Peripheral Nervous System (PNS)

1
Peripheral Nervous System (PNS)

• All the nerves and associated cells that are not
  a part of the brain and the spinal cord
• Cranial nerves, spinal nerves, ganglia
• Sensory (afferent) sense organs to CNS
• Motor (efferent) CNS to the muscles or glands

2
Peripheral Nervous System (PNS)

• Somatic Nervous System regulates activities that
  are under conscious control
• Autonomic Nervous System regulates activities
  that are automatic, or involuntary
• Parasympathetic
• Sympathetic

3
(No Transcript)
4
Example Autonomic Nervous System
5
Physiological Effects of the Autonomic Nervous
System
6
The Senses

• Sensory Receptors located throughout the body
  but are concentrated in the sense organs
• Pain Receptors
• Thermoreceptors
• Mechanoreceptors
• Chemoreceptors
• Photoreceptors

7
Types of Sensory Receptors
8
The Senses

• Vision
• Hearing and Balance
• Smell
• Taste
• Touch and Related Senses

9
Vision

• Pupil small opening in the middle of the iris
  through which light enters the eye
• Lens transparent object behind the iris that
  changes shape to help adjust the eyes focus to
  see near or distant objects

10
Vision

• Retina innermost layer of the eye
• Rod photoreceptor in eye that is extremely
  sensitive to light
• Cone in the retina of the eye, a photoreceptor
  that responds to light of different colors,
  producing color vision

11
Hearing and Balance

• Cochlea fluid-filled part of the inner ear
  sends nerve impulses to the brain through the
  cochlear nerve
• Semicircular Canal one of three structures
  within the inner ear that help an organisms
  maintain balance

12
Smell and Taste

• Both an ability to detect chemicals
• Taste Bud sense organ that detects the flavor of
  a substance

13
Touch and Related Senses

• Your largest sense organ SKIN!
• Skin has sensory receptors that respond to
• Temperature
• Touch
• Pain
• The greatest density of touch receptors is found
  on your fingers, toes and face

14
Drugs That Affect The Synapse

• Stimulants
• Depressants
• Cocaine
• Opiates

• Marijuana
• Alcohol
• Alcohol and Disease

15
Stimulants

• Increase the actions regulated by the nervous
  system
• Increase heart rate
• Raise blood pressure
• Increase breathing rate
• Increase the number of neurotransmitters at some
  synapses in the brain
• Examples amphetamines, cocaine, nictotine,
  caffeine

16
Depressants

• Decrease the rate of functions regulated by the
  brain
• Decrease heart rate
• Decrease breathing rate
• Lower blood pressure
• Relax muscles
• Relieve tension
• Example alcohol

17
Cocaine

• Causes the sudden release in the brain of a
  neurotransmitter DOPAMINE
• Addiction uncontrollable craving for more of a
  drug
• Powerful stimulant

18
Cocaine
19
Opiates

• Opium poppy produces a powerful class of
  painkillers opiates
• Mimic natural chemicals in the brain known as
  endorphins, which normally help to overcome
  sensations of pain

20
Marijuana

• The most widely abused illegal drug
• Species of hemp plant
• THC active ingredient (tetrahydrocannabinol)

21
Alcohol

• One of the most dangerous and abused depressant
  drugs
• Slows down the rate at which the CNS functions
• Can lead to the DISEASE Alcoholism

22
Effects of Blood Alcohol Concentration
23
Psychoactive Drugs of Abuse
24
Drug Abuse

• Use of any drug in a way that most doctors would
  not approve