Unit 1 - Nervous Systems Pt1 Flashcards
(20 cards)
What is the difference between the nervous system and the endocrine system?
Nervous:
Uses electrical charge to carry messages
Allows system to react quickly but effect is short
Endo:
Uses chemicals to carry messages
Hormones secreted directly into blood
Travel long distances - body reacts slowly but activity is sustained
What is included in the nervous system?
Brain, spinal cord, nerves, ganglia, and special sense organs
What is the function of the nervous system?
Regulation + coordination of body activities, detection of changes both int + ext, consciousness and learning
What is included in the CNS?
Brain + spinal cord
What is included in the PNS?
Nerves that link the CNS with the rest of the body
What are the three basic functions?
sensory, integrating, motor
What do the 3 basic functions do? (sensory, integrating, motor)
sensory - senses changed int/ext of body, conveys info to brain+spinal cord
Integrating - sensory info received is analysed, stored and integrated to prod. a response
Motor - the response ex. muscles moving away or prod. glandular secretions
What can neurons and neuroglia also be called?
Neurons - nerve cells
Neuroglia - glia
What are the functions of neurons and neuroglia
Neurons - conduct nerve impulses
neuroglia - protect and support neurons
What does the basic structural unit - the neuron, do?
- monitor changes in int + ext enviro
- convert stimuli to nerve impulses
-conduct these impulses to other neurons, muscle cells or gland cells
What are neuroglia? what do they do?
special CT of nervous tissue
insulate, nourish, support and protect neurons
What are the 3 basic parts of a neuron?
Cell body, dendrites, Axon
Describe the cell body of a neuron
AKA soma or perikaryon
Has a nucleus + cytoplasm, contains normal cellular organelles
Describe what dendrites are of a nerve body
High branched, short, numerous cell processes
Func - receives stimuli from other neurons + may be modified as sensory receptors for heat, stretch, pressure
brings impulses towards the bod
Describe what the axon of the cell body is
A single process
conducts nerve impulses away from cell body to other cells, (nerve, muscle, gland cells)
A single axon is called a nerve fiber
Bundles of axons are called Tracts (CNS) and Nerves (outside CNS)
can be very long
What is myelin?
Cell membrane of glial cells tightly wrapped around axon
Schwann cells in the PNS
Oligodendrocytes in the CNS
Is an insulator that speeds conduction of impulses along axon
Myelin is white; nervous tissue which contains lots of myelinated axons is white matter, no myelin is gray matter
Which direction of impulse is Afferent and Efferent?
Afferent (Sensory) towards CNS
Efferent (Motor) away from CNS
Describe the somatic nervous system - conscious
Somatic motor func voluntary control of skeletal muscles ex movement
Somatic sensory func information consciously perceived by the brain ex includes info sent from muscles, skin, eye or ear
fibers are often myelinated
