chapter 19 Flashcards
6 main areas of the brain
- medula oblongata
- pons
- midbrain
- cerebellum
- diencephalon
- telencephalon
the spinal cord
45 cm long 1 cm diameter
provides for two way flow of communication between brain and periphery via nerve tracts and sensory receptors
how many pairs of nerves in the PNS
31 pairs of spinal nerves
12 pairs of cranial nerves
afferent neurons enter spinal cord via ______ to transmit ________
dorsal root & sensory input
efferent signals return via __________ to the __________
anterior motor neurons & effector organ
the number of muscle fibers per motor neuron is related to a ___________
muscles function
motor unit
one motor neuron and the specific muscle fibers it innervates
motor neuron pool
collection of motor neurons that innervate a single muscle
interneuronal transmission is…
inhibitory or excitatory
neuromuscluar transmission is
always excitatory
types of channels that maintain resting membrane potential
- na/k pump
- voltage gated channels (na & k)
- transmitter gated channels
- slow leak Ca++ channel
inhibitory postsynaptic potentials
- NT is gaba and glycine
-hyperpolarizes the neuron and prevents the initiation of an action potential to occur
excitatory postsynaptic potentials
- NT is acetylcholine
- depolarizes the neuron and can create action potential if there is enough summation
gradation of force for muscle
- number of motor units recruited
- discharge frequency
- neuromuscular fatigue
muscle spindles provide:
information on fiber length and tension, and allows for adjustments in muscle tension or force
