Chp 3.3: Nervous System

Question 1

What are the three major types of neurons?

Answer 1

Sensory Neurons, Motor Neurons, Interneurons

Question 2

Sensory neurons

Answer 2

Carry input messages from the sense organs to the spinal cord and brain

Question 3

Motor neurons

Answer 3

Transmit output impulses from the brain and spinal cord to the body’s muscles and organs

Question 4

Interneurons (4)

Answer 4

• Perform connective or associative functions within the nervous system
• Far outnumber sensory and motor neurons
• The activity of interneurons makes possible for the complexity of our higher mental functions, emotions, and behavioural capabilities

Question 5

What are the 2 major divisions of the nervous system?

Answer 5

• The Central Nervous System

- The Peripheral Nervous System

Question 6

The Central Nervous System

Answer 6

consisting of all the neurons in the brain and spinal cord

Question 7

The Peripheral Nervous System

Answer 7

Composed of all the neurons that connect the central nervous system with muscles, glands, and sensory receptors

Question 8

What are the 2 divisions of the Peripheral Nervous System?

Answer 8

• Somatic Nervous System

- Autonomic Nervous System

Question 9

Somatic Nervous System (4)

Answer 9

• Voluntary control of body movements
• Sensory and motor neurons bind to create nerves
• Transmit messages to sensory receptors
• Allow you to sense and respond to your environment

Question 10

What are the 2 divisions of the Autonomic Nervous System ?

Answer 10

1) Sympathetic nervous system

2) Parasympathetic nervous system

Question 11

Autonomic Nervous System (4)

Answer 11

• Controls glands & smooth muscles in body organs
• many involuntary bodily processes (e.g., heart rate, digestion)
  1) Sympathetic nervous system: Arouses body (‘fight or flight’) and acts as a centralized unit
  2) Parasympathetic nervous system: Slows down body processes (‘rest or digest’) and can operate more specifically

Question 12

What is the use of the sympathetic and parasympathetic nervous system working together?

Answer 12

the 2 divisions can maintain homeostasis.

Question 13

Spinal cord (2)

Answer 13

(Central Nervous System)

• Most nerves enter/leave through spinal cord
• Spinal reflexes do not involve brain

Question 14

The Brain (4)

Answer 14

• The most complex structure known
• The brain is the most active energy consumer of all your body organs
• The brain accounts for only about 2 percent of your total body weight, yet it consumes about 20 percent of the oxygen you use in a resting state
• The brain never rests; its rate of energy metabolism is relatively constant day and night

Question 15

Name 4 methods to study the brain.

Answer 15

• Neuropsychological Tests
• Destruction & Stimulation
• (Electrical Recording) Electroencephalography (EEG)
• (Brain Imaging) Functional magnetic resonance imaging (fMRI)

Question 16

Electroencephalography (EEG)

Answer 16

A non-invasive technique that, using many electrodes on the scalp, measures electrical activity from populations of many neurons in the brain.

Question 17

Pros and cons of Electroencephalography (EEG)

Answer 17

High temporal resolution, poor spatial resolution

Question 18

Functional magnetic resonance imaging (fMRI)

Answer 18

Variant of MRI.
-Measures localized patterns of brain activity.

-Activated neurons provoke increased blood flow, which can be quantified by measuring changes of oxygenated and deoxygenated blood to strong magnetic fields.

Question 19

Pros and cons of Functional magnetic resonance imaging (fMRI)

Answer 19

Okay temporal resolution, good spatial resolution

Question 20

Blood oxygen level-dependent (BOLD) signal

Answer 20

The ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain neurons that are most involved in a task