PERIPHERAL NERVOUS SYSTEM Flashcards
PNS
It is composed of a network of nerves that extend throughout the body.
Peripheral Nervous System
detect pain, heat, and pressure through the different receptors in the skin and send the signals to the spinal cord.
Sensory neurons or the afferent neurons
are small sacs of clustered neurons found outside the spinal cord which serve as receiving point of nerve impulses
Ganglia
are the basic units of the nervous system and comprise the PNS.
Neurons
control the contractions of the different muscle organs
Motor neurons or the efferent neurons
It is responsible for the voluntary movement of the muscles, organs and the reflex movement
Somatic Nervous System
carry information into and out of the brain stem.
Cranial nerves
carry sensory information into and motor commands out of the spinal cord
Spinal nerves
How many Cranial nerves are there?
12
How many Spinal nerves are there?
31
are sensory in terms of function, motor, or both.
Cranial nerves
12 Cranial Nerves
olfactory
oculomotor
trochlear
abducens
vestibulocochlear
hypoglossal
optic
trigeminal
facial
glossopharyngeal
vagus
spinal accessory
Transmits olfactory or data of smells to brain
Olfactory
Associated with vision
Optic
Controls eye muscles
Trochlear, Abducens
Associated with the area around the eyes, mandibles, and middle part of the face
Trigeminal
Movement of face, taste, neck and head
Facial
For equilibrium, balance, and sound
Vestibulocochlear
Associated with the tongue and the throat
Glossopharyngeal
Associated with the throat, ears, and tongue
Vagus
Controls neck muscles
Spinal Accessory
Associated with tongue muscles
Hypoglossal
are nerves associated with the spinal cord.
They are named based on which segment of the spine they are found in.
Spinal nerves
SNS is associated with skeletal muscles in order to provide voluntary and conscious control over these muscular movements.
Voluntary movements
. A reflex arc involves a reflex, which is an involuntary but fast response to stimuli that are detected.
Reflex Arcs
controls the involuntary movement of visceral muscles, cardiac muscles, smooth muscles, and glandular tissues.
Autonomic Nervous System
initiates the “fight or flight” response.
Sympathetic division
initiates the “rest and digest” response.
Parasympathetic division
It increases respiration and heart rate, release adrenaline, and decrease digestion.
Sympathetic division
It is associated with the lumbar and thoracic segments of the spinal cord.
Sympathetic division
It decreases respiration, increase digestion, and allow the elimination of wastes.
Parasympathetic division
It is associated with the cranial and sacral segments of the spinal cord.
