Flashcards in Test 3 Deck (148):
What are the two cells of nervous tissue?
neurons and glia
Which cranial nerve controls the Lateral Ptyregoid?
V. Trigeminal Nerve
What is another name for a neuron's cell body?
What is another name for chromatophilic substance?
Membranous organelles located in neuronal cell bodies and dendrites. Rough endoplasmic reticulum making peptide chains. It is not found in either axons or the axon hillock
Lower Motor Neurons are located where?
Brainstem and Spinal Cord
Which neurotransmitter does lower motor neurons use to communicate with the muscles?
How many pairs of spinal nerves are their?
Autoimmune disease that decreases cholinergic receptors. Acetylcholine is inhibited to help with this disease.
stiffening of the body after death, contraction of the muscles.
-Glia of CNS found in high density in white matter
Ventricle that contains Cerebral Spinal Fluid in center of spinal cord
Stores and sequesters calcium ions in muscle cells; smooth endoplasmic reticulum
Smooth muscle contraction of tubular internal organs; digestive tract
-Region of sarcomere with only actin present
-they shorten when sarcomere contracts
-held by direct attachments to structures called Z lines
Nodes of Ranvier
Unmyelinated regions of axons
Protein located in grooves of actin that blocks myosin attachment
-They connect to actin and pull actin toward the center, which contracts the sarcomere
-Loaded with ATP
Sliding filament hypothesis
the contraction of sarcomeres; theory of muscle contraction
proteins(thick & dark) that, with actin, forms the filaments that interact to contract muscle fibers
Protein in a muscle fiber that forms the thin filaments(light) that slide between filaments of the protein myosin, shortening the muscle fibers.
the striations form a repeating pater of units along the muscle fiber
the second part of the striation pattern, which composes thick myosin filaments overlapping thin actin filaments
-an enzyme found in myosin heads
-it catalyzes the breakdown ATP to ADP and a phosphate
-rod-shaped and occupy the longitudinal grooves of the actin helix
-Prevents myosin cross bridges from binding/attaching to actin
-High affinity for calcium
-attached to actin
Basic process of muscle contraction
Calcium is attached to troponin causing it to change shape and push tropomyosin out of the actin helix. With the removal of tropomyosin the myosin cross bridges can now attach to the actin, which causes the sarcomere to contract
cross bridges have to be loaded with ATP, which allows the cross bridges to disconnect from the actin.
Region where the actin and myosin filaments overlap
-axon terminal of lower motor neuron
-motor end plate
Motor end plates
-Where nuclei and mitochondria are abundant and the sarcolemma is extensively folded
controlled by a motor neuron and a muscle fiber
a small gap that separates the membrane of the neuron and the membrane of the muscle fiber
Biological messenger molecules that convey neural information
3 ways to terminate a neurotransmitter
tiny vesicles that stores neurotransmitters
small cellular processes that receive input
carries information away from the cell in the form of impulses
-neuroglia that encase the large axons of peripheral neurons in lipid-rich sheaths(PNS)
-make the axons faster; insulates; myelinated
jumps from Node of Ranvier to Node of Ranvier. Only on myelinated axons
-designed to be quick for protection reasons
-lower motor neurons
What makes action potentials different?
How many neurons are involved in the patellar knee jerk reflex?
2 its the simplest reflex of the human body
-comes off the midbrain
-highest cranial nerve
multipolar neuron, the first part of the axon; makes the action potential
-provide support and hold structures together with abundant cellular processes
form the inner lining of the central canal that extends downward through the spinal cord
-specialized capillaries associated with he ventricles of the brain
-they regulate the composition of the cerebrospinal fluid
-lipid material that forms a sheath like covering around some axons
Not graded all or nothing
-rapid change in the membrane potential
What is the most important job of the neuronal body?
Summation of EPSP and IPSP to determine whether or not to fire an action potential
Where are upper motor neurons found?
enzymes required for neurotransmitter synthesis are produced in the cell body and transported to the axon terminals
the potential difference across the cell membrane
-the membrane becomes more positive than the resting potential
-can be caused by sodium entering
-means the threshold is lowered for an action potential
-if the membrane potential becomes more negative than the resting potential
-the threshold is raised
Which is bigger a mono peptide or a neuropeptide?
Name 4 cranial nerves with parasympathetic outputs?
Vagus holds 75% of all parasympathetic fibers
an amino acid that is modified to make serotonin
What are classic neurotransmitters made from and where are they synthesized?
A single amino acid and are synthesized in the axon terminal
Neuropeptides are synthesized where?
perikaryal and dendrites;
What is the difference between classic neurotransmitters and neuropeptides
-classic are fast, onset, but quickly end
-neuropeptides don't act quickly but have a longer life
Which part of a neuron has the lowest threshold?
What is neuromodulation?
Raises or lowers the threshold
-Most prevalent inhibitory of neurotransmitters in the CNS
-most important for excitation
What are two types of neuropeptides
enkephalins and endorphins
absolute refectory period
-first in the refractory period of an axon
-not responsive no action potentials
relative refractory period
-second in the refractory period of an axon
-re-establishes resting potential
-enable one neuron to affect the other
EPSP(Excitatory Postsynaptic Potential)
-opens the sodium ion channels, which depolarizes the membrane possibly triggering an action potential
IPSP(Inhibitory Postsynaptic Potential)
-Increases membrane permeability to potassium ions, which diffuse outward hyperpolarizing the membrane
Generally inhibitory; reduce pain by inhibiting substance P release (CNS)
Generally excitatory (CNS)
-inactivates the monamine neurotransmitters epinephrine and norepinephrine after reuptake
-It is found in the mitochondria in the synaptic knob
-Primarily inhibitory; leads to sleepiness; action is blocked by LSD, enhanced by selective serotonin reuptake inhibitor antidepressant drug(CNS)
Creates a sense of well-being; deficiency in some brain areas associated with Parkinson disease (CNS)
Any group of neuropeptides synthesized in the pituitary gland and hypothalamus that suppress pain
Two parts of the ANS(Autonomic Nervous System)
Sympathetic & Parasympathetic
thoracolumbar output(spinal nerves)
-fight or flight
Craniosacral output(cranial nerves)
-"rest and digest"
This happens when the vagus shuts the body down which is why we pass out
Which division has postganglionic neurons closer to the target organs?
-located between the bones and the soft tissues of the nervous system
-they have three layers the dura mater, arachnoid mater, and the pia mater
ascending and descending tracts of spinal cord
-ascending tracts of the spinal cord are afferent information dealing with sensory neurons
-descending tracts of the spinal cord deal with efferent information and motor neurons
Peripheral Nervous system
Consists of Cranial and spinal nerves
-the ends of neurons in the pos provide the sensory function of the nervous system
-they gather information by detecting changes inside and outside of the body
autonomic nervous system
communicates instructions from the cns that control viscera, and thus causes involuntary subconscious actions; heart and various glands
-they lie within the brain or spinal cord
-relay information from one part of the brain or spinal cord to another
-broadly defined, projection neurons are neurons whose axons extend from the neuronal cell body within the central nervous system to one or more distant regions of the CNS.
-extensions of the cerebral cortex just beneath the frontal lobes
X-shaped structure on the underside of the brain formed by optic nerve fibers that cross over
-Part of the brain located below the thalamus and forming the floor of the third ventricle
-ANS: controlling our emotional side
-Endocrine gland attached to the base of the brain that consists of anterior and posterior lobes; the hypophysis
-small region of the brainstem between the diencephalon and the pons
-Part of the brainstem above the medulla oblongata and below the midbrain
-communicates with other parts of the CNS by tracts; integrates sensory information concerning the position of body parts; coordinates muscle activities and maintains posture
Part of the brainstem between the pons and the spinal cord
-separates the occipital lobes of the cerebrum from the cerebellum
-it is a dural fold in the dural jacket
Somatic nervous system
-communicates voluntary instructions originating in the CNS to skeletal muscles, causing contractions
Which layer of the meninges is the most superficial?
The cerebellum is ____ to the brain stem?
Which occurs second int he refractory period of an axon?
relative refractory period
Descending tracts in the spinal cord are what?
T/F Hyperpolarization causes the membrane potential to become less negative?
T/F both unmyelinated and myelinated axons exhibit saltatory conduction
T/F The sympathetic division of ANS is known as "the fight or flight" response.
List one region/ part of the brains stem.
pons, medulla oblongata, midbrain
List one example of a neuropeptide
Endorphin, enkephalins, Substance P
What sensation is processed in the olfactory bulbs?
Which cranial nerves are only sensory?
What connects the hippocampus to the hypothalamus?
What does hippocampus relate to?
CN1 Olfactory Nerve
-receptors only found in nasal cavity
-goes into the olfactory bulbs then into the white matter tracts(olfactory tracts) that go into the cerebrum
-largest part of the diencephalon
-processes all sensations except for smell
bridge that allows the two lobs to communicate and is only found in some people
-controls the ANS
-controls endocrine glands-makes a lot of hormones
-controls the pituitary gland
-center for desires= hunger, thirst, and sexual desires
-melatonin is produced here
-biological clock - circadian rhythms
What is part of the diencephalon
thalamus, 3rd ventricle, hypothalamus, pineal gland, pituitary gland, optic chiasm, optic nerves2
What is the function of the superior colliculi?
gaze- directs eyes, neck, head to look at interesting things in our environment
What is the function of the inferior colliculi?
Only deals with sound, CN8, goes to thalamus, processes auditory information
In the brain stem where is sensory information processed?
In the brain stem where is motor information processed?
What are the superior colliculi and inferior colliculi apart of?
What connects the 3rd ventricle to the 4th?
spinal accessory 11 and cervical spinal nerves 2-3. The origin and insertion can be flipped
-spinal accessory 11
-lies on top of rhomboid major
How many pairs of cervical spinal nerves are there?
What is the most superficial muscle in the body?
Which two muscles can flip flop origin and insertion?
pectoralis minor and sternocleidomastoid
What is going to establish the resting membrane potential?
Sodium and Potassium pump
What is the most prevalent ion in a cell?
What is the most prevalent ion outside of a cell?
What ion causes depolarization?
Whats the most important ion for neuronal communication?
Summation, which determines whether to fire an action potential
What are the three major groups of neurons based off of structural differences?
Multipolar, Bipolar, & Unipolar Neuron
Where can Multipolar neurons usually be found?
outside the brain and spinal cord
Where can Bipolar neurons usually be found?
specialized parts of the eye, nose, and ears
Where can Unipolar neurons usually be found?
What are the three classifications of neurons based off of their functional differences
Sensory neuron, interneuron, and motor neuron
Sensory neurons are usually classified as what structure of neuron?
What is the structure of an interneuron classified as?
What structure is a motor neuron classified as?
What are the four types of CNS neuroglia?
astrocytes, oligodendrocytes, microlgia, ependyma