AP chapter 9 Flashcards
The system as a whole consists of two principal divisions called the ___ and the ___
central nervous system and the peripheral nervous system
The brain and spinal cord together are called the ___
central nervous (CNA)
The usual designation for the nerves of the body is the ___
Peripheral nervous system (PNS)
A subdivision of the PNS, called the ___, consists of structures that regulate the body’s automatic or involuntary functions
Autonomic nervous system (ANS)
Two major type of cells that are found in the nervous tissue are ___ and ___
neurons (nerve cells) and glia
Each neuron consists of 3 parts :
#1 A main part called the neuron cell body #2 one or more branching projections called dendrites #3 one elongated projection known as an axon
___ are the process or projections that carry impulses to the neuron cell bodies
Dendrites
___ are the process that carry impulses away from the neuron cell bodies
axons
___ carry impulses to the spinal cord and brain from all parts of the body
Sensory neurons
Sensory neurons are also called ___
afferent neurons
___ carry impulses in the opposite direction - away from the brain and spinal cord.
Motor neurons
Motor neurons do not conduct impulses to all parts of the body - only two kinds of tissue :
muscle and glandular epithelial tissue
Motor neurons are also called ___
efferent neurons
___ conduct impulses from sensory neurons to motor neurons. They also often connect with each other to form complex, central networks of nerve fibers.
Interneurons
Interneurons are sometimes called ___
central or connecting neurons
Glia - or ___ - do not specialize in transmitting impulses. Instead, they are special types of supporting cells
neuroglia
What are 2 important functions of Glia?
#1 hold the functioning neurons together and protect them #2 bring the various functions of nervous tissue together into a coordinated whole ; regulates the neuron function
What is the most common type of brain tumor and what does it develop from?
glioma, develops from glia
Some glia’s are relatively large cells that look somewhat like stars because of the threadlike extensions that jut out from their surfaces, they are called ___
astrocytes
___ attach to neurons and to small blood vessels, holding these structures close to each other
astrocytes
Astrocyte branches form a two-layer structure called the ___
Blood-brain barrier (BBB)
The ___ separates the blood tissue and nervous tissue to protect vital brain tissue from harmful chemicals that might be in the blood
Blood-brain barrier (BBB)
___ remain stationary, but in inflamed or degenerating brain tissue, they enlarge, move about. They surround the microbes, draw them into their cytoplasm, and digest them. They also help to clean up cell damage resulting from injury or disease.
Microglia
The ___ help to hold nerve fibers together. They also produce the fatty myelin sheath that envelops nerve fibers located in the brain and spinal cord
Oligodendrocytes
The ___ affects nerve conduction speed
myelin sheath
___ are glial cells that also form myelin sheaths but do so only in the PNS
Schwann cells
Neurons with myelin-wrapped axons are called ___
myelinated fibers
___ are gaps between adjacent Schwann cells
Nodes of Ranvier
The outer wrapped layer of a Schwann cell is called the ___
neurilemma
A ___ is a group of peripheral nerve fibers (axons) bundled together like the strands of a cable
nerve
Each axon in a nerve is surrounded by a thin wrapping of fibrous connective tissue called the ___
endoneurium
Groups of these wrapped axons are called ___
fascicles
Each fascicle is surrounded by a thin, fibrous ___
perineurium
A tough, fibrous sheath called the ___ covers the whole nerve
epineurium
Bundles of axons in the CNS are called ___
tracts
Brain and spinal cord tissue composed of cell bodies and unmyelinated axons and dendrites is called ___
gray matter
Nerve impulses are also called
action potentials
A basic type of neuron pathway is called a ___
reflex arc
A two-neuron arc consist of only two types of neurons :
#1 sensory neurons #2 motor neurons
Three-neuron arcs are consist of all three kinds of neurons :
#1 sensory neurons #2 interneurons #3 motor neurons
Impulse conduction normally starts in ___, they are the beginnings of dendrites of sensory neurons
Receptors
A ___ is a group of nerve-cell bodies located in the PNS
ganglion
A microscopic space separates the axon ending of one neuron from the dendrites of another neuron. This gap serves as a junction between nerve cells called a ___
synapse
A three-neuron arc reaction is called the ___
withdrawal reflex
___ are chemicals by which neurons communicate
neurotransmitters
___ is released at some of the synapses in the spinal cord and at neuromuscular (nerve-muscle) junctions
acetylcholine (ACh)
norepinephrine, dopamine, and serotonin belong to a group of compounds called ___, which may play a role in sleep, motor function, mood, and pleasure recognition
amines
Two morphinelike neurotransmitters are called :
#1 endorphins #2 enkephalins
___ diffuses directly across the plasma membrane of neurons rather than being released from vesicles
nitric oxide (NO)
What is the function of ACh
Excitatory or inhibitory; regulates parasympathetic effectors; involved in memory
What is the function of Norepinephrine (NE)
Excitatory or inhibitory; regulates sympathetic effectors; involved in emotional responses
What is the function of Dopamine
Mostly inhibitory; involved in emotions and moods
What is the function of Serotonin
Mostly inhibitory; involved in sleep, emotions, and moods
What is the functions of endorphins and enkephalins
mostly inhibitory; involved in blocking pain
What is the function of Nitric Oxide (NO)
Signal from presynaptic to postsynaptic neuron
The brain and spinal cord are also protected by three membranes called ___
meninges
The brain consists of 4 major divisions, named in ascending order, beginning with most inferior part :
#1 Brainstem a. medulla oblongata b. Pons c. Midbrain #2 Cerebellum #3 Diencephalon a. hypothalamus b. thalamus c. pineal gland #4 Cerebrum
The lower part of the brainstem is the ___
medulla oblongata
The medulla, pons, and the midbrain form the ___
brainstem
The large hole in the occipital bone is called the ___
foramen magnum
The ___ bulges out a bit more than the medulla, forming a bridge to the narrower midbrain
pon
___ conduct impulses up from the spinal cord to other parts of the brain, and ___ conduct impulses down from the brain to the spinal cord
sensory fibers ; motor fibers
In the brainstem, small bits of gray matter mix closely and intricately with white matter to form the ___
reticular formation
The ___ is the second largest part of the human brain
cerebellum
What are some functions of the cerebellum? (3)
#1 produce smooth coordinated movements #2 maintain equilibrium #3 sustain normal postures
The diencephalon consists of 3 major structures :
#1 hypothalamus #2 thalamus #3 pineal gland
What is the function of Medulla oblongata
2-way conduction pathway between the spinal cord and higher brain centers; cardiac, respiratory, and vasomotor control center
What is the function of Pons
2-way conduction pathway between areas of the brain and other regions of the body; influences respiration
What is the function of Midbrain
2-way conduction pathway; relay for visual and auditory impulses
What is the function of Hypothalamus
regulation of body temperature, water balance, sleep-cycle control, appetite, and sexual arousal
What is the function of Thalamus
Sensory relay station from various body areas to cerebral cortex; emotions and alerting or arousal mechanisms
What is the function of Pineal gland
Adjusts output of melatonin in response to changes in external light, to keep the body’s internal clock on time
What is the function of Cerebrum
sensory perception, emotions, willed movements, consciousness, and memory
The ___ is the largest and uppermost part of the brain
cerebrum
Inferior central band called the ___, which is made up of white matter tracts
corpus callosum
A thin layer of gray matter called ___
cerebral cortex
Within white matter are a few islands of gray matter known as ___, whose functioning is essential for producing automatic movements and postures
basal nuclei or basal ganglia
Reflexes that result from conduction over arcs whose centers lie in the spinal cord are called ___
spinal cord reflexes
A loss of sensation is called
anesthesia
A loss of the ability to make voluntary movements is called
paralysis
What are the 3 layers of the spinal meninges
#1 dura mater, which is the tough outer layer that lines the vertebral canal #2 pia matter, which is the innermost membrane covering the spinal cord itself #3 Arachnoid mater, which is the membrane between the dura and the pia mater
Fluid fills the subarachnoid spaces between the pia mater and arachnoid in the brain and spinal cord. This fluid is called ____. It also fills spaces in the brain call cerebral ventricles
cerebrospinal fluid (CSF)
CSF forms continually from fluid filtering out of the blood in a network of brain capillaries known as ___ and into the ventricles
choroid plexus
The autonomic nervous system (ANS) consists of certain motor neurons that conduct impulses from the spinal cord or brainstem to the following kinds of tissue (3)
#1 cardiac muscle tissue #2 smooth muscle tissue #3 glandular epithelial tissue
ANS controls the involuntary functions.. motor nerves that control the voluntary actions of skeletal muscles are sometimes called the ___
somatic nervous system
The ANS consists of two divisions called the :
#1 sympathetic division #2 parasympathetic division
___ are the motor neurons that make up the ANS
autonomic neurons
Autonomic neurons are called ___ because they conduct impulses between the spinal cord and a ganglion
preganglionic neurons
___ conduct impulses from a ganglion to cardiac muscle, smooth muscle, or glandular epithelial tissue
postganglionic neurons
Autonomic or ___ are the tissues to which autonomic neurons conduct impulses
visceral effectors
___ have dendrites and cell bodies in the gray matter of the thoracic and upper lumbar segments of the spinal cord
Sympathetic preganglionic neurons
Sympathetic systems are also referred to as the ___
thoracolumbar systems
What is the function of the Olfactory
sense of smell
What is the function of the Optic
vision
What is the function of the Oculomotor
eye movements
What is the function of the Trochlear
eye movements
What is the function of the Trigeminal
sensations of face, scalp, and teeth; chewing movements
What is the function of the Abducens
eye movements
What is the function of the Facial
sense of taste; contraction of muscles of facial expression
What is the function of the Vestibulocochlear
Hearing; sense of balance
What is the function of the Glossopharyngeal
Sensations of throat, taste, swallowing movements, secretion of saliva
What is the function of the Vagus
sensations of throat and larynx and of thoracic and abdominal organs; swallowing, voice production, slowing of heartbeat, acceleration of peristalsis (gut movements)
What is the function of the Accessory
Shoulder movements; turning movements head
What is the function of the Hypoglossal
tongue movements
