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70 Cards in this Set
- Front
- Back
Stages of Animal Development
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-Gametogenesis
-Fertilisation -Cleavage -Gastrulation -Organogenesis -Growth -Birth -Juvenile phase -Maturity -Death |
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Stages of Animal Development;
Gametogenesis |
Early embryo (2-3 weeks) - eggs and sperm formed by meiosis
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Stages of Animal Development;
Fertilisation |
Fusion of gametes (sperm and egg)
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Stages of Animal Development;
Cleavage |
No growth; Partition of fertilised egg into smaller units
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Stages of Animal Development;
Gastrulation |
Embryo turns inside out bringing embryo cells in contact with other cells forming the 3 layers of an embryo
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Stages of Animal Development;
Organogenesis |
Formation of individual organs
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Stages of Animal Development;
Growth |
9 months for humans, then birth occurs and animal lives life...
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Stages of Early Mammalian Development;
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-Fertilisation
-Cleavage -Blastocyst formation -Implantation; Egg buried into uterine stroma -Bilaminar embryo formed (2 layers) -Gastrulation -Trilaminar Embryo formed (3 layers) |
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Stages of Fertilisation
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1. Spermatozoa penetrates corona radiata; Outer layer of spermatozoa stripped
2. Spermatozoa penetrates zona pellucida 3. Fusion of oocyte and sperm membranes |
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Corona Radiata
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Cellular layer around ovum
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Zona Pellucida
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Glycoprotein membrane that surrounds the egg
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Oocyte
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Egg Cell
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Spermatozoa
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Sperm Cell
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Responses to Fertilisation
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-Cortical and zona reaction; Prevents further penetration/another sperm cell entering
-Resumption of 2nd meiotic division -Metabolic activation of egg; Action potential on surface of embryo, Calcium ions initiates activation |
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Consequences of Fertilisation
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-Diploid chromosome number restored
-Sex determination (XX male or XY female) -Cleavage begins |
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Trilaminal Embryo
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-Ectoderm
-Mesoderm -Endoderm |
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Ectodermal Germ Layer Derivatives
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-Nervous system
-Skin (epidermis) -Sensory epithelia of nose, ear and eye |
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Ectodermal Germ Layer Derivatives;
Neurulation |
-Formation of neural tube and neural crest
-Gives rise to nervous system -Brain/Spinal Cord arise from neural tube -Peripheral nervous system arise from neural crest -End of this process starts formation of epidermis |
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Mesodermal Germ Layer Derivatives; Mesoderm of Trunk
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-Paraxial
-Intermediate -Lateral plate Forms dermis, muscle, connective tissue, vertebrae, kidney and mesoderm lining the body cavity & viscera |
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Mesodermal Germ Layer Derivatives; Mesoderm of Trunk;
Paraxial |
-Segmented to somites (blocks of tissue/discrete units)
-Divides into sclerotome and dermomyotome -Sclerotome forms vertebra and ribs -Dermomyotome forms skeletal musculature and dermis of trunk |
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Mesodermal Germ Layer Derivatives; Mesoderm of Trunk
Intermediate |
Forms kidney and gonads
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Mesodermal Germ Layer Derivatives; Mesoderm of Trunk
Lateral Plate |
Forms somatopleure (lines of body walland splanchnopleure (hollow viscera);
-Heart -Smooth Muscle -Spleen -Limb |
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Mesodermal Germ Layer Derivatives; Mesoderm of Head Differences To The Trunk
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-Only divided into 2 parts; Paraxial and Lateral plate
-Segmentation not visible anatomically -Cells of head mesoderm have 2 origins; mesodermal germ layer and neural crest |
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Mesodermal Germ Layer Derivatives; Mesoderm of Head
Neural Crest |
Forms;
-Facial skeleton -Connective tissue lining great vessels of head and neck |
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Mesodermal Germ Layer Derivatives; Mesoderm of Head
Mesodermal Germ Layer |
Forms;
-Dermis -Muscle -Rest of skull -Mesoderm lining the body cavity and viscera |
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Mesodermal Germ Layer Derivatives; Mesoderm of Head
Paraxial |
Forms;
-Most of skull bones -Skeletal muscles of head |
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Mesodermal Germ Layer Derivatives; Mesoderm of Head
Lateral Plate |
Forms;
-Cartilaginous structures of the face eg nose... |
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Endodermal Germ Layer Derivatives; GI Tract
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-Main derivative is the gastrointestinal tract
-Formation of GI tract requires cephalo-caudal and lateral folding of embryo |
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Endodermal Germ Layer Derivatives;
What Causes Cephalo-caudal Folding? |
Caused by rapid longitudinal growth (particularly of neural tube)
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Endodermal Germ Layer Derivatives;
What Causes Lateral Folding? |
Caused by rapid lateral growth (particularly the somites)
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Pharyngeal Arch Derivatives; Cranial Nerves and Muscles
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As the mesoderm migrates away the nerves are attached to the muscles and follow them where ever they grow and innervate them
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Cranial Nerves Formation
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Nerves come from the brainstem
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Muscular Formation
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Muscles come from the mesoderm
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Pharyngeal Arch I Derivatives; Nerve and Muscles
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-Cranial Nerve V2 & V3 of Trigeminal Nerve
-Muscles of mastication -Anterior Digastric -Mylohyoid -Tensor Veli Palatini -Tensor Tympani |
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Pharyngeal Arch II Derivatives; Nerve and Muscles
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-Cranial Nerve VII (Facial Nerve)
-Muscles of facial expression -Posterior Digastric -Stylohyoid -Stapedius |
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Pharyngeal Arch III Derivatives; Nerve and Muscles
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-Cranial Nerve IX (Glossopharyngeal)
-Stylopharyngeus |
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Pharyngeal Arch IV & V Derivatives; Nerve and Muscles
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-Cranial Nerve X (vagus) & XI (spinal accessory)
-Muscles of pharynx -Soft palate -Larynx |
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Embryonic Foregut
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-Formation of pouches lined with endoderm
-Pouches grow until contact with epidermic As pouches grow: -Endoderm & Epiderm lie adjacent (no tissue between) as mesoderm gets squeezed -Increase density of mesoderm |
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Skeletal Derivatives
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Arise from mesoderm
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Pharyngeal Arch I; Skeletal Derivatives
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-Becomes jaw
-Meckel's Cartillage -Maxillary & Mandibular Processes -Malleus and Incus |
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Pharyngeal Arch II; Skeletal Derivatives
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-Stapes
-Styloid Process -Lesser cornu and upper part of body of hyoid -Stylohyoid Ligament |
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Pharyngeal Arch III; Skeletal Derivatives
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-Greater cornu of hyoid
-Lower part of body of hyoid |
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Pharyngeal Arch IV & VI; Skeletal Derivatives
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Cartilages of laryngeal framework
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Pharyngeal Pouches
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Look like clefts between pharyngeal arches
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Pharyngeal Pouch 1 Derivatives
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-Tubotympanic Recess
-Pharygo-tympanic Tube -Middle ear cavity |
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Pharyngeal Pouch 2 Derivatives
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-Palatine tonsil
-Tonsillar Fossa |
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Pharyngeal Pouch 3 Derivatives
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-Thymus
-Inferior parathyroid glands |
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Pharyngeal Pouch 4 Derivatives
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-Superior parathyroid glands
-C cells of thyroid gland |
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Which Pharyngeal Pouches Produce Immune Tissue & Cells that Regulate The Calcium Ion Metabolism In Plasma?
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Pharyngeal Pouches 2-4
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Development of The Face
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5 swellings at front of embryo
-Frontonasal prominence (where forebrain located) -2 maxillary swellings (Pharyngeal arch 1) -2 mandibular swellings (Pharyngeal arch 1) |
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Development of The Face; Frontonasal Prominence
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Forms
-Nasal pit (where nostrils develop) -Median and lateral nasal swellings |
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Development of The Face; Median Nasal Swelling
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-Fuses in midline
-At 10 weeks the maxillary swelling grows pushing the median nasal swellings together -Philtrum is the site of median nasal swelling fusion |
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Development of The Face; Lateral Nasal Swelling
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-Lateral nasal swellings fuse with maxillary swellings
-Forms the nasolacrimal duct |
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Derivatives of the Frontonasal Prominence
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-Forehead
-Nose -Philtrum (indentation above lip where median swellings fuse) -Primary palate |
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Derivatives of the Maxillary Prominence
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-Part of cheek
-Maxilla -Zygomatic bone -Lateral portion of upper lip -Secondary palate (hard and soft palate) |
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Derivatives of the Mandibular Prominence
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-Lower lip
-Part of cheek -Mandible |
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Development of the Tongue
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-Tongue first appears at 28 days of development
-2 lateral lingual swellings -1 medial swelling (tuberculum impar) from 1st Pharyngeal Arch |
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Development of the Tongue; Lateral Lingual Swellings
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-Form anterior 2/3 of tongue innervated by lingual nerve (1st Pharyngeal Arch)
-Swellings overgrow tuberculum impar |
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Development of the Tongue; Hypobranchial eminence
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-3rd and 4th Arches overgrow the 2nd Arch
-Eventually forms the posterior 1/3 of the tongue innervated by the glossopharyngeal nerve (3rd Pharyngeal arch) |
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Development of the Tongue; 4th Arch (3rd Median Swelling)
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Forms epiglottis and arytenoid swellings
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Development of the Tongue; Sensory Innervation
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Innervation of anterior and posterior parts of tongue split by sulcus terminalis
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Development of the Tongue; Tongue Muscle Innervation
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-Tongue muscles derived from occipital somites which migrate to tongue
-Innervated by Hypoglossal nerve (XII) |
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Palate Development
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-Formed by fusion of primary and secondary palates
-Primary plate derived from intermaxillary segment -Secondary plate derived from palatal shelves |
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Intermaxillary Segment
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-Arises from the fusion of both medial nasal processes and the frontonasal process
-Forms anterior 1/3rd of palate where maxillary incisors develop (primary palate) |
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Palatal Shelves
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-Forms secondary palate by the growth of the two palatal shelves medially and their fusion in midline
-Forms posterior 1/3rd of palate -Initially grow downward then elevate and fuse with the primary palate at the incisive foramen |
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Hard Palate
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-Separates the oral cavity from the nasal cavity
-Formed from the 2 bones; palatine bone and palatine process of maxilla |
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Defects of Palate Closure
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-Common disorder preventing fusion of palate
For palate to fuse; -Palatal shelves need to swing up -Epidermis cells covering palatal shelves need to die -Mesodermal cells beneath need to proliferate |
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Defects of Palate Closure; Primary Defects
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Defects anterior to incisive fossa
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Defects of Palate Closure; Secondary Defects
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Defects posterior to incisive fossa
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Other Craniofacial Defects
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Arise from failure of fusion of facial swellings
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