Nervous System (without Brain)

Question 1

Sensory Impulses

Answer 1

• To monitor changes occurring inside and outside the body

- Changes = stimuli

Question 2

Interpretation

Answer 2

-To process and interpret sensory input and decide if action is needed

Question 3

Motor Output

Answer 3

• A response to integrated stimuli

- The response activates muscles or glands

Question 4

Central Nervous System vs. Peripheral Nervous System

Answer 4

• Central nervous system (CNS)
  - Brain
  - Spinal cord
  
  • Peripheral nervous system (PNS)
    
    • Nerves outside the brain and spinal cord
      
      • Spinal nerves (31 pairs)
      • Cranial nerves (12 pairs)

Question 5

Neurons

Answer 5

-also called nerve cells; cells of the nervous system that specialize in transmitting messages throughout the body

Question 6

Functions of Neurons

Answer 6

1. sensory (afferent) neurons
2. motor (efferent) neurons
3. interneurons

Question 7

Sensory Afferent Neurons

Answer 7

-carrying two or toward the center nurse that convey impulses to the CNS from sensory receptors

Question 8

Motor (Efferent)

Answer 8

-carrying away are from, carries impulses from the CNS to effector organs, the muscles, and glands

Question 9

Interneurons

Answer 9

-also called association neurons, they complete the pathway between afferent and efferent neurons

Question 10

Neurons (Structural)

Answer 10

• Classified by irritability (ability to respond to stimuli) and conductivity (ability to transmit an impulse)
• Multipolar neuron
• Bipolar neuron
• Unipolar neuron

Question 11

Multipolar, BiPolar, Unipolar

Answer 11

• multipolar neurons: several processes extending from the neuron
• bipolar neurons: neurons that have two processes, and axon and a dendrite
• unipolar neurons: a single process emerging from the cell body

Question 12

Factors that Affect Transmission

Answer 12

• Myelinated or unmyelinated
• Lack or excess of sodium and potassium
• amount of nodes of ranvier
• Number of poles

Question 13

Reflex Arc

Answer 13

1. Stimulus at distal end of a neuron
2. Receptor
3. Sensory Neuron
4. Spinal cord, Integration center (Interneuron)
5. Motor Neuron
6. Effector
7. Response
   • 2 Neuron Reflex Arc
     
     • Sensory straight to effector
     • Ex: Knee-Jerking

Question 14

Synapse

Answer 14

• Gap between the two neurons
• Makes sure that the impulse goes in the correct direction
• the region of communication between neurons, or a neuromuscular junction between a neuron and a muscle cell

Question 15

Salvatore Conduction

Answer 15

• The Impulses Jump
  
  • Fibers that have myelin sheaths conduct impulses much faster because the impulse leaps from node of rancher to node of ranvier along the length of the fiber
    
    • No electrical current can flow across an axon membrane that is insulated by fatty myelin

Question 16

Nissl Substance (Multipolar Neuron Diagram)

Answer 16

-Specialized rough endoplasmic reticulum

Question 17

Neurofibrils (Multipolar Neuron)

Answer 17

• Intermediate cytoskeleton

- Maintains cell shape

Question 18

Nucleus (Multipolar Neuron)

Answer 18

-Holds DNA and Chromosomes

Question 19

Mitochondria (Multipolar Neurons)

Answer 19

-Produces energy for the cell

Question 20

Dendrites (Multipolar Neurons)

Answer 20

-Conduct impulses toward the cell body

Question 21

Axons (Multipolar Neurons)

Answer 21

-conduct impulses away from the cell body

Question 22

Axon Terminals (Multipolar Neurons)

Answer 22

• contain vesicles with neurotransmitters

- separated from the next neuron by a gap

Question 23

Schwann Cells (Multipolar Neurons)

Answer 23

• produce myelin sheaths in jelly roll–like fashion

- Cannot conduct impulses

Question 24

Nodes of Ranvier (Multipolar Neurons)

Answer 24

• gaps in myelin sheath along the axon

- Help in Saltatory Conduction

Question 25

Axon Hillock (Multipolar Neurons)

Answer 25

-Attaches main axon to cell body

Question 26

Collateral Branch (Multipolar Neuron)

Answer 26

-Split in an axon that allows the impulse to travel to another area

Question 27

Neuroglial Cells

Answer 27

- non-neuronal tissue of the CNS that performs supportive and other functions - Also called glia - Support, insulate, and protect delicate neurons

Question 28

Astrocytes (Neuroglial Cell)

Answer 28

- star-shaped cells that make up most neural tissue - form a living barrier between capillaries and neurons - help to protect the neurons from harmful substances that might be in the blood

Question 29

Microglia (Neuroglial Cells)

Answer 29

- Spider-like phagocytes that monitor the Health of nearby neurons - dispose of debris - including dead brain cells and bacteria

Question 30

Ependymal Cells (Neuroglial)

Answer 30

- lines the central cavities of the brain and spinal cord | - fluid forms a protective cushion around the CNS

Question 31

Oligodendrocytes (Neuroglial Cells)

Answer 31

-flat extensions that wrap around neurons producing the myelin sheath

Question 32

Roles of the Nervous System

Answer 32

1. Sensory Impulses 2. Interpretation 3. Motor Output