Veterinary-Developmental-anatomy-2.pdf

VETERINARY DEVELOPMENTAL ANATOMY The Basics  TERMINOLOGIES Embryology Germ Layer Epithelium Mesenchyme Connective tissues Embryology Prenatal development of an organism Growth and differentiation of an organism https://www.google.com/imgres?imgurl=...

VETERINARY DEVELOPMENTAL ANATOMY The Basics  TERMINOLOGIES Embryology Germ Layer Epithelium Mesenchyme Connective tissues Embryology Prenatal development of an organism Growth and differentiation of an organism https://www.google.com/imgres?imgurl=https%3A%2F%2Fpreview.free3d.com%2Fimg%2F2018%2F10%2F2202378378869212318%2F32x85dgk-900.jpg&imgrefurl=https%3A%2F%2Ffree3d.com%2F3d-model%2Fovum-cell-5110.html&tbnid=EVESYFbH6eS9EM&vet=12ahUKEwjKzuuJ- uzrAhUDTZQKHZOPCGwQMygKegUIARDsAQ..i&docid=Okdgjkny77z9hM&w=900&h=675&q=ovum&ved=2ahUKEwjKzuuJ-uzrAhUDTZQKHZOPCGwQMygKegUIARDsAQ Germ Layer Sheet of cells giving rise to all tissues and organs of the body 3 primary germ layers Ectoderm Mesoderm Endoderm Epithelium Tissue composed of a single or several layers of cells resting on a laminar base and are closely joined together at their lateral surfaces May differentiate into a mesenchyme https://www.google.com/imgres?imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fe%2Fe9%2FEpithelial_Tissues_Brush_Border_in_Simple_Columnar_Epithelium_%252827854453998%2529.jpg&imgrefurl=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2 FFile%3AEpithelial_Tissues_Brush_Border_in_Simple_Columnar_Epithelium_(27854453998).jpg&tbnid=vR1Ub3e-vO4jIM&vet=12ahUKEwjPtK_V- uzrAhUQCpQKHY7xCYEQMygEegUIARDXAQ..i&docid=WHnLwwrr8FdoBM&w=3264&h=1840&q=simple%20columnar%20epithelium&ved=2ahUKEwjPtK_V-uzrAhUQCpQKHY7xCYEQMygEegUIARDXAQ Mesenchyme Group of loosely and irregularly arranged embryonic cells separated by extensive extracellular matrix May differentiate into an epithelium or into adult structures Connective tissues Connects and supports other tissues of the body https://www.google.com/imgres?imgurl=https%3A%2F%2Fthumbs.dreamstime.com%2Fz%2Flight-micrograph-white-adipose-tissue-stained-hematoxylin-eosin-adipocytes-fat-cells-contain-large-lipid-droplet-117240715.jpg&imgrefurl=https%3A%2F%2Fwww.dreamstime.com%2Flight- micrograph-white-adipose-tissue-stained-hematoxylin-eosin-adipocytes-fat-cells-contain-large-lipid-droplet-image117240715&tbnid=uVnj7T442l2_0M&vet=12ahUKEwjvu9Kh-- zrAhXhIaYKHdrkAyIQMyhGegUIARCBAQ..i&docid=zp_7TcYp4W4TlM&w=1300&h=1130&q=adipose%20tissue&ved=2ahUKEwjvu9Kh--zrAhXhIaYKHdrkAyIQMyhGegUIARCBAQ  EARLY STAGES OF DEVELOPMENT Gametogenesis Fertilization Cleavage Gastrulation Neurulation 1. Gametogenesis Process of development and maturation of sex cells or gametes 2 types: Ovum Spermatozoon Types of Ovum According to Yolk amount Microlecithal (mammals) Mesolecithal (amphibians) Macrolecithal (birds) According to Yolk distribution Isolecithal Telolecithal CHANGES DURING SPERMIOGENESIS Parts of Changes Parts of the Spermatozoon Spermatid Nucleus Becomes compact Head Centrosome Becomes motile Axial Filament of the Tail Cytoplasm Becomes reduced Envelope around the head and middle piece of the tail Golgi Apparatus Becomes Acrosome Mitochondria Arranged in a helical Spiral filament of middle piece manner Sex Determination Mammals Sex is determined by chromosome (Y) of the spermatozoon that fertilizes the ovum (X) XY- Male/ XX- Female Birds Sex is determined by chromosome (W) of the female thatn is fertilized by the spermatozoon (Z) ZZ- Male/ ZW- Female 2. Fertilization Insemination Sperm capacitation Migration Acrosome reaction Formation of fertilization cone Penetration of the ovum by the sperm Formation of the fertilization membrane Formation of the female and male pronuclei 3. Cleavage Blastomeres formation Starts at anaphase stage Types: Holoblastic Meroblastic Morula- compact ball Blastula- blastomeres https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.dreamstime.com%2Fstock-illustration-initial-period-fetal-development-structure-zy-zygote-blastocyst-infographics-vector-illustration-isolated- image87305056&psig=AOvVaw1E6kpHRZnpebvrqkEsGGWs&ust=1600321383454000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCID67_H77OsCFQAAAAAdAAAAABAD  Early Embryonic Development in Birds Meroblastic cleavage occurs as the egg passes down the oviduct By the time the egg is laid, gastrulation has began Cleavage occurs at the whitish blastoderm located at the top of the yolk  Central blastomeres Marginal blastomeres Hypoblast Blastocoele Epiblast Trophoblasts 4. Gastrulation Formation of primary germ layers Well- ordered rearrangement of cells Acquisition by embryonic cells of the capacity to undergo morphogenetic movements and a certain degree of differentiation Stages of Gastrulation in Primates and Domestic Animals Formation of the Primitive Streak Formation of Primitive groove, Endoderm, and Mesoderm Regression of primitive streak, formation of notochord and ectoderm 5. Neurulation Early CNS development Initial development of the gut and heart Appearance of segmented paraxial mesoderm Early Development of the Central Nervous System Neural plate Neural groove---->>> neural folds Neural tube Surface ectoderm Neural crest cells Anterior and posterior neuropores  Initial Development of the Heart Coelom Pericardial coelom Cardiogenic plate Endocardial vesicles---->>> endocardial tube Epimyocardium---->>> Endomyocardium---->>> Pericardial coelom 6. Embryonic Duplication and factors affecting such Formation of separately ovulated ova Complete or partial separation of blastomeres and blastocysts during cleavage stages Duplication after gastrula stage when specific organ- forming regions “fields” are being organized Complete separation of twins but there is only one blood supply https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.theprairiehomestead.com%2F2018%2F08%2Ftwin-cows-sterile.html&psig=AOvVaw3xLp1e9CAVv5zdpbjvTlRO&ust=1600321771935000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCPDFlZT- 7OsCFQAAAAAdAAAAABAZ 7. Development of extraembryonic membranes Types Amnion Chorion Allantois Yolk sac  Mammalian Placenta Fetal Maternal Classifications (Based on # of Layers) Epitheliochorial Syndesmochorial Endotheliochorial Hemochorial  Classifications (Based on Shape and distribution of attachment sites) Diffuse Cotyledonary Zonary Discoid Classifications (Based on Status of endometrium during parturition) Deciduate Adeciduate  Implantation – attachment of the trophoblast to the epithelial lining of the uterus Types Non- invasive Invasive The Diffuse Placenta The Zonary and Discoid Placentas The Cotelydonary Placenta  CONCEPTS AND MECHANISM OF DEVELOPMENT Growth Morphogenesis Patterning Differentiation  Morphogenesis Epithelial expansion Delamination Mesenchymal aggregation Placode formation Invagination Vesicle formation Budding and branching Evagination  PRACTICE QUIZ 1. Animal which has a Syndesmochorial cotelydonary type of placenta; allantois first appearance is at 14- 21st day of gestation; and has a gestation period of 148- 150 days: Answer: _____________________ 2. Animal which has a Hemochorial Double Discoid type of placenta; allantois does not develop fully, amnion and chorion form the fetal placenta; has a gestation period of 160days: Answer: _____________________ 3. Type of morphogenetic development wherein neural tube is being developed: Answer: _____________________ 4. The nucleus pulposus of intervertebral disks is a remnant of the embryonic: Answer: _____________________ 5. The golgi apparatus of the spermatid becomes what part of the spermatozoon? Answer: _____________________ 6. Diffuse placentation is present in: a. horses and pigs b.horses and cattle c.dogs and cats d.dogs and ferrets e.horses and dogs 7. Stage of embryonic development where mesoderm is formed: Answer: _____________________ 8. Initial development of Gut and Heart happens on this stage of embryonic development : Answer: _____________________ 9. An embryo in the form of compact ball of cell: Answer: _____________________ 10. Sperm viability in bitches upon migration from cervix to fallopian tube: Answer: _____________________ 11. The Spiral Filament of Middle Piece of the Spermatozoon is from what part of the spermatid: Answer: _____________________ 12. Enzymatic alteration in protein coating the cell membrane of sperm increasing sperm motility: Answer: _____________________ 13.The sex chromosome of a rooster: Answer: _____________________ 14. Adenohypophysis is derived from what germ layer origin of tissues: Answer: _____________________ 15. Process of sperm production: Answer: _____________________