECHNIQUES;44
12.9;PREPARATION OF SERIAL SECTIONS;45
12.10;INSTRUMENTS;46
12.11;COMMON ABNORMALITIES;46
13;Chapter 3 - Early Stages;48
13.1;FERTILIZATION AND PRE-LAYING;48
13.2;NORMAL TABLES;50
13.3;THE EARLY POST-LAYING STAGES;51
13.4;GASTRULATION MOVEMENTS;56
13.5;INGRESSION AND CELL MIGRATION AWAY FROM THE PRIMITIVE STREAK;59
14;Chapter 4 - Establishment of the Embryonic Body;62
14.1;HEAD PROCESS AND REGRESSION;64
14.2;THE TAILBUD;65
14.3;NEURAL INDUCTION;66
14.4;FORMATION OF THE NEURAL PLATE AND NEURAL TUBE;67
14.5;REGIONALIZATION OF THE NEURAL TISSUE;68
14.6;FORMATION OF THE NOTOCHORD AND SOMITES;69
14.7;THE LATERAL PLATE MESODERM AND THE INTERMEDIATE MESODERM;73
14.8;THE NEURAL CREST;73
15;Chapter 5 - External Appearance and Polarity;78
15.1;FACE;79
15.2;ORIGIN OF THE LIMBS;80
15.3;GROWTH OF THE EMBRYO;82
15.4;APOPTOSIS;82
15.5;POLARITY: SYMMETRY AND ASYMMETRY;82
16;Chapter 6 - Heart, Blood Vessels and Lymphatics;84
16.1;HEART;84
16.2;PRIMARY AND SECONDARY HEART FIELDS;84
16.3;THE BLOOD VESSELS;92
16.4;EMBRYONIC BLOOD VESSELS;93
16.5;THE VENOUS SYSTEM;95
16.6;THE ENDOTHELIAL AND HAEMOPOIETIC STEM CELLS;98
16.7;THE LYMPHATICS;98
17;Chapter 7 - Urino-Genital System;100
17.1;THE URINARY SYSTEM;100
17.2;THE GENITAL SYSTEM;104
18;Chapter 8 - Gut, Coelom and Respiratory System;110
18.1;EARLY STAGES;110
18.2;THE INTESTINES;117
18.3;THE COELOM, MESENTERIES AND RESPIRATORY SYSTEM;119
18.4;THE RESPIRATORY TRACT;121
19;Chapter 9 - Nervous System;124
19.1;THE BRAIN;124
19.2;HISTOLOGY OF THE SPINAL CORD AND DEVELOPMENT OF THE FIBRE TRACTS;126
19.3;SPINAL NERVES;127
19.4;THE CRANIAL NERVES AND GANGLIA;128
19.5;THE AUTONOMIC NERVOUS SYSTEM;130
19.6;ORGANS OF SPECIAL SENSE;131
20;Chapter 10 - Skeleton and Muscles;136
20.1;SKELETON;136
20.2;THE MUSCLES;145
21;Chapter 11 - The Integument;150
21.1;THE FEATHERS;150
21.2;THE PERIDERM;153
21.3;BEAK AND CLAWS;153
21.4;THE COMB;154
21.5;THE UROPYGIAL GLAND;154
21.6;PIGMENTATION;154
21.7;INNERVATION AND SENSORY RECEPTORS IN THE INTEGUMENT;155
22;Chapter 12 - Endocrine Glands;156
22.1;THE PITUITARY GLAND;156
22.2;THE THYROID GLAND;157
22.3;THE PARATHYROID GLANDS;157
22.4;THE ADRENAL GLANDS;158
22.5;THE PANCREAS;158
22.6;THE GONADS;158
22.7;GUT ENDOCRINE CELLS;158
23;Chapter 13 - Extra-Embryonic Membranes;160
23.1;THE YOLK SAC;160
23.2;THE AMNION AND CHORION;161
23.3;THE CHORIOALLANTOIC MEMBRANE;161
24;Photographic Plates;164
24.1;Plate 1 Oocytes and sperm;165
24.2;Plate 2 Shell, shell membranes and vitelline membrane;167
24.3;Plate 3 Light micrographs of whole-mounted twin embryos;169
24.4;Plate 4 Extra-embryonic blood vessels;171
24.5;Plate 5 Light micrographs showing Cleavage;173
24.6;Plate 6 Subgerminal layer;175
24.7;Plate 7 Dorsal side of early embryos;177
24.8;Plate 8 Dorsal side: primitive streak and neural folds;179
24.9;Plate 9 Primitive streak;181
24.10;Plate 10 Primitive streak sections: medial and lateral;183
24.11;Plate 11 Scanning electron micrographs of the primitive streak;185
24.12;Plate 12 Stage 4 (19–20 h) transverse sections (TS);187
24.13;Plate 13 Stage 5 (20–22 h);189
24.14;Plate 14 Stage 6 (23–25 h);191
24.15;Plate 15 Head region;193
24.16;Plate 16 Body flexures and area opaca;195
24.17;Plate 17 Neural folds and neural tube;197
24.18;Plate 18 Closure of the anterior neuropore;199
24.19;Plate 19 Neural tube;201
24.20;Plate 20 Scanning electron micrographs of notochord;203
24.21;Plate 21 Somites and segmental plate;205
24.22;Plate 22 Scanning electron micrographs of somites and nephric duct;207
24.23;Plate 23 Somite differentiation;209
24.24;Plate 24 Neural crest I;211
24.25;Plate 25 Neural crest II;213
24.26;Plate 26 Scanning electron micrographs of otic placodes and pits;215
24.27;Plate 27 Scanning electron micrographs of otic pits and nasal placodes;217
24.28;Plate 28 Scanning electron micrographs of the lens placode;219
24.29;Plate 29 Light micrographs of whole embryos and skeletally stained feet;221
24.30;Plate 30 Scanning electron and light micrographs of limbs;223
24.31;Plate 31 Scanning electron micrographs of the tail bud;225
24.32;Plate 32 Heart development I;227
24.33;Plate 33 Heart development II;229
24.34;Plate 34 Heart development III;231
24.35;Plate 35 Heart development IV;233
24.36;Plate 36 Heart development V;235
24.37;Plate 37 Heart development VI;237
24.38;Plate 38 Internal organs: heart and lungs;239
24.39;Plate 39 Internal organs: intestinal and urogenital systems;241
24.40;Plate 40 Internal organs: heart and gizzard;243
24.41;Plate 41 Internal organs: liver and ventricle;245
24.42;Plate 42 Aortic arches;247
24.43;Plate 43 Blood vessel formation;249
24.44;Plate 44 Vascularization of the chorioallantoic membrane;251
24.45;Plate 45 Pharyngeal arch arteries I;253
24.46;Plate 46 Pharyngeal arch arteries II;255
24.47;Plate 47 Blood vessels in the trunk I;257
24.48;Plate 48 Blood vessels in the trunk II;259
24.49;Plate 49 Intestinal and urogenital systems;261
24.50;Plate 50 Nephric duct;263
24.51;Plate 51 Mesonephros;265
24.52;Plate 52 Mullerian duct and mesonephros;267
24.53;Plate 53 Head and face;269
24.54;Plate 54 External genitalia I;271
24.55;Plate 55 External genitalia II;273
24.56;Plate 56 Scanning electron micrographs of the lung;275
24.57;Plate 57 Parabronchial architecture;277
24.58;Plate 58 Central nervous system;279
24.59;Plate 59 Amnion;281
24.60;Plate 60 Stage 8 (26–29 h);283
24.61;Plate 61 Stage 8 (26–29 h) TS;285
24.62;Plate 62 Stage 8 (26–29 h) TS;287
24.63;Plate 63 Stage 9 (29–33 h);289
24.64;Plate 64 Stage 9 (29–33 h) TS;291
24.65;Plate 65 Stage 9 (29–33 h) TS;293
24.66;Plate 66 Stage 10 (33–38 h);295
24.67;Plate 67 Stage 10 (33–38 h) LS: sagittal;297
24.68;Plate 68 Stage 10 (33–38 h) TS;299
24.69;Plate 69 Stage 10 (33–38 h) TS;301
24.70;Plate 70 Stage 11 (40–45 h) TS;303
24.71;Plate 71 Stage 11 (40–45 h) TS;305
24.72;Plate 72 Stage 11 (40–45 h) TS;307
24.73;Plate 73 Stage 12 (45–49 h) LS;309
24.74;Plate 74 Stage 12 (45–49 h) LS: coronal;311
24.75;Plate 75 Stage 12 (45–49 h) LS: coronal;313
24.76;Plate 76 Stage 13 (48–52 h);315
24.77;Plate 77 Stage 13+ (52 h);317
24.78;Plate 78 Stage 13 (48–52 h) LS: coronal;319
24.79;Plate 79 Stage 13 (48–52 h) TS;321
24.80;Plate 80 Stage 14 (50–53 h);323
24.81;Plate 81 Stage 14 (50–53 h) LS: coronal;325
24.82;Plate 82 Stage 14 (50–53 h) LS: coronal and sagittal;327
24.83;Plate 83 Stage 14 (50–53 h) LS: coronal and sagittal;329
24.84;Plate 84 Stage 14 (50–53 h) TS;331
24.85;Plate 85 Stage 14 (50–53 h) TS;333
24.86;Plate 86 Stage 14 (50–53 h) TS;335
24.87;Plate 87 Stage 14 (50–53 h) TS;337
24.88;Plate 88 Stage 16 (52–64 h);339
24.89;Plate 89 Stage 17 (52–64 h) TS;341
24.90;Plate 90 Stage 17 (52–64 h) TS;343
24.91;Plate 91 Stage 17 (52–64 h) TS;345
24.92;Plate 92 Stage 17 (52–64 h) TS;347
24.93;Plate 93 Stage 17 (52–64 h) TS;349
24.94;Plate 94 Stage 18 (65–69 h);351
24.95;Plate 95 Stage 18 (65–69 h) LS;353
24.96;Plate 96 Stage 18 (65–69 h) LS;355
24.97;Plate 97 Stage 18 (65–69 h) LS;357
24.98;Plate 98 Stage 18 (65–69 h);359
24.99;Plate 99 Stage 18 (65–69 h) TS;361
24.100;Plate 100 Stage 18 (65–69 h) TS;363
24.101;Plate 101 Stage 18 (65–69 h) TS;365
24.102;Plate 102 Stage 18 (65–69 h) TS;367
24.103;Plate 103 Stage 18 (65–69 h) TS;369
24.104;Plate 104 Stage 18 (65–69 h) TS;371
24.105;Plate 105 Stage 18 (65–69 h) TS;373
24.106;Plate 106 Stage 20 (70–72 h);375
24.107;Plate 107 Stage 23 (day 4) LS: coronal and sagittal;377
24.108;Plate 108 Stage 23 (day 4) LS: coronal and sagittal;379
24.109;Plate 109 Stage 23 (day 4) TS;381
24.110;Plate 110 Stage 23 (day 4) TS;383
24.111;Plate 111 Stage 23 (day 4) TS;385
24.112;Plate 112 Stage 23 (day 4) TS;387
24.113;Plate 113 Stage 24 (day 4.5) TS;389
24.114;Plate 114 Stage 24 (day 4.5) TS;391
24.115;Plate 115 Stage 24 (day 4.5) TS;393
24.116;Plate 116 Stage 24 (day 4.5) TS;395
24.117;Plate 117 Stage 24 (day 4.5) TS;397
24.118;Plate 118 Stage 26 (day 5) LS: sagittal;399
24.119;Plate 119 Stage 26 (day 5) LS: sagittal;401
24.120;Plate 120 Stage 26 (day 5) LS: sagittal;403
24.121;Plate 121 Stage 26 (day 5) LS: sagittal;405
24.122;Plate 122 Stage 26 (day 5) LS: sagittal;407
24.123;Plate 123 Stage 26 (day 5) LS: sagittal;409
24.124;Plate 124 Stage 26 (day 5) LS: sagittal;411
24.125;Plate 125 Stage 26 (day 5) LS: oblique;413
24.126;Plate 126 Stage 26 (day 5) TS;415
24.127;Plate 127 Stage 26 (day 5) TS;417
24.128;Plate 128 Stage 26 (day 5) TS;419
24.129;Plate 129 Stage 28 (day 6) LS: sagittal;421
24.130;Plate 130 Stage 28 (day 6) LS: sagittal;423
24.131;Plate 131 Stage 28 (day 6) LS: sagittal;425
24.132;Plate 132 Stage 28 (day 6) LS: sagittal;427
24.133;Plate 133 Stage 28 (day 6) LS: sagittal;429
24.134;Plate 134 Stage 28 (day 6) LS: sagittal;431
24.135;Plate 135 Stage 28 (day 6) LS: sagittal;433
24.136;Plate 136 Stage 28 (day 6) LS: sagittal;435
24.137;Plate 137 Stage 28 (day 6) LS: sagittal;437
24.138;Plate 138 Stage 28 (day 6) LS: sagittal;439
24.139;Plate 139 Stage 28 (day 6) LS: sagittal;441
24.140;Plate 140 Stage 28 (day 6) LS: sagittal;443
24.141;Plate 141 Stage 28 (day 6) LS: coronal;445
24.142;Plate 142 Stage 28 (day 6) LS: coronal;447
24.143;Plate 143 Stage 28 (day 6) LS: coronal;449
24.144;Plate 144 Stage 28 (day 6) TS;451
24.145;Plate 145 Stage 28 (day 6) TS;453
24.146;Plate 146 Stage 28 (day 6) TS;455
24.147;Plate 147 Stage 28 (day 6) TS;457
24.148;Plate 148 Stage 31 (day 7) LS: sagittal;459
24.149;Plate 149 Stage 31 (day 7) LS: sagittal;461
24.150;Plate 150 Stage 31 (day 7) TS;463
24.151;Plate 151 Stage 31 (day 7) TS;465
24.152;Plate 152 Stage 31 (day 7) TS;467
24.153;Plate 153 Stage 31 (day 7) TS;469
24.154;Plate 154 Stage 31 (day 7) TS;471
24.155;Plate 155 Stage 31 (day 7) TS;473
24.156;Plate 156 Stage 31 (day 7) TS: enlargements;475
24.157;Plate 157 Stage 35 (day 9) LS: sagittal;477
24.158;Plate 158 Stage 35 (day 9) TS;479
24.159;Plate 159 Stage 35 (day 9) TS;481
24.160;Plate 160 Stage 35 (day 9) TS;483
24.161;Plate 161 Stage 35 (day 9) TS;485
24.162;Plate 162 Stage 35 (day 9) TS;487
24.163;Plate 163 Stage 35 (day 9) TS;489
24.164;Plate 164 Stage 35 (day 9) TS;491
24.165;Plate 165 Stage 35 (day 9) TS;493
24.166;Plate 166 Stage 35 (day 9) TS;495
24.167;Plate 167 Stage 35 (day 9) TS;497
24.168;Plate 168 Stage 35 (day 9) TS;499
24.169;Plate 169 Stage 35 (day 9) TS;501
24.170;Plate 170 Stage 35 (day 9) TS;503
24.171;Plate 171 Stage 35 (day 9) TS;505
24.172;Plate 172 Stage 35 (day 9) TS;507
24.173;Plate 173 Stage 35 (day 9) TS;509
24.174;Plate 174 Stage 35 (day 9) TS;511
24.175;Plate 175 Stage 35 (day 9) TS;513
24.176;Plate 176 Stage 35 (day 9) TS;515
24.177;Plate 177 Stage 35 (day 9) TS;517
24.178;Plate 178 Stage 36 (day 10);519
24.179;Plate 179 Stage 36 (day 10) LS: coronal;521
24.180;Plate 180 Stage 36 (day 10) LS: coronal;523
24.181;Plate 181 Stage 36 (day 10) LS: coronal;525
24.182;Plate 182 Stage 36 (day 10) LS: coronal;527
24.183;Plate 183 Stage 36 (day 10) LS: coronal;529
24.184;Plate 184 Stage 37 (day 11) LS: sagittal;531
24.185;Plate 185 Stage 37 (day 11) LS: sagittal;533
24.186;Plate 186 Stage 37 (day 11) LS: sagittal;535
24.187;Plate 187 Stage 37 (day 11) LS: sagittal;537
24.188;Plate 188 Stage 37 (day 11) LS: sagittal;539
24.189;Plate 189 Stage 37 (day 11) LS: sagittal;541
24.190;Plate 190 Stage 37 (day 11) LS: sagittal;543
24.191;Plate 191 Stage 37 (day 11) TS;545
24.192;Plate 192 Stage 37 (day 11) TS;547
24.193;Plate 193 Stage 37 (day 11) TS;549
24.194;Plate 194 Stage 37 (day 11) TS;551
24.195;Plate 195 Stage 37 (day 11) TS;553
24.196;Plate 196 Stage 37 (day 11) TS;555
24.197;Plate 197 Stage 37 (day 11) TS;557
24.198;Plate 198 Stage 37 (day 11) TS;559
24.199;Plate 199 Stage 37 (day 11) TS;561
24.200;Plate 200 Stage 37 (day 11) TS;563
24.201;Plate 201 Stage 37 (day 11) TS;565
24.202;Plate 202 Stage 37 (day 11) TS;567
24.203;Plate 203 Stage 37 (day 11) TS;569
24.204;Plate 204 Stage 37 (day 11) TS;571
24.205;Plate 205 Stage 37 (day 11) TS;573
24.206;Plate 206 Stage 37 (day 11) TS;575
24.207;Plate 207 Stage 37 (day 11) TS;577
24.208;Plate 208 Stage 39 (day 13) LS: sagittal;579
24.209;Plate 209 Stage 39 (day 13) LS: coronal and sagittal;581
24.210;Plate 210 Stage 39 (day 13) TS;583
24.211;Plate 211 Stage 39 (day 13) TS;585
24.212;Plate 212 Stage 39 (day 13) TS;587
24.213;Plate 213 Stage 39 (day 13) TS;589
24.214;Plate 214 Stage 39 (day 13) TS;591
24.215;Plate 215 Stage 39 (day 13) TS;593
24.216;Plate 216 Stage 39 (day 13) TS;595
24.217;Plate 217 Stage 39 (day 13) TS;597
24.218;Plate 218 Stage 39 (day 13) TS;599
24.219;Plate 219 Stage 39 (day 13) TS;601
24.220;Plate 220 Stage 39 (day 13) TS;603
24.221;Plate 221 Stage 39 (day 13) TS;605
24.222;Plate 222 Stage 39 (day 13) TS;607
24.223;Plate 223 Stage 39 (day 13) TS;609
24.224;Plate 224 Stage 39 (day 13) TS;611
24.225;Plate 225 Stage 39 (day 13) TS;613
24.226;Plate 226 Stage 39 (day 13) TS;615
24.227;Plate 227 Stage 39 (day 13) TS;617
24.228;Plate 228 Stage 39 (day 13) TS;619
24.229;Plate 229 Stage 39 (day 13) TS;621
24.230;Plate 230 Stage 37 (day 11);623
24.231;Plate 231 Stage 39 (day 13);625
24.232;Plate 232 Stage 45 (Day 19.5);627
25;Appendices - Normal Tables;630
26;Appendix I - Normal Table of Eyal-Giladi and Kochav (1975);632
26.1;CLEAVAGE STAGES;632
26.2;FORMATION OF AREA PELLUCIDA;632
26.3;HYPOBLAST FORMATION (EARLY STAGES OF INCUBATION);632
26.4;APPENDIX I PLATE 1;633
26.5;Appendix I Plate 2;634
26.6;APPENDIX I PLATE 3;634
26.7;Appendix I Plate 4;635
26.8;Appendix I Plate 5;635
27;Appendix II Normal Table of Hamburger and Hamilton (1951; 1992);636
27.1;Appendix II Plates 1;641
27.2;APPENDIX II PLATES 2;642
27.3;APPENDIX II PLATES 3;643
27.4;APPENDIX II PLATES 4;644
27.5;APPENDIX II PLATES 5;645
27.6;APPENDIX II PLATES 6;646
27.7;APPENDIX II PLATES 7;647
27.8;APPENDIX II PLATES 8;648
27.9;APPENDIX II PLATES 9;649
27.10;APPENDIX II PLATES 10;650
27.11;APPENDIX II PLATES 11;651
27.12;APPENDIX II PLATES 12;652
27.13;APPENDIX II PLATES 13;653
27.14;APPENDIX II PLATES 14;654
28;APPENDIX III - ADDITIONAL NORMAL TABLES;656
28.1;CHICK;656
28.2;DUCK;656
28.3;PHEASANT;656
28.4;QUAIL;656
28.5;TURKEY;656
29;References;658
30;Index;686

Leseproben

Glossary
Achondroplasia   several mutant types of dwarfism in which ossification of bones is premature, reducing growth, e.g. nanomelia in birds (Greek: a = not: chondro = cartilage; plasia = plastic). Acrosome   vesicular structure at the anterior end of the sperm containing hydrolytic enzymes (Greek: akron = extremity, top). Activation of the egg   the stimulation of an egg cell, normally by fusion with a sperm, resulting in the onset of development (Latin: activus = active). Activation of the sperm   the acquisition of motility by a sperm. Agenesis   failure of part of the body to develop (Greek: a = not; genesis = to come into being). Air space   the space between the two shell membranes at the blunt end of the egg. The chick pushes its beak into this space shortly before hatching and takes its first breath of air. Albumen   the egg-white of a bird’s egg (Latin: albus = white). Allantoic stalk   the base of the allantois, which connects it to the hindgut. Allantois   sac-like outgrowth from the hindgut consisting of endoderm covered with splanchnic mesoderm. It becomes highly vascularized and fuses with the chorion (see Chorioallantois). Excretory products are stored in its lumen (Greek: allas = sausage; eidos = form). N.B.: the chick allantois is balloon-like, not sausage-shaped. Amniocardiac vesicle   bilaterally situated spaces forming in the mesoderm on either side of the head process. The dorsal wall of each cavity is composed of ectoderm and somatic mesoderm and gives rise to the amnion. The cavities become continuous medially with the cardiac cavity (becoming the pericardial coelum) and with the coelomic cavity laterally. Amnion   the sac that envelops the embryo from about 3 days of incubation (Greek: amnos = a lamb). Amniotes   the three classes of truly terrestrial vertebrates, reptiles, birds and mammals, all of which possess a true amnion. Amniotic fluid   the proteinaceous fluid contained within the amnion and whose main function is to prevent dehydration and adhesions between the limbs and other regions of the body prior to cornification of the epidermis. Amniotic folds   the folds of ectoderm, together with adherent somatic mesoderm, which fuse with one another to form the amnion and chorion. Angiogenesis   development of certain parts of the vascular system (e.g. in the area vasculosa) by the formation of blood islands, which then join together by sprouting (but see also Vasculogenesis) (Greek: angeion = vessel; genesis = generation, development). Animal pole   the uppermost surface of the fertilized egg, as opposed to the vegetal pole, the lowermost side. Anlagen   (German) see Primordium. Anteriorcranial, rostral   towards the head end (Latin: ante = in front of). Anterior intestinal portal   the opening of the foregut in the early embryo into the lumen of the yolk sac (Latin: ante = before; intus = within; porta = door). Anterior necrotic zone (ANZ)   a patch of dead cells that appears on the anterior surface of the limb bud at stage 22 (about 3.5–4 days) (Latin: ante = before; Greek: nekros = dead body). Anterior neuropore   the gap left between the unfused region of the neural folds at their most anterior end (see Plate 18). This pore becomes lost when the neural folds fuse at about stage 11 (see also Posterior neuropore). Apical ectodermal ridge   the thickened epithelium at the tip of a limb bud, which is essential for limb development (see  Plate 30 ). Apoptosis    see Programmed cell death (Latin: ap = before; Greek: ptosis from piptein = to fall). Area centralis   the central area of a bird’s blastoderm before the establishment of the area pellucida and area opaca. Area opaca   the peripheral region of a young blastoderm, encircling the area pellucida. When removed from the yolk mass and viewed by transmitted light, the tissue appears opaque because of the large amount of intracellular yolk droplets. Area pellucida   the central area of a young blastoderm, which possesses little intracellular yolk and is therefore relatively transparent compared with the area opaca. Area vasculosa   the proximal part of the area opaca after it has become vascularized. Area vitellina   the distal part of the area opaca that remains unvascularized. Atresia   the reduction or elimination of the lumen of an organ, or the failure of a duct to canalize (Greek: a = not; tresio = perforate, passage). Atrio-ventricular canal   the constriction between the initial atrium and ventricle in the developing heart, which becomes divided into left and right sides by the growth of the atrio-ventricular cushions (Latin: atrium = vestibule; ventriculus = small belly; canalis = channel). Atrophy   the wasting away of an organ or tissue. Although the term implies that this results from a lack of sufficient nourishment, this is not necessarily the case (Greek: a = not, trophe = food). Auditory (otic) vesicle    see Otic vesicle (Latin: auditus = hearing). Autopodium   the distal, flattened end of a limb bud that will give rise to a foot or hand (Greek: autos = self; podium = foot). Axial mesoderm   mesoderm lying in the midline (notochord) or immediately on either side of it (somitic mesoderm), which will take part in the formation of the axial structures, i.e. tissues arranged along the anterior–posterior axis of the body. Axis   in a bilaterally symmetrical embryo there are three body axes, antero-posterior (head–tail, cranio-caudal), dorso-ventral (back–belly) and left–right (Greek: axis = axis). Balbiani body   a region of the early oocyte rich in Golgi apparatus and mitochondria. Bilaminar embryo   a blastoderm consisting of two layers only, epiblast and a lower layer, the hypoblast. Blastoderm, blastodisc, germinal disc, embryonic disc   the flattened disc of cells that forms during cleavage in the early embryo and persists until the end of gastrulation. By the time of laying two major regions are visible, the centrally situated area pellucida and the peripherally located area opaca (Greek: blastos = bud; derma = skin). Blastodisc    see Blastoderm. Blastomeres   cleavage stage cells, each completely enclosed by a cell membrane (see also Open cells) (Greek: blastos = bud; meros = part). Blastula   an embryo during cleavage (see also Blastoderm). Blood islands   isolated clusters of mesoderm cells in the area vasculosa (developing yolk sac), each consisting of a vesicle of endothelial cells surrounding the earliest red blood corpuscles. Body folds   head, lateral and tail folds that raise the...