Chapter 3 Flashcards
What are neurons?
Specialized cells that make up the nervous system
What are the 3 main parts of a neuron?
Cell body (soma); dendrites; axon
What is the cell body (soma)?
Structures that keep the cell alive
What are the dendrites in a cell?
“Branches” from cell body, receive signals
What does the axon in the cell do?
Conducts electrical impulses away from the soma
What are the functions of glial cells?
Hold neurons in place; make and move nutrients; form Meylin Sheath; remove toxins
What is the blood-brain barrier? And what cell is it associated with?
Wall of blood vessels that are covered in glial cells that protect toxins from entering our brain as the spaces are slightly larger in the brain
What are the 2 basic functions of a neuron?
- Generate electricity (Create nerve impulses)
- Release chemicals (Communicate with other cells)
What are the 3 steps of neural impulses?
- At rest with electrical resting potential
- Stimulated and electrical charges (ions) flow across cell membrane
- Restore distribution of ions, cell at rest again
What is the charge of a neuron at resting potential?
Pos outside + Neg inside with a -70mV difference
What are the 2 main elements that give charge to a neuron?
Sodium (Na+) and Potassium (K+)
What is depolarization?
When the cell is stimulated and electrical charges (ions) flow across cell membrane
What are the different stages that a neural impulse goes through when activated?
Resting potential->action potential->refractory period-> resting potential
What is the All-or-None Law?
Action potentials occur at a uniform and maximal intensity, or they don’t occur at all
When the rate of cell firing is increased what happens?
More action potentials are created
What is a myelin sheath?
A fatty, whitish insulation layer derived from glial cells during development (insulates neurons)
What are the Nodes of Ranvier?
Places where the myelin is either extremely thin or absent; Allows conduction to “skip ahead”
What are synapses?
Functional (not physical) connections between neurons and their target
What are neurotransmitters?
Chemical substances that carry messages across the synapse to either excite other neurons, or inhibit their firing
What are the 2 basic functions of a neurotransmitter?
- Generate electricity
- Release chemicals
What are the 5 stages of chemical communication?
- Synthesis
- Storage
- Release
- Binding
- Deactivation
In chemical communication, what is the synthesis stage?
Chemical communications are made in the neuron
In chemical communication, what happens in the storage stage?
Chem comm. is held in the synaptic vesicles
In chemical communication, what happens in the release stage?
Chem com. is released into the synaptic space
In chemical communication, what happens in the binding stage?
Chem com. attach to receptor sites
In chemical communication, what happens in the deactivation stage?
Stops the neurotransmitter signal
What is the difference between an excitatory and inhibitory transmitter?
Excitatory - decrease resting potential of post-synaptic neuron; may even fire; depolarization
Inhibitory - increase resting potential of post-synaptic neuron; hyperpolarization
What is associated with the neurotransmitter glutamate?
Excitatory; expressed in the whole brain; control of behaviours (learning + memory)
What is associated with the neurotransmitter GABA?
Inhibitory; expressed in whole brain; control of behaviours (anxiety + motor control)
What is associated with the neurotransmitter acetylcholine?
Excitatory; function at synapses involved in muscle movement and memory; memory loss in Alzheimer’s disease
What is associated with the neurotransmitter norepinephrine?
Excitatory + inhibitory; involved in learning, memory, wakefulness, eating; depression + panic disorders
What is associated with the neurotransmitter serotonin?
Inhibitory (mostly); functions at various sites; mood, eating, sleep, arousal; depression
What is associated with the neurotransmitter dopamine?
Excitatory/Inhibitory; Functions at various sites; voluntary movement, learning, motivation, pleasure; depression, Parkinson’s disease, Schizophrenia
What are some methods of studying the brain?
Postmortem studies; studying live non-human animals; studying live humans (surgical techniques, brain imaging, etc.)
What are some features of neuropsychological tests? Plus an example of a type of test?
Looking at the brain to determine behaviour relations & measure verbal and non-verbal behaviours; Trail making test
What are the 3 parts of the brain?
Forebrain; midbrain; hindbrain
What is the forebrain?
Highly developed portion of the brain that has numerous functions
What does the midbrain control?
Reflex actions and voluntary movements
What does the hindbrain control?
Vital functions and coordinating movements
What are the 4 components of the hindbrain?
Brainstem; medulla; pons; cerebellum
What does the medulla do?
Controls heart activity and largely controls breathing, swallowing, and digestion; All sensory and motor nerve tracts ascend from the spinal cord and descend from the brain
What is the pons?
Relay station for signals of the nervous system
What does the pons do?
Regulates sleep and dreaming; controls muscles and glands in face and neck
What does the cerebellum?
Controls bodily coordination, balance, and muscle tone; Involved in procedural memory (motor skills)
Reticular formation, superior colliculi, and inferior colliculi are within what section/part of the brain?
Midbrain
What is the midbrain physically made of?
Grey matter; red nucleus, substantia nigra, ventral region
What is the superior colliculi involved in?
Involved in vision (especially visual reflexes)
What is associated with the inferior colliculi?
Involved in hearing
What is the reticular formation associated with? And where is it located?
Involved in regulation of consciousness (conscious awareness and control); regulates sleep, wakefulness, and attention; extends into hindbrain and lower forebrain
What are the 4 parts of the forebrain?
Thalamus; basal ganglia; hypothalamus; limbic system
Where is the thalamus? And what does it do?
Above the midbrain; like a relay station; visual, auditory, and body senses
What is the basal ganglia (voluntary)?
Collections of neurons crucial to motor function
What does the hypothalamus do? What system is it part of?
Regulates basic biological drives; endocrine system
What are the 3 main parts of the limbic system?
Hippocampus; amygdala; nucleus accumbens
What is the hippocampus main function?
Forming and retrieving memories
What is the amygdala associated with?
Emotions (esp. aggression and fear)
What is associated with the nucleus accumbens?
Reward and motivation; dopamine is important; cues for pleasure
What are the 4 lobes of the cerebral cortex?
Frontal; parietal; occipital; temporal
What is the Broca’s area associated with?
Speech formation
What is the Wernicke’s area associated with?
Speech understanding
The primary motor cortex (voluntary movement) is associated with what lobe of the brain?
Frontal lobe
The somatic sensory cortex (body sensations) is associated with what lobe of the brain?
Parietal
The primary visual cortex is associated with what lobe of the brain?
Occipital lobe
The primary auditory cortex (hearing) is associated with what lobe of the brain?
Temporal lobe
What animal has one of the lowest brain to body ratio?
Koala
