Sensory and Nervous System Changes Flashcards
(26 cards)
What part of the brain is responsible for memory formation?
Hippcampus
What are association areas responsible for?
Sensory input is conneted to meaning.
Ex: Visual asscoiation area: visual input is connected with memory and names of shapes
What is the Limbic System responsible for?
What does it consist of?
Motivation and Emotion
It also monitory drives for food, water, sexual gratification and attaching emotion to meaning and actions
-amygdala, hippocampus and cingulate gyrus
How does a neuron communicate with other neurons?
Generates an action potential (up to 1000 per second) followed by a refractory period
What is the function of myelin?
Covers axons to increase the speed of nerve impulses
What structurs are responsible for the production of myelin?
Oligodendrocytes - CNS
Schwann Cells - PNS
What are the 4 types of neurons found in the CNS?
- Bipolar - sensory
- Multipolar - motor
- Pseudounipolar - sensory (seem unipolar)
- Unipolar - embryonic; function determines number of branches
What are the functions of neuroglia/ glial cells?
Provide support, nutrition and protection
Neurons cannot survive w/o glial cells
Injury to CNS and repair
What are the types of glial cells and what are their functions?
- Macroglia -
- Astrocyte - makes up BBB which regulates the influx of substance; also found in spinal cord; produce a glial scar
- Oligodendrocyte - produce myelin in CNS
- Microglia - macrophages that clean cellular debris (develop in late fetal period)
- Ependymal - line cavities and involved in CSF production
At what age do children start to show “handedness”?
2-3 years old
cause for concern if there is asymetry before age 2
child’s speech can be delayed if the dont have a preferred hand
What is “pruning” in the brain?
Neural connections that decay due to lack of usage
What is “toxic stress?”
Without an adult present, stress response activated and doesn’t go back to normal until parent reutrns. Can lead to permanent damage and cause brain to be in high alert permamently
- Caused by abuse, neglect and lack of stimulation
What does the diencephalon consist of? What are their functions?
- Thalamus - all sensory systems relay here (exepct olfaction); basal ganglia relays info here, too
- Hypothalamus - Maintains homeostasis; controls eating, reproduction and circadian rhythm
What is the function of the basal ganglia?
Regulates posture, muscle tone and force production. Involved in cognitive functions in movement
What is the function of the cerebellum?
Initiating and timing of movements and in monitoring postural tone.
- It takes sensory information and compares with anticipated motor performance
- It is a comparator, regulator and initiator
What does the brainstem consist of? What are the functions?
- Midbrain - reflex center for visual, auditory and tactile responses
- Pons - breathing rate and head orientation response
- Medulla - CV response, breathing and swallowing. Controls eye and head movements
What is the RAS?
Reticular Activating System is responsible for keeping us alert to adverse stimuli
- responsible for arousal
What are the 2 primary ascending tracts of the spinal cord?
Descending?
- Dorsal Column - proprioception, deep touch and vibration
- Anterolateral Column - pain and temperature
_____
- Corticospinal tract - control distal muscle movements in arms finger legs and feet. Essential for planning and initiation
- Vestibulospinal tract - feedforward; change in body posture and movements
Which motor unit is more sensitive: one that innervates 5 muscle fibers or one that innervates 100?
5 bc sensitivity of motor neurons is based on the number of branches it contacts
What are the 4 types of cortical connections?
- Association Fibers - unite different parts of the same berebral hemisphere
- Commisural Fibers - unite 2 hemispheres (corpus callosum made up of many)
- Projection Fibers - unite the cerebral cortex and other areas of brain and spinal cord
- Corpus Callosum - communication between 2 hemispheres
What is a critical period?
What are the critical periods?
- Activity dependent changes enduce neural circuitry
- 6-8, 10-12, 18 y.o.
What are the 2 types of neural plasticity?
How are connections made?
- Experience expectant
- Experience dependant (more cultural)
_____________________
Dendritic branching, synaptic remodeling & experience dependant
Identify when the following pre-natal changes occur:
- CNS develops from ecoderm
- Neural Tube
- Spinal Reflexes
- Head is half of the body size
- Spinal Cord and brainstem forms
- Cerebral hemispheres formed
- 1st Endocrine gland produced
- 3 weeks ges.
- 4 weeks ges.
- 7-8 weeks ges.
- 8 weeks ges.
- 10 weeks ges
- 20 weeks ges
- 24 days ges. (thyroid produces thyroxin; triggers decrease in cell prolifernation and causes migration;¡Without it, axons improperly migrated and dendrites fail to branch)
Lifes Span changes in childhood and adolescence:
- Development of fundamental skills
- Refine Skills
- Increase in kinestetic acuity*
When is the peak performance in adulthood?
After that, what happens?
- 3 - 6 y.o.
- 6 - 10 y.o
- 5 - 12 y.o.*
___________________
20 - 29 y.o
decrease in just about everything (ex: nerve velocity). Frontal and Temporal lobes more affected than Parietal
