Physiological Psychology Flashcards
neuron
specialized cell directly involved in mental processes and behavior
present at birth
die at a rate of 10,000/day
neurogenesis = creation of new neurons
State the three distinct components of a neuron
dendrite
cell body
axon
dendrite
part of neuron
branch-like structure that receives information from other cells and conduct it toward cell body, which integrates info received
cell body
receives input from dendrites and integrates and sends information to the axon
part of the cell body
nucleus
mitochondria
ribosomes
Golgi complex
mitochondria
sites where cell performs metabolic activities
ribosomes
cell synthesizes new protein molecules
Golgi complex
system of membranes that prepare neurotransmitters and other substances for secretion
axon
transmits information from all body to other cells
usually only 1
covered by myelin sheath (fatty substance that acts as an insulator and speeds up conduction of nerve impulses)
made up of glial cells (hold neurons together, providing neurons with nutrients, remove cellular debris
conduction
electrical process of transmitting messages from neuron’s dendrite to axon
there are resting states ( negatively charged on inside) and active states (where sodium channels open which allows for positively charged sodium to enter cell and creates depolarization
action potential
electrical impulse that travels quickly through the cell
repolarization
sodium channels close and potassium channels open, which allows charged K to leave the cecll
all or nothing principle
whenever stimulation received by neuron exceeds a given threshold, resulting action potential will be same intensity
chemical mediation
occurs when an action potential reaches axon terminal (synaptic transmission)
synaptic cleft- small gap between the axon terminal of presynaptic cell and receptor on the dendrite of postsynaptic cell
List 7 different types of neurotransmitters
acetylcholine (Ach) dopamine norepinephrine serotonin gramma-aminobutyric acid glutamate endorphins
acetylcholine
found in peripheral and central nervous systems and acts on 2 different receptors (muscarinic and nicotinic)
how does acetylcholine act in the peripheral nervous system?
Ach is released in neurotransmitter junction where it causes muscles to contract
autoimmune disorder called myasthenia gravis attacks Ach receptors at neurotransmitter junctions resulting in profound weaknesses of skeletal muscles
how does acetylcholine act in the central nervous system?
involved in REM sleep, regulation of sleep-wake cycle, and learning and memory
nicotine might enhance alertness by mimicking Ach @ nicotine receptor sites
degeneration of cholinergic cells in entorhinal cortex and other areas that communicate irectly with hippocampus is believed to underlie memory deficits with AD
name a few examples of cholinesterase inhibitors used to slow memory decline and the mechanism of action
mechanism of action: slowing down the breakdown of Ach -tacrine (cognex) -donepezil (aricept) galantamine (reminyl) -rivasstigmine (exelin)
dopamine
type of catecholamine (w/ epinephrine and norepinephrine)
involved in mood, memory, sleep, personality
dopamine hypothesis
predicts that schizophrenia is due to elevated dopamine levels OR oversensitivity of dopamine receptors
name a few disorders that are linked to dopamine
Tourette’s - oversensitivity to or excess DA in caudate nucleus
PD- degeneration of DA receptors in substantia nigra, and nearby areas, underlies the tremors, muscle rigidity, and other motor sx’s
-stimulant drug action (opiates, alc, nicotine) increase DA in mesolimbic system
e.g., cocaine blocks reuptake of DA at synpases
norepinephrine
role in mood, attention, dreaming, learning, and certain autonomic fx’s
catecholamine hypothesis predicts that some forms of depression are due to lower than normal levels of it
serotonin
exerts inhibitory effect
implicated in mood, hunger, temperature regulation, sexual activity, arousal, sleep, aggression, migraine headache
increased levels of serotonin –d/o
decreased levels of serotonin –d/o
increase levels — schizophrenia, autistic d/o, food restriction 2/2 anorexia
decreased levels– aggression, depression, SI, bulimia, PTSD, PCD, possibly social phobia too
Gamma-aminobutyric acid (GABA)
plays a role in eating, seizure, anxiety disorders, motor control, vision, and sleep
evidence for role of GABA in motor control is provided by studies showing degeneration of cells that secrete GABA in basal ganglia contributes to motor sx’s in Huntington’s disease
decreased levels– anxiety disorder, benzos, and other CNS depressants reduce anxiety by enhancing GABA
glutamate
excitatory neurotransmitter
roles in learning and memory- long-term potentiation (LTP): brain mechanism believed to be responsible for formation of LTM
excitotoxicity (excessive glutamate receptor activity)– can lead to seizures and may contribute to stroke-related brain damage, Huntington’s disease, AD, etc.
endorphines
inhibitory neuromodulators that lower sensitivity of postsynaptic neurons to neurotransmitters
analgesic properties, may be responsible for pain relief produced by acupuncture
may be due to ability to prevent release of P( transmission of pain impulses)
implicated in certain pleasurable experiences “runner’s high”, emotions, memory and learning, sexual behavior
what is the central nervous system made up of?
Brain structures
spinal cord
brain structures in CNS
thalamus pineal gland cerebral cortex corpus callosum caudate nucleus midbrain cerebellum medulla oblongota pons hippocampus pituitary gland hypothalamus
spinal cord (CNS)
made up of bundles of myelinated axons (nerve tracts) and dendrites, axons, and interneurons
carries information between brain and PNS, coordinates activities and L and R sides of body, and controls simple reflexes that do not involve brain
list and specific the types of nerve fibers that are in the spinal cord
dorsal horns– carry sensory (afferent) message and are in the superior portion of the spinal cord
ventral horns– carry motor (efferent) messages and are i the inferior portion of the spinal cord
how many segments is the spinal cord consist of and the 5 groups it is divided in
31 segments
from top to bottom: cervical, thoracic, lumbar, sacral, and coccygeal
quadriplegia
loss of sensory and voluntary motor fx in arms and legs
damage at cervical level
aka tetraplegia
paraplegia
loss of sensory and voluntary function in legs
damage at thoracic level
complete transection
lack of sensation ad voluntary movement below level of injury
incomplete transection
some sensory motor function below level of injury are maintained
e.g., may have sensation in 1 limb or parts of body cannot be moved or may be able to move 1 limb more than other
peripheral nervous system
made up of nerves (bundles of axons) that relay messages between CNS and body’s sensory organs, muscles, glands
12 pairs of cranial nerves that connect directly to brain
31 sets f sensory and motor nerves - spinal nerves that connect with spinal cord
what are the two divisions of the peripheral nervous system?
somatic nervous system (SNS)-
autonomic nervous system (ANS)
somatic nervous system
sensory nerves that carry information from sense receptors to CNS and motor nerves that carry information from CNS to skeletal muscles
governs activities that are ordinarily voluntary
autonomic nervous system
comprised of sensory nerves that convey signals from receptors in viscera to CNS and motor nerves that carry signals from CS to smooth muscles, cardiac muscles, and glands
associates with involuntary activities, biofeedback, hypnosis, and other techniques
what are the two branches of the autonomic nervous system?
sympathetic
parasympathetic
sympathetic nervous system
arousal and expenditure of energy
e.g., reaction to external threat0 sympathetic branch causes dilation of pupils, inhibition of peristalsis, dry mouth, sweating, high BP, increased heart rate
parasympathetic nervous system
conservation of energy, active during digestion and periods of ret and relaxation
meditation, hypnosis, biofeedback, and other responses foster “relaxation response”
the sympathetic and parasympathetic NS usually function _______________
cooperatively
e.g., during sex, parasympathetic mediates erection in males while sympathetic stimulations ejaculation
Name the five main stages of development of the human brain
- proliferation
- migration
- differentiation
- myelination
- synaptic genesis
proliferation
new cells produced inside neural tube beginning when embryo is 2.5 weeks old
migration
immature neurons migrate to their final destination at around 8 weeks
once cells reach their destination, they begin to aggregate with other cells to form structures of the brain
differentiation
neurons initially look very much like other cells of the body, but following migration develop axons and dendrites
myelination
axons of some neurons myelinate, which occurs when glial cells form an insulating sheath around cell’s axon
occurs postnatally
synaptic genesis
forming of synapses
depends on specific area of brain, but most occur postnatally
appears to be influenced by BOTH endogenous (genetic) and exogenous (experience) factors
apoptosis
natural pruning process in which neurons that are initially overproduced are pruned during prenatal development and for several years following birth
List and briefly describe the steps to evaluate spinal cord injuries and disease
- initial starts with a spinal x-ray (can identify fractures, dislocations, or other injuries to bone/spine
- MRI (permits evaluation of soft tissues of spinal column
- computer tomography with myelogram (injecting a dye into spinal canal may be used to obtain more detail about the extent of the injury)
- electromyography (EMG), somatosensory evoked potentials (SSEP), or other electrodiagnostic monitoring (to determine if injury or disease has impacted conduction of nerve signals in spinal cord
List the two major types of neuroimaging techniques
- structural
- functional
list and briefly describe the 2 types of structural neuroimaging
A. computed tomography (CT) AKA computerized axial tomography (CAT)
-utilizes X-rays to obtains images of horizontal slices of brain tissue
B. MRI
-provides cross sectional images of brain by using magnetic fields and radio waves
Advantages and disadvantages of MRI vs. CT
Advantages: does not use X- ray, better resolution and more detailed images, images at any angle (not just in horizontal plane), 3-D pictures of brain
Disadvantages: more $$, may require sedation
Name and briefly describe the three main types of functional neuroimaging
- Positron-emission tomography (PET)– injected with radioactive trace substance that is taken up by active brain cells
images provide information on regional cerebral blood flow, glucose metabolism, and oxygen consumption
correlates with neural activities and used to determine cerebrovascular disease (although early stages of AD may not be detected with it)
identify brain areas that are active during performance of ordinary tasks and experience of ordinary emotions - Single proton emission computed tomography (SPECT)– similar to PET but has lower resolution
- fMRI– MRI + info on brain activity (blood oxygenation); images have better temporal and spatial resolution
List the three major divisions of the brain
hindbrain
midbrain
forebrain
name the three major structures of the hindbrain
medulla (in brainstem)
pons (in brainstem)
cerebrellum
medulla
(in hindbrain)
flow of information between spinal cord and brain
coordinates swallowing, coughing, sneezing
regulates vital functions: breathing, heartbeat, blood pressure
damage = fatal
pons
(hindbrain)
connects 2 halves of cerebellum and plays role in integration of movements to R and L sides of body
cerebellum
(hindbrain)
important for balances and posture
vital for performance of coordinated and refined movement (along with basal ganglia and motor cortex)
timing and coordination of motor movements and correct of errors
also impacted by sensorimotor learning and some aspects of cognitive function
**abnormalities linked to: autism, schizophrenia, ADHD
**ataxia
ataxia
damage to cerebellum
slurred speech, severe tremors, loss of balance
mimics the effects of EtOH consumption
what is the major function of the midbrain and list the three major structures
send neural information between brain and spinal cord
- superior and inferior colliculi
- substantia nigra
- reticular formation
superior and inferior colliculi
superior— routes for VISUAL information
inferior— routes for AUDITORY information
substantia nigra
motor activity; plays a role in the brain’s reward system
reticular formation
extends from spinal cord through the hindbrain and midbrain into the hypothalamus in forebrain
consists of over 90 nuclei that are involved with: respiration, coughing, vomiting, posture, locomotion, and REM sleep
contains the reticular activating system
reticular activating system
(in reticular formation in midbrain)
vital to consciousness, arousal, wakefulness
screens sensory input (esp during sleep)
arouses higher centers in brain when important information must be processed
damage can disrupt sleep/wake cycle and produce permanent coma-like state
What are the two major divisions of the forebrain?
cortical vs subcortical structures
name the subcortical structures of the forebrain
thalamus
hypothalamus
basal ganglia
limbic system (amygdala, hippocampus, cingulate cortex)
name the cortical structures of the forebrain
Cerebral cortex (which is comprised of L and R lateralization and the 4 lobes- frontal, parietal, temporal, and occipital)
thalamus
(part of forebrain)
motor activity, language, memory
“relay station” that transmits incoming sensory information to appropriate areas of cortex for all senses EXCEPT olfaction
Wernicke-Korsakoff syndrome can occur if there is damage to this area