Flashcards in Final Deck (56)
Electrical impulses in nervous system
Information from tissues to CNS
No dendrites (only sensory receptor), unipolar neuron
Between sensory (afferent) and motor (efferent)
Within the spinal cord
Usually multipolar neuron
Nerve impulse from CNS to peripheral tissue
Somatic nervous system is under ___________ control of __________ muscle
Information about external environment in form of touch, temp, sight, smell, taste
Monitor the position and movement of skeletal muscle and joints
Monitor digestive, respiratory, cardiovascular, urinary, and reproduction
What two properties must a neuron have?
Excitability- ability to respond to a stimulus
Conductivity- ability to transmit a signal
What is the function of a neurotubule?
Intracellular transport of proteins and other substances in both directions between cell body and end the cell processes
What is a neurofilament?
Skeletal framework for the axon
Threadlike cytoplasmic projections which are actually extensions of the cell body
Conduct nerve impulses toward the cell body
A neuron axons originates from the____________
What is the site called where the nerve impulse is initiated and lies immediately after axon hillock
The fine extensions at the end of an axon are _____________ which end in tiny swellings called ___________________________
The junction between end bulb and the axon/cell body/dendrite
The lipid sheath surrounding a neuron is __________? Made up of ______________ cells in PNS and ____________ cells in CNS.
What is the purpose of this lipid sheath?
Increase speed of nerve impulses
What are the functional segments of a neuron
Initial segment -trigger zone for action potential
What facilitates slow axonal transport and what is being transported?
Peristaltic waves of axon membrane
Transport of materials necessary to maintain axon and dendrites
What facilitates fast axonal transport and what is carried?
Convey neurotransmitter vesicles down neurotubles, requires ATP
Anterograde or retrograde
Material transported form cell body along axon to axon terminal
Material returned to cell body where it is degraded or recycled.
Sensory fibers deliver info to CNS and motor fibers carry motor commands to peripheral effectors
Stimulus trigger production of a hormone which leads to a reduction in magnitude of a stimulus
Spinal cord is integrating center
eg. Contracting muscle pulls hand away form a painful stimulus
Negative control mechanism: corrective mechanism that opposes variation from normal limits
Sense stimulus and control output
Eg. Cranial nerve II (optic) detects light changes -> brainstem and cranial nerve III adjusts pupil diameter
Most simple reflex
Sensory neuron directly synapse on motor neuron
Sensory nerve ->spinal cord -> motor neuron -> effector organ
Large myelinated type A fibers
Eg. Oppose sudden changes in muscle fibe length (maintain normal skeletal muscle)
One or more interneurons synapse with sensory and motor neurons
Produce more complicated responses because the interneurons can control several different groups