Chapter 2 Flashcards
Nervous System
A network of specialized cells that carry information to and from parts of the body.
Neuroscience
A branch of the life sciences that deals with the structure and functioning of the brain and the neurons, nerves, and nervous tissue that form the nervous system.
Relating to behavior and mental process.
Neurons
Specialized cell of the nervous system that receives and sends messages within that system.
Types: Sensory (afferent), motor (efferent)
Parts: dendrites, soma, and axon
Dendrites
“tree-like” or “branch” structure that are attached to the cell body (soma) and receives messages.
Soma
The part of the cell that contains the nucleus and keeps the entire cell alive and functioning. Also called the cell body.
Axon
A fiber attached to the soma, and its job is to carry messages out to other cells.
Glial Cells
Grey fatty cells;The second type of primary cells with a variety of functions including:
- Provide support
- Produce myelin
- Serving as a structure on which the neurons develop and work and that hold the neurons in place
- Getting nutrients to the neurons
- Cleaning up the remains of neurons that have died
- Communicating with neurons and other glial cells
- Proving insulation for neurons
Sensory (afferent) Neurons
Sense organs to CNS.
Motor (efferent) Neurons
CNS to body- muscles and glands.
Ions
Charged particles located inside(-) and outside(+) of a cell (most are positively charged due to diffusion).
Diffusion
The process of ions moving from areas of high concentration to ares of low concentration, and electrostatic pressure, the relative electrical charges when the ions are at rest.
Resting Potential
When the cell is resting, the electrical potential is at a state of rest.
Sodium atoms cannot enter at this time because the particular channels for big sodium ions aren’t open yet.
Action Potential
Electrical charge reversal where the electrical potential is now in action and each action potential sequence takes about one thousandth of a second (neural message travels very fast).
Now cell is positive on inside and negative on outside.
Neural impulse where sodium ion enter the cell change.
All-or-none
When a neuron fires at full strength or not at all.
There is no “in-between” or “partial” firing.
Excitatory Neurotransmitter
Tells next cell to FIRE.
Inhibitory Neurotransmitter
Tells next cell to STOP.
Neurotransmitters
Inside the synaptic vesicles are chemicals suspended in fluid, which are molecules of substances.
They are inside a neuron and they are going to transmit a message.
Synapse (synaptic gap)
Space between the axon terminal and the dendrite that allow sodium ions to rush in.
Receptor Sites
.
Excitatory synapses
.
Inhibitory synapses
.
Antagonist
A chemical substance that blocks or reduces the effects of a neurotransmitter.
Agonists
A chemical substance that mimics or enhances the effects of a neurotransmitter.
Acetycholine
Muscle action, learning, & memory
Excitatory or inhibitory; involved in arousal, attention, memory, and controls muscle contractions
Dopamine
Movement, attention, & learning.
Excitatory or inhibitory; involved in control of movement and sensations.
Serotonin
Regulation of mood, sleep, arousal.
Excitatory to inhibitory; involved in sleep, mood, anxiety, and appetite.
Norepinephrine
Control of alertness & wakefulness.
Mainly excitatory; involved in arousal and mood.
Gaba-aminobutyric acid (GABA)
Major inhibitory NT, associated w/sleep & eating disorders.
Major inhibitory neurotransmitter; involved in sleep and inhibits movement.
- Acetylcholine
- Dopamine
- Serotonin
- Norepinephrine
- GABA
A. Regulation of mood, sleep, arousal
B. Muscle action, learning, & memory
C. Control of alertness & wakefulness
D. Major inhibitory NT, associated w/sleep & eating disorders
E. Movement, attention, & learning
- B
- E
- A
- C
- D
The Somatic Nervous System
Carries sensory information and controls movement of the skeletal muscles.
PNS-voluntary action
Sensory System (afferent)
Compromises all the nerves carrying messages from senses to CNS.
Motor System (efferent)
All of the nerves carrying messages from CNS to the voluntary or skeletal muscles and glands of the body.
The Autonomic Nervous System
Automatically regulars glands, internal organs and blood vessels, pupil dilation, digestion, and blood pressure.
Divided into two systems:sympathetic division and parasympathetic division
PNS- involuntary actions
Sympathetic Division
Prepares the body to react and expend energy in times of stress. “fight or flight”
*dilates pupil and stimulates tear glands, decreases salivation, increases heart, dilates bronchi, decreases digestive functions of stomach, pancreas, and intestines, and inhibits bladder contract.
Parasympathetic Division
Maintains body functions under ordinary conditions; saves energy.
*Constricts pupil and inhibits tear glands, slows heart, increases salivation, constricts bronchi, increases digestive functions of stomach, pancreas and intestines, and allows bladder contraction.
The Central Nervous System
Composed of the brain and spinal cord which are composed of neurons and glial cells that control the life-sustaining functions of the body as well as thought, emotion, and behavior.
Deep Lesioning
.
Electrical Stimulation of the brain (ESB)
Simulating a specific area of the brain, but no neurons are damaged. Causes neurons to react as if they had received a message.
Human Brain Damage
Clinical study
Electroencephalograph (EEG)
Device used to study the activity of the living brain by recording electrical activity of the cortex just below the skull.
Computed Tomography (CT)
Involves mapping “slices” of the brain by computer.
Can show stroke damage, tumors, injuries, and abnormal brain structure. Can see when there is metal in the body and is useful for imaging possible skull fractures.
Magnetic Resonance Imaging (MRI)
Allows doctors to see effects of small strokes.
Placed inside a machine that generates a powerful magnetic field to align hydrogen atoms in the brain tissues then radio pulses are used to make the atoms spin at a particular frequency and direction.
Functional MRI (fMRI)
The computer tracks changes in the oxygen levels of the blood, providing information on the brain’s functions as well.
Can identify what parts of the brain are active during specific tasks.
Positron Emission Tomography (PET)
The person is injected with a radioactive glucose; the computer detects the activity of the brain cells by looking at which cells are using up the radioactive glucose and projecting the image of that activity onto a monitor.
Uses different colors to indicate different levels of brain activity, with lighter colors indicating great activity.
The Brain Stem
.
Medulla
Part of the hindbrain that controls heartbeat, breathing, and swallowing.
Life-sustaining functions
Pons
Part of the hindbrain that relays messages between the cerebellum and the cortex.
Alertness, coordination, and arousal.
Reticular Formation (RF)
A system of nerves running from the hindbrain and through the midbrain to the cerebral cortex, controlling arousal and attention (selective).
Cerebellum
Part of the hindbrain that controls balance and maintains muscle coordination.
Movement.
Structures Under the Cortex
.
Limbic System
Involved in learning, emotions, memory, and motivation.
Includes thalamus, hypothalamus, hippocampus, amygdala, and the cingulate cortex.
Thalamus
Part of the forebrain that relays information from sensory organs to the cerebral cortex.
Relay station.