Ch 1. Principles of signaling and organization Flashcards
neurobiology
consists of anatomy, physics, biochemistry, molecular biology, cognitive science and more
the nervous system continuously…
-receives info
-analyzes it
-creates perception (meaning) around it
-makes decision
-acts and moves
how does the NS act and move?
by producing coordinated and coherent muscle contractions
Sensory neurons
translate sensory info into electrical signals that are then transmitted from one nerve cell to another across specific connections
what does neurobiology try to do?
it tries to decode the info transmitted by signals
How can neurobiology decode signals?
by determining where the signal came from, where it goes, the frequency and the temporal pattern
ex: signals in the optic nerve carry info from the retina.
define the complexity of reading a book to demonstrate how complex the brain is even when it does seemingly simple things
- the brain needs to distinguish between black and white to make up the letters
-the brain needs to take info from both eyes to make it into 1
-the brain needs to make sure the image stays still even tho we are constantly moving
-the brain must accurately calculate the distance between the hand and the page
-the brain must comprehend what you are reading
-the brain must remain focused long enough to complete the task
-the brain has to keep you breathing, blinking, awake and aware
-the brain has to hold your head and body up
challenges in studying the NS
-dense packing of nerve cells
-intricacy of connections
-heterogeneous population
- ex. cells in the cerebellum tells us little about cells in the retina
the brain creates perception, makes decisions and acts
The complexity of perception
it requires the activation of multitude of cells and 1000+ neurons engaging in each stage of processes.
fMRI
functional magnetic resonance imaging
can reveal locations of structures that activate given a task
How does the NS create new messages that convey meaning?
it intergrates new information it gets from sensory nerves. Ex: sensory nerve in finger tips + previous knowledge/information = “i’m touching sandpaper”
What did Santiago Ramon y Cajal do?
he was a great student of the NS
-mapped out the shapes and position of neurons
-mapped out origin and destination of its process in the neural network
-drew lots of photos of neurons using the golgi staining method
what does the brain use to transmit information?
electrical signals
what is the ultimate defining difference between a local graded potential and an action potential?
a change in voltage, if local graded potential meets the threshold, an action potential will fire
what are two types of electrical signals the brain uses?
local graded potential and action potential
local graded potential
spreads over short distance from origin
ex. you won’t feel a lego you just stepped on in your fingers
generated by extrinsic physical stimuli
ex. photoreceptors, touch
action potential
also known as a nerve impulse
initiated when local graded potential is large enough to depolarize the cell membrane
rapid and long distance
depolarization
signal that lessens the negativity inside a neuron
hyperpolarization
signal that hightens the negativity inside a neuron
neuronal signals rely on the cell’s ___
membrane potential
threshold
voltage needed to depolarize a cell so to produce action (an action potential)
all neurons have a resting potential and it is ___ in nature
negative
Ex of graded local potential and action potential in retina
light creates a local graded potential in photoreceptors which then creates a local graded potential in bipolar cells which then creates a local graded potential in ganglion cells which then creates an action potential in the ganglion cells to conduct that signal to higher centers which will convert that information into new perceptive information
resting potential
the potential difference of mV between the inside and outside of a cell
the inside of the cell is negative at resting potential
(-)70 mV
