Chapter 22 Flashcards
Neurons
carry electrical and chemical messages to and from the brain
Nerves
are bundles of neurons transmitting the electrical signal or nerve impulse through the body
Nerve Impulse
electrochemical signal that controls the activities of muscles, glands, organs, and organ systems
Central Nervous System (CNS)
composed of the brain and spinal cord
Peripheral Nervous System (PNS)
is composed of all other nervous tissue other than CNS
Effectors
the tissues that respond to the impulses from the neurons
Neurotransmitters
one of many chemicals released by the presypnaptic neuron in the synapse, which then diffuse across the synapse and bind to receptors on the membrane of the postsypnaptic neuron
Sensory Neurons
a neuron that conducts impulses from a sense organ to the central nervous system
Motor Neurons
neuron that carries information away from the brain or spinal cord to muscles or glands
Interneurons
a neuron located between sensory and motor neurons that functions to integrate sensory input and motor output
Sensory Receptors
a neuron that conducts impulses from a sense organ to the central nervous system
General Senses
are temperature, pain, touch, pressure, and body position
Special Senses
are smell, taste, equilibrium, hearing , and vision
Spinal Cord
is the pathway of nerve impulse flow to and from the brain
Vertebrae
protect the spinal cord
Reflex Arc
nerve pathway followed during a reflex consisting of a sensory receptor, a sensory neuron, an interneuron, a motor neuron, and an effector
Cerebrospinal Fluid
protective liquid bath that surrounds the brain within the skull
Glial Cells
a type of cells within the brain that does not carry messages but rather supports neurons by supplying nutrients, repairing the brain after injury, and attacking invading bacteria
Cerebral Cortex
deeply wrinkled outer surface of the cerebrum where conscious activity and higher thought originate
Cerebellum
controls balance, muscle movement, and coordination
Midbrain
deals with auditory and visual reflexes
Pons
relays messages between brain and spinal cord
Medulla Oblongata
controls heart rate and respiration rate
Myelin Sheath
protective layer that coats many axons, formed by supporting cells such as Schwann cells. The myelin sheath increases the speed at which the electrochemical impulse travels down the axon
Nodes of Ranvier
small indentation separating segments of the myelin sheath. Nerve impulses “jump” successively from one node of Ranvier to the next
Schwann Cells
forms the myelin sheath in the PNS
White Matter
is composed of myelinated neurons
Gray Matter
is composed of unmyelinated neurons
Synaptic Transmission
neurons communicate chemically across the synapse
