Chapter 7-Development Flashcards
Exam 1
When is the largest brain growth observed? (weight)
From birth to age 5
When does brain weight begin to deteriorate?
Around age 30
What causes the nervous system to be highly organized?
- During all stages of development the nervous system is highly organized due to genes, environment/experience, and the interaction of the two
- (Think nature vs nurture)
Ex. rats with low maternal licking and grooming will have genes altered in a way that causes high stress hormone levels, high anxiety, and low licking and grooming themselves. A rat with high maternal licking and grooming will have low stress hormone levels, low anxiety, and high self-licking and grooming
What does the mesoderm layer of the embryo give rise to?
The skeleton and muscles
What does the endoderm layer of the skin give rise to?
The internal organs
What does the ectoderm layer turn into?
The nervous system and skin
How is the neural plate formed?
- The neural plate is formed by the thickening of the extoderm
- The whole process is called neurulation
What is neurulation?
The whole process of the neural plate being formed via thickening of ectoderm
How is the neural groove formed and what does it give rise to? What is it?
- The neural groove is a shallow median groove of the neural plate
- Formed by uneven rates of cell division in the neural plate
- The neural plate is the future CNS
formed around day 20
What is the neural crest?
- The neural crest cells are progenitors for the entire PNS
- Seen on top edges (tips) of the neural groove
formed around day 20
What happens on day 18 of development?
The embryo consists of three layers of cells:endoderm, mesoderm, and ectoderm
-thickening of the ectoderm leads to development of the neural plate (first structure of the brain)
What happens on day 20 of development?
- The neural groove begins to develop
How is the neural tube formed?
- The neural groove joins together to form the Neural Tube with a fluid-filled central canal
- The neural crest cells are located on top of the canal
What does the central canal and neural tube form?
- The central canal (fluid filled canal inside neural tube) will form ventricles and the spinal cord canal- w cerebral spinal fluid
- The cells lining the neural tube will be the progenitors for the entire CNS
What happens on day 22 of development?
- The neural tube and fluid-filled central canal are formed by the neural groove joining together
- The rudimentary begininning of the brain is located at the anterior end
- The cranial end forks out to form the brain plate
How is the brain plate formed?
- The cranial end of the ectoderm forks out to form the brain plate
What happens on day 24?
The major brain divisions are discernible via sepearate sections within the brain plate area forming
What does the telencephalon turn into?
- the cerebral cortex, limbic system, and basal ganglia
What does the diencephalon turn into?
The thalamus and hypothalamus