Embryology 2: Development of Face to Prenatal - 2.1 PDF
Document Details
Uploaded by InnocuousSilver3002
Tags
Summary
This document provides detailed notes on the development of the face and related structures in prenatal embryonic development, including key events, processes, and contributing factors. It also covers associated conditions and environmental factors. The document is visually-rich, including numerous diagrams and images, and is suitable for undergraduate-level study.
Full Transcript
**[Embryology 2: Development of face to prenatal - 2.1]** **Key events after gastrulation:** 1. 2. 3. 4. **Neural tube formation - Neurulation** 1. 2. 3. 4. 5. 6. 7. 8. -  **Vesiculation** +-----------------+-----------------+-----------------+---------...
**[Embryology 2: Development of face to prenatal - 2.1]** **Key events after gastrulation:** 1. 2. 3. 4. **Neural tube formation - Neurulation** 1. 2. 3. 4. 5. 6. 7. 8. -  **Vesiculation** +-----------------+-----------------+-----------------+-----------------+ | ant/cranial | Prosencephalon | Telencephalon | Cerebrum | | portion of NT | | | | | | Forebrain | | | +=================+=================+=================+=================+ | | | Diencephalon | Thalamus | +-----------------+-----------------+-----------------+-----------------+ | | Mesencephalon | | Midbrain | | | | | | | | Midbrain | | | +-----------------+-----------------+-----------------+-----------------+ | | Rhombencephalon | Metencephalon | PONS | | | (8 bulges) | | | | | | | cerebellum | | | Hindbrain | | | +-----------------+-----------------+-----------------+-----------------+ | | | Myelencephalon | Medulla | +-----------------+-----------------+-----------------+-----------------+ | NCC | Forms: | | | | | | | | | | - - - - | | | | | - - - | | | +-----------------+-----------------+-----------------+-----------------+ | Caudal portion | Marginal zone | | | | of NT | | | | +-----------------+-----------------+-----------------+-----------------+ | | Mantle zone | Alar plate | Posterior grey | | | | | horn | | | | | | | | | | Sensory neurons | +-----------------+-----------------+-----------------+-----------------+ | | Neural | Vasal plates | Anterior grey | | | epithelial zone | | horn | | | | | | | | | | Motor neurons | +-----------------+-----------------+-----------------+-----------------+ Rhombomeres formation and NC migration - - -  **Formation of somites** Parts of the mesoderm: - - - = the mesodermal segments of vertebrate embryos that become the vertebral column, skeletal muscle and dermis which arise within the paraxial mesoderm by the periodic, bilaterally symmetric process of somitogenesis Cranial portion of paraxial mesoderm does not form somites but forms head mesoderm Paraxial mesoderm is mesenchymal Somites = sections of paraxial mesoderm 3 components: 1. 2. 3. Dermatome and myotome are closely ass so sometimes called dermomyotome  **Neural crest** - - - - - NCC induction - - -  NCC fate decisions in head region - - - - Form: **C**hromaffin cells **R**ostral tissues - con tis, bones, muscles of head and neck **E**nteric N.S **S**chwann cells and satellite cells **T**he PNS - spinal nerves **C**arotid bodies **E**ndocardial cushions **L**ight/dark skin - melanocytes **L**eptomeniges **Signalling mechanisms** Craniofacial dev: 1. 2. 3. 4. Epithelial - mesenchymal interactions also important **Branchial (pharyngeal arches)** Stomodeum = primitive oral cavity Buccopharyngeal membrane = breaks down to form oral cavity **Pharyngeal arches and grooves**  +-------------+-------------+-------------+-------------+-------------+ | | **Arch - | **Groove/cl | **Pouch - | **Nerves** | | | mesochyme** | eft | endoderm** | | | | | - | | | | | | ectoderm** | | | +=============+=============+=============+=============+=============+ | **1** | **Bones:** | Ex aud | Tympanic | CNV3 +CNV2 | | | | meatus | mem | | | | Mandible | | | Trigeminal | | | | | | ganglion | | | Maxilla | | | | | | | | | | | | Zygomatic | | | | | | | | | | | | Temporal | | | | | | | | | | | | Meckel\'s | | | | | | cartilage - | | | | | | incus + | | | | | | malleus, | | | | | | sphenomandi | | | | | | bular | | | | | | lig | | | | | | | | | | | | **Muscles:* | | | | | | * | | | | | | | | | | | | Muscles of | | | | | | mast | | | | | | | | | | | | Ant | | | | | | digastric | | | | | | | | | | | | Mylohyoid | | | | | | | | | | | | Tensor veli | | | | | | palatini | | | | | | | | | | | | Tensor | | | | | | tympani | | | | +-------------+-------------+-------------+-------------+-------------+ | **2** | Reicherts | | Tonsil | CNVII | | | cart: | | | | | | | | | Geniculate | | | - - | | | ganglion | | | | | | | | | Hyoid | | | | | | lesser | | | | | | horns + | | | | | | upper body | | | | | | | | | | | | Muscles of | | | | | | facial ex | | | | +-------------+-------------+-------------+-------------+-------------+ | **3** | Hyloid | | Inf | CNIX | | | lower body | | parathyroid | | | | | | g | Inf sensory | | | Stylopharng | | | gang of | | | eus | | Thymus | CNIX | +-------------+-------------+-------------+-------------+-------------+ | **4** | Larynx cart | | Sup | CNX | | | | | parathyroid | | | | Thyroid | | g | Inf sensory | | | cart | | | ganglion of | | | | | | CNX | | | Cricothyroi | | | | | | d | | | | | | | | | | | | Levator | | | | | | veli | | | | | | palatini | | | | | | | | | | | | Palatogloss | | | | | | us | | | | | | | | | | | | Pharyngeal | | | | | | constrictor | | | | | | s | | | | +-------------+-------------+-------------+-------------+-------------+ | **5** | Cricoid | | | | | | cart | | | | | | | | | | | | Laryngeal m | | | | +-------------+-------------+-------------+-------------+-------------+ **Development of face** Occurs between 4th - 10th weeks of intrauterine life 1.  5th week in utero - 6th week in utero - - - -  **Formation of secondary palate** - Secondary palate = distinction of oral and nasal cavity   **Formation of tongue** 4th week Arch 1 = sensory ant â…” - CNV3 - lingual swellings and tuberculum impar Arch 2 = special ant â…” - CNVII Arch 3 = special + sensory post â…“ - CNIX Arch 4 =special + sensory + motor (palatoglossus) base - CNX Occipital myotomes = motor for rest of tongue - CNXII Lingual swellings and tuberculum impar - formed from 1st arch **Development of skull** 1. 2. 3. Membranous bone = cranial vault and face Endochondral ossification = cranial base  **Development of mandible** From 1st pharyngeal arch Independent from Meckle's cartilage  Further growth after birth influenced by 3 secondary (growth) cartilages: 1. 2. 3. **Development of condylar cartilage** - - - **Development of maxilla** - - - - **Development of maxilla sinus** - - - **Development of TMJ** - - - - - **Conditions** **Holoprosencephaly** - - - -  **Clefts** - -  **First arch syndromes** - - - - - - - Features: - - - - - - - - - Features: - - - - **Foetal alcohol spectrum disorder** - - - - **Environmental factors causing congenital defects** - - - - - - 
