Module 1: Nervous System Flashcards
Anatomy
Structure of the body
Physiology (2)
1) How the body parts function together
2) The physiology of the body depends on the anatomy of the body
Nervous system (3)
1) Receives information
2) Processes information
3) Sends out signals to muscles and glands to elicit an appropriate response
Nervous tissue (3)
1) Responsible for communication between cells of the body
2) Done by forming system of electrical impulses that communicate rapidly
3) Like the wiring of the body
Central nervous system (2)
1) Brain, protected by skull
2) Spinal cord, protected by vertebrae
Skull
Protects brain
Vertebrae
Protect spinal cord
Nuclei
Collections of cell bodies inside the CNS
Tracts
Collection of nerve axons in the CNS
Peripheral nervous system (2)
1) All nerves not in the brain or spinal cord
2) Includes cranial nerves and spinal nerves
Brainstem regions (3)
1) Midbrain
2) Pons
3) Medulla
Cranial nerves (2)
1) Project from brainstem
2) Innervate the face, head and neck
Spinal nerves (2)
1) Project from either side of the spinal cord
2) Spread out to innervate the trunk and extremities
Ganglia
Collection of cell bodies inside the PNS
Nerves
Collection of nerve axons in the peripheral nervous system
Two divisions of peripheral nervous system (2)
1) Sensory (afferent) division
2) Motor (efferent) division
SAME acronym (2)
1) Sensory = Afferent
2) Motor = Efferent
Afferent division (2)
1) Receives impulses from the sensory organs
2) PNS to CNS
Efferent division (2)
1) Relays signals or impulses from the CNS to muscles and glands
2) CNS to PNS
Efferent division subdivisions (2)
1) Somatic nervous system
2) Autonomic nervous system
Somatic system (2)
1) Conscious control
2) Controls movements of skeletal muscles, skin and joints
Autonomic nervous system
1) Involuntary control
2) Control glands and smooth muscles of internal organs
Autonomic system subdivions (2)
1) Sympathetic nervous system
2) Parasympathetic nervous system
Sympathetic nervous system
Prepares body for vigorous muscular activity, stress and emergencies
Parasympathetic system
Operates during normal situations, permits digestion and conserves energy
Nervous System graph
Neurons
Nerve cells that conduct electrical impulses and relay information throughout the body
Three basic parts of neuron (3)
1) Dendrites
2) Cell body
3) Axon (which end in axon terminals)
Unique features of neuron structure
Do neurons undergo mitosis (cell division)?
Can neurons be replaced?
How long can neurons survive without oxygen?
No, neurons can survive a person’s entire lifetime
Neurons cannot be replaced, which is why brain and spinal cord damage is so serious
Just minutes
Neuron cell body (3)
1) Receives information from dendrites
2) Synthesizes all nerve cell products
3) Sends information toward axon
Features of neuron cell body (4)
1) Large nucleus
2) Cytoplasm
3) Contain all normal organelles except centrioles (responsible for mitosis, no cell division)
4) Main function is to manufacture neurotransmitters
Dendrites (3) - IN
1) Receiving end of neuron
2) Numerous short extensions that emanate from cell body
2) Conduct nerve impulses TOWARD the cell body
Axon (5) - OUT
1) Conducts nerve impulses AWAY from the cell body to axon terminals
2) Composed of cell components but lack rough ER
3) Depend on neuron’s cell body to send necessary proteins down length of axon
4) Terminates in axon terminals
5) Vary in length
Axon terminals (2)
1) Store neurotransmitters inside secretory vesicles at end of axon terminals
2) When neurotransmitters released from axon terminal vesicles, they carry nerve impulse from one neuron to next