Lecture 1 - introduction to neuroscience Flashcards
What is an astrocyte?
A glial cell found in the CNS named for its characteristic star-like shape with long cytoplasmic processes
In an astrocyte, what does the long cytoplasmic processes do?
bridge neurons and capillary endothelial cells;
What do astrocytes provide?
these cells provide both mechanical and metabolic support for neurons,
What do astrocytes regulate?
The environment where they function; they contribute to the blood-brain barrier and control transport of substances from the blood to neural tissue; they also help coordinate nerve pathway development;
What do astrocytes develop from?
they develop from embryonic ectoderm.
What is an oligodendrocyte?
A glial cell found in the CNS which is named for its characteristic limited number of dendritic processes;
What do the oligodendrocyte processes do?
processes provide electrical insulation for a few adjacent neurons by forming a part of the myelin sheath for their axons, and, thereby, increasing the speed of transmission of action potentials along that axon (salutatory conduction);
What do oligodendrocytes develop from?
they develop from embryonic ectoderm.
What is a microglia?
A glial cell found in the CNS named for its characteristic small size
Where are microglia derived from?
these cells are derived from hematopoetic sources
What is the function of microglia?
To provide a protective function to nervous tissue in that they can become phagocytic.
What are the best predictors of intelligence?
Foliation and neuronal density
What is Galvani’s Method?
attach cut end of a nerve to two rods of different metals, suspend the cut nerve by brass hook attached to ground, with foot touching grounded silver plate, kick repeated indefinitely
What are the three major functional classes of neurons?
1) sensory / afferent neurons 2) motor / efferent neurons 3) interneurons
Sensory afferent neurons
long dendrite and short axon, and carry messages from sensory receptors to the central nervous system
Motor efferent neurons
long axon and short dendrites, and transmit messages from the central nervous system to the muscles (or to glands)
Interneurons
found only in central nervous system where they interconnect neurons
Different types of neurosensory receptors found in the skin are
specialized for processing different types of information
Free nerve endings
with little or no myelin (most sensitive to pain and temperature)
Thicker myelinated axons
arise from several classes of mechanoreceptors: Pacinian and Meissner corpuscles (light touch and vibration), Ruffini corpuscles and Merkel disks (sustained pressure)
Pacinian corpuscle
vibration
Meissner corpuscle
light touch
Ruffini corpuscles and Merkel disks
sustained pressure
Ensembles of neurons acting together create
functional responses and representations of the body superimposed on cellular maps
Lower level
spinal cord ensembles
Upper level
cortical ensembles
What happens in the knee jerk response?
1) hammer tap stretches sensory receptors in the leg extensor muscle 2) sensory neuron excites motor neuron (to extensor muscles) and interneuron in spinal cord which inhibits motor neurons to flexor muscles 3) motor neuron to extensor muscle causes contr
Example of upper level ensembles
somatotopic maps in cortex
Functional stretch reflex
tilting of the platform results in rapid adaptation
What are the distinguishing features of the advanced nervous system?
1) cellular specializations 2) areal specializations (collections of cells grouped together for common purpose) 3) Functional cooperation (ensembles of neurons acting in synchrony to produce desired outcome) 4) Adaptability 5) High information storage cap
Why do we need high information storage capacity?
To avoid being ruled by our environments ie to make more meaningful choices
