NERVOUS Flashcards
Brain
Spinal cord
CENTRAL NERVOUS SYSTEM
Nerve OUTSIDE the brain and spinal cord
PREIPHERAL NERVOUS SYSTEM
Nerve fibers that CARRY INFORMATION TO the central nervous system
SENSORY (AFFERENT) DIVISION
Nerve fibers that CARRY IMPULSES AWAY from the central nervous system
MOTOR (EFFERENT) DIVISION
subdivisions of Motor (efferent) division:
voluntary
SOMATIC NERVOUS SYSTEM
subdivisions of Motor (efferent) division:
involuntary
AUTONOMIC NERVOUS SYSTEM
· ABUNDANT, STAR-shaped cells
· Brace neurons
· Form BARRIER between capillaries
and neurons
· Control the CHEMICAL ENVIRONMENT of the brain (CNS)
ASTROCYTES
· SPIDER-like phagocytes
· DISPOSE of debris
· EPENDYMAL cells (CNS)
· Line cavities of the brain and spinal cord
· Circulate CEREBROSPINAL FLUID
MICROGLIA
PRODUCE MYELIN SHEATH around nerve fibers in the central nervous system
OLIGODENDROCYTES
Most brain tumors are
GLIOMAS
these DIVIDE
NEUROGLIA
these do not divide
NEURONS
Most brain tumors involve the _______ cells
NEUROGLIA
Protect neuron cell bodies
SATELLITE CELLS
Form MYELIN SHEATH in the PERIPHERAL NS
SCHWANN CELLS
Cells specialized to TRANSMIT messages
NEURONS
also known as NERVE CELLS
NEURONS
NUCLEUS and METABOLIC CENTER of the cell
CELL BODY
FIBERS that extend from the cell body (dendrites and axons)
PROCESSES
conduct impulses TOWARD the cell body
DENDRITES
conduct impulses AWAY from the cell body (only 1!)
AXONS
Axons end in
AXONAL TERMINALS
contain VESICLES with NEUROTRANSMITTERS
AXONAL TERMINALS
Axonal terminals are SEPARATED from the next neuron by a
GAP
gap between ADJACENT neurons
SYNAPTIC CLEFT
JUNCTION between nerves
SYNAPSE
produce myelin sheaths in JELLY-ROLL like fashion
SCHWANN CELLS
GAPS in myelin sheath ALONG THE AXON
NODES OF RANVIER
In _________ the myelin sheath is DESTROYED
MULTIPLE SCLEROSIS
In Multiple Scleroses the myelin sheath is _____
DESTROYED
The myelin sheath hardens to a tissue called
SCLEROSES
An autoimmune disease where the myelin sheath is DESTROYED
MULTIPLE SCLEROSIS
Most NEURON CELL BODY are found in the
CENTRAL NERVOUS SYSTEM
cell bodies and unmyelinated fibers
GRAY MATTER
CLUSTERS of cell bodies within the WHITE MATTER of the central nervous system
NUCLEI
COLLECTIONS of cell bodies OUTSIDE the central nervous system
GANGLIA
· Carry impulses from the SENSORY RECEPTORS
· CUTANEOUS sense organs
· Proprioceptors – detect stretch or tension
SENSORY (afferent) NEURONS
Carry impulses from the CENTRAL NERVOUS SYSTEM
MOTOR (efferent) NEURONS
detect stretch or tension
PROPRIOCEPTORS
association neurons
INTERNEURONS
· Found in NEURAL PATHWAYS in the central nervous system
· CONNECT sensory and motor neurons
INTERNEURONS
INTERNEURONS are found in the ______ in the CNS
NEURAL PATHWAYS
MANY EXTENSIONS from the cell body
MULTIPOLAR NEURONS
one axon and one dendrite
BIPOLAR NEURONS
have a SHORT SINGLE PROCESS leaving the cell body
UNIPOLAR NEURONS
ability to RESPOND to stimuli
IRRITABILITY
ability to TRANSMIT an impulse
CONDUCTIVITY
The plasma membrane at rest is
polarized
a stimulus DEPOLARIZES the neuron’s membrane
DEPOLARIZATION
A depolarized membrane allows _________ to FLOW INSIDE the membrane
SODIUM (Na+)
The EXCHANGE of ions initiates an ______ in the neuron
ACTION POTENTIAL
If the action potential (nerve impulse) starts, it is ________ over the entire axon
PROPAGATED
_________ rush out of the neuron after SODIUM IONS RUSH IN, which
REPOLARIZES the membrane
POTASSIUM IONS
The sodium-potassium pump restores the
ORIGINAL CONFIGURATION
Impulses travel _____ when fibers have a myelin sheath
FASTER
Impulses travel FASTER when fibers have a ______
MYELIN SHEATH
Impulses are able to cross the _______ to another nerve
SYNAPSE
_________ is released from a nerve’s axon terminal
NEUROTRANSMITTER
The _______ of the next neuron has receptors that are stimulated by the neurotransmitter
DENDRITE
The dendrite of the next neuron has ______ that are stimulated by the neurotransmitter
RECEPTORS
The dendrite of the next neuron has receptors that are stimulated by the _________
NEUROTRANSMITTER
An action potential is started in the
DENDRITE
rapid, predictable, and involuntary responses to stimuli
REFLEX
DIRECT ROUTE from a sensory neuron, to an interneuron, to an effector
REFLEX ARC
· Smooth muscle regulation
· Heart and blood pressure regulation
· Regulation of glands
· Digestive system regulation
AUTONOMIC REFLEXES
Activation of skeletal muscles
SOMATIC REFLEXES
CNS develops from the
EMBRYONIC NEURAL TUBE
The neural tube becomes the ____ & the _____
BRAIN & SPINAL CORD
The opening of the neural tube becomes the _____
VENTRICLES
· Paired (left and right) SUPERIOR PARTS of the brain
· Include MORE THAN HALF of the brain MASS
CEREBRAL HEMISPHERES (CEREBRUM)
The surface of CEREBRUM is made of
RIDGES (gyri) & GROOVES (sulci)
ridges
gyri
grooves
sulci
divide the CEREBRUM into LOBES
FISSURES
deep grooves
FISSURES
RECEIVES impulses from the body’s SENSORY RECEPTORS
SOMATIC SENSORY AREA
SENDS impulses to SKELETAL MUSCLES
PRIMARY MOTOR AREA
involved in our ability to SPEAK
BROCA’S AREA
involved in SPECIAL SENSES
CEREBRAL AREAS
Layers of the Cerebrum:
· OUTER layer
· Composed mostly of NEURON CELL BODIES
GRAY MATTER
Layers of the Cerebrum:
· FIBER tracts INSIDE THE GRAY MATTER
· Example: corpus callosum connects hemispheres
WHITE MATTER
INTERNAL ISLANDS of gray matter
BASAL NUCLEI
· Regulates VOLUNTARY MOTOR ACTIVITIES by modifying info sent to the motor cortex
· Problems = ie unable to control muscles, spastic, jerky
· Involved in Huntington’s and Parkinson’s Disease
BASAL NUCLEI
BASAL NUCLEI are involved in what diseases
HUNTINGTON’S DISEASE
PARKINSON’S DISEASE
· Sits ON TOP of the brain stem
· ENCLOSED by the cerebral hemispheres
· Made of THREE parts
· Thalamus
· Hypothalamus
· Epithalamus
DIENCEPHALON
THREE PARTS OF DIENCEPHALON
· Thalamus
· Hypothalamus
· Epithalamus
DIENCEPHALON is enclosed by the
CEREBRAL HEMISPHERES
· Surrounds the THIRD VENTRICLE
· The RELAY STATION for sensory impulses
· TRANSFERS IMPULSES to the CORRECT PART OF THE CORTEX for localization and interpretation
THALAMUS
· UNDER the thalamus
· Important autonomic nervous system center
· Helps REGULATE BODY TEMPERATURE
· Controls WATER BALANCE
· Regulates METABOLISM
HYPOTHALAMUS
An important part of the LIMBIC system (emotions)
HYPOTHALAMUS
The PITUITARY GLAND is attached to the
HYPOTHALAMUS
· Forms the ROOF of the third ventricle
· Houses the PINEAL BODY (an endocrine gland)
· Includes the CHOROID PLEXUS – forms cerebrospinal fluid
EPITHALAMUS
Epithalamus Forms the ______ of the third ventricle
ROOD
Epithalamus Houses the
PINEAL BODY
forms cerebrospinal fluid
CHOROID PLEXUS
· Attaches to the spinal cord
BRAIN STEM
Parts of the brain stem
· Midbrain
· Pons
· Medulla oblongata
· Mostly composed of TRACTS OF NERVE FIBERS
· Reflex centers for VISION and HEARING
· Cerebral aquaduct – 3rd-4th ventricles
MIDBRAIN
· The BULGING CENTER part of the brain stem
· Mostly composed of FIBER TRACTS
· Includes nuclei involved in the CONTROL OF BREATHING
PONS
· The LOWEST PART of the brain stem
· Merges into the spinal cord
· Includes important fiber tracts
· Contains important control centers
· Heart rate control
· Blood pressure regulation
· Breathing
· Swallowing
· Vomiting
MEDULLA OBLONGATA
· Two hemispheres with CONVOLUTED surfaces
· Provides involuntary coordination of BODY MOVEMENTS
CEREBELLUM
Meninges
· DOUBLE-LAYERED EXTERNAL COVEINR
· FOLDS INWARD in several areas
DURA MATER
attached to SURFACE OF THE SKULL
PERIOSTEUM
OUTER COVERING of the
brain
MENINGEAL LAYER
Meninges
· MIDDLE layer
· WED-like
ARACHNOID LAYER
Meninges:
· INTERNAL layer
· CLINGS to the surface of the brain
PIA MATER
· Similar to BLOOD PLASMA composition
· Formed by the choroid plexus
· Forms a WATERY CUSHION to protect the brain
· Circulated in arachnoid space, ventricles, and central canal of the spinal cord
CEREBROSPINAL FLUID
Cerebrospinal Fluid forms a _____ to protect the brain
WATERY CUSHION
Cerebrospinal Fluid is formed by
CHOROID PLEXUS
· Includes the LEAST PERMEABLE capillaries of the body
· EXCLUDES many potentially HARMFUL
substances
· Useless against some substances
· Fats and fat soluble molecules
· Respiratory gases
· Alcohol
· Nicotine
· Anesthesia
BLOOD BRAIN BARRIER
· SLIGHT brain injury
· NO PERMANENT brain damage
CONCUSSION
· Nervous tissue DESTRUCTION occurs
· Nervous tissue DOES NOT REGENERATE
CONTUSION
· SWELLING from the INFLAMMATORY response
· May COMPRESS and KILL brain tissue
CEREBRAL EDEMA
· Commonly called a STROKE
· The result of a RUPTURED BLOOD VESSEL supplying a region of the brain
· Brain tissue supplied with oxygen from that BLOOD SOURCE DIES
· Loss of some functions or death may result
CEREBROVASCULAR ACCIDENT (CVA)
Below T12 is the
CAUDA EQUINA
a collection of SPINAL NERVES
CAUDA EQUINA
occur in the CERVICAL and LUMBAR regions
ENLARGEMENTS
· Progressive DEGENERATIVE disease
· Mostly seen in the ELDERLY, but may begin in middle age
· Structural changes in the brain include ABNORMAL PROTEIN DEPOSITS and TWISTED FIBERS within neurons
· Victims experience memory loss, irritability, confusion and ultimately, hallucinations and death
Alzheimer’s Disease
Spinal Cord Anatomy:
conduction tracts
EXTERIOR WHITE MATER
Spinal Cord Anatomy:
mostly cell bodies
INTERNAL GRAY MATTER
Spinal Cord Anatomy:
filled with cerebrospinal fluid
CENTRAL CANAL
cover the spinal cord
MENINGES
collections of cell bodies outside the central nervous system
DORSAL ROOT GANGLIA
bundle of neuron fibers
NERVE
Neuron fibers are bundled by
CONNECTIVE TISSUE
surrounds each fiber
ENDONEURIUM
Groups of fibers are bound into ______ by perineurium
FASCICLES
Groups of fibers are bound into fascicles by ___________
PERINEURIUM
_______ are bound together by epineurium
FASCICLES
both sensory and motor fibers
MIXED NERVES
total pairs of the spinal cord
31 pairs
· The INVOLUNTARY branch of the nervous system
· Consists of ONLY MOTOR NERVES
· Divided into two divisions
· Sympathetic division
· Parasympathetic division
AUTONOMIC NERVOUS SYSTEM
· Response to UNUSUAL STIMULUS
· Takes over to INCREASE ACTIVITIES
· Remember as the “E” division = exercise, excitement, emergency, and embarrassment
SYMPATHETIC - FLIGHT OR FLIGHT
· CONSERVES ENERGY
· Maintains DAILY necessary BODY FUNCTIONS
· Remember as the “D” division - digestion, defecation, and diuresis
PARASYMPATHETIC - HOUSEKEEPING ACTIVITIES
The nervous system is formed during the ______ of embryonic development
FIRST MONTH
one of the LAST areas of the brain TO DEVELOP
HYPOTHALAMUS
No more neurons are formed after
BIRTH
The brain reaches maximum weight as a
YOUNG ADULT
we can always grow
DENDRITES
an area of skin that is supplied by a SINGLE SPINAL NERVE
DERMATOME
a group of muscles that a SINGLE SPINAL NERVE ROOT innervates
MYOTOME
one of the only diseases that causes a rash in a DERMATOMAL PATTERN, and as such, this is its defining symptom
SHINGLES
A common childhood disease caused by the varicella-zoster virus.
CHICKENPOX
the motor equivalent of a dermatome
MYOTOME
an injury or wound to someone’s body.
LESION
any DAMAGE or ABNORMAL CHANGE in the TISSUE of an organism, usually caused by DISEASE or TRAUMA
LESION
myotome distributions:
Neck flexion / extension
C1/C2
myotome distributions:
Neck lateral flexion
C3
myotome distributions:
Shoulder elevation
C4
myotome distributions:
Shoulder abduction
C5
myotome distributions:
Elbow flexion/wrist extension
C6
myotome distributions:
Elbow extension/wrist flexion
C7
myotome distributions:
Finger flexion
C8
myotome distributions:
Finger abduction
T1
myotome distributions:
Hip flexion
L2
myotome distributions:
Knee extension
L3
myotome distributions:
Ankle dorsi-flexion
L4
myotome distributions:
Great toe extension
L5
myotome distributions:
Ankle plantar flexion/ankle eversion/hip extension
S1
myotome distributions:
Knee flexion
S2
myotome distributions:
Anal reflex
S3-S4
