Study Guide 3 - Biology Of Behavior Flashcards
Glial Cells
- supportive cells
- help grow
- provide nutrients
- get rid of waste
- form insulating sheath
Neurons
- basic unit of structure and function in the nervous system
- receive information
- process information
- transmit information
- semi permeable outer membrane and mitochondria
Dendrite
- part of the neuron that receives messages
- carry signal to cell body
Cell body
- the support center of the cell
- soma contains the nucleus (DNA) and other parts of the cell
Axon
-carries messages away from the cell body
Terminal buttons
- form junctions with other cells
- have neurotransmitters
Myelin sheath
- fatty substance that covers the axon and speeds up the impulse
- Schwann cell (glial)
- larger axon diameter = faster
Synapse
-tiny gap between neurons that they communicate across
Polarization
-normally, the inside of the cell is slightly more negative than the outside
Depolarization
- positive and negative molecules attract
- normally channels for positive molecules are closed
- but changes in environment can depolarize part of the membrane allowing gates to open, and + molecules to enter
- continues, spreading down axon
Action Potential
-abrupt wave of electrochemical changes in the axon when a neuron becomes depolarized
All or nothing Principle
-cell fires action potential at full strength or not at all
Multiple Sclerosis
- disorder that destroys myelin
- may occur because myelin is similar to some viruses, so when the immune system attacks the viruses it also destroys myelin
Refractory Period
- time between action potentials when neuron cannot fire
- after repolarization, (+ molecules pumped back outside membrane) neuron CAN fire
Sensory Neurons
- Afferent!
- information from sensory receptors to central nervous system
Motor Neuron
- efferent
- information from the CNS to muscles and glands
Interneurons
-neurons within the CNS, between sensory and motor
Mirror Neurons
- Neurons that mirror other people’s actions/emotions
- ex) yawning
- help humans connect
Neurotransmitters
- bind to receptors on postsynaptic neuron and stimulates channels to open
- charged molecules enter -> change in membrane potential
- they are in vesicles in the axon terminal
- EXCITATORY: help reach threshold so can fire (depolarizing)
- INHIBITORY: less likely to reach threshold (hyper-polarization)
- combined effect of excitatory and inhibitory decides if neuron will fire
Reuptake
- presynaptic neuron sucks neurotransmitter back up
- “recycle”
Lock and Key Fit
- neurotransmitter fits exactly in receptor
- each receptor recognizes only one type of neurotransmitter
- each each neurotransmitter can bind to different receptors -> different effects
Peripheral Nervous System
- nervous system not in bone
- carries out sensory and motor function
Central Nervous System
- in bone
- brain and spinal chord
- info is sent here to be processed
Somatic Nervous System
- PNS
- transmits info from senses to CNS and from CNS to muscles
- ex) involved in feeling sensations of warmth
- ex) movement - Neurons from spinal chord to muscles
Autonomic Nervous System
- carries messages back and forth between CNS and heart, lungs, and other organs/glands
- messages influence activity of these organs
- controls activities outside of conscious control ex) digestion
- SYMPATHETIC: body for action during stress, fight or flight ex) increase heart rate
- PARASYMPATHETIC: conserve energy ex) decrease heart rate
Acetylcholine
- learning, memory, voluntary movement
- Alzheimer’s if too little
Dopamine
- involuntary motor activity, reward pathway, motivation
- too much = Schizophrenia
- too little = Parkinson’s
Serotonin
- sleep, dreaming, appetite, sexual behavior, mood
- shortage = depression
- SSRIs prevent serotonin from being taken back in
GABA
- primary inhibitory neurotransmitter
- too little = anxiety and seizure
Substance P
- allows you to feel pain
- shortage = CIPA which prevents feeling sensations such as pain
Endocrine System
-hormones in blood communicate and regulate
Pituitary Gland
- master gland, controls endocrine organs
- growth, metabolism
- hypothalamus controls pituitary
- Bottomless pit
Adrenal Gland
- preps body for action
- fight/flight
PET
- function
- locate cell activity by tracking the brain’s use of a radioactive tagged molecule like glucose
MRI
- structure
- magnetic field bombards brain and creates a highly detailed image of brain
fMRI
- function
- images of active areas of the brain
- combines advantages of PET and MRI
- can detect changes in blood flow that reflects changes in Neuron activity