Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

30 Cards in this Set

  • Front
  • Back
When does the first neural tissue appear during development?
End of 3rd week
The embryo is a trilaminar disc composed of 3 primary germ layers. Name them.
- Endoderm

- Mesoderm

- Ectoderm
Endoderm will give rise to?
- Lungs
- Liver
- Guts
Mesoderm will give rise to?
Connective tissue
- Vascular structures
- Blood cells
- Bone marrow
- Portions of internal organs
Ectoderm will give rise to?
- Epidermis
Between 16 and 21 days of development, a structure forms from the embryonic mesoderm known as the?
The notochord:
1. defines the longitudinal axis of the embryo
2. determines the orientation of the vertebral column
3. persists as the nucleus pulposus of the intervertebral discs
4. induces the overlying ectoderm to form the neural plate (process known as induction)
1) Between days 16 and 21 -

2) Around day 18 -

3) By day 21 -

4) Begins around day 20 and goes to day 42 -
1) development of notochord

2) neural groove and neural folds formed

3) Primary neurulation (forming of neural tube)

4) Secondary neurulation
1) Anterior neuropore closes on day ____.

2) Posterior neuropore closes on day ____.
1) ~24

2) ~26
Primary neurulation gives rise to?
brain and spinal cord thru lumber levels
Secondary neurulation gives rise to?
sacral and coccygeal levels of spinal cord
Process by which neural plate infolds forming neural tube. Most of neural tube is formed this way. During this process, the lumen of the neural tube remains continuous with the amniotic cavity on both ends. Creates openings called neuropores.
Primary Neurulation
Prcess consists of formation of a group of cells called the caudal eminence. As caudal eminence grows, it also develops a central cavity and then connects with the neural tube. Cavities of neural tube and caudal eminence become continuous with each other.
Secondary Neurulation
Failure of anterior neuropore to close causes:
Failure of posterior neuropore
Spina bifida
Brain not formed, surrounding meninges and skull may be absent, facial abnormalities present. Occurs in 5/10,000 live births. Fatal
Failure of vertebral arches to form completely
Spina bifida
Failure of vertebral arches to form, and if the skin is closed over the defect, the condition is?

Found in ~10% of population. No neurological deficits. Site of defect marked by patch of dark hair.
spina bifida occulta
Spina bifida that is accompanied by a cystic mass that protrudes through the defect.
Spina bifida cystica
If the cyst in spina bifida cystica contains only meninges and CSF it is known as?
If the cyst contains meninges, CSF, and spinal neural tissue it is known as?
Obstruction of the foramen magnum obstructs the flow of CSF resulting in hydrocephaly. What is this called?
Arnold-Chiari Malformation
Congenital abnormalities associated with defects in secondary neurulation are called? What is the most common type?
Myelodysplasia; Tethered Cord Syndrome
Three layers formed in wall of tube
1) Internal (Luminal) Layer - ventricular zone; neuroblasts arise from dividing cells in this zone

2) Marginal zone (on albuminal surface) - devoid of cells

3) Intermediate zone - migrating cells. Between ventricular and marginal zones
Almost all neurons have been produced by _______
24 weeks gestation
After 24 weeks, _____ occurs.
Apoptosis (programmed cell death)
_____,_____, and others limit programmed cell death.
Nerve growth factor, fibroblast growth factor
Critical period
period of time during which plastic changes can occur
Neural tube enlarges to form 3 primary brain vesicles:
1) Prosencephalon (Forebrain)

2) Mesencephalon (Midbrain)

3) Rhombencephalon (Hindbrain)
Two bends or flexures develop in neural tube:
1) Cervical Flexure - at rhombencephalon/spinal cord junction

2) Cephalic Flexure - at level of mesencephalon