exam 2 chapter 3 psyc 1

the biological bases of behaviour

neurons (brain cells)

are the basic components of the entire nervous system

synapses

tiny gaps between neurons

dendrites (tress)

receiving portion of neuron and many branches to increase neuron’s surface area

Soma (Cell Body)

makes proteins and building blocks of neurotransmitters (chemical messengers) - is vital to cell function

Axons

sending portion of neuron; long thin fibre

axon terminal:

end of the axon which contains synaptic vesicles with neurotransmitters

myelin sheath:

white, fatty substance that insulates signal

synapse:

gap between neurons - information is exchanged here

what are the 3 types of neurons

sensory

motor

interneurons

what the sensory neurons (receptors) do?

receive input from the sensory organs (eyes, ears, nose, mouth, skin) and send it to the brain

what the motor neurons (effectors) do?

send output from the brain to muscles and organs, enabling the body to move

what are the interneurons (processors)?

are thousands of times more numerous than sensory and motor neurons, and relay information between neurons in the brain

how do neurons communicate?

neurons communicate by chemical and electrical activity, messages within or inside neurons are electrical

what is the 3 different types of ions passing in and out of them different rates

chloride (-)

potassium (+)

sodium (+)

neurons at rest are…

are polarized

what being polarized?

electrical charge inside is negative (-), but electrical charge outside is positve (+)

what incoming messages from other neurons can generate

neural impulse

action potential

sodium ions rush in and out along the axon, propagating the electrical signal

how is the electrical state on the action potential?

it is depolarized

how is the all-or-none law

once impulse = generated

what happens with neurons after firing?

cannot fire again for a brief time

how we called the period after firing

absolute refractory period

how is the electrical state

hyperpolarized

what hyperpolarized means

electrical charge inside is even more negative than at rest

why the electrical charge inside is even more negative than at rest

chloride negative ions flow in and positive neurons flow out and neuron must get back to resting potential

how neurons communicate

by chemical and electrical activity

what is chemical

messages between or outside neurons

what are the neurotransmitters

the neurotransmitters

after an action potential, the neurotransmitters…

are released from the axon terminal into the synapse and received by dendrites of the next neuron

who said that single neurons don’t influence behavior

Donald Hebb

Donald Hebb explained…

that neurons constantly communicate with each other,

the basis of learning they fire together so forms links together “fire together, wire together”

what is the long term potentiation

persistent strengthening of synapses based on recent patterns of activity

so… the hebbian learning is…

when two joining cells fire simultaneously, the connection between them strengthens

what are the two types of messages from neurotransmitters?

• excitatory

• inhibitory

the excitatory neurotransmitters…

increases the chance that the postsynaptic neuron will activate and generate an action potential

the inhibitory neurotransmitters…

decreases the chance that the postsynaptic neuron will activate and generate an action potential

what are the two ways to call the chemicals mimic neurotransmitters

• agonists

• antagonists

acetylcholine

found in all motor neurons; it stimulates the muscles to contract, but also involved in learning and memory

what are the monoamines?

dopamine

serotonin

noretonin

dopamine

linked to feelings of pleasure or desire, but also involved in body movement, memory, attention, sleep

serotonin

linked to mood/emotion, anxiety, behavior, learning, sleep, sexuality, appetite

norepinephrine (noradrenaline)

linked to body’s response to fear or threat, but also involved in sleep, learning, memory

Gaba (gamma-aminobutyric acid)

has an inhibitory effect on the nervous system - it slows down transmission of nerve impulses, relaxes muscles

glutamate

has an excitatory effect on the nervous system - important for learning memory, and sensory processes

endorphins

chemically similar to morphine (and other opiates), and are released in response to stress, trauma, and pain

glia

support cells (glue) of the nervous system 10 x more numerous than neurons

oligodendrocytes

form myelin sheath covering of axons (in the brain and spine) or Schwann cells (in the rest of the body)

astrocytes

provide nutrients to neurons, help communication between neurons, and provide connections between neurons and blood vessels

microglia

remove debris, waste, and damaged cells from nervous system

nervous system

peripheral

central (brain and spinal cord)

peripheral

• autonomic (controls self-regulated action of internal organs and glands)

• somatic (controls voluntary movements of skeletal muscles)

autonomic

• sympathetic (arousing)

• parasympathetic (calming)

somatic nervous system:

control voluntary behavior

contains sensory and motor nerves

sends sensory info to CNS, and carries info from CNS along motor nerves for voluntary movement

autonomic nervous system:

controls involuntary functions (heartbeat, breathing, digestion)

activates fight-or-flight response

sympathetic nervous system:

body’s emergency system (activates body in response to threat or emergencies)

parasympathetic nervous system:

body’s conservation system (conserves and maintains body’s resources, calms you down after an emergency)

how the brain is protected

by the skull and cranium

how the spinal cord is protected

by the vertebral column

what are the 3 membranes that evelop the brain and spinal cord

dura mater

arachnoid mater

pia mater

what is cerebrospinal fluid (CSF)

located between the arachnoid mater and pia mater

what is the primary function of cerebrospinal fluid

protect the CNS

what are the 3 main components

forebrain

midbrain

hindbrain

cerebrum

largest part of the brain

controls voluntary actions, senses, and cognitive functions

how the surface is called

cerebral cortex

cerebral cortex

is made up of gray matter (neuron cell bodies) and is folded up so that it can fit inside the skull

hills or bumps

gyri (singular = gyrus)

valleys or grooves

sulci (singular = sulcus)

the right hemisphere of the cerebrum

controls voluntary limb movements on left side of the body - contralateral control

left hemisphere of cerebrum

controls voluntary limb movements on right side of the body - contralateral control

what links the two cerebral hemispheres

corpus callosum

nerve fibres

white matter

myelin

white, fatty substance that forms an electrically insulating

what are the 4 cerebral lobes

frontal

pariental

occiptal

temporal

frontal lobe

primary motor cortex: voluntary body movements

broca’s area: language production

executive functions: thinking, planning, decisions

contains mirror neurons

pariental lobe

primary somatosensory cortex: sensations of pressure, pain, temperature

space and object orientation

occipital lobe

vision

temporal lobe

hearing, complex facial tasks

wernicke’s area: language understanding

frontal lobe damage

phineas gage

phineas gage

difficulty reasoning, making decisions

inability to control emotions

goal-directed behavior impairments

damage on broca’s area

expressive aphasia - difficulty producing speech

occipital lobe damage

blindness/visual hallucinations

temporal lobe damage

wernicke’s area

receptive aphasia (difficulty understanding language)

basal ganglia

control of voluntary movement (with the help of the motor cortex), routine behaviors or habits such as teeth grinding, eye movements, cognition, and emotion

basal forebrain

activates cerebral cortex, attention

thalamus

sensory gateway to the cerebral cortex functions as a relay station for all sensory impulses to the cerebral cortex EXCEPT for smell

Limbic system

emotional center

networked with the autonomic nervous system to influence blood pressure, heart, and endocrine system

conveys information about our internal state

the limbic system consists:

hypothalamus

amygdala

cingulate cortex

hippocampus

hypothalamus:

maintains the body’s internal states (homeostasis) by overseeing the endocrine and autonomic nervous systems

amygdala:

plays a key role in the processing of emotions, especially fear and pleasure, and also plays a role in memory

cingulate cortex:

involved in emotional expression

knowledge of socially appropriate behavior

regulates autonomic nervous system

hippocampus

spatial memory, fear conditioning

midbrain

integrates sensory processes, such as vision and hearing

contains an important network of dopamine-producing neurons

reticular formation

modulates muscle reflexes, breathing, pain perception, sleep and arousal

hindbrain

contains two important structures

brainstem

cerebellum

brainstem

oldest part of the brain, beginning where the spinal cord swells and enters the skull

responsible for automatic survival functions

what are the 3 structures make up the brainstem

medulla oblongata

pons

midbrain

medulla oblongata

crucial for life, it controls breathing, swallowing, blood pressure, and heart rate

pons (latin for bridge)

links cerebrum to cerebellum and relays signals between them - also plays a key role in sleep and dreaming

midbrain

controls rudimentary vision and hearing

cerebellum (little thing under the cerebral)

means little brain in latin

responsible for balance and coordination of muscles

important for voluntary tasks (walking, reaching, writing)