Early Brain Development Chapter 9 Section 1 21st Century Families
Experience Matters
Dendrites: Extensions from the neuron cell body that take information TO the cell body. Nucleus: part of the neuron that contains chromosomes. (genetic material) Cell Body: Also called the soma; the part of the cell that contains the nucleus. Myelin: Fatty substance that surrounds some axons. Speeds up communication. Node of Ranvier: Gaps in the myelination of axons. Axon: The part of the neuron that takes information AWAY from the cell body. Synaptic Terminal: The end of the axon containing vesicles with neurotransmitters. Also known as axon terminals. Neurotransmitters: The chemicals released by an axon and cross the gap to the dendrite of another nerve cell. That gap is called a synapse.
Can you find the…. What is going on here? Axon Soma Dendrites Myelin Node of Ranvier Nucleus Synaptic Terminal
How Neurons Work Step 1: Step 2: Dendrites receive information from other neurons. Each dendrite can have many different branches. Step 2: The dendrites pass that information to the body of the nerve cell, where the information is processed.
Step 3: The nerve cell sends messages through axons, which transmits the messages to the dendrites. The axons are coated with a waxy protein-based substance called myelin. Myelin allows information to be transmitted more easily. Step 4: Chemical called neurotransmitters are released by the axon and cross the gap to the dendrite of another cell. This gap is called the synapse.
Developing the Brain More dendrites indicate increased learning. An increased number of neural pathways results from sensory input. Each child’s brain gets organized in a unique way, depending on his or her experiences. dendrite A branchlike feature at the end of each axon that receives the messages from other neurons. neural pathway The link between neurons.
Developing the Brain Repetitive action causes the neurons to work together so that action becomes easier. The brain can be reorganized. Sensory activities increase neural pathways.
Developing the Brain The brain continues to develop through responses to life’s experiences. Caregivers can increase the speed of brain development with a stimulating environment. How can a stimulating environment encourage brain development?
Experience Can Change the Actual Structure of the Brain Brain development is “activity-dependent” Every experience excites some neural circuits and leaves others alone Neural circuits used over and over strengthen, those that are not used are dropped resulting in “pruning”
Neglect Impedes Brain Development Limited exposure to language, touch or social interactions Emotional or cognitive neglect Structural Changes Lack of brain growth beyond effects of poor nutrition Neuronal death beyond “pruning”
Fun Facts Average number of neurons in the human brain 100 billion Average number of neurons in an octopus brain 300 million Rate of neuron growth during development of a fetus (while in the womb) 250,000 neurons per minute
CEREBRUM The cerebrum is the largest part of the brain and controls all conscious thoughts, experiences, and actions. Speech, memory, and problem solving Its outer folded layer is called the cerebral cortex.
THALAMUS Connects the spinal cord and cerebrum. Controls expression of emotions.
PITUITARY GLAND The pea-sized gland that releases the hormones that regulate growth and sexual development. Found in the center of the skull
CEREBELLUM The cerebellum is the second largest part of the brain. It controls posture and balance. Replace this with, "It also helps with the timing and coordination of our movements, making them smooth and precise.
BRAIN STEM It controls processes basic for survival, such as heart rate, breathing, digestion, heart rate, and sleep. It is the main route of communication between the rest of the brain.
Spinal Cord Transmits information from the body to the brain and from the brain to the body. It coordinates the activities of the left and right sides of the body and controls simple reflexes that do not involve the brain.