Chapter 3: Biological foundations of behavior Flashcards
What are neurons
Nerve cells which form the basic building blocks of the nervous system
What is the cell body of the neuron
It contains biochemical structures that maintain the neuron and the nucleus, which carries DNA
What does the axon do
Send signals to other neurons
What do dendrites do
Receive signals from other neurons
What are myelin sheath
Fatty insulators that cover the axon
What are nodes of ranvier
Intervals in the myelin sheath where there is little or not fat
What does myelination do
It increases the speed on nerve impulses, with the signal jumping from node to node across the axon
What is multiple sclerosis (MS)
MS is neurological disorder in which the immune system attacks the myelin sheath, causing neurons to be demyelinated. This leads to a range of problems (vision, stamina etc.)
What are glial cells
They help support, nourish, protect neurons in many ways and there are a 10-1 ratio of glial cells to neurons
What is the blood brain barrier (BBB)
A lining of specialized tightly packed glial cells in the brain’s blood vessels that screen out foreign toxins. The potency of drugs are defendant on how they cross the BBB.
What is a state of polarization in neurons
When neurons are in resting potential at -70mV due to an uneven distribution of ions.
What is an action potential
Sodium channels opening up and Na+ flowing into the cell from outside causing a shift in potential from -70-+40. This is referred to as depolarization
What is repolarization
K+ channels being opened and flooded out
What is the all or none law
Action potentials aren’t fired unless a threshold is reached.
What are graded potentials
Small changes in the resting potential that do not reach the threshold required to trigger an action potential
What is the absolute refractory period
A period after an action potential is fired where another can’t be fired as the neuron restores balance
Describe modifying neuron firing in the medical field with an exampl
Using numbing cream in the mouth to prevent action potentials from being fired in reaction to pain during surgery
Where and how do interactions between neurons occur
It occurs in the synaptic cleft and is done through neurotransmitters
What are neuotransmitters
Chemical messengers which excite or inhibit neurons
What are the 5 stages of neurotransmission
- Synthesis: formation in neuron
- Stroage: in synaptic vesicles
- Release from presynaptic membrane to postsynaptic
- Binding to receptor sites
- Deactiviation via break down and chemical re-uptake
What is a cause of Parkinson’s
Not enough neurotransmitters being transmitted
How do neurotransmitters excited or inhibit neurons
By either stimulating the flow of Na+ (excitation) or release of K+(inhibition)
What are neuromodulators
Neurotransmitters with more widespread effects.
What is glutamate
The primary excitatory neurotransmitter which is important for learning and memory (think of a green light). Not enough can lead to depression
What is GABA
The primary inhibitory neurotransmitter which is important for motor control and anxiety. Breakdown of GABA leads to Huntington’s disease, which can cause tremors and personality changes
What is acetylcholine
An excitatory neurotransmitter involved with memory and muscle activity. Overproduction leads to seizures and underproduction can lead to Alzheimer’s disease
What is norepinephrine
Mainly involved with “fight or flight” response. Also involved with learning, memory, wakefulness, and eating. Lacking can cause depression, too much can cause panic attacks
What is dopamine
Involved with motivation, reward, feelings of pleasure, and voluntary motor control
What is seratonin
Involved with mood, apatite, sleep, arousal and learning. Imbalances can cause depression and anxiety in this is the target for anti-depressants
What are endorphins
Opiate-like substances produced by the body and released when in pain to reduce it. Increase feeling of pain is a lack of endorphins
What are agonists
Drugs that bind to neurotransmitters that increase their activity
What are antagonists
Drugs that bind to neurotransmitters that decrease their activity
What are the parts of the central nervous system (CNS)
The brain and the spinal chord
What makes up the peripheral nervous system
The neurons that connect the CNS with muscles, glands, and sensory receptors
What are the somatic and autonomic nervous system
Somatic- related to voluntary behavior
Autonomic- related to involuntary behavior
Describe spinal reflexes
Simple spinal movements that don’t need any communication with the brain in order to occur (ie. burning your hand against a candle)
What is the purpose of the somatic division of the PNS and what is it made up of
The somatic division allows us to sense and respond to our environment via sensory and motor nerves
What is the purpose of the autonomic division of the PNS.
To control the bodies internal environment and is involved with breathing, digestion, circulation etc
What are the two divisions of the autonomic division of the PNS
Parasympathetic- Inhibits, calms
Sympathetic- excites/activates
Give an example of interactions with the sympathetic and parasympathetic systems
If a fight or flight response is needed, the sympathetic system activates and increases heart rate. The parasympathetic system will then return things to hemostasis
What can test verbal and non-verbal behaviors
Neuropsychological tests
What is destruction and stimulation and why is it important
Opening up the skull of someone and stimulating the brain and seeing how the body reacts. This is done to provide insight to the brain and examine known areas of damage
What is an electroencephalogram (EEG)
They record electrical activity in the brain via a cap that has electrodes which pick up electron activity. We can use it to also study event-related potentials (ERP), which is how the brain changes in response to certain events
What is a computerized tomography (CT) scan
Uses x-rays to find the physical structure of the brain
What is a positron emission tomography (PET) scan
A person is injected with a harmless radioactive tracer and brain activity is traced
What is Magnetic resonance imaging (MRI)
Used to measure biological structures by measuring response to magnetic pulses (more high resolution anatomy)
What is a fMRI
Measure neural activity by detecting changes in magnetic response to hemoglobin
Where is the brain stem and what are its parts and purposes
The brain stem is closest to the spinal chord and it contains the medulla which modulates the heart and respiration and pons which regulate sleeping, dreaming, and respiration
What is the cerebellum
In charge of muscular movement (mostly reflexive/fast), coordination, learning/memory
What is in the hind brain
The brain stem and the cerebellum
What is reticular formation important for
Consciousness and attention
What do the ascending and descending parts of the mid brain do
The ascending part sends inputs to higher regions while the descending blocks off or admits signals
What are the parts of the forebrain and describe them
The thalamus which routes sensory info to other parts of the brain, the basal ganglia which controls voluntary movements and plays a role in learning/reward. Finally, the hypothalamus is important for controlling drives and with the pituitary gland, affects hormones
What are the parts of the limbic system and describe them
The hippocampus forms and retrieves memories, the amygdala organizes emotional response patterns (mostly aggression and fear), and the nucleus accumbens are associated with dopamine release and feelings of reward/motivation
What are the four lobs of the cerebral cortex
The frontal, occipital, parietal and temporal
Describe the frontal lobe
Involved with decision making, self-awareness, speech, skeletal motor function, and emotional regulation
Describe the parietal lobe
Body sensations, integrations of sensory information
Describe the temporal lobe
Contains the primary auditory cortex, complex visual processing, memory, language
Describe the occipital lobe
Contains the primary visual cortex (basic visual processing)
What is the primary motor cortex
Controls voluntary/complex movements and located near the frontal lobe
What is the somatic sensory cortex
Receives sensory input from various parts of the body and found in the parietal lobe
What does it mean to be contralateral in terms of the somatic sensory cortex and primary motor cortex
It means signals from one side of the body are received at the opposite side of the hemisphere
What is involved with touch
The somatic sensory cortex
Which senses aren’t specialized in areas of the cortex
Smell/taste
Describe association cortex
Areas of the brain that have no motor/sensory function and are involved in higher level cognition
Where is language production involved (talking)
Broca’s area (frontal lobe)
Where is language comprehension involved (understanding)
Wernicke’s area (temporal lobe)
What is neural plasticity
The ability for neurons to change structure/function over time(eg. as you get better at guitar, parts of your motor/sensory cortex change)
What is nerugenesis
Creation of new neurons, perhaps by decrease in stress or as exercise decreases
What separates the two hemispheres of the brain
The corpus callosum
What is lateralization
The tendency for some cognitive functions to be localized in one hemisphere.
What are split brain patients
Patients with no corpus callosum which can restrict presentation of stimuli to a specific hemisphere in these patients
