MEC322: Nervous System Flashcards
Which of the 11 body systems play the most important roles in maintaining homeostasis?
nervous system and endocrine system
What are the three basic functions of the nervous system?
detecting stimuli (sensory function); analyzing, integrating, and storing sensory information (integrative function); responding to integrative decisions (motor function).
What does CNS stand for?
Central nervous system
What does PNS stand for?
Peripheral nervous system
What is part of the CNS?
Brain
Spinal cord
What is part of the PNS?
Cranial nerves Spinal nerves Ganglia Enteric plexuses in small intestine Sensory receptors in skin
What are the two divisions of the peripheral nervous system?
Afferent- brings sensory info to CS
Efferent- carries motor commands from CNS to muscles glands etc
What are the subdivisions in the efferent division?
Somatic nervous system SNS
Automatic nervous system ANS
What does the SNS provide?
voluntary control over skeletal muscles
What does the ANS provide?
involuntary control of cardia and smooth muscle, and glands
What is a neuron cell?
cells specialised for nerve impulse conduction and provide most of the unique functions of the nervous system
e.g. sensing, thinking remembering, controlling muscle activity
What is a neuroglia cell?
they support, nourish and protect the neurons and maintain homeostasis in the interstitial fluid that bathes neurons
What are the three parts of a neuron?
Dendrites
Cell body
Single axon
What is the dendrite in a neuron?
main receiving or input region
What is the cell body in a neuron?
integration occurs here
What is the axon in a neuron?
output part
conducts nerve impulses towards another neuron, muscle fibre or gland cell
Structurally what are the three classifications of neuron?
multipolar, –|–o <
bipolar, -|-o– <
unipolar –o-|-
How are neurons classified functionally?
Sensory neurons
Motor neurons
Interneurons
What do sensory neurons do?
carry sensory info into the CNS
approx 10^6
What do motor neurons do?
carry info out of CNS to effectors (muscles and glands)
approx 500000
What do interneurons do?
located within the CNS between sensory and motor neurons
approx 20^9