Chapter 3 Flashcards
what is the nervous system
the body’s major controlling and communicating system
what are the characteristics of the nervous system
complexity, integration, adaptability, and electrochemical transmission
what does the term neuroplasticity mean
the brains special capacity for change (ability to form new neural connections)
what are the specialized pathways made up of in the nervous system
- afferent nerves, efferent nerves, and neural networks
what are afferent nerves
- which are known as the sensory nerves: they carry information to the brain and spinal cord
- the sensory pathways communicate information about the external/internal environment from sensory receptors to the brain and spinal cord
what are efferent nerves
motor nerves:
- that carry info out of the brain and spinal cord and communicate info from there to the rest of the body, instructing them what to do
what are the major divisions of the human nervous system
- central nervous system (brain and spinal cord) and the peripheral nervous system (network of nerves that connect the brain/spinal cord to the rest of the body)
what are the major divisions of PNS
- somatic nervous system (system consisting of sensory nerves and motor nerves) and the
autonomic nervous system, which takes messages to/from internal organs, monitoring breathing, heart rate, etc.
what are the divisions of the autonomic nervous system
sympathetic nervous system:
- arouses the body to mobilize it for action (fight/flight)
- parasympathetic nervous system: calms the body
what are the two types of cells in the nervous system
neurons: nerve cells that handle info processing
Glial cells: provide support, nutritional benefits, etc.
- glia helps neurons run smoothly
what are mirror neurons
neurons that play a role in imitation and are activated when we perform an action and watch someone else do that activity
- they are also thought to be involved in language, motor skills, empathy, etc.
what parts makes up a neuron
- cell body: has the nucleus, which controls the building of essential substances for the growth/manitenance
- dendrites: The “arms” of the neuron that receive and process signals from other neurons
- axon: long, thin extension of the cell body that transmits nervous impulses to other cells or structures.
The axon is covered by a layer of myelin that insulates and accelerates the transmission of the nerve - terminal buttons: structures at the very end of each terminating axon fibre that send information to other neurons in the form of chemicals released into the synapse (also called synaptic boutons)
- myelin sheath: protective coating along axon made up of glial cells which increase the speed of neural signal transmission
what is neuroscience
- the scientific study of the nervous system in humans and non-human animals
what is an example of latent behaviour
researchers put hungry rats in a maze:
- 1/2 found food at the end and the other 1/2 didn’t
- operant conditioning principles would infer that eats who had food would learn the maze better (which happened)
- BUT, when some rats from the non reinforced group were given food at the end, they quickly began to know the maze as much as the others
- this shows their learning was latent, as the rates learned a lot about the maze but it wasn’t expressed behaviourally
what is insight learning
- form of problem solving in which the organism develops a sudden insight/understanding of a problems solution
synapses
different specialized connections btwn neuros
hippocampus
known to be responsible for navigation and helping you form memories about where you are in space
acquired savant syndrome
example of brains plasticity
- individuals gaining special skills or talents after suffering brain injury or disease
resting potential
- separation of charges across membrane=polarization
- -60mV to -75mV is the resting potential
-provided by the unequal distribution of ions across the two sides of the membrane (fluid outside is high in Na+ and low in K+ and vice versa)
- inside neuron= more negatively charged a.a. but theyre too big to move across the membrane
- Cl- has very little contribution
action potentials
- neurons communicatif information over long distances via a series of electrical impulses
-signals that transmit info
HOW ARE THEY GENERATED?
- through the change in ion flow creating a change in voltage
- change in voltage=gate opens=Na+ and K+ enter the channel
they also have POSTSYNAPTIC POTENTIALS: small voltage fluctuations in receiving neuron
- excitatory: increase likelihood of generating action potetial
- inhibitory: ^ opposite
neurotransmitters
- chemicals that ares stored within the terminals that are released through electrical impulses
example:
-acetylcholine (muscle contractions, learning, memory, and attention)
- GABA (inhibiting neurons from firing, low levels=anxiety)
- glutamate (MOST PREVALENT NEUROTRANSMITTER, stimulate neurons to fire, involved in learning and memory, too much=seizures, migraine, depression, etc.)
norepinephrine- stress, inhibits firing of some neurons and excite the heart muscle, intestines, and urinary tract
dopamine- affects voluntary movement, sleep, mood attention, learning motivation, and recognize opportunities as rewarding experiences
serotonin- regulation of sleep and waking activity, mood, attention, and learning
resting value made to a less negative value
depolarization
what region has a higher concentration of Na and K channels along axon
axon hillock or trigger zone
neuropeptides
- sequences of a.a.
- synthesized in cell body, enveloped by vesicles, and transported to axon terminals
examples: endorphins, oxytocin,
parts of the brain
- cerebral cortex: thinking, learning, problem-solving, language, + behaviour
most recently evolved
largest part (40%) - thalamus: relay center
- hypothalamus: eating, drinking, and equilibrium
- reticular formation: arousal, consciousness, and movement
- hippocampus: memory and navigation
- amygdala: emotions (fear and survival instincts)
- pituitary gland: growth, hormones, maturation
- medulla: breathing and reflexes
- cerebellum: motor coordination
- pons: sleep and wakefulness
- corpus callosum: integrating and relaying info btwn 2 hemispheres
voluntary loss of control of movement
paraplegia
substania nigra
and what is the largest division of the brain
found at bottom of midbrain
- major sources of dopamine
larget divison: forebrain
limbic system
loosely connected network of structures that border the cortex and thalamus and hypothalamus
- memory and emotion
- 2 components: amygdala and hippocampus
what is above the thalamus and under the cerebral cortex
basal ganglia
- works will cerebellum and parts of cerebral cortex to coordinate and control voluntary movement
- automates everyday behaviour (walk, talk, chew, etc)
left and right hemisphere
- language=left
people who had difficulty with language had damage in Wernicke’s area (left temporal lobe)
-nonverbal cues=right
idea that there is a division of labour btwn the 2: brain lateralization
lobes of the brain
frontal: personality, intelligence, voluntary movement
motor: voluntary movement
broca: speech and language production (converts thoughts and nonverbal cues to words/understanding)
prefrontal: complex human behaviours (planning, decision making, responding)
occipital: visual stimuli and process information
primary visual: conscious processing of visual field
visual association: translate basic sensory input into info
temporal: hearing, language, and memory
primary auditory: basic processing of sound
wernicke: damage to this area will allow for you to hear sounds without being able to understand them, its on the left temporal lobe
auditory associaton: processing signals related to speech, music, or tones
parietal: spatial location, attention, and motor ctrl
somatosensory: perceiving touch ad pressure
insula
resides in Sulci of cortex
- stimulation produces odd tastes (metallic tastes in mouth, nausea, and bloating)
- integrates your inner bodily state with emotional state (butterflies in stomach when nervous)
brain lesioning
and how can we study brain function
experimentally damaging brain tissue in non-human animals through surgical removal, currents, heat, or chemicals
we can study brain function with EEG: electrodes attached to scalp to measure electrical activity of neurons
- can’t locate where the signals originate
endocrine system
glands (organs or tissues that produce chemicals that ctrl bodily functions) that regulate the activities of certain organs by releasing chemical products into bloodstream
- chemical messengers produced by glands=hormones
pineal gland
- secrets melatonin to control circadian rhythms and regulate activity of some reproductive hormones
melatonin is light sensitive and is involved in sleep
additional components:
thyroid gland
parathyroid
thymus
adrenal glands
pancreas
ovaries + testes
thyroid gland-use Iodine to produce hormones to regulate metabolism
parathyroid-regulate levels of Ca+
thymus- produce WBC (located btwn lungs and behind sternum)
adrenal glands-located atop kindeys; regulate mood, energy levels and stress (secret epinephrine / adrenaline)
pancreas: glad that helps with digestion and produces hormones like insulin
ovaries and testes: sex-related glands, produce hormones involved in sexual development and reproduction
3 processes that allow the damaged brain to be repaired
1) collateral sprouting: axons of healthy neurons adjacent to damaged cells grow new branches
2) sub of function: damaged regions function is taken over by another area of the brain
3) neurogenesis: process of involving the generation and integration of new neurons in the neural circuits of the adult brain
