1. Central Nervous System (CNS) Peripheral Nervous System (PNS)
The Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)

2. Do Now: Get Your Clicker! Contract a K-W-L chart on loose-leaf
List everything you already Know about the Nervous System in the K-column
List everything you Want to know in W-column

3. Functions Monitors internal and external environments
Integrates sensory information
Coordinates voluntary and involuntary responses of other organ systems
2 subdivisions:
CNS – brain and spinal cord
Intelligence, memory, emotion
PNS – all other neural tissue
sensory, motor

4. Receptors and Effectors
Receptors – receive sensory info
Afferent division – carries info from sensory receptors to the CNS
Efferent division – carries info from CNS to PNS effectors (muscles, glands, adipose)
Somatic Nervous System (SNS)
Controls skeletal muscles (voluntary)
Autonomic Nervous System (ANS)
Controls involuntary actions
Sympathetic Division (increase heart rate)
Parasympathetic Division (decreases heart rate)

6. Classwork:
Construct a flow chart detailing the direction in which information flows in the nervous system

7. The sensory part of the PNS is...
Somatic division
Sympathetic division
Parasympathetic
Afferent division
Efferent division
Control center

8. The fight or flight response is the...
Somatic division
Sympathetic division
Parasympathetic division
Afferent division
Efferent division
Control Center

9. A change in ambient temperature would be detected by
Somatic division
Sympathetic division
Afferent division
Efferent division
Control Center

10. Label Neuron
Read the functions to determine the structure of a typical neuron

11. Neurons Communicate w/other neurons Soma-Cell body
Dendrites - receive info
Axon- sends signal to synaptic terminals (terminal buds)
Synapse – site of neural communication (gap)
Myelin – fatty insulation
Node of Ranvier – exposed axon between myelin
3 structural types:
Multipolar – multiple dendrites & single axon (motor neurons)
Unipolar – continues dendrites & axon, cell body lies to side (sensory neurons)
Bipolar – one dendrite and one axon w/cell body between them (special senses)

12. Types of Neurons 3 functional types Sensory – afferent division
info about surrounding environment
position/movement skeletal muscles
digestive, resp, cardiovasc, urinary, reprod, taste, and pain
Motor – efferent division (response)
skeletal muscles
cardiac and smooth muscle, glands, adipose tissue
Interneurons
Brain and spinal cord - memory, planning, and learning

13. Neuroglia
Regulate environment around neurons; can be phagocytes; actively divide
Functions in CNS:
maintains the blood-brain barrier
create myelin (lipid) to coat axon
Nodes – gaps between myelinated sections
Internodes – areas covered in myelin
Phagocytic cells
Secrete cerebrospinal fluid (CSF)

14. The most common type of neuron is
multipolar
bipolar
unipolar

15. The part of the neuron that has receptor proteins on its surface is
Dendrites
soma
axon
Myelin sheath

16. The part of the neuron that increases the speed of transmission is the
Dendrites
soma
axon
Myelin sheath

17. Complete Action Potential POGIL
Remember:
Discuss each question and answer with your group
Use the information from the models to support your responses
You may use any resources to assist you

18. Membrane Potential Cells are polarized (measured in volts)
Resting potential of neuron -70mV
Remains stable due to Na+/K+ Pumps
Leak channels – always open (K+ diffuses out) K+
Proteins-
Net - charge
Na+
Cl-
Gated channels – open/closed under specific circumstance

19. Changes in Membrane Potential
Depolarization
Stimulus opens Na+ gated channels
increase +charge of cell towards 0mV
Action Potentials
Affects entire surface of cell membrane
(+) feedback as nerve impulse continues
Hyperpolarization
Stimulus opens K+ gated channels
Increases –charge (from -70mV to -80mV)
Restores resting potential

20. Action Potential: All or Nothing Principal
Only skeletal muscle fibers and neuron axons have excitable membranes
Graded potential increases pressure until sufficient enough to reach action potential
Resting potential (-70mV)
Reaches Threshold (-60mV)
Refractory Period – cell cannot respond to stimulation
Depolarization
Repolarization
Continuous Propagation
chain rxn until reaches cell memb
Unmyleinated – 1m/s (2mph)
Salatory Propagation
Myelinated (blocks flow of ions except at nodes)
Action potential jumps from node to node
18-40m/s (30-300mph)

21. Neural Communication
Nerve impulse – info moving in the form of action potentials along axons
At end of axon the action potential transfers to another neuron or effector cell by release of neurotransmitters from synaptic terminal (only occur in 1 direction)
Activity of neuron depends on balance between:
Excitatory neurotransmitters - depolorization
ACh & Norepinephrine
Inhibitory neurotransmitters -hyperpolarization
Dopamine, Seratonin, GABA

22. An excitatory neurotransmitter
Increases electrical impulse
Causes the release of more neurotransmitters
Is released in a synaptic cleft
All of the above

23. The resting membrane potential inside a neuron is
0mV
30mV
-60mV
-70mV

24. After stimulus, the rush of sodium ions into the cell is called
depolarization
repolarization
hyperpolarization

25. The action potential is propagated by
More Na+ rushing into the cell
K+ leaving the cell
Neurotransmitters binding to dendrite
Vesicles release neurotransmitters

26. The cell’s charge at the peak depolarization is
0mV
30mV
-60mV
-70mV

27. During repolarization
The resting potential is restored
K+ diffuse out of cell
The cell membrane becomes negatively charged again
All of the above

28. Once the action potential reaches the axon terminal, the signal will be carried to the next neuron by
Na+ ions
Neurotransmitters
K+ ions
All of the above

29. If an excitatory neurotransmitter binds to neuron number one, how will that affect the number of neurotransmitter released?
more
less
No effect at all

30. If previous neuron releases GABA, an inhibitory neurotransmitter, how will that affect neuron #2
Increase electrical stimulus
Decrease electrical stimulus
Increase neurotransmitters released
decreased neurotransmitters released
1&3
2&4
0 of 30

31. Reflexes
Reflex – involuntary response to stimulus w/o requiring the brain
Reflex arc- sensory neuron Interneuron motor neuron (opposes initial stimulus)
Ex. Knee jerk reflex
Babinski reflex (infants only)
Stroke sole of foot  toes fan out
Plantar reflex (adults only)
Stroke sole of foot toes curl
Signals sent to brain by interneurons allow for control
Ex. Toilet training, gag, blink

32. Testing reflexes activity