5 The Nervous System

Question 1

What are the main components of the Central Nervous System?

Answer 1

brain and spinal cord

Question 2

What are the general functions of the nervous system?

Answer 2

1. sensory
   
   • detection and input
2. integrative
   
   • procsessing/storing/analyzing of sensory info
   • decision-making
3. motor
   
   • output

Question 3

What are the 2 types of nervous tissue cells?

Answer 3

neuroglia and neurons

Question 4

What are the general functions of neuroglia?

Answer 4

• support
• nourish
• protect

Question 5

What are the 3 parts of nerve cells?

Answer 5

dendrite, cell body, axon

Question 6

Describe a multipolar neuron and where they tend to be found in the body.

Answer 6

• several dendrites and one axon
• most neurons in the brain and spinal cord and all motor neurons

Question 7

Describe a bipolar neuron.

Answer 7

one main dendrite and one axon

Question 8

Describe unipolar neurons.

Answer 8

• peripheral axon has sensory receptors
• central axon has axon terminals
• all sensory neurons in the PNS are unipolar

Question 9

How are neurons functionally classified?

Answer 9

• sensory neurons
• motor neurons
• interneurons

Question 10

What are the two types of synapses?

Answer 10

electrical and chemical

Question 11

Define neurotransmitter.

Answer 11

a chemical released by the pre-synaptic neuron to affect (excite or inhibit) the post-synaptic neuron(s) or effector (muscle/gland)

NB: neurotransmitter (NT) receptors are specific to the NT released (think lock and key)

Question 12

How do electrical synapses work?

Answer 12

APs conduct directly between the plasma membranes of adjacent cells through gap junctions (faster than chemical; allows for syncyhronization of function)

Question 13

How do chemical synapses work?

Answer 13

• when the AP reaches the end of the pre-synaptic neruon, it causes the release of a neurotransmitter that diffuses across the synaptic cleft, binds to the post-synaptic neuron
• if the nuerotransmitter is excitatory, continuation of the AP is more likely
  if the nuerotransmitter is inhibitory, continuation of the AP is less likely
• chemical synapses are slower (than electrical)

Question 14

Are acetylcholine (ACh), dopamine, and seratonin neurotransmitters?

Answer 14

yes

Question 15

What are the four types of neuroglia of the CNS?

Answer 15

• astrocytes
• oligodendrocytes
• microglia
• ependymal cells

Question 16

What are the structures of the PNS?

Answer 16

• cranial nerves and their branches
• spinal nerves and their branches
• ganglia
• enteric plexuses
• sensory receptors

Question 17

Referencing the nervous system, what’s a:

• nucleus
• ganglion
• tract
• nerve

Answer 17

• nucleus: a cluster of neuronal cell bodies in the CNS
• ganglion: a cluster of neuronal cell bodies in the PNS
• tract: a bundle of axons in the CNS
  
  • tracts interconnect neurons in the spinal cord and brain
• nerve: a bundle of axons in the PNS
  
  • spinal nerves connect the spinal cord to the periphery
  • cranial nerves connect thye brain to the periphery

Question 18

What are the four structural parts of the bain?

Answer 18

• brain stem
• cerebellum
• diencephalon
• cerebrum

Question 19

What are the 3 regions of the brain stem?

Answer 19

• medulla oblongata
• pons
• midbrain

Question 20

This contains centres (necluei) for the control of heart rate, blood pressure, breathing, swallwing, and vomiting:

Answer 20

medulla oblongata

Question 21

Along with the medulla, this contains centres for the control of breathing:

Answer 21

pons

Question 22

This contains:

• centres for reflex visual activities (e.g. reading, tracking moving objects, scanning stationary objects), hearing
• nuclei called the substantia nigra – neurons that make dopamine extend from it

Answer 22

midbrain

Question 23

This is a net-like formation of neural tissue that spreads throughout the brain stem:

Answer 23

reticular formation

Question 24

The reticular formation contains the reticular activating system (RAS) which helps:

Answer 24

• consciousness
• maintain attention
• prevent sensory overload by filtering out insignificant information
• regulates muscle tone

Question 25

The hypothalamus, thalamus and epithalamus are located in which part of the brain?

Answer 25

diencephalon

Question 26

What are the major functions of the hypothalamus?

Answer 26

* major regulator of homeostasis * controls and integrates the autonomic nervous system * hormone production * emotion and behavious (with the limbic system) * eating, drinking * body temperature * circadian rhythm (a 24 hour cycle in the biochemical, physiological and/or behavioural processes of living things)

Question 27

What's the major function of the thalamus?

Answer 27

the major relay station for most sensory input to the cerebral cortex

Question 28

This is involved in smelling (especially emotional responses to smells). It also contains the pineal gland.

Answer 28

the epithalamus

Question 29

What functions does the white matter of the brain deal with?

Answer 29

contains areas that deal with complex functions like memory, emotions, reasoning, will, judgment, personality traits, intelligence

Question 30

What sorts of things is the basal ganglia (aka basal nuclei) responsible for?

Answer 30

* helps to regulate the starting and stopping of movements * helps control subconscious contraction of skeletal muscles * helps suppress unwanted movement * helps to set resting muscle tone * functionally, the basal ganglia are linked to the substantia nigra

Question 31

What are functions the limbic system is involved in and what parts of the brain does it include?

Answer 31

* involved in emotion, smelling and memory * it includes parts of the hypothalamus, the hippocampus, amygdala, and other nearby structures

Question 32

What are the main functions of the hippocampus?

Answer 32

* functions in memory (necoding, consolidation and retrieval) * very important in converting short term memory into long term memory)

Question 33

Anterior median ___ and posterior median \_\_\_

Answer 33

* anterior fissure * posterior sulcus