exam 8 Flashcards
ch: 18-19
ultimately what does the nervous and endocrine system together do?
allows body functions to unify which allowed homeostasis to be maintained
what’s the nervous system?
made up of brain, spinal cord, and nerves
what’s the central nervous system?
structural and functional center of the entire nervous system and it consists of the brain and spinal cord
what does the central nervous system do?
combines pieces of info, evaluates it, and then initiates a response
what’s the peripheral nervous system?
consisted of nerve tissues in the outer regions of the nervous system
what are the two nerve pathways categorized by their direction
afferent and efferent
what’s an afferent division?
incoming sensory info
what’s an efferent divion?
outgoing sensory info
what’s the somatic nervous system?
regulates the skeletal muscles
what’s the autonomic nervous system?
carries info to mainly smooth muscles, cardiac muscle, glands, adipose tissue
what is the autonomic nervous system divided into?
sympathetic and parasympathetic divions
what’s the sympathetic division?
involved in preparing body to deal with immediate threats to internal environment
(fight or flight)
parasympathetic divions?
coordinates body’s typical resting activities
(rest and repair)
what are neurons? function
they conduct impulses that make all nervous system functions possible
what is the glia? function
support functions of neurons
what are the main types of glia?
- astrocytes
-microglia - epymendal cells
- oligodendrocytes
- schwaan cells
what are the types of nervous system cells?
neurons and glia
where are neurons found?
brain, spinal cord, and peripheral nerves
where are glial cells found?
throughout nervous system supporting neurons
which is most abundant neurons or the glia?
glial cells
what is an astrocyte?
star shaped and provide nutrients to neurons, regulate chem environment, and support BBB
what are oligodendrocytes?
they insulate axons in the CNS
what are microglia?
immune cells; defend against pathogens and remove debris
what are ependymal cells?
line ventricles of brain
where is the synaptic knob located?
at the end of an axon
how to describe a multipolar neuron?
single axon with multiple dendrites
how to describe a bipolar neuron?
single axon with a single higher branched dendrite
how to describe a unipolar neurons?
single process branches to form a central and peripheral process
what’s the function of multipolar neuron?
to process info and conduct impulses along motor pathways
what’s the function of a bipolar neuron?
conduct info along sensory pathways
what’s the function of a unipolar neurons?
conduct info along sensory pathways
example of multipolar neuron?
- motor neurons
- interneurons
example of bipolar neurons?
- olfactory system
- retina
examples of unipolar neurons?
- dorsal root ganglia of the spinal cord
what are the fastest nerve fibers in the body?
A-alpha fibers
how fast can A-alpha fibers conduct impulses?
120 m/s
what’s the reflex arc?
signal conduction route to and from the CNS that consisted of afferent and efferent neurons
what are the steps of the reflex arc? 5
- activation of sensory receptors
- transmission of sensory input
- integration of info in CNS
- transmission of motor output along efferent neurons
- response by effector organ
what’s the relationship between afferent and efferent?
it’s crucial to the reflex arc process.
afferent carries sensory info towards the CNS, while efferent transmit motor commands away from CNS
what is action potential?
membrane potential of an active neuron that’s conducting an impulse
what are the steps of action potential? 6
- stimulus triggers sodium channels and membrane depolarizes
- as threshhold potential releases sodium channels open
- as more sodium, enters the cell through sodium channels, the membrane continues to depolarize
- magnitude of action potential peaks at 30mV when sodium channels close
- repolarization begins when potassium channels open allowing outward diffusion of potassium
- RMP is restored by sodium potassium pump
what are neurotransmitters?
means by which neurons talk to one another
what is serotonin?
a neurotransmitter that helps memories remain long and in the brain
which neurotransmitters are fully excitatory?
glutamate
which neurotransmitters are fully inhibitory? 2
GABA
glycine
which neurotransmitters can be either? 3
- acetycholine
- epineephrine
- norpineephrine
which neurotransmitters are mostly excitatory? 2
- histamine
- substance P
which neurotransmitters are mostly inhibitory? 3
- serotonin
- dopamine
- endorphins
which antidepressant blocks MAOs?
phenelzine (nardil)
why do nervous system cells have trouble with regenerating?
- they don’t divide like other cells
- they also cant repair themselves effectively once damaged
- their environment doesn’t conduct regeneration
what’s the difference in sodium and potassium regarding action potential?
sodium involves depolarization while potassium involves hyperpolarization and repolarization
which membrane receptor changes with charge?
voltage-gated ion channels
