Textbook Notes (362,730)
Canada (158,028)
Psychology (9,541)
PSYB65H3 (479)
Ted Petit (185)

PSYB65 Ch 13

8 Pages
Unlock Document

University of Toronto Scarborough
Ted Petit

PSYB65 Ch 13Early Dvlpt of the Nervous SystemEarly in embryonic life approx 3 weeks after conception the neural plate a patch of cells that are on the dorsal surface of the embryo which eventually becomes the nervous system forms f the ectoderm the outermost of the 3 layers of cells that are in the early embryo will form the nervous system and the epidermis of the skin of the embryoThe cells of the dorsal ectoderm in the neural plate are stem cells that are pluripotent meaning that they have the potential to dvlp into diff types of nervous system cells bc they are in the nervous system they cannot turn into any other type of cell such as skin cells The neural plate then begins to fuse to form the neural tube the tube thats formed out of the ectodermembryonic day 24 it will eventually become the spinal cord and brain Btwn the 3rd and 5th months of gestation the dominant events are neural migration and proliferation the process of cell division that results in new neuronsBy embryonic day 40 there are 3 prominent bumps on the anterior portion of the neural tube that eventually form the forebrain midbrain and hindbrain of the central nervous system CNSAs migration occurs f the inside out its actually the deepest later of neurons that dvlp first and the subsequent layers of neurons must migrate through the already estbd neurons to reach their destinationonce neurons migrate they begin to grow axons and dendrites and to differentiate into their final form cell differentiation is completebirth Although the brain is extra vulnerable during the last 45 months of gestation failuresany point in CNS dvlpt can have significant impact on the final form of the brain Adverse events can originate f problems within the neurons themselves like genetic or chromosomal abnormalities or by external factors such as intrauterine trauma or exposure to toxins lead alcoholCongenital Malformations of the CNSCraniorachischisis a fatal defect of the neural tube that results when theres a complete failure of the closure of the neural tubethe CNS appears as a groove in the top of the head and body Spina bifida a neural tube defect that is characterized by spinal cord defects failure of the neural tube to close completely not necessarily fatal though can vary in severityResults in neurological difficulties that are associated w locomotion rather than cognitive difficulties due to the effects on the spinal cord Anencephaly a generally fatal failure of the rostral part of the neural plate to fuse characterized by a general absence of the cerebral hemispheresBy the 7th month of prenatal dvlpt most neurons have migrated and have differentiated into their final forms but neurons still undergo a long period of synaptogenesis the production of new synapses and dendritic branching the branching of dendrites that can result in increased numbers of synapses Rapid growth of synapse formation happens shortly before birth to 2 years of age and synapse reduction reaches it maximal rate during puberty
More Less

Related notes for PSYB65H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.