Somatic Reflexes Flashcards
prepare for the prelab quiz
What is the functional unit of the nervous system?
neuron
what does the neuron consist of?
cell body, dendrites, and axon
what is another name for the cell body of a neuron?
soma
what consists of the cell body in a neuron?
nucleus and metabolic center
what is the role of the axon?
transmits an impulse to another neuron or effector organ.
what is the axon often surrounded by?
an insulating myelin sheath
what does the myelin sheath do?
increases the speed of an impulse
how do neurons communicate with each other?
via synapses
what does the nervous system do?
coordinates all voluntary and involuntary actions and transmits signals to and from different parts pf the body.
where is the central nervous system located?
brain and spinal cord
what is the nervous system consisted of?
central nervous system and peripheral nervous system
peripheral nervous system
nerves that extend outside of the brain and spinal cord peripherally
what two subdivisions is the PNS divided into?
somatic nervous system (SNS) and Autonomic nervous system (ANS)
what does the SNS do?
innervates voluntary skeletal muscles and relays sensory information from the skin, muscles and joints.
what does the ANS do?
innervates glands and smooth cardiac muscle and relays sensory information as part of the sympathetic and parasympathetic nervous system
what are the neurons of the PNS?
sensory neuron and motor neuron
how is a spinal nerve of the PNS formed?
via a combination of both sensory neuron axons and motor neuron axons
what is a spinal nerve also known as? why?
mixed nerve because it contains both types of axons (sensory neuron axon and motor neuron axon)
how many paris of spinal nerves do humans have?
31 pairs
what are the regions of the vertebral column?
cervical(8) , thoracic (12), lumbar(5), sacral(5) and coccygeal (1).
what are the two ascending pathways?
spinothalamic tract and the dorsal column-medial lemniscal tract
what is the descending motor pathway?
corticospinal tract (pyramidal) and extrapyramidal
what are the 5 components of a reflux arc?
receptor, sensory neuron, integration center, motor neuron, and effector
what are types of refluxes?
autonomic reflux and somatic reflux
what are two types of somatic reflux arcs?
monosynaptic and polysynaptic
