Development Of The Nervous System Flashcards
How is the nervous system formed?
Where at the end of gastrulation the notochord is laid down and embryo changes from circular organization to to an axial one
How do the the germ layers form?
During gastulation the cells will move to the inside of the Embryro and for 3 germ layers
What are the 3 germ layers and their function?
The Endoderm which is the deepest layer and it gives rise to the guts
The Mesoderm which is the middle layer which will give ruse to the rest of the organs
The ectoderm which will give rise to the skim and nervous system
What is cephalisation?
It’s the development of the anterior portion of the CNS
What is neurulation?
When the neural tube forms from the ectoderm
How does the neural plate form?
The the notochord sends out signals to certain type of cells
What does the anterior end of the neural tube give rise to?
Three primary vessicles which are the
Procesaphalon
Mesencephalon
Rhombencephalon
What are the secondary vessdicles and their origin?
The Telencephalon and Diencephalon -Forebrain
The Mesencephalon remains undivided
-The Metencephalon and Myelencephalon gives rise to hindbrain
What does the descending tracts do?
The will conduct nerve impulses from brain to motor neurons reaching muscles and glands
What the ascending tracts do?
They will conduct nerve impulses to the brain
What is the primary motor cortex?
It us by the frontal lobe and it controls voluntarily the skeletal muscles
What is the primary sensory cortex?
It is the parietal lobe
It controls perception,touch,temperature,pain ect.
What is the Olfactory and Auditory cortex?
It is the temporal lobe and It controls the olfactory and auditory stimuli
What is the visual cortex?
It is the the occipital lobe and controls perception of visual stimulus
What is association areas?
It is all the lobes and it’s for intergration and processing
What are the 3 types of functional areas?
Motor areas
-Controlling voluntary movement
Sensory areas
-Conscious of perception and sensation
What is the somatic motor pathway?
The uppr motor neurons and the lower motor neurons
What are the upper motor neurons?
These neurons cell body is located in the central nervous system processing center and the will synapse with the lower motor neurons in the brainstem or spinal cord
These are usually known as the Pyrimydial neurons and full classification is multipolar projection neurons
What are the lower motor neurons?
They are located in the brain stem or spinal cord and synapse with a skeletal muscle fibers which forms a single motor unit which where the lmn when activated will cause contraction of the skeletal muscles
What is the prefrontal area?
It is the are that forms and plans and initates movement
What is the promoter area?
It is an area that organises motor functions before they are initiated on the primary motor cortex
What is the primary motor cortex?
It initiates the motor plan that is found on the prescentral gyrus and it is organized as the motor homuniculus and this ensures finess of controled movement much of it is dedicated to moving muscles of fingers and for speech and the stimulation of a specific motor neuron in primary motor cortex will generate contraction of a specific skeletal muscle
What is the primary sensory cortex?
Located in the postcentral gyrus and its known to be the sensory homuniculus where the front has enormous features than the back this is due to the fact that the areas such as lips and tongue have more cortical neurons than the back because more neurons are required to process information from tongue to back
What is the multimodal association areas?
It recieved inputs from multiple sensory neurons and sends outputs to multiple areas and thus allows us give meaning to information recieved ,store it as memory,compare to previous memory and decide on what action to take
What are the three parts of the multimodal association area?
Anterior (prefrontal cortex)
Posterior
Limbic
What is the anterior association area?
It is the most complicated
It is involved with intellect recognition and personality
Development depends on feedback from social environment and contains working memory needed for judgment and reasoning
What is the posterior association area?
Involves with understanding written and spoken language (Wernickes area)
Also it’s the last portion in the occipital temporal and parietal lobes
It’s responsible for recognizing patterns and faces
What is the limbic association area?
It is part of the limbic system and provides emotional impact that helps to create memories
