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