Lecture 3: Biological Psychology Flashcards
3 Types of Neurons
AFFERENT NEURONS (Sensory):
- takes signals from body or environment to brain
INTERNEURONS:
- integrate information
- neurons between neurons
- most numerous
- located in CNS
EFFERENT NEURONS (Motor)
- takes signal from brain to the rest of the body
Neuron Communication
WITHIN-NEURON COMMUNICATION:
- electrical communication
BETWEEN-NEURON COMMUNICATION:
- chemical communication
Parts of the Neuron
DENDRITRES:
- RECEIVES chemical messages from other/ previous neuron
- connected to soma
SOMA:
- PROCESSES the information from dendrites
- the cell body
- contains nucleus
- the command centre of neuron
AXON:
- TRANSMITS/ carries electrical signals to subsequent neuron
- transmitter of neurons
AXON TERMINAL:
- located at the far end of the axon
- end/ stopping point of electrical signal
SYNAPSE:
- junction/ gap between neurons
- meeting point between two neurons
MYELIN SHEATH:
- cells wrapped around axon
- work as insulation, keeps chemical signal
- made of fat
Action Potential keep researching
ACTION POTENTIAL is the electrical signal sent down the axon
- triggers the release of neurotransmitters
- either fires or doesn’t fire
Myelin Sheath
MYELIN SHEATH:
- cells wrapped around axon
- work as insulation, keeps
- made of fat
NODES OF RANVIER are the gaps between myelin sheath
- action potential jumps between nodes which speeds up the electrical signal
- insulation also strengths electrical signal
- lots of sodium channels there that rejuvenate the action potential
Ions Inside and Outside neurons
IONS are charged particles
- some positive, others negative
- basis of electricity is positive and negative charges
INTRACELLULAR FLUID:
- fluid found inside cell
- contains ions?
EXTRACELLULAR FLUID:
- bodily fluid outside the cell
POLARIZED NEURONS = neurons at rest
- more negatively charged ions inside the cell, and more positively charged ions outside
- positive pole; positively charged particles kept outside
- negative pole; negatively charged particles kept inside
DEPOLARIZED NEURONS = neurons during action potential
- during action potential, ion particles flow into the axon
- sequential wave of external exchange of particles creates the action potential
Synapse
SYNAPSE: the junction/space between two connecting neurons through which messages are transmitted chemically
PRESYNAPTIC SIDE: sending the message/ signal
POSTSYNAPTIC SIDE: receiving the message/ signal
VESICLES:
- located in axon terminal
- a sac/packet containing the neurotransmitters
- morph or fuse into cell membrane and send out neurotransmitters
NEUROTRANSMITTERS: are chemical signals that diffuse across synaptic gap to deliver message/ signal
RECEPTORS: A molecule that binds to a specific substance/ neurotransmitter and causes a specific effect in the cell
- how the neurotransmitters know where to go
Receptors
RECEPTORS: A molecule that binds to a specific substance/ neurotransmitter and causes a specific effect in the cell
- how the neurotransmitters know where to go
LOCK & KEY PRINCIPLE:
- chemical shape fits into specific receptor types
- key/ dopamine will only open dopamine door/ receptor
1) neurotransmitter “binds” to the receptor
2) receptor is activated
3) the neuron becomes excited and the next neuron and the next, etc.
REUPTAKE: unused neurotransmitters are re-absorbed by the pre-synaptic axon terminal and recycled
- cleanup system
- controls the amount of neurotransmitters that are being detected by the post-synaptic dendrites
Excitation and Inhibition
EXCITORY NEUROTRANSMISSION:
- Gas Pedal/ Accelerator
- some neurotransmitters excite the post-synaptic neurons, making it more likely for the post-synaptic neuron to fire an action potential
INHIBITORY NEUROTRANSMISSION:
- Brake Pedal/ Decelerator
- some neurotransmitters inhibit the post-synaptic neurons, making it less likely for the post-synaptic neuron to fire an action potential
EXCITATION/INHIBITION BALANCE:
- there needs to be a balance between excitation and inhibition
- too much excitation and too much inhibition at once can be harmful
- how we coordinate actions or know to stop an activity
Types of Neurotransmitters
GLUTAMATE:
- accelerator
GABA: Gamma-
aminobutyric acid
- brakes
GLUTAMATE & GABA: used a lot with memory & learning
some neurotransmitters are both excitatory and inhibitory, depending on what receptors they activate
DOPAMINE:
- excitatory & inhibitory
- reward learning/ motivation
- dopamine motivates you to continue whatever is giving you pleasure - not pleasure chemical - it’s reinforcement
ENDORPHINS:
- inhibits pain signals
SEROTONIN:
- excitatory & inhibitory
- well-being & mood
The Nervous System
I. CENTRAL NERVOUS SYSTEM:
- consists of brain & spinal cord
II. PERIPHERAL NERVOUS SYSTEM:
- all nerve structure outside brain and spinal cord
- connects to muscles, joints, skin, and organs
II. a) SOMATIC NERVOUS SYSTEMS
- voluntary movement
- body sensations (feel, temperature, pain)
- knowing where body is in space/ environment
II. b) AUTONOMIC NERVOUS SYSTEM:
- involuntary/ automatic functions like heart rate, breathing
- two modes:
1. SYMPATHETIC NERVOUS SYSTEM
- fight or flight
- contracts blood vessels & increases blood pressure, accelerates heart rate, dilates pupils
- readies you for action
2. PARASYMPATHETIC NERVOUS SYSTEM
- rest & digest
- calms us down and allows for normal function/ state
Cerebral Cortex
CEREBRAL CORTEX: outer layer of brain
HEMISPHERES:
- there’s left and right
- separated by LONGITUDINAL FISSURE
SULCI: grooves (ditch)
GYRI: ridges (hills)
- function is to maximize surface area!
CORPUS CALLOSUM:
- connects hemispheres
- mostly made up of axons
Brainstem and Cerebellum
BRAINSTEM:
where spinal cord connects to brain
- 3 parts:
1. PONS:
- means “bridge”
- associated with sleep/ wake cycle
- relay station for other senses (like hearing passes through pons before they go to other parts of brain)
- MEDULLA:
- controls autonomic nervous system (breathing, heart rate, etc.)
- damage will likely cause death - MIDBRAIN: sends sensory information to Cerebral Cortex
- sensory relay system (except smell)
CEREBELLUM: “little brain”
- (finely timed) movements like piano
- language and timing
- located at the bottom
Lobes of the Brain
separated by major sulci but not strict divisions
4 Lobes:
1. FRONTAL LOBE
- front of the brain
- planning, language, decision making, personality
- MOTOR CORTEX is located here = where movements are initiated
- PARIETAL LOBE
- behind frontal lobe
- SOMATOSENSORY CORTEX is located here = touch/ body sensations
- integrates sensory informations (sight mixed with touch mixed with sound)
- attention to 3D space/ environment - OCCIPITAL LOBE
- back of brain
- vision - TEMPORAL LOBE
- boxing glove thumb
- hearing (pitches, tones)
- little bit of vision
Orientation Terms
terminology used to describe areas of brain (relative to one another)
ANTERIOR = front or in front of
POSTERIOR = back
DORSAL/ superior = top (think dorsal fin of shark)
VENTRAL/ inferior = bottom
MEDIAL = inside/ centre of brain
