Head & Neck Anatomy: Composition Of The Nervous System Flashcards
(22 cards)
The nervous system sends messages between the brain and parts of the body by means of
Chemical messengers and neurotransmitters
What is a nerve cell called? It is composed of a nucleus, dendrite, body and axon
Neuron
What branch off the body of the neuron and act like tiny antennae picking up signals from other cells
Dendrites
What is a thin long fiber that carries the signal
Axon
An axon is insulated by a ___ (fat tissue) made up of segments called ___ cells
Myelin sheath; Schwann cells
Gaps between adjacent Schwann cells are called
Nodes of Ranvier
*the impulses jump to the nodes and are conducted faster
Bundle of neurons that connect the body parts to the central nervous system
Nerves
Junction between two neurons, or between a neuron and an organ
Synapse
Collection of nerve cells outside the CNS
Ganglion
Central nervous system (CNS) is composed of
Brain and spinal cord
Peripheral nervous system (PNS) consists of
All nerves outside of the CNS
PNS is composed of __ and __ nervous system
Motor (efferent) and sensory (afferent)
Motor (efferent) ___ information to muscles and glands
Sends
Sensory (afferent): ___ information from peripheral parts and sends them to the CNS
Gathers
Motor (efferent) somatic nervous system controls __ responses
Voluntary
Motor (efferent) autonomic nervous system controls ___ responses
Involuntary
Autonomic nervous system is divided into what 2 subcategories
Parasympathetic and sympathetic
Fight or flight responses is correlated with the
Sympathetic nervous system
Rest and digest responses are associated with the
Parasympathetic nervous system
The sympathetic nervous system (fight or flight) ___ salivary and digestive function; ___ heart rate and blood pressure and dilates pupils
Reduces; raises
The parasympathetic nervous system (rest and digest) ___ digestive and salivary function, ___ blood pressure and heart rate
Increases; lowers
