1. Christopher Reeve as Superman

2. Christopher Reeve as a super man

3. In a horseback riding accident..
Christopher Reeve severely damaged his ascending and descending spinal tracts at C3.
He was not able to breathe on his own
He was not able to move his arms or legs
He was not able to feel his arms or legs

4. But he could… See, hear, taste Feel and move his face and neck
Beat his heart
Digest food
Process waste
Have an erection
How?

5. What we have studied so far?
The somatic part of the nervous system has neurons that connect only to SKELETAL muscles
But skeletal muscles do not run the heart or digestion.

6. We place neurons into groups based on their function.
Some receive information and pass it to the brain.
Others send information from the brain to glands and muscles.
Figure 11.2
Central nervous system (CNS)
Brain and spinal cord
Integrative and control centers
Peripheral nervous system (PNS)
Cranial nerves and spinal nerves
Communication lines between the
CNS and the rest of the body
Parasympathetic
division
Conserves energy
Promotes house-
keeping functions
during rest
Motor (efferent) division
Motor nerve fibers
Conducts impulses from the CNS
to effectors (muscles and glands)
Sensory (afferent) division
Somatic and visceral sensory
nerve fibers
Conducts impulses from
receptors to the CNS
Somatic nervous
system
Somatic motor
(voluntary)
Conducts impulses
from the CNS to
skeletal muscles
Sympathetic division
Mobilizes body
systems during activity
Autonomic nervous
system (ANS)
Visceral motor
(involuntary)
cardiac muscles,
smooth muscles,
and glands
Structure
Function
Sensory (afferent)
division of PNS
Motor (efferent)
Somatic sensory
fiber
Visceral sensory fiber
Motor fiber of somatic nervous system
Skin
Stomach
Skeletal
muscle
Heart
Bladder
Parasympathetic motor fiber of ANS
Sympathetic motor fiber of ANS

8. Different neurons go to organs and glands
These neurons are part of the ANS Or
AUTONOMIC part of the Nervous System

9. Functions of ANS
These nerves act on glands, cardiac muscle, and smooth muscle
They do NOT act on skeletal muscles
These nerves control :
HR, BP, temp, digestion, waste elimination

10. Autonomic nervous system
Nerves called SYMPATHETIC nerves
Adjust body function for excitation
Increase heart rate
Turn off digestion
Nerves called Parasympathetic nerves
Adjust body function for resting and digesting
Decrease heart rate
Turn on digestion

11. Anatomy of the ANS The sensory pathway of the ANS uses
the spinal nerves to enter the spinal cord and
the sensory cranial nerves to enter the brainstem.

12. Anatomy of the ANS
The MOTOR pathway to the glands, heart, and smooth muscle.
This pathway needs TWO neurons to get there (instead of ONE like the PNS)
The motor neuron leaving the spinal cord synapses with another neuron in a GANGLIA. This neuron that sends an axon to the glands, heart or smooth muscle.

14. Somatic vs autonomic
Notice that the somatic nervous system has only one motor neuron going to an effector.
Notice that the autonomic nervous system (sympathetic and parasympathetic) needs 2 motor neurons to reach an effector.

15. ANS: Sympathetic part
Prepares the body for physical activity (exercise, excitement, embarrassment, emergency)
Increased heart beat
To provide more oxygen and glucose to cells of body
releases blood glucose from storage
To provide more sugar to cells of the body
Increases air flow to lungs
To allow more oxygen to be used for ATP production
Increases blood flow to heart and skeletal muscles
To allow more ATP production

19. ANS: Parasympathetic part
Has a calming effect on body functions that allow normal metabolic process to occur (digestion, defecation, diuresis)
Starts salivation
to break down food
Increases stomach intestinal movements
Starts urination and defecation
To eliminate wast
Stores food that has been eaten
For use when needed later
Slows heart rate
Less oxygen and nutrients needed by body while resting

23. Sympathetic &Parasympathetic ANATOMY
Compare the places they leave the CNS!
Sympathetic? Through spinal cord to ganglia, then to effectors.
Parasympathetic? Mainly avoids spinal cord by using cranial nerves, and goes to effectors.

24. Sympathetic and Parasympathetic ANATOMY
Compare the organs that the nerves extend towards. (p571 and 575)
Which are the same?
Different?

25. Dual innervation Antagonistic effects examples:
Parasympathetic: slows heart down
Sympathetic: speeds heart up
Parasympathetic: increases digestive motility
Sympathetic: decreases digestive motility

26. Single innervation Sympathetic nerves Sweating
Arector pili muscles (hair standing on end)
Constricts blood vessels, , blood pressure
Adrenalin release
Decreased urine output

27. In a horseback riding accident..
Christopher Reeve severely damaged his ascending and descending spinal tracts at C3.
He was not able to breathe on his own
He was not able to move his arms or legs
He was not able to feel his arms or legs

28. But he could… See, hear, taste Feel and move his face and neck
Beat his heart
Digest food
Process waste
Have an erection
How?

29. Through visceral reflexes!
Much of running the organs is reflex activity
digesting food
beating heart
raising and lowering blood pressure
Some visceral reflexes occur through cranial nerves
Some visceral reflexes occur through the spinal nerves