1. Human Systems Nervous System Integumentary System Skeletal System
Muscular System
Circulatory System

2. What is the function of the nervous system?
To receive
information from
a sensory neuron
To process
info. by the
brain & spinal cord
To respond by an
effectors (muscle/gland)

3. Neuron Nucleus Axon terminals Cell body Myelin sheath Dendrites Axon
nodes

4. Structure of Neurons Cell body Nucleus
Dendrites- carries impulses toward the cell body.
Axon- carries impulses away from the body.
Myelin sheath- covers part of some axons.
Synapse: at the end of the axon

5. The Synapse
The location at which a neuron can transfer an impulse to another cell.

6. Two connecting neurons:
Axon ending
Impulse direction
Dendrite of
new neuron
Axon
Cell Body

7. STOP Here

8. The Central Nervous System:
1) Spinal Cord
2) Brain
medulla for
breathing
cerebellum for
balance
cerebrum for
higher thinking bw

9. Divisions of the Nervous System- The nervous system has two major divisions:
central nervous system
peripheral nervous system

10. b. processes information c. analyzes information
The central nervous system- is made up of the brain and the spinal cord.
Functions:
a. sends messages
b. processes information
c. analyzes information

11. The brain- is the place to which impulses
flow and from which impulses originate.
The brain contains approximately 100
billion neurons

12. Regions of the Brain i. The cerebrum- controls voluntary actions.
ii. The cerebellum- coordinates involuntary actions.
iii. The brain stem- controls basic body functions.
iv. The thalamus- receives impulses from the senses and sends them to the cerebrum.
v. The hypothalamus- connects the nervous and endocrine systems.

13. The spinal cord- connects the brain with
the rest of the body. Some reflexes are
processed in the spinal cord.
a. Reflex- is a quick automatic response
to stimulus.

14. Cerebral Cortex= higher thinking

15. Parts of the Cerebrum

16. Cerebellum & “old brain” controls basic body functions

17. Right versus left Cerebrum

18. Infrared Tools to Study the brain . . . .

19. Multiple Sclerosis (MS)
Autoimmune disease
Myelin sheaths destroyed  reduced to hardened lesions (scleroses)
Blindness, muscle weakness, speech disturbance, urinary incontinence
Treatment: interferons, glatiramer (hold off attacks)

21. Any blow to the head does brain damage Example of amnesia & processing skills

23. from the sensory neurons to the central nervous system.
The peripheral nervous system- transmits impulses from sense organs to the central nervous system and back to muscles or glands.
The sensory division- sends impulses
from the sensory neurons to the
central nervous system.
The motor division- sends impulses
from the central nervous system to
muscles and glands.
somatic- control voluntary actions.
autonomic- regulates activity that are automatic.

24. The 2 types of nervous responses
a. Voluntary or Somatic System that use
the brain &
spinal cord
b. Involuntary or
Autonomic System
Sympathetic (Fight or Flight)
Parasympathetic (Rest and Digest)

25. 2c. Effectors that do actions are the
Muscles =
voluntary use the somatic system
involuntary use autonomic
system
Glands =
make hormone messengers

26. The involuntary system: Autonomic basic body functions & reflex arcs

27. The Autonomic Nervous System

30. Reflexes Rapid, predictable, involuntary responses to stimuli
Somatic Reflexes: stimulate skeletal muscles
Eg. jerking away hand from hot object
Autonomic Reflexes: regulate smooth muscles, heart, glands
Eg. salivation, digestion, blood pressure, sweating

31. Reflex Arc (neural pathway)
Five elements:
Receptor – reacts to stimulus
Sensory neuron
CNS integration center
Motor neuron
Effector organ – muscle or gland

33. Patellar (Knee-jerk) Reflex
Reflex Activities
Pupillary Reflex
Patellar (Knee-jerk) Reflex
Stretch reflex
Tapping patellar ligament causes quadriceps to contract  knee extends
Help maintain muscle tone, posture, & balance
Optic nerve  brain stem  muscles constrict pupil
Useful for checking brain stem function and drug use

34. Flexor (withdrawal) reflex:
painful stimulus  withdrawal of threatened body part
Pin prick
Plantar reflex:
draw object down sole of foot  curling of toes
Babinski’s sign: check to see if motor cortex or corticospinal tract is damaged

35. Reflex = Involuntary Reaction
Voluntary Reactions
More neurons and synapses are involved  longer response times
Reflex = Involuntary Reaction
Voluntary Reaction