Chapter 9 Nervous System Flashcards
(28 cards)
Composition of the diencephalon
connects midbrain to the forebrain, lies above the brain stem; contain thalamus, hypothalamus, epithalamus, and subthalamus
Describe function and purpose of dendrites and axons
axons help messages move throughout the body systems; dendrites receive and process those messages
Describe the cells of the nervous system
neurons - transmit nerve impulses along nerve fibers to other neurons, typically have a cell body, axons, and dendrites; neuroglia - carry out a variety of functions to aid and protect components of the nervous system
Describe the function of motor (efferent) neurons and sensory (afferent) neurons
sensory neurons - conduct impulses from peripheral receptors to the CNS, usually unipolar; motor neurons - conduct impulses from the CNS to effectors, multipolar
Describe the functions of the major lobes of the brain
Frontal - voluntary movement, expressive language; Parietal - sensory perception, in charge of taste, hearing, sight, touch, and smell; Temporal - auditory processing, encoding of memory; Occipital - visual perception, color, form, and motion
Describe the composition of the meninges
lie between bone and soft tissue; three layers to protect brain and spinal cord; delicate inner layer - pia mater; middle layer - arachnoid, web-like structure filled with fluid to cushion the brain; tough outer layer - dura mater
During an action potential, what causes repolarization?
the closing of sodium ion channels and the opening of potassium ion channels
Know the parts of a reflex arc
sensory receptor, sensory neuron, interneuron in the spinal cord, motor neuron, and an effector
Know all the divisions of the nervous system and their functions
The CNS - brain and spinal cord, brain controls how we think, feel, learn, and move, spinal cord carries messages back and forth between the brain and the rest of the body; Peripheral Nervous System - sensory, connects brain and spinal cord to skin in order to feel pain and other sensations; autonomic - controls involuntary movement (i.e. digestion, heart rate, blood pressure, etc.) motor - connects brain and spinal cord to muscles to stimulate movement
action potential
the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell
autonomic nervous system
the part of the nervous system responsible for control of the bodily functions not consciously directed (i.e. breathing, heartbeat, digestive processes)
axon
the long, threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells
central nervous system
the complex of nerve tissues that controls the activities of the body; comprises brain and spinal cord
convergence
when two or more things come together to form a new whole
dendrite
any of the usually branching protoplasmic processes that conduct impulses toward the body of a nerve cell
divergence
where a main presynaptic neuron splits its neurotransmitters to affect a large number of postsynaptic neurons
effector
a cell that performs a specific function in response to a stimulus
facilitation
the lowering of the threshold for reflex conduction along a particular neural pathway, especially from repeated use of that pathway
ganglion
a collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system
meninges
the three thin layers of tissue that cover and protect the brain and spinal cord
myelin
an insulating layer or sheath that forms around nerves, including those in the brain and spinal cord
neurilemma
the thin sheath around a nerve axon
parasympathetic nervous system
a network of nerves that relaxes your body after periods of stress or danger
peripheral nervous system
part of your nervous system that lies outside your brain and spinal cord
