chapter 2 Flashcards
Afferent neurons
(sensory)
relay messages from sense organs, receptors to brain or spinal cord
Efferent neurons
motor
signals from the brain, spinal cord to glands, muscles movement.
interneurons
thousand times more neurons than motor or sensory neurons
carry information
transmits between neurons in brain and neurons in spinal cord
3 parts of neuron
cell body: contains nucleus, carries out metabolic function
Dendrites: branch like extensions of neuron receive signal from other neurons
Axon: transmits signals to other parts of neurons and muscles, glands, other body parts
Glial cells
hold neurons together
remove dead neurons
make myelin
synaptic clefts
gaps between axon terminals
fluid filled
synapse
axon terminal of sending neuron communicates with receiving neuron across synaptic cleft
resting potential
neural impulse
neuron firing
inside axon normally more - than +
at rest neurons carry negative electrical potential
action potential
neural impulse
neuron is stimulated positive ions flow into axon
changes to positive value
sudden brief reversal
Myelin sheath
all or none law
white fatty coating around some axons
impulses up to 100 times faster along axons with myelin sheaths
receptor sites
neurotransmitters
sites on dendrite or cell body of neuron
interacts with neurotransmitters
Reuptake
neurotransimtter
Neurotransmitter taken from synaptic cleft into axon terminal
Acetylcholine (ACh)
neurotransmitter
Excitatory or inhibtory
excites skeletal muscle fibres
Dopamine (DA)
monoamine transimtter
ability to feel pleasure or fear
learning, attention, movement, reinforcement
Norepinephrine (NE)
monoamine transmitter
eating habits, alertness
involved in mood regulation
epinephrine ( adrenalin)
monoamine transmitter
completes NE
affects metabolism of glucose
Serotonin
monoamine transmitter
inhibitory
mood, sleep, impulsivity, aggression, appetite, depression, anxiety disorders
Glutamate (glutamic acid)
Amino acid neurotransmitter
excitatory
active in higher brain structures
GABA (gamma-aminobutyric acid)
amino acid neurotransmitter
inhibitory
widely distributed throughout CNS
controls anxiety in humans
Endorphins
neurotransmitter
opiate like substance
relief from pain or stress of vigorous exercise
produce feelings of pleasure and well-being
2 parts of nervous system
central nervous system (CNS) brain spinal cord Peripheral nervous system (PNS) connects CNS to all other parts of body
Spinal cord
extension of brain
links body with brain
transmits info from brain to PNS and PNS to brain
Brainstem
begins at site where spinal cord enlarges as it enters skull
Medulla
1 of 3 major structures
controls automatic function
ex. heart beat, breathing, blood pressure, coughing
Reticular formation
2 of 3 major structures
AKA Reticular activating system (RAS)
regulates arousal and attention
screens messages entering the brain
Pons (bridges)
3 of 3 major structures
connects left and right cerebellum
plays role in movement, sleep, dreaming
Cerebellum
means little cerebrum
contains 2 hemispheres
executes smooth, skilled body movement
regulates muscle tone and posture
Thalamus
relay station for info flowing into and out of higher brain centre
learn new and verbal info
regulates sleep cycle
Hypothalamus
regulates hunger, thirst, sexual behaviour, emotional behaviours
regulates body temp
regulates our biological clock
Amygdala
part of limbic system
associations between external events and emotions
learned fear responses
responds to aversive stimuli
Hippocampus
part of limbic system
LTM navigational maps
Cerebrum
part of cerebral hemispheres
two cerebral hemispheres connected by corpus callosum
Corpus Callosum
part of hemispheres
thick band of nerve fibres
transfer of info and coordination between the 2 hemispheres
cerebral cortex
covers cerebral hemispheres
higher mental processes
language, memory, thinking
cortex
grey matter
frontal lobe
controls moving, speaking, thinking
contains motor cortex brocas areas frontal association area
motor cortex
controls voluntary body movement
Wilder Penfields homunculus map
plasticity can adapt to changes
brocca’s area
frontal lobe left hemi controls speech sounds injury = brocca's aphasia understand language
frontal association areas
thinking, motivation, future planning, impulse control, emotional responses,
ex. Phineas Gage
Parietal Lobes
touch
reception of touch stimuli
lobes contain somatosensory cortex
Somatosensory cortex
touch, pressure, temperature, heat register in this cortex
awareness of body movements and position
occipital lobe
sight
contain primary visual cortex
involved in reception and interpretation of visual information
primary visual cortex
area at back of occipital lobe
vision registers in cortex
temporal lobes
hearing
lobes contain primary auditory cortex, Wernicke’s area (left lobe) and association areas
primary auditory cortex
where hearing registers in cortex
injury = damage to hearing
Lateralization
specialization of cerebral hemisphere
Left hemisphere
language and mathematics
controls right side of body
coordinates complex movements
Right hemisphere
visual-spatial relations controls left side of body how we hear language creativity and intuition recognizing and expressing emotion
split brain
performed in severe cases of epilepsy
corpus callosum is cut
lessens severity and frequency of seizures
brain lifespan
grows in spurts
gains and loses synapses through life
brain weight declines around age 30
brain damage
Hippocampus can regenerate neurons
damaged neurons can sprout new dendrites
axons can regenerate and grow
reorganization of brain= plasticity or neuroplasticity
EEG
electroencephalogram record of brainwave activity
measures 4 types of waves (beta, alpha, theta, delta)
Microelectrode
tiny wire, can be inserted into a single neuron
4 types of waves
beta= mental or physical activity (13 or more cycles per second) alpha= deep relaxation (8 to 12 cycles per second) Theta= light sleep (just before deep sleep) delta= slow wave sleep (1-3 cycles per second)
CT scan
computerized axial tomography
computerized cross-sectional images of brain structure
MRI
magnetic resonance imaging
cleaner more detailed images of brain than CT scan
PET scan
positron emission tomography
map patterns of blood flow, oxygen and glucose use
SQUID
superconducting quantum interference device
magnetic changes in electric current that neurons discharge
MEG
magnetoencephalography
neural activity in brain as it happens
PNS (peripheral nervous system)
nerves connect CNS to body
sends info to other prats of body
divided into somatic and autonomtic
SNS(somatic nervous system)
voluntary muscle control
sense receptors to CNS
motor nerves from CNS to skeletal muscles
ANS(autonomic nervous system)
automatic and involuntary
CNS messages to glands, cardiac(heart) muscle, and smooth muscles
Sympathetic nervous system
stress system
parasympathetic nervous system
relaxation system
endocrine system
series of ductless glands in the body
manufactures secretes hormones
Hormones
released in one part of the body
affects other parts of the body
pituitary gland
master gland
controlled by hypothalamus
releases hormones that activates other glands
thyroid gland
in front lower part of neck below voice box
produces hormone thyroxine
regulates food metabolism
adrenal glands
2 above kidneys produces epinephrine and norepinephrine activates sympathetic nervous system releases corticoids to control salt balance releases sex hormones
pancreas
regulates blood sugar levels
releases insulin and glucagon into bloodstream
sex glands (Gonads)
ovaries and testes
activated by pituitary gland
gonads release sex hormones for reproduction
