1. Peripheral Nervous System
Your Nervous System
Peripheral Nervous System

2. IQ Test Labs

3. Overview Section 35-3 The Nervous System is divided into
Central nervous system
Peripheral nervous system
Sensory nerves
Motor nerves
which consists of
that make up
Autonomic nervous system
Somatic nervous system
which is divided into
Sympathetic nervous system
Parasympathetic nervous system

4. PNS=peripheral nervous system
NERVES that connect the central nervous system to the rest of the body
Motor Division – impulses from CNS to muscles or endocrine glands
Two Parts:
Somatic Nervous System
Autonomic Nervous System
Sensory Division – transmits impulses from sense organs to CNS

5. Motor Division PNS

6. Somatic Nervous System
Controls voluntary movement of the skeletal muscles

7. Autonomic Nervous System
Controls involuntary actions
Subdivided into two system that have opposite effects on the same organs:
Parasympathetic – decreases heart rate
Controls internal organs during normal activity
Sympathetic – increases heart rate
Controls internal organs during high stress activity

9. Sensory Division PNS

10. Sensory Receptors
5 categories

11. 1. Pain Receptors Throughout body; except brain
Respond to chemical released by damaged cells
Important to recognize
Danger
Injury
Disease

12. 2. Thermoreceptors In skin, body core, hypothalamus
Hot
Cold
Vasodilation
Arterioles dilate (enlarge) so more blood enters capillaries in skin and heat is lost
Vasoconstriction
Arterioles get smaller to reduce blood going to skin and help the core of the body to warm
Sweating
Glands secrete sweat/water as hydrogen bonds in water are broken and water changes its form
Shivering
Rapid contraction and relaxation of skeletal muscles producing heat via respiration.
Pilorelaxation
Body hairs flatten
Body hair stands up on end
Stretching out
By opening up, the body increases surface area allowing heat to escape
Curling up
Make yourself smaller decreasing surface area; keeping heat in the body
In skin, body core, hypothalamus
Detect variations in body temperature

13. 3. Mechanoreceptors Skin, skeletal muscle, and inner ears Sensitive to
Touch
Pressure
Stretching of muscles
Sound
motion

14. 4. Chemoreceptors Smell and Taste
Nose and Tongue
Chemical in external environment
Chemoreceptors pick up chemical reception in nose and mouth
Smell – olfactory bulb
Taste – taste buds
Salty
Bitter
Sour
Sweet

15. 5. Photoreceptors--Vision
Cornea
Helps focus light
Filled with aqueous humor
Iris
Back of cornea
Colored part of eye
Pupil
Tiny muscles regulate the size
Regulates amount of light
Lens
Small muscles change its shape to focus on object near and far away
Behind lens eye filled with vitreous humor
Retina
Has photoreceptors
No photoreceptors where optic nerve passes through the back of the eye; blind spot
Two types
Rods – black and white
Cones – color

16. Pathway for Vision Reception
Light
cornea
iris and pupil
lens
Retina to photoreceptors
Rods
Cones – Fovea
Optic Nerve
Brain

17. Hearing and Balance Ear Two Functions Hearing
Detecting Positional change to movement

18. Hearing Sound – air vibrations
Auditory canal – funnels air to tympanum (ear drum)
Tympanum – vibrates
Hammer, Anvil, Stirrup- vibrate and transmit vibrations to oval window
Cochlea – filled with fluid and vibrations create pressure waves in the inner ear
Tiny hairs respond to waves and send messages to brain via the cochlear nerve
Semicircular Canals
3 canals that form half circles
Filled with fluid and hairs that detect motion of head in relation to gravity

19. Touch and Related Senses
Largest sense organ?
SKIN
Sensory Receptors
Temperature
Touch
Pain
Greatest density of touch receptors
Fingers
Toes
Face

20. Concept Map Section 35-3 The Nervous System is divided into
Central nervous system
Peripheral nervous system
Sensory nerves
Motor nerves
which consists of
that make up
Autonomic nervous system
Somatic nervous system
which is divided into
Sympathetic nervous system
Parasympathetic nervous system