Biology 12

Chapter 5 The Nervous System • MHR 163

CHAPTER 5 REVIEW

Summary of Expectations

Briefly explain each of the following points.

• An essential function of the nervous system is
  maintaining homeostasis in the body. (5.1)


• The human nervous system is composed of
  two parts, the central nervous system and the
  peripheral nervous system. (5.1)


• The fight-or-flight response to dangerous
  situations illustrates how the sympathetic
  nervous system regulates many essential
  physiological processes in the body. (5.1)


• The nervous system is composed largely of
  neurons, which are specialized body cells. (5.1)


• Reflex arcs are constructed to produce quick
  responses to certain stimuli without input
  from the brain. (5.1)


• The medulla oblongata is the region of the
  brain that is the primary control centre of the
  autonomic nervous system. (5.1)


• The cerebrum is the centre of human
  consciousness. (5.1)


• A nerve impulse is actually composed of a
  wave of electrical depolarization that travels
  down the cell membrane of a neuron. (5.2)


• The polarity of cell membranes of neurons is a
  result of unequal concentrations of positive
  ions on either side of the membrane. (5.2)


• The action of neurotransmitters determines
  the direction of nerve impulses travelling in
  the nervous system. (5.2)


• The all-or-none principle determines whether
  a particular stimulus will initiate a new nerve
  impulse in a stimulated neuron. (5.2)


• Even though all nerve impulses are essentially
  the same, the brain can still distinguish
  between weak and strong sensory stimuli, and
  between stimuli originating from different
  types of sensory structures and locations in
  the body. (5.1, 5.2)


• Schwann cells can repair some types of
  damage to nerve tissue. (5.2)


• A healthy eye is capable of focussing on and
  forming sharp images of both near and distant
  objects. (5.3)


• In bright light, we see clearly in colour. In low
  light, our colour vision is diminished. (5.3)


• The human ear is a multifaceted sensory
  structure that is sensitive to sound waves of
  various frequencies and that helps us maintain
  equilibrium. (5.3)
  
  
  • The skin is the largest sensory structure of the
    human body. (5.3)
  
  
  
  

Language of Biology

Write a sentence using each of the following words or

terms. Use any six terms in a concept map to show

your understanding of how they are related.

• central nervous system • Schwann cell


• peripheral nervous • node of Ranvier
  system • synapse


• autonomic nervous • presynaptic neuron
  system • postsynaptic neuron


• somatic nervous system • synaptic vesicle


• sympathetic nervous • excitatory response
  system • inhibitory response


• parasympathetic • cholinesterase
  nervous system • acetylcholine


• sensory nerve • noradrenaline


• motor nerve • glutamate


• reflex • GABA


• neuron • dopamine


• nerve • seratonin


• reflex arc • sclera


• cell body • cornea


• dendrite • conjunctiva


• axon • choroid layer


• wave of depolarization • iris


• medulla oblongata • pupil


• cardiac centre • ciliary body


• vasomotor centre • lens


• respiratory centre • suspensory ligament


• cerebellum • retina


• thalamus • rod


• hypothalamus • cone


• cerebrum • aqueous humour


• cerebral cortex • vitreous humour


• corpus callosum • accommodation


• frontal lobe • rhodopsin


• parietal lobe • pupillary reflex


• occipital lobe • fovea centralis


• temporal lobe • cataract


• resting potential • glaucoma


• neurotransmitters • myopia


• all-or-none principle • hyperopia


• action potential • astigmatism


• refractory period • mechanoreceptor


• myelin sheath • adaptation