Sem. 1 - Unit 2 Flashcards
neuron
nerve cells
cell body
the cell’s life-support control center
soma
cell body
dendrites
receive messages from other cells
axon
passes messages away from the cell body to other neurons, muscles, or glands
myelin sheath
covers the axon of some neurons and helps speed neural impulses
glial cells
“glue cells” - provides nutrients and insulating myelin, guides neural connections, and mop up ions and neurotransmitters
action potential
a neuron sends a message by firing an impulse, called the action potential
threshold (of excitation)
if excitatory signals exceed the inhibitory signals by a minimum intensity, or threshold, the combined signals trigger an action potential
resting potential
1.) Inside of the neuron is more negative compared to the outside.
2.) This negative charge is due to uneven distribution of ions (charged particles) like sodium (Na⁺) and potassium (K⁺).
3.) Sodium-potassium pumps move 3 Na⁺ ions out of the neuron and 2 K⁺ ions in, helping maintain this charge difference.
4.) The resting potential is typically around -70 millivolts (mV).
This electrical difference is crucial for the neuron to be ready to send signals when triggered.
In short, the resting potential keeps the neuron “charged” and ready to fire.
refractory period
Neurons need short breaks (a tiny fraction of an eyeblink). During a resting pause called the refractory period, subsequent action potentials cannot occur until the axon returns to its resting state. Then the neuron can fire again.
all-or-none response
a neuron’s reaction of either firing (with a full-strength response) or not firing.
How do we distinguish a gentle touch from a big hug? A strong stimulus can trigger more neurons to fire, and to fire more often. But it does not affect the action potential’s strength or speed.
depolarization
The loss of the inside/outside charge difference, called depolarization, causes the next section of axon channels to open, and then the next, like falling dominos. This temporary inflow of positive ions is the neural impulse—the action potential.
synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.
neurotransmitter
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
Acetylcholine (Ach)
Enables muscle action, learning, and memory
With Alzheimer’s disease, ACh-producing neurons deteriorate.
Adrenaline/Epinephrine
Dopamine
Influences movement, learning, attention, and emotion
Oversupply linked to schizophrenia. Undersupply linked to tremors and decreased mobility in Parkinson’s disease.
GABA
A major inhibitory neurotransmitter
Undersupply linked to seizures, tremors, and insomnia.
Glutamate
A major excitatory neurotransmitter; involved in memory
Oversupply can overstimulate the brain, producing migraines or seizures (which is why some people avoid MSG, monosodium glutamate, in food).
Norepinphrine
Helps control alertness and arousal
Undersupply can depress mood.
Oxytocin
Oxytocin is a hormone and neurotransmitter that plays a key role in social bonding, emotional regulation, and certain physiological processes.
Serotonin
Affects mood, hunger, sleep, and arousal
Undersupply linked to depression. Some drugs that raise serotonin levels are used to treat depression.
Substance P
involved in pain perception and inflammation
Reuptake
a neurotransmitter’s reabsorption by the sending neuron
Multiple Sclerosis
If the myelin sheath degenerates, multiple sclerosis results: Communication to muscles slows, with eventual loss of muscle control.
Myasthenia gravis
Myasthenia Gravis (MG) is a chronic autoimmune disorder that affects communication between nerves and muscles, leading to muscle weakness.
Reuptake inhibitors
blocks neurotransmitters from going back into the presynaptic neuron
endorphins
Neurotransmitters that influence the perception of pain or pleasure
Oversupply with opiate drugs can suppress the body’s natural endorphin supply.
endocrine system
is a network of glands and organs that produce, store, and release hormones, which are chemical messengers that regulate various body functions
includes the pituitary gland
agonists
a molecule that increases a neurotransmitter’s action
antagonists
decreases a neurotransmitters action by blocking production or release by increasing the production or release of neurotransmitters, or by blocking reuptake in the synspse
explain why psychologists are concerned with human biology
human biology is critical to psychology because it offers insights into how the brain and body work together to shape thoughts, feelings, and behaviors. This understanding allows psychologists to provide more effective treatments and interventions.
know the parts of the neuron and how neural impulses are generated
parts of a neuron:
1. cell body
2. dendrites
3. axon
4. axon terminals
5. myelin sheath
How neural impulses are generated:
1. resting potential
2. depolarization
3. action potential
4. repolarization
5. refractory period
6. return to resting potential
explain how specific neurotransmitters influence behavior and how drugs and other chemicals affect transmission
explain how nerve cells communicate with other nerve cells
- An action potential travels down the axon of the presynaptic neuron.
- At the axon terminal, the action potential triggers the release of neurotransmitters into the synaptic cleft.
- The neurotransmitters cross the synaptic cleft and bind to receptors on the postsynaptic neuron.
- Depending on the type of neurotransmitter, the postsynaptic neuron may become either excited or inhibited.
- If the postsynaptic neuron is sufficiently excited and reaches threshold, it generates a new action potential, passing the signal along.
nervous system
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
central nervous system (CNS)
brain and spinal cord
Peripheral nervous system (PNS)
Autonomic and somatic system
nerves
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.
sensory neurons
neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
motor neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
interneurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.
autonomic nervous system
he part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy.
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk response
reflex arc
the pathway that controls quick, automatic reactions, called reflexes, to certain stimuli. It allows your body to respond without thinking
endocrine system
The endocrine system is a collection of glands that produce and release hormones
hormones
Hormones are chemical messengers produced by glands in the endocrine system that travel through the bloodstream to target organs and tissues, regulating various bodily functions. They control processes like growth, metabolism, reproduction, mood, and more.
adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine gland
describe the functions of the nervous system’s main divisions, and what are the three main types of neurons
The CNS (brain and spinal cord) is the control center for processing information.
The PNS connects the CNS to the body and is responsible for voluntary (somatic) and involuntary (autonomic) actions.
The three main types of neurons are:
Sensory neurons: Carry information from the body to the CNS.
Motor neurons: Carry commands from the CNS to muscles and glands.
Interneurons: Process and relay information between sensory and motor neurons within the CNS.
brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.
cerebellum
ballerina balancing a bell on her head
the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
medulla (oblongata)
medals cover your hear and lungs
the base of the brainstem; controls heartbeat and breathing
pons
in the brain stem - helps coordinate movements and control sleep.
reticular formation
a diffuse network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum, and mediating the overall level of consciousness.
lesion
lesion is any abnormal damage or change in the tissue of an organism, often caused by injury, disease, or surgery.
EEG
MRI
fMRI
Thalamus
Hal and amus traffic cop sending the signals to be processed at different parts of the brain
the brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla. except smell
Limbic system
neural system (including the amygdala, hypothalamus, and hippocampus) located below the cerebral hemispheres; associated with emotions and drives
Amygdala
myg rhymes with wig which can be scary
fear and aggression in limbic system
Hypothalamus
hypo the llamas
part of limbic system that is in chsrge of homeostasis (hunger, thirst, body temp)
Hippocampus
hippo uses a compass to help him remember his way back home
part of lumbic system that controls memory
