Chapter 7 - Nervous System Flashcards
What are the three major functions of the nervous system
Sensory input, integration, motor output
What is the function of sensory input
Gathering information, monitoring changes occurring outside and inside the body
What is the function of integration
To process and interpret sensory input and decide if action is needed
What is the function of motor output
A response to integrated stimuli, the response activates muscles or glands
What are the two major parts of the central nervous system
brain and spinal cord
What does the central nervous system act as
Acts as integrating and command center, interprets incoming sensory information and issue instruction based on past experiences and current conditions
What makes up the peripheral nervous system
Nerves outside the brain and spinal cord
What are the functional classifications of the peripheral nervous system
Sensory (afferent) divisions and Motor (efferent) division
What is the Sensory (afferent) division
Nerve fibers that carry information to the central nervous system
What is the motor (efferent) division
Nerve fibers that carry impulses away from the central nervous system
What are the two divisions of motor (efferent) division
Somatic nervous system and autonomic nervous system
What is the somatic nervous system
Voluntary nervous system - skeletal muscle reflexes such as stretch reflex are initiated involuntarily by same fibers
What is the autonomic nervous system
involuntary system - sympathetic and parasympathetic divisions
What is another name for the nervous tissue support cells
astrocyte
What is the function of aastrocytes
form barrier between capillaries and neurons and make exchanges between the tow - control the chemical environment of the brain by capturing ions and neurotransmitters
What is the function of microglia cells
Dispose of debris - dead cells and bacteria
What is the function of ependymal cells
Circulate cerebrospinal fluid with cilia
What is the function of oligonuclecytes cells
Produce myelin sheath around nerve fibers in the central nervous system
What is the function of satellite cells
Protect neuron cell bodies
What is the function of schwann cells
Form myelin sheath in the peripheral nervous system
What is unique about the neuroglia cells
Are not able to transmit nerve impulses but do not lose their ability to divide, unlike neurons
What is another name for a neuron
Nerve cells
What is the major function of a neuron
Cells specialized to transmit messages
What are the two major regions of neurons
Cell body and processes
What is the cell body region of a neuron
Nucleus and metabolic center of the cell
What is the processes region of a neuron
Fibers that extend from the cell body
What is the function of nissl substances in the neuron cell body
Specialized rough endoplasmic reticulum
What is the function of neurofibrils in the neuron cell body
Intermediate cytoskeleton that maintains cell shape
What is the function of the nucleus in the neuron cell body
What is the function of the nucleolus in the neuron cell body
Essential for the growth of developing neurons
What is the function of dendrites
Conduct impulses toward the cell body
What is the function of axons
Conduct impulses away from the cell body
What are some characteristics of axons
End in axonal terminals, axonal terminals contain vesicles with neurotransmitters, axonal terminals are separated from the next neuron by gap
What is nerve cell covering - schwann cells
Produce myelin sheaths in jelly-roll like fashion
What is the nerve cell covering - nodes of ranvier
Gaps in myelin sheath along the axon
What is another name for a bundle of nerve fibers in the central nervous system
Tracts
What is another name for a bundle of nerves in the PNS
Nerves
What is gray matter in nerve tracts
Cell bodies and unmyelinated fibers
What is white matter in nerve tracts
Myelinated fibers
What is nerve ganglia
Collections of cell bodies outside the central nervous system
What is the function of Sensory (afferent) neurons
Carry impulses from the sensory receptors to CNS
What is the function of motor (efferent) neurons
Carry impulses from the central nervous system
What is the function of interneurons (association neurons)
connect sensory and motor neurons
What is the function of proprioceptros
Detect stretch or tension in muscles, tendons, joints
Describe a multipolar neuron
Many extensions from the cell body
Describe a bipolar neuron
One axon and one dendrite
Describe a unipolar neuron
have a short, single process leaving the cell body
What are the two main properties of neurons
Irritability and conductivity
What is irritability
Ability to respond to a stimuli
What is conductivity
Ability to transmit an impulse
The plasma membrane at rest is ___________________________
Polarized
What are the three initiations of a nerve impulse
Depolarization (stimulus depolarizes the neuron’s membrane), A depolarized membrane allows sodium to flow inside, exchange of ions initiates the action potential
Once the action potential (nerve impulses) starts it’s an ______________________ response
All or none
What are the four characteristics of a nerve’s action potential
If action potential starts it is propogated over the entire axon, potassium ions rush out of the cell (repolarizing it), sodium potassium pump restores original configuration, neuron cannot conduct another impulse until repolarization occurs.
What are the three characteristics of a nerve impulse propagation
the impulse continues to move toward the cell body, impulses travel faster when fibers have a myelin sheath, nerve impulse literally jumps from node to node because it cannot cross the myelin insulation
Explain the continuation of the nerve impulses between neurons
Neurotransmitter is released from a nerve’s axon terminal, the dendrite of the next neuron has receptors that are stimulated by the neurotransmitter, an action potential is started in the dendrites of the next neuron
What is reflex
Rapid, predictable, and involuntary responses to stimuli
What is the reflex arc
direct route from a sensory neuron to an interneuron to an effector
What are the three types of nerves in the reflex arc
Autonomic , somatic, simple
What are the 5 types of autonomic reflexes
smooth muscle regulation, size of eye pupils, heart and blood pressure regulation, regulation of glands and sweating, digestive system and elimination of regulation
List one type of somatic reflex
Activation of skeletal muscles
List the four elements of a reflex arc
A sensory receptor, an effective receptor, afferent and efferent neurons connecting the two, the CNS integration center
Where does the CNS develop from
Embryonic neural tube (a simple tube)
What are the four main regions of the brain
Cerebral hemispheres, diencephalon, brain stem, cerebellum
List the four characteristics of the cerebrum (cerebral hemispheres)
Paired (left and right) superior parts of the brain, include more than half of the brain mass, the surface is made of elevated ridges (gyri) and shallow grooves (sulci)
What is the function of the brain fissures
Divide the cerebrum into lobes
What are the four major lobes
Frontal, parietal, occipital, temporal
What is the function of the frontal lobe
Voluntary movement, expressive language, and for managing higher level executive functions
What is the function of the parietal lobe
vital for sensory perception and integration, management of taste, hearing, sight, touch, and smell
What is the function of the occipital lobe
visual perception; color, form, and motion
What is the function of the temporal lobe
processing auditory information and with encoding memory
How are the lobes named
named for the cranial bone over them
What is the function of broca’s area
involved in our ability to speak
List four areas in the cerebrum that are involved in special sense
Gustatory area (taste), visual, auditory, olfactory
List three functions of the interpretation areas of the cerebrum
Speech/language, language comprehension, general interpretation
What are the 3 layers of the cerebrum
Grey matter, white matter, basal nuclei
What are the characteristics of gray matter
outermost layer, composed mostly of neuron cell bodies, cerebral cortex
What are the characteristics of white matter
fiber tracts inside the gray matter; Example: corpus callosum connects hemispheres
What are the characteristics of basal nuclei
internal islands of gray matter, helps regulate voluntary motor activities by modifying instructions sent to the skeletal muscles
What are the 3 parts of the diencephalon (interbrain)
Thalamus, hypothalamus, epithalamus
What is the function of the thalamus
transfers impulses to the correct part of the cortex for localization and interpretation
What is the function of the hypothalamus
Helps regulate body temperature, controls water balance, regulates metabolism
What is the function of the epithalamus
houses the pineal body (an endocrine gland)
What are the 3 parts of the brain stem
Midbrain, pons, medulla oblongata
What are the functions of the midbrain
vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation
What are the functions of the pons
involved in the control of breathing
What is the function of the medulla oblongata
contains important control centers; heart rate control, blood pressure regulation, breathing, swalling, vomiting
What is the function of the sympathetic and parasympathetic division
sympathetic - mobilizes the body
parasympathetic division - allows the body to unwind
