Generating an AP
What is the function of an action potential?
it is a way for neurons to send signals; a means of log distance neural communication
What are the two types of refractory periods?
absolute refractory period and relative refractory period
What are the two types of postsynaptic potentials?
excitatory and inhibitory
the _____ _____ is the site of the conscious mind
Cerebral cortex is the site of the conscious mind. It is a thin, superficial layer of gray matter that encases the brain
- functions in: Self-awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding
____ matter: myelinated and nonmyelinated axons
Gray matter: short, nonmyelinated neurons and cell bodies
White matter: myelinated and nonmyelinated axon
What is resting membrane potential in mV?
-70mV
What cannot occur during a refractory period?
Refractory period: time in which neuron cannot trigger another AP
What does the CNS consist of?
brain and spinal cord
Each hemisphere is concerned with _____ side of body
Each hemisphere is concerned with the contralateral (opposite) side of the body.
- right side of the brain controls the left side of the body and vice versa
It explains why damage to one side of the brain results in functional impairment (like paralysis) on the opposite side of the body.
____ fissure seperates the brain into two hemispheres
Major Fissures:
Longitudinal fissure: Separates two hemispheres
Transverse cerebral fissure: Separates cerebrum and cerebellum
What ion rushes into during depolarization
Sodium (Na+) ion
absolute refractory period ensures that each action potential is a _____ event
Absolute refractory period: Ensures that each AP is an all-or-none event.
an EPSP brings a neuron ____ to AP threshold while an IPSP brings a neuron ____ to AP threshold
closer; farther
An EPSP is a local depolarization; it says "fire!"
An IPSP is a hyperpolarization; it says, "don't fire!"
There are three functional areas of the cerebral cortex: motor areas, sensory areas, and association areas. List the functions of at least 2 of them.
cerebral cortex contains three types of functional areas:
- Motor areas: control voluntary movement
- Sensory areas: conscious awareness of sensation
- Association areas: integrate diverse information
The term that describes that all muscles of body can be mapped to area on the cerebral cortex is...
somatotopy
What does the term repolarization mean?
The membrane returns to resting membrane potential (-70mV)
Only an exceptionally ____ stimulus could stimulate an AP during ______ refractory period.
Relative refractory period
◦ Threshold for AP generation is elevated
◦ Only exceptionally strong stimulus could stimulate an AP
Name the 4 out of the 5 lobes of the brain
frontal, parietal, temporal, occipital, and insula
- Insular lobe is buried under portions of temporal, parietal, and frontal lobes
The olfactory cortex and gustatory cortex are both found at the temporal lobe. What do they function in?
olfactory cortex: Involved in conscious awareness of odors
gustatory cortex: involved in taste perception
What is lateralization?
Lateralization: division of labor between hemispheres. Hemispheres are not identical.
Left hemisphere
Controls language, math, and logic
Right hemisphere
Visual-spatial skills, intuition, emotion, and artistic and musical skill
What does hyperpolarization mean, and what ion causes it?
hyperpolarization is a slight dip below resting voltage caused by an excessive K+ efflux
Rate of AP propagation depends on two factors. What are they?
- larger axon diameter: faster conduction
-Myelinated axons propagate APs faster
What lobe would contain the visual area?
occipital lobe; The occipital lobe contains the brain's visual areas, including the primary visual cortex, which processes information from the eyes.
What is the broca's area involved in?
The Broca's area directs muscles involved in motor activity of speech and other voluntary motor activities
What is spatial discrimination?
spatial discrimination: identification of body region being stimulated