CNS
What are the components of the CNS?
1. Brain
2. Spinal cord
what are the components of the PNS?
Nerves! (cranial and spinal nerves)
This neuron is responsible for carrying impulses from sensory receptors to the CNS.
Sensory (afferent) neuron
what are the 4 major lobes of the brain?
1. frontal lobe
2. temporal lobe
3. occipital lobe
4. parietal lobe
What is the difference between white matter and gray matter?
white - myelinated nerve fibers
gray - unmyelinated nerve fibers
What are functions of the CNS?
1. sensory input (gathering info)
2. Integration (processing and interpreting sensory input to decide what to do)
3. motor output (response)
what is the difference between the spinal nerves and cranial nerves? (in other words: what do each of these sets of nerves do?)
spinal nerves carry impulses to and from the spinal cord whereas cranial nerves carry impulses to and from the brain
This neuron has one axon and one dendrite.
Bipolar neuron
What three structures make up the diencephalon?
1. thalamus
2. hypothalamus
3. epithalamus
These receptors allow us to sense touch.
Meissner's corpuscle
We discussed 4 types of glial cells that support the CNS. What are they?
1. astrocytes
2. microglia
3. ependymal cells
4. oligodendrocytes
What are the 2 types of glial cells that support the PNS?
1. Schwann cells
2. Satellite cells
These neurons are found in a three-neuron reflex arc (name them all).
1. sensory/afferent neuron 2. interneuron
3. motor/efferent neuron
This brain structure is involved in control of all of the following: heart rate, blood pressure, breathing, swallowing, vomiting
Medulla oblongata
Name the five elements of a reflex arc.
1. sensory receptor
2. sensory neuron
3. integration center
4. motor neuron
5. effector organ
Name & define 3 of the many brain dysfunctions we learned about in class.
1. concussion (brain injury from impact)
2. contusion (nervous tissue destruction, coma can occur with this)
3. intracranial hemorrhage (bleeding in the brain)
4. cerebral edema (swelling of the brain)
5. CVA/stroke (when blood circulation is blocked and brain tissue dies)
6. TIA (temporary restriction of blood flow/temporary blockage that typically resolves itself)
(cerebral palsy - disorder of movement/muscle tone, anencephaly - underdeveloped brain/incomplete skull, hydrocephalus - fluid build up in the brain, spina bifida - spinal cord issue)
How many pairs of spinal nerves & cranial nerves do we have?
31 pairs of spinal nerves & 12 pairs of cranial nerves
True/False: Neurons with myelinated axons produce faster conduction of impulses.
TRUE
This brain structure plays a role in our sleep/wake cycles.
Reticular formation or reticular activating system (RAS)
These are gaps in myelin sheath along an axon in the PNS.
Nodes of Ranvier
3 items (structures/substances) are responsible for protection of the brain and spinal cord specifically. What are these items & what do they do?
1. Meninges ("membranes" that provide a covering for the brain itself)
2. Cerebrospinal fluid (substance that cushions the brain tissue and spinal cord)
3. Blood-brain barrier (collection of tight junctions/capillaries preventing harmful substances from entering the brain)
Name the 12 pairs of cranial nerves. (You should know each of these & their basic function for the exam!) Remember the mnemonic (Oh, Oh, Oh To Touch And Feel Very Green Vegetables, AH)
1. olfactory 2. optic 3. oculomotor 4. trochlear 5. trigeminal 6. abducens 7. facial 8. vestibulocochlear 9. glossopharyngeal 10. vagus 11. accessory 12. hypoglossal
All neurons have these 3 MAJOR structures anatomically. What are they & what do they do?
1. cell body (nucleus & metabolic center of cell)
2. dendrite(s) (conduct impulses toward the cell body)
3. axon (conduct impulses away from the cell body)
This brain structure regulates voluntary motor activities by modifying instructions sent to skeletal muscles by the primary motor cortex (fine tuning of movements).
Basal nuclei
Name the steps in the process of generation & propagation of an action potential. (HINT: We discussed 6 steps & #1 is the membrane is polarized/in a resting state)
1. Cell membrane is in a resting state/polarized (cell's inside is more negative than outside)
2. Sodium ions diffuse into the cell (cell's inside is now more positive than outside)
3. Depolarization occurs if stimulus is strong enough (reaches threshold) & this results in the creation of an action potential
4. Action potential propagates (spreads along entire cell membrane)
5. Potassium ions diffuse out of the cell to restore the cell membrane (cell's inside is now more negative than outside just like in the beginning & we call this repolarization)
6. Initial cell conditions are fully restored by the Sodium-Potassium pump (3 Na+ out, 2 K+ in)