Your Nervous System

1
Your Nervous System

• Peripheral Nervous System

2
Engage

• As a class visit IQ Test Labs at
  www.intelligencetest.com/reflex/index.htm
• Select various students to come to the computer
  and test their skills on the different
  reflex/reaction tests. This website states that
  scientific tests have shown that reaction times
  to simple tasks have high correlations with g the
  general intelligence factor. Students should
  have fun attempting these reaction time games.

3
Explore

• Muscle Messages

4
Explain
Section 35-3
The Nervous System
is divided into
which consists of
that make up
which is divided into
5
PNS

• NERVES that connect the central nervous system to
  the rest of the body
• Motor Division impulses from CNS to muscles or
  glands
• Two Parts
• Somatic Nervous System
• Autonomic Nervous System
• Sensory Division transmits impulses from sense
  organs to CNS

6
Motor DivisionPNS
7
Somatic Nervous System

• Controls voluntary movement of the skeletal
  muscles

8
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 DivisionPNS
10
Sensory ReceptorsWRITE INFO ON CONCEPT MAP

• 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
• 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

• Nose and Tongue
• Chemical in external environment

15
Figure 35-14 The Eye
Section 35-4
16
5. Photoreceptors

• Eyes
• Sensitive to Light
• DO NOT WRITE NEXT INFO IT IS ON YOUR SHEET

17
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

18
Pathway for Vision Reception

• Light?
• cornea?
• iris and pupil?
• lens?
• Retina to photoreceptors?
• Rods
• Cones Fovea
• Optic Nerve?
• Brain

19
Figure 35-15 The Ear
Section 35-4
20
Hearing and Balance

• Ear
• Two Functions
• Hearing
• Detecting Positional change to movement

21
Hearing

• Sound air vibrations
• Auditory canal funnels air to tympanum (ear
  drum)
• Tymapnum 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

22
Balance

• Semicircular Canals
• 3 canals that form half circles
• Filled with fluid and hairs that detect motion of
  head in relation to gravity

23
Figure 35-15 The Ear
Section 35-4
24
Smell and Taste

• Chemoreceptors pick up chemical reception in nose
  and mouth
• Smell olfactory bulb
• Taste taste buds
• Salty
• Bitter
• Sour
• Sweet

25
The Senses of Smell and Taste
Section 35-4
26
Touch and Related Senses

• Largest sense organ?
• SKIN
• Sensory Receptors
• Temperature
• Touch
• Pain
• Greatest density of touch receptors
• Fingers
• Toes
• Face

27
Concept Map
Section 35-3
The Nervous System
is divided into
which consists of
that make up
which is divided into
28
Elaborate

• Reflex Arc Lab