• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/144

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

144 Cards in this Set

  • Front
  • Back
Nervous System Overview - The NERVOUS system is the body’s
principal control and integrating system.
Nervous System Overview - The nervous system performs 3 main functions
i.sensory, ii. Integrative function, iii. motorsystem…
Nervous System Overview - SENSORY function is
detection of changes inside and outside the body by specialized cells called sensory RECEPTORS/INPUT.
Nervous System Overview - Sensory information is carried
to brain and/or spinal cord along sensory or AFFERENT neurons.
Nervous System Overview - INTEGRATIVE FUNCTION is
(HAPPENS AT INTE CENTER) —interpretation of the changes detected by the sensory mechanisms.
Nervous System Overview - The conscious awareness of sensory stimuli within the brain is called
PERCEPTION (THINK POPCORN SMELL).
Nervous System Overview - The integration of sensory stimuli occurs along
the INTERNEURONS
Nervous System Overview - INTERNEURONS
connect neurons within the brain and spinal cord over short distances.
Nervous System Overview - MOTOR SYSTEM function is
reacting to changes through the action of the organ systems such as the glands and muscles.
Nervous System Overview - Motor information is carried away from the brain toward
the spinal cord to the EFFECTORS along the motor or EFFERENT neurons.
The nervous system has 2 major divisions
the CNS (central nervous system) and PNS (periphial nervous system)
the CNS (central nervous system) and PNS (periphial nervous system)
The CENTRAL nervous system (CNS) consists of:
1. BRAIN, 2. SPINAL CORD (MUCH INVOLUNTARY REGULATION OCCURS)
1. BRAIN, 2. SPINAL CORD (MUCH INVOLUNTARY REGULATION OCCURS)
The PERIPHIAL nervous system (PNS) consists of:
CRANIAL nerves which originate from the brain.
CRANIAL nerves which originate from the brain.
How many cranial nerves in the brain
12 NERVES
SPINAL nerves
originate from the spinal cord.
originate from the spinal cord.
Spinal nerves EXTEND
THROUGHOUT THE BODY
THROUGHOUT THE BODY
The peripheral nervous system is further subdivided into:
i. sns - sematic nervous system ii. Ans – autonomic nervous system iii. ENS - Enteric nervous system
i. sns - sematic nervous system ii. Ans – autonomic nervous system iii. ENS - Enteric nervous system
SEMATIC nervous system (SNS)
includes neurons that conduct impulses to SKELETAL MUSCLES
AUTONOMIC nervous system (ANS)
includes neurons that convey impulses from the brain to smooth muscles, cardiac muscle, and glands.
The autonomic nervous system is subdivided again into:
i. sympathetic division ii. Parasympathetic division
SYMPATHETIC division
generally increases the activity of an organ. (FIGHT OR FLIGHT)
PARASYMPATHETIC division
generally decreases the activity of an organ. (REST AND DIGEST)
ENTERIC nervous system (ENS) is part of the
autonomic nervous system
Enteric nervous system includes
involuntary sensory and motor neurons which control the gastrointestinal (GI) tract.
Enteric nervous system neurons function
independently of the ANS and CNS. (ANYTIME YOU SEE ENTERO THINK DIGESTION)
There are two types of nerve cells
i. neurons ii. neuroglia
i. neurons ii. neuroglia
NEURONS are
cells that conduct nerve impulses. 100 BILLION IN BRAIN 100 MILLION IN SPINAL CORD
cells that conduct nerve impulses. 100 BILLION IN BRAIN 100 MILLION IN SPINAL CORD
NEUROGLIA are
cells that support and protect neurons.
cells that support and protect neurons.
Neuroglia (glial cells) are
smaller and more numerous than neurons.
There are 6 different types of neuroglia within
the CNS and PNS.
Neuroglia of the CNS:
i. oligodendrocyte, ii. Astrocytes, iii. microglial cells, iiii. Ependymal cells
i. oligodendrocyte, ii. Astrocytes, iii. microglial cells, iiii. Ependymal cells
OLIGODENDROCYTE neuroglia
is the most common glial cell type.
is the most common glial cell type.
oligodendrocytes Form
the myelin sheath around more than one axon in the CNS.
the myelin sheath around more than one axon in the CNS.
ASTROCYTES neurologia
attach to blood vessels forming a blood-brain barrier (BBB) that prevents harmful substances and organisms from entering the CNS.
attach to blood vessels forming a blood-brain barrier (BBB) that prevents harmful substances and organisms from entering the CNS.
MICROGLIAL CELL neurologia
engage in phagocytosis of cellular debris and damaged nervous tissue.
engage in phagocytosis of cellular debris and damaged nervous tissue.
PHAGOCYTOSIS is
the ingestion of a smaller cell or cell fragment, a microorganism, or foreign particles by means of the local infolding of a cell's membrane – BREAKDOWN of cells
EPENDYMAL CELLS neurolgia
produce the cerebrospinal fluid (CSF) of the CNS.
produce the cerebrospinal fluid (CSF) of the CNS.
Neuroglia of the PNS:
i. schwann cells, ii. satellite
i. schwann cells, ii. satellite
SCHWANN CELLS Neuroglia
produce the myelin sheath around single axons and participate in axon regeneration.
SATELLITE Neuroglia
are flat cells surrounding neuronal cell bodies in peripheral ganglia. They support neurons in the PNS ganglia.
Most neurons consist of three distinct portions.
i. cell body, ii. Dendrites, iii. axon
CELL BODY (soma) contains
a single nucleus and granular cytoplasm.
DENDRITES receive
the stimuli and convey nerve impulses to the cell body.
AXON conducts
impulses from the neuron to the dendrites of another neuron or to an effector organ of the body.
AXOLEMA is
The cellular membrane of the axon
AXOPLASM is
the cytoplasm contained by the Axolema
axon COLLATERAL are
Side branches of the axon which occur at right angles.
TELODENDRIA aka
axon terminals
Telondendria
The fine filaments terminating the axon and axon collaterals also known as axon terminals
SYNAPTIC END BULBS are
The round nodules at the ends of telodendria
SYNAPTIC VESSICLES are
the membrane-enclosed sacs contained by the synaptic end bulbs NEUROTRANSMITTERS are chemical signals stored by the synaptic vessicles,
The SYNAPSE is
the site of communication between two neurons or between a neuron and an EFFECTOR cell.
Neurons are either
covered or uncovered
Covered or MYELINATED neurons possess
a white phospholipid, MYELIN (FATTY LAYER) , which covers the axons forming the myelin sheath.
MYELIN is produced by two different types of neuroglia
i. oligodendrocytes ii. Schwann cells
OLIGODENDROCYTES form
the myelin sheath of the axons within the CNS.
Myelinated neurons form
the WHITE matter of the CNS.
SCHWWAN cells form
the myelin sheath of the axons within the PNS.
NODES OF RANVIER or neurofibril nodes are
gaps within the myelin sheath that separate Individual Schwann cells
Uncovered or UNMYELINATED neurons form
the GRAY matter of the CNS
Unmyelinated neurons are
SLOWER than the myelinated neurons.
gray matter is on the outside within the
brain
gray matter is on the inside within the
spine (think butterfly)
Classification of neurons is based upon
structural and functional criteria.
Structural classification of neurons
i. multipolar, ii. Bipolar, iii. unipolar…
MULTIPOLAR neurons have
multiple dendrites and one axon.
BIPOLAR neurons have
one dendrite and one axon.
Bipolar Neurons are associated with
the SPECIAL SENSES (EYE, EAR, OLFACTORY)
UNIPOLAR neurons have
only one process extending from the cell body.
Unipolar neurons are found
in the dorsal (sensory) root ganglia of the spine.
The unipolar process (extension) divides into:
i. A central branch which acts as an AXON, ii.A peripheral branch which acts as a DENDRYTE
Functional classification of neurons
i. afferent ii. Efferent iii. interneurons…
AFFERENT neurons are
(sensory) nerve cells that conduct impulses from the SENSORY RECEPTORS towards the BRAIN (OR CENTRAL NERVOUS SYSTEM
Afferent neurons are CORRELATED WITH
CNS
EFFERENT neurons are
(motor) nerve cells that conduct impulses from the BRAIN towards the EFFECTORS
Efferent neurons are CORRELATED WITH
PNS
INTERNEURONS are
(association neurons) that connect sensory to motor neurons. INTERNEURONS are CORRELATED WITH CNS
The cell bodies and axons of neurons form
bundles of ganglions and nucleus
Cell bodies are arranged into bundles called:
i. ganglions ii. nucleus
GANGLIONS bundles are
in the PNS.
NUCLEUS bundles are
in the CNS.
The myelinated axons of afferent and efferent neurons are arranged into bundles called:
i. nerves, ii. fiber
Myelinated NERVES bundles are located
in the PNS.
Myelinated FIBER (nerve) tracts bundles are located
in the CNS.
The ability to produce nerve impulse (nerve action potential) is dependent on:
Membrane potentials.
The membrane of a RESTING (nonconducting) neuron is
POSITIVELY charged outside and NEGATIVELY charged inside.
The membrane of a RESTING (nonconducting) neuron is said to be
POLARIZED and has a resting membrane potential.
POSITIVE charge OUTSIDE the cell is accounted for
by The presence of positive SODIUM ions (cations) outside the membrane accounts.
NEGATIVE charge INSIDE the cell is accounted for
by Organic phosphate groups (PO43-) and protein anions
Ion channels Open or close in response to
specific STIMULI allowing for the flow of ions across the membrane.
Ion channels Maintain and restore
ELECTRO CHEMICAL gradient across the plasma membrane.
Neurons are capable of responding to
stimuli and converting them to impulses through EXCITABILITY
A nerve impulse (action potential) is generated over three steps:
i. depolarization ii. Repolarization iii. refractrion
DEPOLARIZATION occurs when
the inside of the nerve becomes POSITIVE and the outside becomes NEGATIVE
Depolarization - The inside of the nerve becomes positive when
ion channels (gates) open and allow SODIUM ions (Na+) to enter. THE SODIUM CAUSES ADDITIONAL CHANNELS TO OPEN.
Depolarization - Sodium channels are
closed quickly stopping the inflow of Na+.
REPOLARIZATION occurs when
the inside of the nerve becomes NEGATIVE and the outside becomes POSITIVE again.
REPOLARIZATION - POTASSIUM channels are
opened at the same time as the sodium channels are being closed.
REPOLARIZATION - Open channels results in
the outflow of POTASSIUM ions (K+) causing the membrane potential to become negative again. In addition, SODIUM ions are pumped back out of the nerve fiber.
REPOLARIZATION - HIGH AMOUNT OF POTASSIUM WILL CAUSE
PUMP OF POTASSIUM TO STOP
The REFRACTORY period is
a period of time during which the membrane recovers and cannot initiated another action potential.
During The REFRACTORY period
the sodium channels are inactivated.
There are two types of nerve conduction…
i. continuous ii. Salutatory
CONTINOUS conduction occurs only in
unmyelinated nerve fibers.
SALTATORY conduction occurs only in
myelinated nerve fibers.
Nerve Conduction - The MYELIN sheath acts as an electrical insulator and polarization can only occur at the
NODES OF RANVIER (UNMYELINATED SECTIONS)
Nerve Conduction - In salutatory conduction the impulse
appears to “leap” from node to node through the interstitial fluids covering the myelin segments.
The speed of impulse conduction is
greatly INCREASED because of the skipped distances (myelinated) and involves less activity by the sodium-potassium pumps. (ADDITIONAL BENEFIT ACTION REQUIRES LESS ATP)
NERVES ARE NOT MYELINATED AT BIRTH. MYELINATION DEVELOPS WITH AGE. AFFECTING GROSS AND THEN FINE MOTOR SKILLS Tor F
T
The speed of nerve impulses depends upon
i. diameter ii. Myelination iii. temperature
Speed of nerve impulse - larger diameters conduct
impulses FASTER than those with smaller diameters.
Speed of nerve impulse - Myelinated fibers conduct
impulses FASTER than unmyelinated fibers.
Speed of nerve impulse - COLD nerve fibers do not conduct
impulses efficiently.
the application of ICE reduces pain sensations from injuries. Tor F
T
A synapse is a region where communication occurs between
two NEURONS or between a neuron and an EFFECTOR.
EACH NEURON FORMS SYNAPSES WITH 1000 OTHER NEURONS – SO THE NUMBER OF SYNAPSES THAT OCCUR ARE
IN THE 100 TRILLIONS
Synapses may be either:
i. electrical ii. chemical
ELECTRICAL SYNAPSE is where
impulses pass directly from one cell to another through GAP JUNCTIONS.
Electrical synapses are
rare and FASTER than chemical synapses and can contract in unison.
Electrical synapse are
FOUND IN HEART AND GI TRACT
CHEMICAL SYNAPSE is where
a neuron secretes a chemical substance called a NEUROTRANSMITTER that acts upon receptor sites of the next neuron.
CHEMICAL SYNAPSE GOES FROM
ELECTRICAL IMPULSE TO CHEMICAL BACK TO ELECTRICAL
SYNAPTIC VESSICLES are
packages within the synaptic end bulbs of the telodendria which contain the NEUROTRANSMITTER which allows for the conduction of an impulse from one neuron to another or from a neuron to an end organ.
The SYNAPTIC CLEFT exists
at each synapse and is filled with extracellular fluid which separates the synaptic end bulb of one neuron (presynaptic) from the next (postsynaptic) or to the end organ.
the NEUROTRANSMITTER is released
When an impulse arrives at the end bulb and the synaptic vesicles open into the synaptic cleft.
Neurotransmitter RECEPTORS on the postsynaptic neuron
bind/RECEIVE to the neurotransmitter and the impulse passes from one neuron to the next.
There are about 100 known neurotransmitters broken down into 2 classes
i. small-molecule neurotransmitters ii. Neuropeptides
Small-molecule Neurotransmitters
i. amino acids ii. Acetylcholine iii. Biogenic amines
Small-molecule Neurotransmitters - Amino acids are
-aminobutyric acid (GABA)—inhibitory synapses of the BRAIN.
Small-molecule Neurotransmitters – Glycine is
inhibitory synapses of the SPINAL CORD.
Small-molecule Neurotransmitters - ACETYLCHOLINE (ACh) is
the main neurotransmitter at neuromuscular junctions.
Small-molecule Neurotransmitters - Biogenic Amines are
i. norepinephrine ii. Dopamine iii. Serotonin iv. Epinephrine v. histamine
NOREPINEPHRINE responsible for
arousal, dreaming, regulating mood
DOPAMINE responsible for
emotional responses, addictive behavior, pleasure (ADDICTIONS)
SEROTONIN responsible for
control of mood, appetite, induction of sleep (DEPRESSION)
EPINEPHRINE responsible for
fight or flight response (ADRENALINE)
HISTAMINE responsible for
triggers inflammatory response (Allergies)
Neuropeptides
ENDORPHINS (EXERCISE)
Homeostatic Imbalances - Multiple sclerosis (MS)
i. Possible VIRAL or autoimmune etiology. Ii. Demyelinated islands of neuronal sclerosing (scarring) develop in the BRAIN and SPINAL CORD iii. Characterized by REMISSIONS and exacerbations of sensory and motor symptoms—areas of numbness, impaired gait, visual problems, and loss of bladder control iv. Symptoms usually appear in 20-40’S (AGE) v. Course of treatment is varied, but there is no CURE vi. Affects females twice as often as males.
Homeostatic Imbalances - Different drugs affect neurotransmitters
i. CURARE competes with Ach for receptor sites and prevents muscular contractions, ii. BOTULISM toxin inhibits the release of Ach to prevent muscle contraction, iii. BARBITUATES inhibit synaptic conduction, iv. AMPHETAMINES increase synaptic conduction, v. Antidepressants alter SERATONIN , DOPAMINE , and NOREPINEPHRINE levels.
Homeostatic Imbalances – Antidepressants
i. Selective serotonin reuptake inhibitors (SSRIs), ii. Selective serotonin reuptake enhancers COAXAL, iii. Norepinephrine reuptake inhibitors (NRIs) (ADRINOKS SERATAX), iv. Serotonin-norepinephrine reuptake inhibitors (SNRIs) (PRESTIK CYMBALTA), v. Norepinephrine-dopamine reuptake inhibitors (WELBUTRIN ZYBAN), vi. Monoamine oxidase inhibitors (MAOIs) MARPLAN, ARNARDAL, EMARDIPRIL)
Homeostatic Imbalances - AXONAL TRANSPORT occurs where
substances are picked up peripherally and taken back to the nerve cell body.
Homeostatic Imbalances - AXONAL TRANSPORT This mode of infection has been exploited by certain microorganisms
herpes virus, polio virus, rabies virus, and tetanus bacillus.
Homeostatic Imbalances - The HERPESZOSTER (CHICKEN POX) virus becomes
sequestered in the nerve ganglions of the spine to return periodically to cause peripheral tissue inflammation or SHINGLES