Wk5- The Peripheral Nervous System Flashcards
What are 3 key roles of the PNS?
- Links CNS to organs and limbs
- Transmits sensory information to CNS
- Carries motor commands from CNS to PNS muscles and tissues
What are the 2 divisions within the PNS?
- Sensory / Afferent
- Motor / efferent
(SAME)
Sensory / Afferent Division PNS
* Detects stimuli and transmits information to CNS
What are the 2 subdivisions
- Somatic: skin and musculoskeletal system
2. Visceral: internal organs
Motor / Efferent division of PNS
* Motor neurons convey motor instructions to different parts of the body.
What are the voluntary/ involuntary sub divisions?
- Somatic : voluntary motor functions activate skeletal muscles
- Visceral : Autonomic nervous system (ANS)
Involuntary functions
*sympathetic (fight/flight)
*parasympathetic (rest/digest)
Sensory receptors have different types of nerve endings. What are the 2 types?
- Free nerve ending : no specialised structure
2. Encapsulated nerve ending : enclosed special structure - highly sensitive for specificity
There are 8 classes of sensory receptors. 1.exteroceptors 2.interoceptors 3.proprioceptors 4.mechanoreceptor 5.thermoreceptors 6.nociceptors 7.photoreceptors 8.chemoreceptors What are their locations / functions?
- Exteroceptors (external surface of body)
- Interoceptors (internal inside vessels/organs)
- proprioceptors (inside muscles/ joints tendons for articulation body positioning)
- mechanoreceptors (touch/pressure/vibration)
- thermoreceptors (temperature up/down)
- nociceptors (pain- physical/ chemical damage/pain)
- photoreceptors (detect light/vision)
- chemoreceptors (detect chemicals- taste/smell)
The Autonomic Nervous System is the body’s auto pilot.
The ANS maintains homeostatic conditions in physiological systems. What are the 2 sub divisions?
- Sympathetic (fight/flight)
2. parasympathetic (rest/digest)
The ANS Sympathetic sub division ;
- rapidly prepares the body for s-/e-?
- promotes a-?
- uses 2 neurotransmitters A- and N-?
- Adrenaline /E- ?are released into the bloodstream
- Stress and exertion
- Alertness
- Acetylcholine ; norepinephrine
- Epinephrine
The ANS parasympathetic subdivision is responsible for normal body functions.
- promotes relaxation and r-?
- has much s- reactions
- uses 1 neurotransmitter A-?
- Rest
- Slower
- Acetylcholine
Effects of sympathetic division:
Vaso? in heart and skeletal muscle
D? of pupils
Increased heart ? and force of contraction
Inhibition of ? system
Increase in blood glucose and fatty acids
D? of bronchial tubes
Inhibition of ? secretion
Activation of hair follicle pili muscles = ?bumps
Increase blood tendency to clot
Vasodilation Dilation Rate Gastrointestinal Dilation Saliva Goose bumps
Effects of parasympathetic division:
Decrease of heart ? and force of contraction ? of pupils Stimulation of ? system function ? of bronchial tubes Increase in ? secretion Promotion of glycogen synthesis
Rate Constriction Gastrointestinal Constriction Saliva