FINAL: the NS organization

Question 1

What are the 3 main functions of the NS?

Answer 1

sensory, integrative, motor

Question 2

What is the sensory function of the NS?

Answer 2

• detect internal/external stimuli
• carry info to brain via sensory (afferent) neurons

Question 3

What is the integrative function of the NS?

Answer 3

• process sensory info
• analyze/decide responses
• neurons are called: interneurons

Question 4

What is the motor function of the NS?

Answer 4

• responding to integration decision
• motor (efferent) neurons carry info out of brain and spinal cord

Question 5

What is the CNS and what is its role?

Answer 5

• brain +spinal cord
• control center for entire NS
• process + integrate sensory info
• plan + coordinate responses to stimuli
• short term control over activities of other systems

Question 6

What is the PNS and what is its role?

Answer 6

• neural tissue outside CNS: cranial/spinal nerves
• links CNS w/ sense organs and other systems
• nerves have an afferent and efferent division

Question 7

The efferent (motor) portions of the PNS is subdivided into 2 systems:

Answer 7

• somatic NS (SNS)
• autonomic NS (ANS)

Question 8

What is the role of the SNS?

Answer 8

control skeletal m. contractions (voluntary + involuntary reflexes)

Question 9

How does the SNS convey info?

Answer 9

• sensory neurons: FROM cutaneous and special sense receptors primarily in head, body wall (trunk) and extremities (limbs) TO the CNS
• motor neurons: FROM CNS conduct impulses TO skeletal muscles
• 1 continuous myelinated neuron (from spinal cord to effector)
• release of ACh at effector (skeletal m.)

Question 10

What is the role of ANS?

Answer 10

visceral involuntary functions: smooth m., cardiac m., glandular activity

Question 11

How does the ANS convey info? Explain all the pathways to get to the effector(s)/blood.

Answer 11

• sensory: from receptors primarily in viscera (to the CNS)
• motor: CNS to smooth m., cardiac m., and glands
• motor has 2 pathways: sympathetic and parasympathetic
• Sympathetic (1st way): myelinated preganglionic neuron; autonomic ganglion (ACh released); unmyelinated postganglionic neuron; effectors (NE released)
• Sympathetic (2nd way): myelinated preganglionic neuron; adrenal medulla of adrenal gland (ACh released); synapse w/ chromaffin cells (release epinephrine and NE directly into blood vessel)
• Parasympathetic: myelinated preganglionic neuron; autonomic ganglion (ACh released); unmyelinated postsynaptic ganglion; effectors (ACh released)

Question 12

What are the 2 types of cells in the NS?

Answer 12

Neurons: nerve impulse connection
Neuroglia: support/protect NS

Question 13

What are the 3 types of neurons?

Answer 13

multipolar, bipolar, unipolar

Question 14

What are the types of neuroglia (glial cells) in the CNS?

Answer 14

Astrocytes: provide blood brain barrier
Oligodendrocytes: myelinate multiple axons
Microglia: wandering macrophages (remove toxins)
Ependymal cells: form blood CSF barrier (allow certain components of blood to go to CSF)

Question 15

What are the types of neuroglia in the PNS?

Answer 15

Satellite cells: surround neurons
Schwann cells: myelinate 1 neuron at a time