Wk5- The Peripheral Nervous System

Question 1

What are 3 key roles of the PNS?

Answer 1

1. Links CNS to organs and limbs
2. Transmits sensory information to CNS
3. Carries motor commands from CNS to PNS muscles and tissues

Question 2

What are the 2 divisions within the PNS?

Answer 2

1. Sensory / Afferent
2. Motor / efferent
   (SAME)

Question 3

Sensory / Afferent Division PNS
* Detects stimuli and transmits information to CNS
What are the 2 subdivisions

Answer 3

1. Somatic: skin and musculoskeletal system

2. Visceral: internal organs

Question 4

Motor / Efferent division of PNS
* Motor neurons convey motor instructions to different parts of the body.
What are the voluntary/ involuntary sub divisions?

Answer 4

1. Somatic : voluntary motor functions activate skeletal muscles
2. Visceral : Autonomic nervous system (ANS)
   Involuntary functions
   *sympathetic (fight/flight)
   *parasympathetic (rest/digest)

Question 5

Sensory receptors have different types of nerve endings. What are the 2 types?

Answer 5

1. Free nerve ending : no specialised structure

2. Encapsulated nerve ending : enclosed special structure - highly sensitive for specificity

Question 6

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?

Answer 6

1. Exteroceptors (external surface of body)
2. Interoceptors (internal inside vessels/organs)
3. proprioceptors (inside muscles/ joints tendons for articulation body positioning)
4. mechanoreceptors (touch/pressure/vibration)
5. thermoreceptors (temperature up/down)
6. nociceptors (pain- physical/ chemical damage/pain)
7. photoreceptors (detect light/vision)
8. chemoreceptors (detect chemicals- taste/smell)

Question 7

The Autonomic Nervous System is the body’s auto pilot.

The ANS maintains homeostatic conditions in physiological systems. What are the 2 sub divisions?

Answer 7

1. Sympathetic (fight/flight)

2. parasympathetic (rest/digest)

Question 8

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

Answer 8

1. Stress and exertion
2. Alertness
3. Acetylcholine ; norepinephrine
4. Epinephrine

Question 9

The ANS parasympathetic subdivision is responsible for normal body functions.

• promotes relaxation and r-?
• has much s- reactions
• uses 1 neurotransmitter A-?

Answer 9

1. Rest
2. Slower
3. Acetylcholine

Question 10

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

Answer 10

Vasodilation 
Dilation 
Rate 
Gastrointestinal 
Dilation 
Saliva 
Goose bumps

Question 11

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

Answer 11

Rate 
Constriction 
Gastrointestinal 
Constriction 
Saliva