Introduction to Nervous System Flashcards
What is the nervous system?
Mass of interconnecting cells possessing the properties of irritability and conductivity
What is irritability in the nervous system?
Response to a stimulus with the initiation of a nervous impulse
What is conductivity in the nervous system?
Transmission of a nervous impulse
What cells are involved in the nervous system?
Neurons
Glial Cells
What are neurons?
Structural and functional units of the nervous system carrying the impulse
What are glial cells?
Located in the CNS and associated with neurons; provide supportive function
What are the two parts of a neuron?
Cell body
Cell fibers
What is a group of cell bodies called within the CNS?
Nucleus
What is a group of cell bodies called within the PNS?
Ganglion
What is a dendrite?
Conducts nervous impulse towards the neuron cell body
What is an axon?
Conduts nervous impulse away from the neuron cell body
What is a dendritic axon?
Part of sensory neurons - pseudounipolar neurons of dorsal root ganglia
What is afferent?
Sensory (impulses to CNS)
What is efferent?
Motor (impulses away from CNS)
What is a group of fibers in the PNS?
Nerve
What is a group of fibers in the CNS?
Tract
What are the special sensations?
Vision
Hearing & Equilibrium
Taste (gustation)
Smell (olfaction)
What are the general sensations?
Touch Temperature Pain Pressure Proprioception
Define proprioception
Detection of position and movements of body via the stretch of muscles, ligaments, and tendons
What are the sensations of environmental changes?
Changes in basic sensations
Changes in spatial orientation
Changes in body function
Changes in internal environment
What is included in changes in internal environment?
Hydration
Internal temperature
Oxygen and electrolyte levels
Blood pressure
What are the structural divisions of the nervous system?
CNS
PNS
What are the functional divisions of the nervous system?
VNS
INS
How many pairs of cranial nerves are there?
12 pairs of spinal nerves
How many pairs of spinal nerves?
31 pairs of spinal nerves
What is the VNS functional division of the nervous system?
Voluntary Nervous system - voluntary areas of brain
Corticospinal and certain other spinal tracts
Cranial and spinal nerves (except those parts in INS)
What is the INS functional division of the nervous system?
Involuntary Nervous system
- involuntary areas of the brain and certain spinal tracts
Sympathetic (thoracolumbar) of ANS
Parasympathetic (craniosacral) of ANS
Describe the simplest sequence of function
Stimulus
Sensory Neuron
Motor Neuron
Effector
What are two types of sensory fibers?
Somatic Receptors
Visceral Receptors
What are three types of somatic receptors?
Teleceptors
Exteroceptors
Proprioceptors
What are two types of visceral receptors?
Interoceptors
Chemoreceptors
What are teleceptors?
Vision and hearing things that are distant
(SSA) special somatic afferent
What are exteroceptors?
Found in skin and deeper tissues of body wall Temperature Touch Pressure Pain Proprioception GSA (general somatic afferent)
What are proprioceptors?I
Found in skeletal muscles (muscle spindles) and tendons (golgi tendon apparatus) Detect position and movements of body via strength in muscles and tendons and stretch or compression in joints
GSA (general somatic afferent)
What are interoceptors?
In Viscera
Visceral sensations
Senses smoot muscle contraction and secretory activities of glands
GVA (general visceral afferent)
What are chemoreceptors?
In nasal and tongue mucosae - smell and taste
SVA (special visceral afferent)
What are the three types of motor fibers?
General Motor Fibers (skeletal)
Special Motor Fibers (skeletal muscles of branchial arches)
Visceral Motor Fibers (smooth muscle, cardiac muscle, glands)
What are general motor fibers?
Skeletal muscles
Run via spinal nerves from anterior horn of spinal cord
Run via certain cranial nerves from brain
GSE (general somatic efferent)
What are special motor fibers?
Skeletal muscles of branchial arches
(Mastication, facial expression, swallowing, phonation)
Run via certain cranial nerves from the brain
SVE (special visceral efferent)
What are visceral motor fibers?
Smooth muscle, cardiac muscle, glands
Run via spinal and autonomic nerves
Via certain cranial nerves
GVE (general visceral efferent)
What is the first neuron cell body in a chain in the CNS?
Preganglionic
What is the second cell body in chain in an autonomic ganglion in PNS?
Postganglionic