Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Organogenesis
Sem1
| Question | Answer |
|---|---|
| What is the name given to the process of organ formation? | Organogenesis |
| When does organogenesis usually start? | In the first trimester of pregnancy |
| When can gender be determined? | Around the 12th week of pregnancy |
| When is 'it' referred to as an embryo? | From conception to the 9th week (LMP) |
| When is 'it' referred to as a foetus? | From the 9th week (LMP) until the rest of the term |
| How do the lungs develop? | Branching morphogenesis |
| Which germ layers supply most of the alveoli of the lungs? | Endoderm and mesoderm |
| Which germ layer is responsible for neural innervention? | Ectoderm |
| Which germ layer gives rise to musculoskeletal support? | Mesoderm |
| Which longitudinal channel will later become the digestive tract? | Primitive gut |
| Which germ layer does the GI system initially develop from in week 2/3? | Endoderm |
| What does the mesoderm contribute regarding GI system development? | Messentry, smooth muscle and blood vessels |
| What does the ectoderm contribute regarding GI system development? | Enteric nervous system |
| What do the following form? A)Foregut B)Midgut C)Hindgut | A)Oral cavity, oesophagus, trachea and stomach B)Small intestine and pancreas C)Colon |
| Where does somite development occur? | Alongside the neural tube, in pairs |
| When does somite development occur? | Starts around day 19 post-fertilisation |
| How does somite development occur? | Develops in succession from anterior to posterior. A new somite pair develops every 90 minutes, and 44 develop in total |
| What does somite development result in? | Produces muscle, and vertebral and rib bones |
| When does neural tube closure usually occur? | Days 23-26 post-LMP |
| How does the neural tube close? | The neural plate (neural ectoderm) rolls up to form the neural tube, with the neural crest forming at the boundary with the ectoderm |
| Why is neural tube closure important? | Closure is important for the development of the brain and spinal cord. Failure to close could lead to conditions such as Exencephaly or Spina Bifida |
| What does embryonic folding result in? | The entire surface being covered with ectoderm |
| What does the ectoderm later become? | The epidermis of the skin |
| What happens to the mesoderm? | The mesoderm splits into two layers; One adhering to the ectoderm, the other to the endoderm. This creates the coelom |
| When does nervous system development start to occur? | 19-21 days post-fertilisation |
| From which layer does the nervous system develop? | The ectoderm |
| What gives rise to the brain? | The neural plate, in the anterior region |
| What gives rise to the spinal cord? | The neural tube along the dorsal region |
| Which two cavities can the body cavity be divided into? | Thoracic cavity and Peritoneal cavity |
| What separates the Thoracic and Peritoneal cavities? | The diaphragm |
| What does the Thoracic cavity sub-divide into? | The Pleural and Pericardial cavities |
| Through what three ways can birth defects arise? | -Genetic (inherited or de novo mutations) -Environmental (exposure to teratogens) -Infections (maternal disease) |
| How does the ear develop? | From placodes (ectodermal thickening visible on surface) |
| Why is the development of the ear important? | For sensory organ formation |
| How does the inner ear develop? | From the Octic placode: visible from week 4, disappears from surface by week 5 |
| When does the embryonic stage of pregnancy occur? | The 6 weeks that follow the first 16 days post-fertilisation |
| How does the shape of the embryo change during the embryonic stage of pregnancy? | -The cephalic and caudal ends curve around the yolk sac so that the head and tail are almost touching in a C-shape -At the same time, lateral surfaces of the disc fold around the sides of the yolk sac to form the ventral surface of the embryo |
| When does limb development occur? | External surfaces are visible from early week 4 |
| How do the limbs develop? | -Buds project outwards -Patterning is important; need to specify proximal, distal, dorsal, ventral -Forelimb is present first |
| What shows the precursors of digits? | Condensations of cartilage |
| How do the digits separate? | Apoptosis between the digits |
| When does development of the heart start to occur? | Days 22/23 post-fertilisation |
| Where is development of the heart visible? | On the ventral surface |
| When does the heart start to beat? | Around day 45 |
| What do the kidneys develop from? | The urogenital ridge |
| How do the kidneys develop? | Branching morphogenesis |
| What are the 3 stages in kidney development? | Pronephros (day 18) Mesonephros (day 24) Metanephros (day 35) |
| What does the eye develop from? | The Optic placode |
| When does development of the eye occur? | Visible from the end of the 4th week |
Created by:
SandersE
Popular Genetics sets