The Nervous System Flashcards
At the Resting membrane potential, the inside if a neuron is _______ compared to the outside?
Negative. There are more Na atoms outside the cell than K.
What type of cell produced myelin?
Oligodendrocytes in the CNS
Schwann cells in the PNS
When depolarization occurs, what happens to the membrane potential?
Na atoms flood the cell using Na channels, creating a positive membrane potential.
What occurs to the membrane potential during repolarization?
K atoms leave the inside of the cell using K channels, restoring the negative membrane potential. There is an overshoot, called hyperpolarization, and the cell then returns back to its normal membrane potential.
What’s the difference between an absolute and relative refractory period?
Absolute- no amount of stimulation will cause an action potential to occur
Relative- greater than normal amount of stimulation must occur to cause an action potential.
What is saltatory conduction?
The process of an electrochemical signal (an action potential) hopping from node to node down an axon.
Afferent neurons carry info from _____ to _____.
From the PNS to the CNS
Efferent neurons carry information from _____ to ______.
From CNS to PNS
White/gray matter of the brain is un/myelinated?
White=unmyelinated axons
Gray=myelinated axons (but unmyelinated cell bodies and dendrites)
The forebrain is divided into what two parts?
The telencephalon and the diencephalon.
The cerebral cortex is made up of what type of matter?
Gray matter, and is responsible for high level though and planning.
The diencephalon is composed of what two parts of the brain?
The thalamus and hypothalamus.
What is the role of the midbrain?
To act as an intermediate-relays sensory and visual info to the forebrain, and motor info from the forebrain to the hindbrain.
What structures make up the hindbrain?
The cerebellum, medulla, pons, which all make up the brainstem.
What 4 sections is the spinal cord divided into?
Cervical, thoracic, lumbar, and sacral.
What type of cells bring sensory info from the PNS to the dorsal side of the spinal cord?
Dorsal root ganglia.
Motor neurons exit the spinal cord dorsally or ventrally?
Ventrally
Reflexes function from what part of the PNS?
Somatic (voluntary) nervous system
The knee jerk reflex is an example of what type of reflex arc?
Monosynaptic-single synapse
The withdrawal reflex is an example of what type of reflex arc?
Polysnaptic-at least one inter neuron between sensory and motor neuron
Which one of the 12 cranial nerves is responsible for parasympathetic effects in much of the thoracic and abdominal cavities?
The vagus nerve
What neurotransmitter does the parasympathetic nervous system use?
Acetylcholine
What neurotransmitter does the sympathetic nervous system use?
Presynaptic ganglia use acetylcholine/EPINEPHRINE while post synaptic ganglia use NOREPINEPHRINE.
What type of receptor monitors the internal environment, such as blood volume, blood pH, or ppCO2?
Interoreceptors
