Peripheral Nervous System Flashcards
PNS has two subdivisions…
… the Somatic NS (interact with you) and the Autonomic NS (regulate internal systems)
PNS
nerves outside the CNS with two subsystems
somatic nervous system
31 pairs Spinal Nerves (including Dorsal and Ventral Roots) and 12 pairs of Cranial Nerves
body’s interaction with external environment
Sensory/Motor
Spinal Nerves
31
Sensory mainly from body surfaces and FEEDBACK from skeletal muscles
Motor mainly to skeletal muscles
Cranial Nerves
12
Sensory (Vision, Audition, Tastes, Smell, Tactile for Face) and feedback from some organs (heart, lungs)
Motor control of eye movement, facial expression, chew and swallow, speech, neck muscles, some organs
Autonomic nervous system
regulates body’s internal environment
receives sensory input from organs, sends motor output to control them
can be broken into two subparts: sympathetic and parasympathetic
sympathetic nervous system
ganglia near?
fight or flight
prepares the body for action by increasing heart-rate, blood pressure, etc.
ganglia are NEAR SPINAL CORD, form a tightly-knit chain,
activity is tightly coordinated!!!!
most release NE, a few release ACh (to sweat glands)
parasympathetic nervous system
ganglia near?
para =?
relax/replenish system
Para = beyond, cells about/below Sympathetic cells
opposite effects from Sympathetic NS: fosters digestion, sex, etc…
ganglia not near Spinal Cord, but NEAR TARGET ORGANS
activity NOT coordinated
All release ACh
parasympathetic rebound
after a large amount of sympathetic activity it increases the parasympathetic response (overworking)
fucks everything: anxiety, fainting, immune system degradation, ulcers, death
Both ANS systems are always active…
….although in opposite proportions and their activity is COMPLEMENTARY
Sympathetic effect on:
1) eyes,
2) heart,
3) bronchi (lungs)
4) salivary glands,
5) stomach, intestines
6) bladder
7) genitals
1) dilate, inhibit tears
2) pump fast
3) open
4) inhibit salivation
5) halt activity of
6) hold
7) hinder sexual arousal (although required for orgasm)
Parasympathetic effect on:
1) eyes,
2) heart,
3) bronchi (lungs)
4) salivary glands,
5) stomach, intestines
6) bladder
7) genitals
1) constrict pupils, produce tears
2) pump slow
3) constrict
4) stimulate salivation
5) motility and secretion
6) empty
7) facilitate sexual arousal (erect, lubricate
Stimulated via Sympathetic system only
Adrenal glands and Sweat glands activated
Liver stimulated to release glucose
Blood vessels constrict to increase blood pressure
hair follicles pilo-erection
Parasympathetic Rebound
after radical Sympathetic response, Parasympathetic system gives strong response
> > fainting, ulcers (if cycle repeated), Voodoo Death?
